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Auckland Museum N e w Z e a l a n d N AT U R A L H I S T O RY e ducation k it Tamaki Paenga Hira ACTIVITY SHEETS YEARS 1 TO 8 ©Auckland Museum 2005 CONTENTS PAGE Booking Information Introduction to the Resource Plan of Natural History Galleries 1 2 2 SECTION 1 Teacher Background: Origins Land Oceans Human Impacts 3 14 26 41 SECTION 2 Curriculum Links and SECTION 3 Pre and Post-visit Activities Classroom Activities Gallery Activitites ABOUT THIS RESOURCE: This resource has been designed to meet the needs of Science classes, Years 1–8 The kit includes: Teacher Background Material Curriculum Links and Pre and Post Visit Activities Classroom Activity Sheets Gallery Activity Sheets 50 53 63 BOOKING INFORMATION: All school visits must be booked. Phone: 306 7040 Fax: 306 7075 A small service charge applies to school groups. Charges as at 2000 are: Self-conducted Visits: free Gallery Introductions: free to member schools, $1.00 per student non-member schools Hands-on Sessions: $1.00 per student member schools, $3.00 per student non-member schools www.aucklandmuseum.com 1 Natural History INTRODUCTION he four natural history galleries form a suite with a logical progression, which will encourage the visitor who wants to learn of wonderful and unique life on the islands of New Zealand to take. The first gallery, Origins, is a journey through time where we tell the story of our country’s beginning and how we came to be where we are today with our unique flora and fauna. T The next two galleries, Land and Oceans, take the visitor on a topographical journey from mountain top down to the shore and out to the sea that surrounds us. Their aim is to present our wonderful natural heritage and excite the visitor with its diversity, while telling the individual stories and adaptations of certain plants and animals. The final gallery, Human Impacts, looks at the effects we humans have had on the land and its native inhabitants. Sharing the gallery space with this last gallery is Matapuna — the Natural History Resource Centre. It is seen as crucial to all four galleries and is a place where the visitor will be able to access deeper level information than is possible to convey in the galleries themselves. LAND ORIGINS TE AO TUROA MAORI NATURAL HISTORY MATAPUNA Natural History Resource Centre EAST GALLERY LOGAN CAMPBELL GALLERY MEZZANINE GALLERY FIRST FLOOR WEST GALLERY DISCOVERY CENTRE VOLCANOES OCEANS Visiting schools may book for the following learning opportunities: Self-conducted visit with supporting resource material. Gallery Introduction with Museum Educator (approx 15 minutes), plus resource material. Hands-on activity session with Museum Educator (approx 45 - 50 mins), plus resource material. Students have the opportunity to handle rock collections, fossils, lava bombs etc. Sessions can be tailored to suit the level and focus of your visit. Auckland Museum 2 TEACHER BACKGROUND ORIGINS GALLERY rigins explores New Zealand’s geological history, our isolation from Gondwana and the resulting effect on our unique and vulnerable plants and animals. O The focus for this kit is the concept of New Zealand’s isolation and the uniqueness of our flora and fauna as a result of this isolation. An additional education kit entitled Geology at the Auckland Museum provides a greater range of information on New Zealand’s geology, rock types and volcanism. THE EARTH’S STRUCTURE basins. It solidifies to produce new crust and push4.6 billion years ago the Earth was formed, a es out the older crust symmetrically away from this dynamic planet where the continents con“spreading centre”. This produces a long stantly move on a hot fluid interior. chain of undersea volcanoes, also Radioactive decay in the centre has called a mid-oceanic ridge. Crust generated a heat engine that Outer core powers this motion. Subduction Zones Old oceanic crust is heavy and The Earth is composed of sevdense. Over time, parts of it 3560km 2800 eral layers. The solid inner sink back into the mantle, crecore is surrounded by a liquid ating a tectonic plate boundouter core. The mantle is solid, ary as it slips under another Inner core with the top 250 km plastic piece of crust. Subduction of enough to move and carry the old oceanic crust can happen thin but rigid crust above. under continents, such as the South Mantle American west coast or under younger PLATE TECTONICS / oceanic crust, such as in the TongaCONTINENTAL DRIFT Kermadec area, just north of New Zealand. The Earth’s crust is broken into many fragments As the crust goes into the mantle, a deep trench up called tectonic plates. These move at different to 10km deep develops at the point of subduction. rates. They spread apart, push past, override and A New Zealand example is the Hikurangi Trough, dive under each other, constantly moving the conti- which is off the east coast of the North Island. nents around the globe. During subduction, sediment that has settled on the There are three main types of plate boundaries: ocean floor is scraped off the subducting plate divergent/spreading centres, convergent/ subduc- and gets plastered onto the edge of the upper tion zones and transform margins. plate. The compression causes friction between the two plates, which in turn causes earthquakes and Upwelling in the mantle forms new oceanic crust, pushes up mountains. which then spreads apart. The crust ultimately gets recycled as it cools and becomes subducted under Once this oceanic crust sinks well down into the younger, more buoyant crust. mantle, it starts to soften and become plastic again. But because there are traces of water in this Sea Floor Spreading Zones crust, partial melting occurs and this extra hot The mantle reaches the Earth’s surface through an material rises up in bubbles through the mantle and opening between two tectonic plates, up to 5km over-riding crust. Once it reaches Earth’s surface, it under the sea surface in the middle of some ocean gets erupted to form volcanoes. 3 Natural History World map showing the boundaries of tectonic plates. The arrows show the directions they move in. As the plates move, they pull apart, collide, grind past or dive beneath one another, the way luggage does on an airport conveyer belt. Transform Margins Transform margins occur where 2 plates slide past each other, neither creating or destroying oceanic crust. An excellent example of a transform boundary is the Alpine Fault in the South Island, one of the longest straight lines on Earth. Fossil ferns found in rocks near Port Waikato grew in coastal Gondwana forest 140 million years ago. Fossils of the seed fern Glossopteris have been found in New Zealand, Australia, Antarctica, South America and India. NEW ZEALAND’S GEOLOGICAL ORIGINS Eighty five million years ago, New Zealand began to break The Alpine fault, as seen from away from the supercontinent space. called Gondwana where it had been united with all the other countries in the southern hemisphere. As New Zealand drifted away from Australia taking with it animals (including dinosaurs) and plants that lived on it, the opening between them began to form the Tasman Sea. In the 60 million years since the Tasman Sea opened, erosion, tectonic processes and climate change have drastically altered the shape of New Zealand. These changes have had a huge impact on our plants and animals. New Zealand drifted north away from Antarctica as a heavily eroded lowland plain. As it moved, Earth’s crust stretched and thinned and the land sank. From considerable continental beginnings, New Zealand became an archipelago of small swampy low-lying islands. Remnants of Gondwana in New Zealand Rocks and fossils provide links to our past connection with other countries. Most of the rock types in the Southwest corner of the South Island match up with rocks in south east Australia and Antarctica. As the land area reduced, species that had evolved here faced advancing waters and destruction of habitats, creating a biotic bottleneck. The original Gondwanan flora and fauna was considerably reduced. Later the survivors diversified and Auckland Museum 4 Timeline. Gondwana. new species evolved. Wrens, moa and giant weta tion of many indigenous animals is a legacy of the were all affected. Some modern birds are proba- Pleistocene glaciations which ended some 10,000 bly descendants of a single surviving species. years ago. New Zealand did not remain a small archipelago for long. About 25 million years ago, a plate boundary started to develop through New Zealand between the Australian and Pacific plates. The collision between these two plates has pushed up our mountain ranges within the last 6 million years. Sediments from the continuous erosion of the mountains has extended our coastlines to create new land. Climate Change and the Ice Ages In the course of its history, New Zealand has changed many times in both location and climate from subtropical to subantarctic. All have had a great influence on its plants and animals. The climate changes are mediated by tectonic movements as well as more cosmic events. The current distribu- 5 Natural History During the last 64 million years there has been a global trend towards a cooler climate. In the Paleocene and Eocene the oceans were sluggish and Antarctica had no ice cap. During the Oligocene the movement of Australia away from Antarctica and the opening of the Drake Passage at the bottom of South America allowed the formation of a cold circumpolar current around Antarctica. This thermally isolated Antarctica, allowing an ice cap to form. There was a warming trend in the late Oligocene-Middle Miocene. The drop in temperature at the end of the Miocene is due to the isolation and evaporation of the Mediterranean Sea. This event decreased the salinity of the oceans, allowing them to freeze at higher temperatures. The polar ice cap increased in size. The uplift of the Himalayas drove drier winds over Northern Africa, and affected rainfall in Asia. The ice age climate had a large impact on New Zealand’s flora. This included the expansion of grasslands in both islands and the growth of alpine Three million years ago, North and South America shrubs and herbs at much lower elevations than joined, terminating warm currents around the today. equator and promoting the warm Gulf Stream in the North Atlantic. The Gulf Stream is responsible WHAT ARE FOSSILS? for snowfall on the North Pole, creating the Most fossils are the preserved hard parts of plants Northern Hemisphere Ice Cap. or animals, such as wood, shells, bones and teeth. Less common are the traces of soft parts like leaves A Touch of the Tropics and soft tissues. Some fossils show where an animal 25–14 million years ago warm currents from trop- has been, such as footprints and worm trails. Fossils ical seas washed New Zealand shores and the cli- are found in sedimentary rocks in many parts of mate was subtropical. Coconuts, corals and cone New Zealand, from sea level to mountain tops. shells flourished. Warmth-loving plants established. Some died out later when the climate cooled again, others adapted and stayed. The Ice Ages Earth’s climate has swung between warm and cold about 50 times in the last 2.6 million years. During particularly cold periods called Ice Ages or Glaciations, ice sheets grew on the continents causing sea levels to drop up to 120 m. The frequency and regularity of the oscillations tell us that it is changes in Earth’s orbit that controls the amount of heat reaching Earth’s surface. 2 4 The hard parts may be buried by soil, mud, or sand, which protects them from further decay or damage. Forces deep within the earth may fold or tilt the rock and push some of them up to form land and mountains. 1 3 5 When an animal or plant dies its soft parts are usually eaten by scavengers or decay rapidly. Many layers of sediment may accumulate on top. Eventually, they harden into rock. We find fossils in cliffs and road cuttings where natural erosion or bulldozers have exposed layers of rock. Auckland Museum 6 Animal and plant remains may be preserved as Examples of Fossils found in New Zealand: fossils in a number of ways: Giant Ammonite — Ammonites are extinct shellbearing squid, the closest living relative of which is Shells and skeletons — The most common fossils are the Pearl Nautilus. The cast on display is of the an animal’s hard skeletal parts composed of bone largest Jurassic ammonite fossil ever found. It was or shell. These can remain virtually unchanged in uncovered near Kawhia Harbour. Ammonites the rock. became extinct at the same time as dinosaurs. This ammonite is 145 million years old. Mummification — When both the hard and soft parts of an animal is preserved, it is called mum- Belemnites — Belemnites were related to the mification. Some examples are the mummified ancestors of todays squid. Only the hard bullet-like remains of moa in caves, the freezing of tail skeletons remain. Belemnites became extinct mammoths in ice, or the complete at the same time as dinosaurs. preservation of insects in gum. Trilobites — Trilobites resembled large Petrification — Dissolved minerals sea lice. They were the first animals to that seep slowly through rock develop hard parts that could be fosoften add to or replace the origsilised and were found worldwide. inal fossil. This gradual process They have three parts to their body often increases the fossil’s weight hence the name. Fossil trilobites found and hardness and literally turns it in the Cobb Valley of Nelson are New to stone. Zealand’s oldest fossils, at 530 million years old. Moulds and Casts — After a shell has been buried and the surrounding sediMany other fossils including those of plants ments hardened into rock, water may creep and dinosaurs can also be viewed in the exhibition. through the rock and dissolve the shell. This leaves a cavity, with the same shape and markings as the NEW ZEALANDS DINOSAURS, original shell — a natural mould. PTEROSAURS AND MARINE REPTILES If a fossil shell was hollow inside it may have filled The Age of Reptiles is known as the Mesozoic era, with mud and sand during burial. If the shell dis- which consists of the Triassic, Jurassic and solves, a hardened internal cast of the shell is also Cretaceous periods. At this time, New Zealand was left as a fossil. closer to the South Pole. It is uncertain how the dinosaurs adapted to the cold winters with zero Carbonisation — turned to soot — Where buried daylight hours, but it is now known that some of plants and animals decayed in places without oxy- these dinosaurs must have been warm-blooded. gen, they left a thin flattened fossil behind. These fossils are rich in carbon and have a black colour. No complete dinosaur skeletons have been found in New Zealand and the fragments found have not Trace fossils — leaving tracks — A fossil may also been sufficient to classify as new species or species be the preserved track, burrow, footprint or even found elsewhere. The first dinosaur bone was disexcrement of a passing animal. Burrow shape and covered by Joan Wiffen in the Mangahouanga size can often be used to identify the animal that Valley (Hawkes Bay), and was the tail bone of a once lived in it. theropod dinosaur. Other dinosaurs fossils indicate the existence of agile ornithopod dinosaurs and large fourfooted sauropods. 7 Natural History Theropod Dinosaurs Theropods were agile predators that walked upright on strong hind legs, had short front legs and large heads with sharp teeth. Tyrannosaurus and Allosaurus were theropods. The cast on display is of Cryolophosaurus, an Antarctic dinosaur. One small species of theropods evolved into the first birds around 150 million years ago. Sauropod Dinosaurs Sauropods were large four footed dinosaurs with long necks and tails. They were herbivores which probably lived in herds. A fragment of rib bone has been found in New Zealand. Ornithopod Dinosaurs Ornithopod dinosaurs were bird-hipped dinosaurs which were herbivorous and walked exclusively on their back legs. Part of a pelvis has been found in New Zealand. Pterosaurs Pterosaurs were flying reptiles, not dinosaurs. They had bat-like wings formed by a membrane of skin, although only the fourth finger was elongated to support the wing whereas all four fingers in bats are elongated. Two small bones have been found in New Zealand. Marine Reptiles Mosasaurs, Plesiosaurs and Icthyosaurs Mosasaurs were giant marine lizards similar to Komodo dragons. At least five species were known in New Zealand. Mosasaurs were predators that grew as long as 12 metres. Plesiosaurs were predators with small heads, sharp teeth and limbs which were paddle-shaped. Some grew to 13metres long. Elasmosaurs were longnecked forms, while pliosaurs were short-necked forms. The plesiosaur fossil on display was removed recently from the Kaikoura region. Ichthyosaurs were fast-swimming marine predators like dolphins, although dolphins are mammals. They probably fed on squid-like belemnites. NEW ZEALAND’S ORIGINAL INHABITANTS Despite the 80 million years since New Zealand split from Gondwana, many modern descendants of Gondwanan animals live on in groups including: earthworms, frogs lizards, insects, spiders and tuatara. Tuatara are sometimes called “living fossils” because they have survived virtually unchanged for 200 million years. While they look like lizards, they are not and are in fact a remnant of a group of reptiles which lived during the dinosaur age. Tuatara are carnivorous and their diet consists of earthwor ms, beetles, lizards, frogs, wetas, injured or juvenile birds and sometimes even their own young. They are nocturnal. Tuatara have primitive teeth which are essentially part of the jaw rather than separate. Their young have a vestigial “third eye’which covers over after six months of life. Its purpose is unknown. Tuatara may live for over 100 years. Auckland Museum 8 Native frogs of New Zealand, such as Archey’s frog and Hamilton’s frog, have their own family Leiopelmatidae. Frogs cannot cross sea barriers so the ancestors of our frogs must have been present when New Zealand separated from Gondwana. Hochstetter’s frog Leiopelma hochstetteri Weta have a lifestyle similar to mice. They are nocturnal and feed on a diet of leaves and fruit supplemented by carrion insects and other small animals. Weta habitats range from alpine scree to city gardens. Weta are harmless. New Zealand is home to 100 species of these flightless crickets. A cool windy climate and an absence of predators has resulted in loss of flight and an increase in size in many New Zealand insects. Giant wetas are the largest insect in New Zealand and can weigh up to 70 g, about the same weight as a thrush. The Giant weta has changed little from its ancestors which evolved during the mesozoic era. Giant weta Deinacrida heteracantha Peripatus Peripatus novaezelandiae Kauri snail Pupu rangi Paryphanta busbyi 9 Natural History Peripatus or velvet worms may be the “missing link” between earthworms and arthropods. They have characteristics of both annelid worms and insects and date back to around 500 million years ago. As they would have been unable to make a sea crossing, Peripatus ancestors must have spread before Gondwana split. They live in damp conditions and dessicate quickly in dry habitats. Peripatus eat insects and other small invertebrates. Land snails The family to which Paryphanta (Kauri snail) and Powelliphanta belong is the oldest family of land snails, originating 300 million years ago. A LAND OF BIRDS A visitor to New Zealand soon after separation from Gondwana would have been impressed by the range of birds. Over the next million years, these original and early immigrants across the infant Tasman Sea evolved in genetic isolation into uniquely New Zealand families. Ratite Skeleton. Non-Ratite Skeleton. Ratites Ratites are flightless birds with powerful legs for running and reduced wings. Their breast bone lacks a keel attachment for flight muscles. They have no flight feathers and have a distinctive arrangement of palate bones in the skull. The ratite group includes moa, kiwi, the extinct elephant bird of Madagascar, South American rhea, African ostrich, Australian emu and cassowary. Moa share a common ancestor with ratites from other parts of the world. The ancestors were carried with the land as Gondwana broke up. Eleven species of moa once lived in New Zealand. Different moa species had different lifestyles and habits. We know this by their different shaped beaks and heads. The Dinornis group ate twigs, Euryapteryx ate berries and succulent leaves, while Pachyornis ate the tough local flax. The giant moa was the tallest bird known, reaching up to 3 metres. Moa swallowed gizzard stones to help grind up plant food. Moa died out in New Zealand due to extensive hunting and clearing of forest after the arrival of the first people in New Zealand. Kiwi are more closely related to Australian emu than to moa, according to DNA evidence. This suggests that rather than being a Gondwanan original, the ancestor flew here around 40 million years ago. As it lost its ability to fly, it took on mammallike characteristics such as fur-like feathers, a metabolism and body temperature lower than most birds, whiskers and a nocturnal lifestyle. Kiwis feed at night on insects and grubs, sleeping in burrows (which they dig) in the daytime. Kiwis are the only birds to have nostrils at the tip of their beaks. They have a very good sense of smell and weak eyesight. The female lays an egg that weighs one fifth of its body weight -the largest egg to body ratio among birds. Cassowary Elephant bird Ostrich Emu Kiwi Rhea Moa Global Ratite distribution. Auckland Museum 10 Wattle Birds The wattle bird family is named after the distinctive coloured wattle feathers around the beak. They have short wings and are weak fliers, yet are tree dwellers with powerful legs, claws and beaks. The family includes North and South (extinct) Island kokako, huia and North and South Island saddlebacks. Recent Bird Losses Many distinctive bird species, many flightless, are now extinct. Humans are responsible for this extinction. Evidence of their existence comes from bones found in swamps, caves and Maori kitchen middens. Extinct species include, amongst many others, South Island adzebill , laughing owl, New Zealand goose, piopio (thrush) and huia. Wrens New Zealand wrens are small, short-tailed insecteaters, many of which were flightless or weak fliers. A number of wren species are extinct. The rifleman is the smallest New Zealand bird and is found in bush throughout New Zealand. The bush wren is New Zealand’s most recent extinction, last seen in 1972. Flightless, Drab and Giant Birds Many New Zealand birds are flightless, large, dullcoloured and slow breeding, a result of millions of years of evolution in the absence of predators. Where two or more arrivals of similar colonising birds have occurred, descendants of the earlier arrival show more of these characteristics and are more vulnerable to extinction. Kakapo are the heaviest and flightless parrots in the world. They are nocturnal, ground-dwelling birds. Huia Heteralocha acutirostris Takahe and pukeko descended from an earlier swamp hen. Takahe are flightless and heavier than the more recent pukeko. Pukeko fly but are reluctant to do so. Rifleman Titipounamu Acanthisitta chloris Kokako Callaeas cinerea Weka and banded rail are both flightless. Weka evolved from an earlier Australian rail, while the banded rail is similar to current rail species. Robins and tomtits are both small insect-feeders. Robins arrived 5–10 million years ago and are drab weak fliers. Tomtits arrived around 2 million years ago. They fly from ground to perch to catch food. Black and pied stilts. The black stilt probably originated from an ancestral pied stilt established here millions of years ago. Black stilts are in danger of hybridising out of existence. The New Zealand pied stilt sub-species is similar to that found in Australia and South-East Asia today. Kakapo Strigops habroptilus 11 Natural History MAMMALS Ground-dwelling mammals never made it to New Zealand naturally, but bats ,which fly, did make the journey. New Zealand has been home to 3 species of bat, one of which is now extinct. The ancestors of whales and dolphins were actually hoofed animals. Around 50 million years ago these creatures took up a marine existence, developing fins instead of legs. There are three groups of whales including the primitive extinct form called archaeocetes (28 million year old fossils The lesser short-tailed bat is unique to New have been found in New Zealand) toothed whales Zealand and belongs to its own family. Its ances- (odontocetes) and baleen whales (mysticetes). tors may have arrived 35 million years ago. It flies well but also crawls mouse-like on the ground with Shark evolution accelerated around 50 million its wings folded up. years ago. Carcharodon found in New Zealand waters was a giant, with a mouth that could swalThe long-tailed bat has a longer tail and shorter low a small car! ears. It probably arrived in the last 2 million years and had relatives in Australia. PLANTS IN ISOLATION Eight main groups of plants have evolved on earth, most of which have been in New Zealand at some time. These groups are algae, bryophytes (mosses and liverworts), psilophytes, club mosses, horsetails, ferns, gymnosperms (conifers, ginkgoes, cycads) and angiosperms (flowering Long-tailed bat Pekapeka plants). New Zealand Chalinolobus tuberculatus has many plants with links to Gondwana including algae, sphagnum moss, silver tree Short-tailed bat fern, kauri Pekapeka Mustacina tuberculata and rimu and LIFE IN THE WATER primitive While flightless birds evolved on land, extinction of flowering large marine reptiles allowed new forms of life to p l a n t s evolve in the sea. Penguins and whales appeared, such as and sharks, which already existed, developed rap- rewareidly. wa and horopito. However, not all Around 50 million years ago, a group of diving plants are birds took to the sea. Their wings became flippers G o n d w a n a n and they “flew” under water. So the penguin originals. Grasses, evolved. Fossils of around 14 extinct New Zealand daisies and orchids penguin species have been found in rock dated didn’t evolve until between 40–5 million years old. The world’s after New Zealand’s largest penguin lived in New Zealand 35 million isolation. years ago. Auckland Museum 12 MIGRANT ANIMALS Several bird species, including silver eye, welcome swallows and spur-winged plover have arrived in New Zealand over the last 150 years. Many insects and spiders have also arrived from Australia. The differences between these and New Zealand species are often small, but indicate that the New Zealand forms have been here perhaps since the ice ages. Since human arrival, more insects have arrived. Many of these can survive on plants which humans have also brought eg monarch butterflies on swan plants. MIGRANT PLANTS Plant species arrive naturally on wind, tide and attached to birds, or through human introduction. Manuka seeds are tiny and blow in the wind, New Zealand flax seeds have a wing like structure and are easily airborne. Mangrove seeds are buoyant and float well in water. Kowhai are found in Chile and in the South Atlantic Ocean. It takes about 3 years for seed to drift from South America to New Zealand. Parapara seeds are sticky and cling to birds, in fact many small birds remain trapped in seeds still on the tree and die there. Kowhai distribution. Kowhai is also found in Chile and Gough Island in the South Atlantic Ocean. 13 Natural History TEACHER BACKGROUND LANDS GALLERY ew Zealand’s plant and animal diversity can be explored by taking a topographical journey from the alpine zone to a coastal wetland. In all of these habitats adaptation of organisms to their surrounding environment is observable, as is the interaction between the flora and fauna living alongside each other. N ALPINE ZONES Southern Alps Situated on the “Pacific Ring of Fire" — a geological belt of earthquake and volcanic activity — New Zealand is one of the world’s most active mountain building regions. The Pacific and IndianAustralian plates slide against each other, vigorously uplifting the land. The South Island contains the most extensive alpine areas. The Southern Alps form the island’s backbone. The Alps can grow as much as two centimeters per year. The Alpine zone is rich in biological diversity, despite conditions which can include intense cold, heat, winds and dryness. Almost half of all native plants are found here. Just above the bush line are waist-high tussocks and small leafed shrubs. As you begin to go higher the vegetation gets smaller, a response to the harsh conditions of mountain life. Delicate flowering gentian, celmisia and ourisia are sheltered by low tussock. The world’s largest buttercup, the Mount Cook lily, can also be found in showy clusters. Higher still, buttercups, daisies and edelweiss crouch in between boulders. The vegetable sheep, a type of cushion plant hugs the ground, the leafy shoots are so dense you can sit on the plants without damaging them. New Zealand’s alpine habitats are relatively young, only coming into existence two to three million years ago. This is a short period for so many specialist plants to have evolved from lowland ancestors. Ninety five per cent of New Zealand’s mountain flora is endemic (found nowhere else in the world). The alpine weta also evolved from lowland ances- tors. It is the largest insect of the alpine zone and can survive being completely frozen. Many alpine flowers depend on the butterflies, moths and flies for pollination. Moths fly during the day to take advantage of the warmer conditions. Also living in the alpine vegetation are cicadas, beetles, weevils and grasshoppers. The world’s only alpine parrot, the kea, feeds on nutrient rich snowberries to store fat for the cold winter ahead. Kea retreat below the bushline to nest. Kea chicks are often hatched in the depths of winter, needing a good food supply. The rock wren is a permanent resident of the alpine and subalpine zones. In winter they may forage among rocks insulated by a blanket of snow. It feeds on spiders, beetles, flies and other insects. Central Plateau The alpine landscapes found in the North Island are geologically young and are formed by volcanic activity, which still continues today e.g. Ruapehu and Ngaruhoe. In Tongariro National Park craters, vents, thermal pools and lava flows are easily observed. The flora and fauna is not as diverse as that found in the Southern Alps not having had the time to adapt to specific habitats and periodically being obliterated by volcanic eruptions. Few native birds are found in the North Island alpine zone. Pipit, blue duck and the New Zealand falcon are among the natives present. Some introduced species are common e.g. hedge sparrow. The vegetation includes a few species of tussock, pygmy broom, a cotton daisy, whipcord hebe and pimelea mat. There are also fewer exclusively alpine insects and many which live here are also Auckland Museum 14 Grasshopper Mawhitiwhiti Paprides nitidus Cicada Tatarakihi Melampsalta cingulata New Zealand Pipit Pihoihoi Anthus novaseelandiae Koromiko Hebe tetragona Cave Weta. Weta taipo Gymnoplectron acanthocera Natural History CAVES The most common type of cave in New Zealand is the limestone cave. Other types which exist in New Zealand are marble, lava, sandstone and igneous rock caves. Limestone is formed when an enormous number of shells and skeletons of small marine creatures are cemented and compacted together to form rock. Rain becomes acidic by leaching through organic leaf litter, taking on carbon dioxide to form a mild solution of carbonic acid. When it penetrates cracks in limestone it dissolves the rock, producing caves. Water continues to drip, creating stalactites, stalagmites and other cave formations. Specialised organisms that are found in caves include the cave beetle that has long antennae and long sensory hairs to compensate for its loss of sight. The harvestman, often confused with a spider, is a predator foraging on the floor of the cave preying on adult glowworms. The glowworm, New Zealand’s most famous fly, casts a luminous glow attracting small insects. The insects become trapped in sticky threads hanging like fishing lines from the top of the cave. Once the victim is trapped, the glowworm pulls in the line and consumes its catch. Emerging from a pupa into brief adulthood, the female continues to emit a light, which attracts the male to mate. Glow worm Puratoke Arachnocampa luminosa 15 found at lower altitudes e.g. the one species of grasshopper (compared with the 12 found exclusively in the South Island Alpine zone). There are thought to be 60 different species of cave weta, characterised by long antennae, long legs and non-aggression. Unlike other weta, they neither make sounds with their legs nor can they hear. During the day they scavenge dead animals on the floor of the cave, at night they venture out to forage on plants and fungi. FOREST — THE CHILDREN OF TANE Beech Forest Today beech forest makes up almost 45% of the total area of native forest in New Zealand. New Zealand has four species of beech, red (Nothofagus fusca), hard (N. truncata), black (N. solandri) and silver (N. menziesii). Mountain beech (N. solandri var. cliffortioides) is a form of the black beech. Prolific flowering is usually followed by prolific seed production. The seed set can be reduced by a frost just after the flowers are open, wet or humid weather reducing pollen dispersal. Good flowering years are often 3–5 years apart. Birds or other animals do not spread beech seed. Wind doesn’t carry it far and it doesn’t survive in the ocean. However beech is widely distributed throughout the Southern Hemisphere, being found in New Zealand, South America, Tasmania, Australia, New Caledonia and New Guinea. Not only do the trees in the various locations look alike but they also share the same parasitic fungi, mosses and flightless sucking bugs inhabiting their bark. The distribution of beech (Nothofagus) provides excellent evidence for the theory of continental drift and the super continent Gondwana because they can only disperse across land. The mistletoe Peraxilla tetrapetala is found on some species of beech. It is a semi-parasitic plant relying on the host tree for water and nutrients, also being able to photosynthesize like other plants because it possesses leaves. The mistletoe has a symbiotic relationship with honey-eaters such as tui and bellbirds, providing the nectar while they in turn pollinate the flowers. Mixed Conifer and Broadleaf Forests Mixed conifer and broadleaf forests dominate the lowland regions of New Zealand. These forests are characterised by a large variety of species. Over 1500 flowering plant species, ferns and conifers compete for light and space. A typical North Island conifer broadleaf forest has five layers. The emergent layer is dominated by podocarps e.g. rimu, kahikatea, totara, and matai. Podocarps belong to a very old family of conifers, the Podocarpaceae, which probably originated in Gondwana. They can live from 500–1100 years. Their tall crowns pierce through a main canopy of broad-leaved flowering trees. These include towai, tawa, pohutakawa, rata, vines, epiphytes, kohekohe, puriri, karaka and rewarewa, which grow more rapidly than conifers and are shorter lived. A variety of endemic evergreen species grow in the subcanopy including tarata, the nikau palm, pigeonwood, fivefinger, lancewood, kotukutuku and tree ferns. present day fossil distribution of Nothofagus World distribution of southern beech. Auckland Museum 16 Black beech Nothofagus solandri Hard beech Nothofagus truncata Mountain beech Nothofagus solandri var. cliffortiodes Silver beech Nothofagus menziesii Red beech Nothofagus fusca Mistletoe Peraxilla tetrapetala Totara Podocarpus totara Rimu Red pine Dacrydium cupressinum Kahikatea White pine Dacrycarpus dacrydioides Matai black pine Prumnopitys taxifolia Towai Weinmannia silvicola Northern rata Metrosideros robusta 17 Natural History Rewarewa Knightia excelsa Puriri Vitex lucens At ground level is a twilight world of mosses, ferns, fungi, creeping herbs and forest floor orchids. Nikau palm Rhopalostylis sapida Nikau Palm The nikau palm is a tree of tropical origins and was the only palm in the country to survive the Ice Ages. It has an important relationship with the kereru (wood pigeon), providing succulent fruit for its nourishment and in turn having its seed distributed throughout the forest. Other fleshy fruit producing trees also relying on birds for dispersal of seed include the kohekohe, titoki, taraire, puriri, miro, tawa, karaka, tawapou. Kauri The kauri belongs to the Acaucariaceae family of conifers, which also includes the Norfolk pine (from Norfolk Island), and the monkey-puzzle tree (found in South America). The family evolved in Gondwana and includes some of the most impressive species of trees in the world. Kauri is found in forests in Northland and south to near Raglan and Tauranga where it grows among a variety of hard- Divaricating shrubs woods and podocarps. Many unrelated New Zealand shrubs have interlacing or divaricating branches. It has been sugKauri can seal injuries, fight off diseases and bor- gested that this growth form has evolved as a ing insects by exuding a sticky gum. The gum is defence mechanism for plants in response to the mainly sugar and water which hardens over time. It pressures of moa browsing. Others argue it is a was commercially valuable in the nineteenth and response to a harsh climate. The tough interlaced early twentieth centuries. outer branches protect the growing tips and seeds, which are concentrated in the interior of the plant, Over fifty-three species of higher plants grow in away from moa. kauri branches. “Perchers" include ferns, orchids, lilies, shrubs, and tree saplings. They grow in high Some examples of divaricating shrubs include light at upper forest levels without having grown shrubby pohuehue, matagouri, several pittosporum, their own tree trunk. Vines e.g. kiekie and rata saltmarsh ribbonwood, weeping mapou, korokio, attach by roots produced from their stems, while prostrate kowhai, coastal tree daisy. the New Zealand passionfruit attaches by tendrils. Auckland Museum 18 Lemonwood Tarata Pittosporum eugenioides Kauri Agathis australis Pigeonwood Porokaiwhiri Hedycarya arborea Matagouri Discaria toumatou Five-finger Whauwhaupaku Psuedopanax arboreus Weeping mapou Myrsine divaricata Lancewood Horoeka Psuedopanax crassifolius Bellbird Korimako Anthornis melanura 19 Natural History Parakeet Kakariki Cyanoramphus novaezelandiae Most of New Zealand’s divaricating plants remain as shrubs, but in nine cases, they grow into an adult which is a large-leaved tree. This is a remarkable change in branching pattern and foliage for the shrub to more “normal" adult e.g. matai, pokaka. Lancewood also show a distinct juvenile and adult stage, argued by some to be associated with defence against moa browsing. This phenomenon is called heteroblastism. Forest Birds The forest supplies birds with an abundance of food and with shelter. The thriving invertebrate community is the mainstay for insect eating birds e.g. robin, tomtit, fantail, grey warbler and rifleman. The large New Zealand pigeon or kereru is the only specialised fruit eater, feeding on an extensive range of native trees and shrubs e.g. tawa, miro, nikau, supplejack, pigeonwood. Other forest birds are omnivorous, feeding on a mixed diet of nectar, fruit and insects, which they vary according to the season. The rare kokako, bellbird and tui are all gifted song birds. The yellowcrowned and red-crowned parkeets are fruit and leaf eaters. Other indigenous parrots, kaka and the large kakapo are both omnivorous, scavenging for insects and grubs on the forest floor as well as sampling nuts, fruit and nectar in the canopy. Moths form a major part of the diet of the morepork (ruru) which is New Zealand’s only surviving native owl. It also feeds on weta, beetles, spiders, some lizards, rodents and small birds. Forest floor Flat or fungus bugs feed by sucking fungi and are very common under the bark of decaying logs. Dead trunks and branches also support some termites. Native cockroaches spend the day hidden under stones, logs and loose bark, emerging at night to feed on anything they can find. Native earwigs can also be found in the leaf litter. Some insects only spend their larval stages on the forest floor e.g. flies, cicada and stag beetles. Mites are present in the litter in enormous numbers, either consuming the litter in vast quantities or preying on small invertebrates. Tunnel-web spiders, the trapdoor spiders and the brown vagrant spider are all found on the forest floor, feeding on the wide variety of invertebrates. Most of the snails that live on the forest floor are very small. They dwell in the litter, under rotting logs and loose bark, feeding on a variety of vegetable matter. The large snails belong to an ancient and primitive family of big land snails, Paryphantidae e.g. the kauri snail (7.9 cm in diameter). They are carnivores with voracious appetites for worms, slugs and other snails. New Zealand’s only native amphibians are the most primitive living frogs known, Leiopelma species. Their peculiarities include, lack of eardrums and vocal sacs and the retention of tail wagging muscles in adults. They not go through a water-living tadpole stage. A tiny miniature adult frog emerges from the gelatBlack cockroach Papata Platyzosteria Wet-wood termite Stolotermes ruficeps Morepork Ruru Ninox novaeseelandiae Kaka Nestor meridionalis Trapdoor spider Cantuaria gilliesi Auckland Museum 20 inous capsule that was its egg — its tail is subsequently absorbed. They do require damp conditions, being found under stones or rotting logs. They become active at night catching small inverCommon skink tebrates. There are three species of Leiopelma: Hochstetter’s frog, and Archey’s frog of the northern North Island, and Hamilton’s frog on Stephens and Maud Islands. Lizards living in the forest are either geckos or skinks e.g. Pacific gecko, green tree gecko, copper skink and the forest gecko. The Forest gecko is camouflaged against moss and tree bark, if alarmed it flattens its body and freezes. It is nocturnal, eating small invertebrates especially moths. Mosses and liverworts are primitive land plants, not fully adapted to life on land. New Zealand has some 1100 species of bryophytes, which grow in mats and tufts on the forest floor, on fallen trunks and on living trees. Plant communities change as water level decreases. Sedges give way to raupo, then to New Zealand flax and lastly to scrub containing cabbage trees and manuka. New Zealand has a wide and varied sedge flora. Sedges are generally grass-like with narrow leaves. Raupo is a versatile plant, the lower parts of the plant normally always under water. They grow together in large numbers, often forming dense stands. During the height of summer, a sausage shaped seed head is formed. Maori used raupo as a food, a medicine, for thatching and to make canoes. The most valued part of the plant was the pollen, which was worked into sweet bread. Swamp millet is a slender grass present in wetland vegetation, while toetoe is a large tussock grass with drooping flower heads, which can also grow away from water. Invertebrates associated with wetlands include dragonflies and damselflies. These predatory insects breed in still waters of wetlands and ponds e.g. lancer dragonfly, sentry dragonfly, gossamer damselfly and blue damselfly. Dactylanthus (woodrose) is New Zealand’s only completely parasitic plant. It lacks green tissue, The nurseryweb spider is common around swamps growing underground, attaching itself to tree roots and bush edges. It is a close relative of water spiand absorbing their nutrients. In autumn its scented ders and has an enclosed flowers open and attract short-tailed bats. The web which protects the bats feed on the copious nectar and accidentally young spiders. pollinate the flowers. No other bats are known to pollinate ground flowers. The cabbage tree moth is per4. WETLANDS fectly camWetlands form at the indistinct and ever-changing o u f l a ge d boundary between water and land, covering a against the number of often quite separate habitats e.g. bogs, leaves of swamps, marshes and peatlands. cabbage t r e e s . Wetlands are among the most threatened habitats Caterpillars Nurseryweb spider in the world; in New Zealand ninety per cent have chew young Polomedes minor been destroyed since the arrival of humans. Vital leaves leaving for wildlife they are easily damaged by pollution, distinctive notched drainage or reclamation. edges. 21 Natural History Cabbage tree moth Epiphryne verriculata Dragonfly Kapawai Procordulia smithii Damselfly Tiemiemi Austrolestes colensonis Pukeko Porphyrio porphyrio Manuka Red tea tree Leptospermum scoparium Cabbage tree Ti Cordyline australis Pied shag Karuhiruhi Phalacrocorax varius White heron Kotuku Egretta alba Paradise duck Putangitangi Tadorna variegata Before European settlement many birds lived in New Zealand’s vast wetland habitats. Most wetland birds are adapted for life in wet conditions with specialised beaks and feet. Dabbling ducks have filter feeding bills e.g. paradise shelduck, grey duck, grey teal, brown teal. Australasian bittern Matuku Botaurus stellaris Reef heron Matuku moana Egretta sacra The scaup, New Zealand’s only diving duck, probes the wetland floor for freshwater snails. Herons, bitterns and black shags have fish-seizing bills. Pukeko have long toes to help them walk on swampy ground. The fernbird is a perching bird, feeding mainly on insects. Auckland Museum 22 SPECIES PROFILE: TUI, PARSON BIRD, Prosthemadera novaeseelandiae SPECIES PROFILE: KAKAPO, OWL-PARROT, Strigops habroptilus • Size : 30 cm • Distribution : New Zealand only, found throughout forests and towns in the North, South and Stewart Islands and many offshore islands. • Breeding : tui establish their territories in SeptemberOctober and sing from high perches, especially in the morning and late afternoon. The female alone builds the nest and incubates the eggs. Both parents feed the young. • Behaviour : tui are usually solitary. They are the dominant honeyeater in New Zealand and are aggressive towards other birds near the nest or a prominent food source. The song dialect varies in each district. • Feeding : Preferred diet is nectar, supplemented with fruit and invertebrates. Nectar sources include kowhai, flax, pohutakawa, fuchsia and rewarewa. They feed nestlings at first on small insects and nectar, and later also on berries and larger insects, spiders and moths. • The tufts of white feathers around the tui’s neck gave rise to its early name “the parson bird”. • Larger and more assertive than most native birds, the tui has managed to maintain its numbers and even thrive, in a changed environment. • The tui is a skillful mimic, imitating the sound of a morepork, blackbird and even a cat. • Size: 63 cm, 3.5 kg • Distribution : New Zealand only. Found throughout the North, South and Stewart Islands before and during early Maori times. The population is now in serious decline. The remaining kakapo have been transferred to cat and mustelid free Little Barrier, Codfish and Maud Islands. • Kakapo is one of the most endangered birds in the world. • Breeding : sucessful breeding requires an abundant supply of high quality food throughout the 8 month breeding cycle. Breeding takes place every 3–5 years, during a “mast” (heavy fruiting) year. • Kakapo are unique among New Zealand birds and parrots in having an arena mating system. Males establish a miniature display territory and then call (or boom) to the females to mate. Females travel several kilometres to briefly visit the displaying males to mate. Males take no part tending or defending the nest. • Behaviour : Solitary. Flightless. An adept tree climber and a free ranger. • Feeding : Herbivorous. Kakapo eat a wide variety of fruits, seeds, leaves, stems and roots. The stout beak is used for grubbing and grinding. • Humans, dogs, cats, stoats and rats have all preyed on the kakapo. Deer and possums have eaten its favoured foods. Being a ground nester it proved easy prey for such predators. SPECIES PROFILE: KERERU, NEW ZEALAND PIGEON, Hemiphaga novaeseelandiae • Size : 51 cm • Distribution : They are found throughout the North, South and Stewart Islands and on many forested offshore islands. They favour native lowland forests dominated by podocarps, tawa, taraire and puriri. • The timing of breeding is closely linked to certain fruits being avalilable ; they can breed early or late, depending on fruiting but some or all pairs fail to breed in years when fruit is in poor supply. • They play a key ecological role in the regeneration of native forests by dispersing the seeds of large-fruited trees and shrubs, most of which (e.g. miro, tawa, taraire, puriri and karaka) are too large to be dispersed by other birds. • Feeding: Herbivorous, fruits are preferred and in some parts of the country are the sole diet. When fruits are in short supply, kereru feed on foliage, especially old leaves of kowhai, tree lucerne, broom and clover. Flowers of kowhai, tree lucerne and broom also form an important seasonal part of their diet. • In certain areas they are in serious decline, mainly because of hunting. Conflict occurs between conservationists who want to preserve the bird and Maori traditionalists who claim their rights to harvest the pigeon as of old. • Possums compete for food and destroy nests. • Kereru lay only one egg per clutch. 23 Natural History SPECIES PROFILE: GLOW-WORM, PURATOKE, Arachnocampa luminosa • Found along the banks of streams and in other damp places in the bush, as well as in caves • The larva is carnivorous. As soon as it is hatched, it begins to construct a tunnel of mucus and silk which it suspends on silken ropes from the cave ceiling or from another suitable support. It then spins a large number of silken lines hanging down from the tunnel. At regular intervals along a line the larva places little beadlets of sticky mucus. Midges and other insects, attracted by the glow-worm’s light, rise up and get stuck on the beadlets. At once the larva hauls up the line and eats the victim. • Its lifecycle is about a year, and during this time it casts a luminous glow. • As it transforms from pupa to adult fly, the glow-worm glows erractically. Emerging into brief adulthood, the female continues to emit a light which attracts the male to mate. SPECIES PROFILE: RANGI, KAURI SNAIL, PUPUParyphanta busbyi • Found on the mainland only north of Auckland, in the area where kauri historically grew. Has been translocated to Great Barrier, Poor Knights and the Hen and Chickens Islands. • Large and carnivorous, feeding mainly on worms. • Their heavy shells, as large as 75mm across, are firmly attached to their bodies, enabling the snails to climb vertically. They are also able to travel across several hundred metres across farmland in a night to reach bush. • Belongs to an ancient and primitive family of big land snails. Some species still occur in South Africa, Australia and the South-west Pacific, the greatest variety being found in New Zealand. • It does not actually live in kauri but prefers astelias, bushy undergrowth and scrub. • Lays large, white eggs with limey shells in depressions in the ground under leaf mould where the heat from decaying compost hatches them out. SPECIES PROFILE: LARGE DRAGONFLY, KAPOKAPOWAI, Uropetala carovei • Dragonflies have a very long, narrow abdomen, antennae reduced to tiny threads, and two pairs of large, veined, gauzy wings which glitter in sunlight. • They are predators, taking flying insects on the wing. Their huge compound eyes, linked by nerves to the flight muscles, enable them to locate even very small prey and immediately to change direction to capture it. The victim is scooped up by the dragonfly’s thin legs, which are armed with spines, and taken to the mouth where it is masticated by the strongly toothed mouth parts. • Dragonflies and their relatives the damselflies have teeth (hence their family name Odonata, from the Greek for tooth). • New Zealand has 11 species of dragonflies and six damselflies. Dragonflies are larger and spread their wings when they are resting, whereas damselflies fold their wings loosely over their body. • Dragonflies have incomplete metamorphosis. The eggs hatch into larvae or nymphs which live in fresh water. Nymphs are voracious feeders, eating insects, tadpoles and even small fish; in their turn they are the target of predators such as frogs, birds and trout. After a series of moults the larva leaves the water, the larval skin splits and the adult emerges. • The best known native dragonfly is the giant black and bright yellow “devil’s darning needle” Uropetala carovei. This large insect has a wing span of 130mm and is found in boggy seepage areas in forests. • Dragonflies are the fastest of all insects, capable of cruising at 40 km/hr and increasing their speed in bursts to 58 km/hr. They can also hover and make quick turns up, down or sideways. SPECIES PROFILE : NIKAU PALM, Rhopalostylis sapida • The southern most palm in the world, the nikau palm grows from North Cape down to Banks Peninsula on the east coast and Greymouth on the west. Reaching 10 metres in height, it is New Zealand’s only palm. • The nikau’s ripe berries are an important source or food for kereru. • Several parts of the nikau were eaten by Maori: the immature flower; the berries when green; and the “heart” of undeveloped leaves, the cutting out of which unfortunately killed the tree. • Nikau leaves were traditionally used to thatch the top and sides of whare, and for weaving into bags and kete. • It is slow growing, taking some 30 years before bursting into flower. The flowers are borne on long spikes protruding from the stem on the ring scar just below the oldest leaf. The red berries take three years to ripen. • The nikau’s stem, up to 10 m tall, is marked with leaf scars which give it a distinctive appearance. SPECIES PROFILE: KAURI, Agathis australis • The New Zealand kauri is unrivalled among New Zealand trees for its size and grandeur. It can grow up to 50 m or more tall, with a massive straight, unbranching trunk. • It is a tree with an ancient lineage. Its ancestors were contemporaries of the dinosaurs more than 130 million years ago. Today, kauri species exist around the western Pacific — in the Philippines, Borneo, Malaysia, New Guinea, Vanuatu, Australia, New Caledonia and Fiji. The family evolved in Gondwana. • In the forest the kauri plays host to a wide range of plant and animal life. High up in its crown grow epiphytes, perching plants which are extremely important food sources for birds. Important animals found in kauri forest include the redcrowned and yellow-crowned parakeets, brown kiwi, pied tit, kaka and Hochstetter’s and Archey’s frogs. Short-tailed bats are found in hollow logs on the forest floor. • Kauri trees normally grow some distant apart, with a ground cover of kauri grass and the giant, sharp-leaved ghania. Occasional shrubs and small trees include Kirk’s tree daisy, hangehange, mingimingi and neinei. • To Maori, kauri was ranked second only to totara. Its timber was used for boat building, carving and housing. Kauri gum was used for fire starting and heating, and as a chewing gum once it had been soaked in water and mixed with the milk of puha. The felling of a tree was an important occasion and was accompained by a ritual. Auckland Museum 24 25 GENUS PROFILE: FROGS, Leiopelma archeyi, L. hochstetteri, L. hamiltoni SPECIES PROFILE: BATS , PEKA PEKA, Chalinolobus tuberculatus and Mystacina tuberculata. • New Zealand’s native frog species are survivors of frogs that evolved several hundred million years ago. They are virtually unchanged from frogs of around 135 million years ago. • All three species of native frogs are endangered. Archey’s frog is found in Coromandel, and numbers in the thousands. Hochstetter’s frog is the most widespread and is found from East Cape northwards to Whangarei, and is also numbered in the thousands. Hamilton’s frog is confined to a 600 square metre patch of scree, called the Frog Bank, on Stephen’s Island in Cook Strait, and to forests on Maud Island. This population has been described as a separate species but differs little in form from the Stephens Island population. It is the rarest of the frog species, numbering around 200. • These most primitive frogs live in forests under rocks and stones. They require moisture but not swamps or ponds as other frogs do. • All native frogs are earless and croakless — at best they squeak and pipe softy. Another primitive feature they have retained is tail-wagging muscles, even though they have no tail. • For such small creatures they are relatively long-lived, more than 23 years in the case of Hamilton’s frog. • Besides their protective colouring and freezing tactics, the native frogs may possess a third line of defence against predators — their unpalatability, derived from glandular secretions. • New Zealand’s native frogs do not go through a tadpole stage like other frogs; instead, adults lay eggs and the young metamorphose inside the egg sac — their own personal ponds. After hatching, still with remnant tails, they climb onto their father’s back and spend the final weeks of development there. • New Zealand has two native land mammals — the long-tailed bat (Chalinolobus tuberculatus) and the lesser Short-tailed bat (Mystacina tuberculata). Each has a body size of a person’s thumb and a wingspan of 300mm. • Until 1967 there was a third species, the greater shorttailed bat. It became extinct when rats invaded its home. • The short-tailed bat is the more endangered of the two species, but new populations are being found as new technology enables scientists to track them down. • The short-tailed bat is the only bat in the world to forage on the forest floor. It has several adaptations to assist this behaviour: robust hind legs with small claws and a way of neatly furling the delicate outer wing membrane under thicker sections of membrane so the wings can serve as front limbs. Its unusual hunting habit has also led to its decline, making it an easy target for predators such as cats and rats. • The long-tailed bat was presumed to have blown over from Australia 1 million years ago. Today it is widely distributed in native forests throughout the North and South Islands. • Both species of bat prefer to roost in old, hollow trees rather than caves. Fluttering fantail-like in search of insects along forest marigins, rivers and over lakes, they are often mistaken for birds or puriri moths. • Long-tailed bats keep nursery colonies, babies are carried to the different roosts each night. It is believed both bat species give birth to just one offspring a year, in December or January. • The endangered wood rose (Dactylanthus taylorii) has coevolved with the short-tailed bat and is often pollinated by it. • Bats rely on echolocation to detect prey and to navigate their way through forests in the dark. Bats emit high-frequency sounds, usually through their mouths, in rapid pulses at frequencies too high for the human ear to pick up. • During winter and sometimes during cool periods in summer New Zealand bats go into hibernation. • They are both nocturnal. • They feed predominately on insects and sometimes berries and nectar. Natural History TEACHER BACKGROUND OCEANS GALLERY ew Zealand’s maritime environment extends from sub Tropical to sub Antarctic zones. The coastline is a diverse habitat including areas such as dunes, cliffs, muddy estuaries, ocean beaches, rocky headlands and sheltered bays. Each sustains living communities uniquely adapted to the conditions present. N ESTUARIES Streams running to the sea often form estuaries at the interface — a transition area between freshwater and marine habitats. Although low in species diversity, estuaries are rich in organic sediments that support an abundance of life. In the north of New Zealand, estuaries are lined with mangroves. Mangroves contribute to the high productivity, their decomposing leaves releasing nutrients, the trunks providing shelter and accumulating sediments. At its highest reaches are the salt marshes. Lower down eelgrass and sandy mud cover large flat areas. Just under the muddy surface are beds of bivalve shellfish such as cockles and the wedge shell which is a detritus feeder that vacuums plankton off the surface of the mud on out-going tides. Gastropods such as the mud snail leave feacal trails on the muddy sand. Also patrolling are scavengers and algal grazers. Small crabs and worms are common. Saltmarsh sea rushes, like mangroves continually produce new leaves and get rid of the old ones which are encrusted with salt. The glasswort dilutes salt by storing water in fleshy stems. Wirevine grows in a tangled mass. The water snail grazes on algal films in muddy brackish water at upper tidal areas. The harbour flea mussel is a small black mussel that lives on hard surfaces in brackish water, usually near the tidal limit. Salt Marsh Land as opposed to actual shoreline regularly inundated by seawater, may take the form of salt marsh. Its lower most zone, about the mid-tide level, is often muddy and colonised by flat mat plants. Succulents including clumps of glasswort are found living here. Further inland, plant cover increases becoming a salt meadow of tight turf. At upper tidal levels neptune’s Necklace is the most common salt marsh algae. Its bead like bladders vary in size according to the substrate, larger when on bare unshaded mud and smaller on moist clay. Auckland Museum 26 Mangroves — Trees In The Tide The New Zealand mangrove migrated to our sheltered shores from tropical places further north. Mangrove roots are surrounded by oxygen poor mud and the tree is immersed in salty water twice each day. To survive in this challenging environment it has a number of special features. Pencil like projections emerging from the mud are special “air breathing” roots, pneumatophores. They are covered with corky water resistant bark and arise from an underground root system. Underground roots form a strong network that stablises the tree against tidal currents. Leaves have water storing cells and a shiny cuticle with white hairs underneath to protect them from sunshine glare reflected off the water. Flowers occur in small clusters. Seeds are not dispersed in any of the usual ways. Instead an already germinated young plant, a propagule, is dropped from the plant. It can begin to grow where it dropped, or it may be carried by the tide to grow elsewhere. Mangroves support whole communities of organisms. The mud snail is found within mangrove scrub and on mudflats. It eats surface mud, digesting the organic parts and excreting the rest in a continuous string. The mud whelk can be found scavenging on both mud and mangrove flats. The mud flat horn shell is a herbivore and deposit feeder, locally dense in depressions. The cat’s eye feeds on algae when the tide is in. The modest barnacle is New Zealand’s most common encrusting organism. Larvae settle on any hard surface, including mangrove aerial roots. Rock oysters can also be found 27 Natural History Mud snail Titiko Amphibola crenata Cat’s eye Atata Turbo smaragdus Spiny tubeworm Pomatoceros caeruleus Large dog cockle Glycymeris laticostata Hermit crab Pagurus novazelandiae Stalk eyed crab Macrpthalmus hirtipes Common cushion star Patiriella regularis Arabic volute Pupu rore Alcithoe arabica Snapping shrimp Alpheus novaezelandiae Rock borer Anchomasa similis Mason worm Thelepus spectabilis Hearth urchin Kina pakira Echinocardium australe Sea grass Zostera novazelandica on pneumatophores and mangrove trunks. The spiny tubeworm is a common bristle worm, living inside a tough tube, often found in clusters. Crabs The numerous holes in mud are home to tunneling crabs. They are most abundant among mangroves but can be found high up the estuary beyond the marine mud, burrowing into clay. The tunneling mud crab is endemic; it leaves its burrow to feed when the tide is out. It is territorial. Apart from the tunneling mud crab, the more common crabs of the estuary are the stalk-eyed mudcrab and hairyhanded crab. Both have similar habitats to the tunneling mud crab. The hermit crab is common, its softbody protected by a gastropod shell. The crab moves to a larger one as it grows. It eats organic matter and decaying animals. The harbour top shell is an algae eating herbivore that lives on mud. Cockles are often found in dense beds just below the surface on sandy mud flats. The Arabic volute is a carnivore, which suffocates its prey. The cushion star is a common omnivore with 4–7 arms. The long tailed stingray feeds on molluscs and invertebrates. The snapping shrimp burrows into mud. Its nipper creates an audible “snapping” noise and it eats organic debris. Sand mason worms are mobile worms, feeding on fine organic particles. Its fragile conical tube is made from sand grains. The date shell lives deeply buried in softmud and is common amongst eelgrass. The heart urchin lives buried in soft sandy mud. Pipi form dense beds in coarse shelly sediments of harbours and near mouths of estuaries. Plants Life in and by the sea is not easy. Only specialised plants survive, plants that are able to cope with salty conditions. Taupata grows on dryland by the sea, above the high tide. Roots may still extend into the saltwater table and leaves can be sprayed with saltwater. Tough thick leaves with a glossy cuticle are typical adaptations against glare and water loss. Plants occasionally flooded by the tide include glasswort and the searush. Mangroves occur half in and half out of the tide. Salt glands in the leaves excrete salt absorbed by the roots. Completely covered by the tide — the only New Zealand flowering plant able to live below midtide is eelgrass. Flowering and pollination takes place under water. Behaving more like a seaweed, eelgrass absorbs nutrients directly through its leaves, which only have thin cuticles and no stomata. BORERS Wood borers Woodborers are both destructive and useful. Destructive in that they can cause extensive damage to the wood of boats and wharves, expensive copper sheathing is the only effective protection, useful because they break down deadwood that has drifted out to sea. Our oceans would be full of Auckland Museum 28 Banded dotterel Tuturiwhatu Charadrius bicinctus Pied stilt Poaka Himantopus himantopus Little blue penguin Eudyptula minor Caspian tern Taranui Hydroprogne caspia Black-billed gull Karoro Larus dominicanus Fairy prion Titi wainui Pachyptila turtur Wandering albatross Toroa Diomedea exulans 29 Natural History wood if not for these important recyclers. A type of isopod, and a relative of the garden slater uses “rasp and file” mandibles to tunnel beneath the surface of the wood. An amphipod lives in holes bored by the isopod. Teredo settles on wood as larvae bores into wood using razor-sharp shell valves and coats its burrow with calcium carbonate. Stone borers Rock boring molluscs (piddocks) have shell structures similar to the sharply ribbed drilling bit of an oilrig. They drill down by twisting and rocking the two shell valves against the stoney substrate, enlarging the hole as the shell grows. No food is derived from the stone, the substrate providing protection for the organism. The piddocks extend siphons up into the seawater to collect food. The date mussel uses chemicals instead of physical abrasion to sculpt its stony home. It protects itself from the acid with a thick, tough outer covering. BIRDS OF THE OCEAN AND THE SHORELINE Birds have adapted to take advantage of every habitat found along New Zealand’s shoreline. Mudflats are rich feeding grounds for huge numbers of birds. Cliffs, rocky ledges and stacks provide breeding sites for a wide variety of sea birds. The open ocean is a feeding ground for the larger varieties of petrels. For each of these distinct environments the birds found there have evolved specialised behaviours, physiological components and physical structures to allow them to cope with the demands of the conditions present. Wading birds Wading birds specialise in probing for food in the soft mud of estuaries and harbours. New Zealand is the destination for some of the world’s Arctic waders. Breeding in the Arctic, they undertake a spectacular journey from one end of the earth to the other, to spend the northern winter in the Southern Hemisphere e.g. bar-tailed godwit, lesser knot, turnstone, Pacific golden plover, rednecked stint, sharp-tailed sandpiper, whimbrel. Some Waders breed locally and migrate within Petrels New Zealand and feed alongside Arctic migrants New Zealand has many petrels, a group that e.g. South Island pied oystercatcher, pied stilt. includes albatrosses, mollymawks, shearwaters, prions and storm petrels. Feeding at sea, their effortPenguins less gliding flight enables much of their lives to be Penguins are flightless seabirds found only in the spent far from land. Predators have now driven Southern Hemisphere. Descended from flying them to breed on inaccessible islands and headbirds, their wings are now short, stiff flippers. They lands. fly underwater, propelled by flippers alone. Their short, densely packed feathers form a smooth, Larger species build open nests, but most medium firm, water-resistant coat. Their legs are short and and small species nest in burrows. on land give them their distinctive waddle e.g. blue penguin (the world’s smallest penguin), Fiordland e.g. fluttering shearwater, black petrel, flesh-footcrested penguin and yellow eyed penguin. ed shearwater, mottled petrel, fairy prion, and broad-billed prion. Plovers and Dotterels These small waders have a rounded, plump body, Albatrosses and Mollymawks short legs and a short bill and tail. The bill is Nearly three-quarters of the world’s albatross adapted for picking up vertebrates from wet sand species can be found in the New Zealand region. or mud. When feeding they characteristically All have a graceful, soaring flight. Many follow “walk and stop”, or “run-stop-peck” e.g. New boats especially fishing vessels. Large numbers of Zealand dotterel, banded dotterel, shore plover, albatrosses come to grief by swallowing baited wrybill and spur-winged plover. hooks. Mollymawks are small albatrosses e.g. royal albatross, wandering albatross, buller’s mollyShags mawk, black browed mollymawk. New Zealand has twelve breeding species of shag, about a third of the world’s shag species. SANDY EXPOSED BEACHES AND DUNES Unprotected except by distant headlands, these They are mostly seen in sheltered coastal waters, beaches are formed by ocean waves and prevailbut sometimes far inland near lakes, streams and ing winds. An exposed sandy shore is one of the rivers e.g. black shag, pied shag, little shag, spot- most exacting and extreme habitats, supporting a ted shag. group of highly specialised plants and animals. These have to withstand drying by unchecked They are excellent fishermen, diving into the water onshore winds, and cope with burning salt spray, and seizing fish with their strong beak. high temperatures and low nutrients. Pakiri (north of Auckland) is an example of a sandy exposed Gulls and Terns beach. Gulls and terns usually prefer coastal situations near shore. They are sociable, feeding in flocks They are composed of sand, gravel, or a mixture and breeding in colonies. Terns are more aerial of both. Gravel beaches tend to be steep and and dainty than gulls with narrower pointed wings tiered; sand beaches have a gentler gradient. The and usually a deeply forked tail. Terns have short- highest part of the intertidal area is generally the er legs and smaller feet e.g. Arctic skua; black- steepest. Dunes occur above the spring tide line backed gull, red-billed gull, black-billed gull, and out of reach of waves, formed by the action of black fronted tern, fairy tern, and caspian tern. wind. Fine sands are blown inland until they meet a dune crest, log or other obstruction — they gradually build up to form a dune line. Auckland Museum 30 While not as diverse as the rocky shore, open sandy beaches are rich in molluscs, especially bivalves. Tuatua Paphies subtriangulata Ostrich foot Struthiolaria papulosa Toheroa Paphies ventricosa Violet snail Janthina janthina Shells found in the strand line usually come from animals that lived within and just beyond the wave zone. However, on-shore winds can cause pelagic ocean drifters to strand on the driftline. Larger items are carried further up the shore creating the upper strand line. Items tend to get progressively smaller all the way down to the lower strand line. Both open and protected beaches are divided into three zones: upper, middle and lower. On the sandy shore these areas are characterised by the upper strand line, lower strand line and beneath the water line. Characteristic bivalves include the tuatua and the toheroa. Echinoderms and worms are also present. Knobbed whelk Kakara Austrofusus glans Helmet shell Semicassis pyrum Sandhopper Namu mawhitiwhiti Corophium acutum Upper Strand line Ostrich foot shells are common at below low tide on sandy and sandy-mud flats in estuaries and on the open coast. They are sometimes washed ashore in vast numbers. The knobbed whelk is a carnivore found from low tide to deeper water in fine sand or silty mud habitats throughout New Zealand. The shells are often washed up on beaches. The helmet shell is plentiful on open sandy beaches. It feeds on bivalves and sea urchins. Cask shell Pupu tangimoana Tonna cerevisina The hairy trumpet lives on reefs among brown seaweed covered in a thick hairy coating. Portuguese man-of-war Physalia physalis By the wind sailor Velella velella 31 Natural History Violet janthina shells use a raft of bubbles to float on the surface of the ocean. They feed on other floating organisms, like the by-the-wind sailor and portuguese man-of-war. Rams horn shells are the internal shells of a small squid that live in water about 200–2000m deep. Thousands can be found washed up on open coastal beaches. Sand hoppers are amphipod crustaceans that Beneath the water spring up and down when you disturb a piece of Paddle crabs emerge from their offshore sandy seaweed or wood lying on the beach. burrows to hunt at night. The paddles on the rear legs help the crab to swim and burrow. By-the-wind sailors are colonies of hydroids that resemble jellyfish. They rely on wind to skim along The fan scallop can swim by snapping its shell shut. the surface of the ocean. Portuguese man-of-war The tuatua is a surf clam with a truncated end usuor bluebottles are large, gas filled sacs. These ally just above or lightly covered with sand. keep the colony of animals afloat and acts like a sail. The geoduck lives about 20–40 cm in the sand, offshore, in calm water beyond breaking waves, so Cask shells are very large, thin shelled molluscs that they are not normally subjected to dislodgement or live in moderately deep-water. They are active predation. carnivores feeding on burrowing bivalves and echinoderms. Small animals on a sandy beach From the strand line to the dunes, a sandy beach is Low Strand line no place to live unless you happen to be one of a The pink sunset shell lives buried deep in the sand select cluster of crustaceans, insects, spiders and feeding on surface detritus with its long siphons. their relatives, who have adapted to the harsh conThe necklace shell uses its teeth (radula) to drill ditions. Here temperatures vary between extremes. holes in the shells of its victims. Wind and salt spray suck away the moisture, the sand shifts and tears. The strand line is a transient The sand dollar or snapper biscuit is a flattened environment. Seaweed and carrion (the bodies of urchin that is eaten by snapper. birds, fish, seal) provide food for a specialised group of invertebrates, which speed up its decomThe wheel shell burrows in fine sand and eats the position. Other invertebrates, shore birds and organic matter between the sand grains. lizards eat them in turn. The tiger beetle is a predator of small insects and is well camouflaged on greyish-white sand dunes. Necklace shell Tanea zelandica Cake urchin Kina papa Fellaster zelandiae The sand scarab is a bulky beetle which leaves conspicuous tracks in the sand from its nocturnal wanderings. During the day it burrows deep in the sand, the plump larvae can be found under partly buried logs. The ground beetle has short stocky legs, which help this predator to burrow through sand. Our largest native earwig is the shore earwig. A scavenger and predator, it hides under driftwood, seaweed and stones. Females are often found brooding eggs. Fan scallop Chlamys zelandiae Wheel shell Umbonium zelandicum Auckland Museum 32 Kelp flies lay eggs in freshly stranded kelp. Their conditions, from dry most of the time to wet all the maggots thrive in the kelp and help to break it time. Just who lives where depends upon the pardown. ticular conditions present. The black spider-hunter wasp stings and paralyses small wolf spiders, then takes them to its nest in the sand. An egg is laid on the body, which is later consumed by the developing wasp larva. The native bee burrows through the loose, hot, dry sand above high water to nest in the damp sand beneath. Sand hoppers are one of the main decomposers of stranded kelp. They flee predators by burrowing into the sand with their peculiar sand-digging leg paddles. The sand centipede can be found in damp sand under driftwood. The endangered katipo spiders make a tangled cobweb at the base of dune plants and debris. The black cockroach is found at the top of beaches, in driftwood piles, under stones and other debris. It makes an objectionable smell when disturbed. The common copper butterfly lives in the dunes where its caterpillars feed on leaves of the tough pohuehue vine. At most this butterfly lives for 10 days, so time is limited for egg laying. The surging water, crashing against the rock and rushing through crevices, makes the exposed, steep rocky shore a dangerous place. Animals and plants need to be well adapted to live there. Animals adapt in various ways. Often their bodies are streamlined to lessen the effect of onrushing water. Many have powerful means of clinging to the rock. Others are especially fleet of foot so they can take cover quickly. Those that have no special adaptations have to rely on the shelter provided by crevices, seaweed or other animals. An example of this type of shore is Piha on Auckland’s West Coast. The highest plants covered by water are karengo, while at low tide mark, streamers of kelp stand up from their tough, woody holdfasts. Agar weed on a rock overhang helps hide sponges in the tide pool. Paua and cooks turban shells graze on the seaweed forest. At high tide level the barnacles and snakeskin chitin are getting their brief twice-daily immersion. Above them, spray barely reaches the crusts of lichen. Beneath the karengo fronds, red anemones share a crevice with the purple rock crab just above the mussel zone where hunchedreef starfish tear prey off the rocks before receding with the tide. Blue maomao feed on small animals in mid-water while a cruising snapper picks busily among the mussels. An example of a moderately sheltered rocky shore The convolvulus hawk moth sucks flower nectar at is Oneroa on Waiheke Island. dusk and caterpillars feed on native shore convolvulus. At the highest point of a jagged outcrop of sandstone, a pohutukawa sends tenacious roots down ROCKY SHORE into cracks that reach almost to the wave splash The hard shores offer very different habitats from line. Clinging colonies of surface creatures: barnathose of sandy beaches and mudflats; consequent- cles, oysters, little black mussels, tube worms and ly the animal and plant communities that occupy green mussels form bands across the rocks. Below them are quite different. The ebbing and flowing the mussels, pink corralline algae is fringed by tide influences an amazing variety of plants and small red algae. Below that flapjack swirls in the animals compressed into just a few metres of rocky swell. shoreline. In that narrow space species have evolved to cope with an array of environmental 33 Natural History Sand scarab Mumutawa pango Pericoptus truncatus Common copper butterfly Pepe parariki Lycaena salustius Agar weed Pterocladia lucida Common tiger beetle Papapa Neocicindella tuberculata Black cockroach Papata Platyzosteria novaeseelandiae Snakeskin chiton Papatua Sypharochiton pelliserpentis Snapper Tamure Chrysophrys auratus Seashore earwig Mata Anisolabis littorea Ground beetle Megadromus vigil Katipo spider Latrodectus katipo Karengo Porphyra columbina Cook’s Turban shell Karaka Cookia sulcata Paua Haliotis iris Lessonia kelp Lessonia variegata Neptunes necklace appears on low rocky surfaces in single clumps. Between rocky outcrops, storm debris; shells, seastars and dying weed from deeper places, collects on sand. Less exposed coasts e.g. Stanley Bay, Devonport, provide greater security and more variety. Wave action wears at softer mudstones creating undercut slabs and steps. Some slabs break off, the undersides rich with life; mostly small organisms that present little profile even to the gentle waves. Neptunes necklace Homosira banksii Red sea anemone Kotore moana Actinia tenebrosa The edge of the wave-cut platform is densely covered with neptunes necklace. Pink coralline algae covers large areas. Intertidal plant growth is good but less diverse than on moderate exposed shores. Piddocks (rock borers) are plentiful in the stone, their dwelling holes visible through broken slabs. Auckland Museum 34 Common sea urchin Kina Evechinus chloroticus Flapjack Carpophyllum maschalocarpum Bladder kelp Macrocystis pyrifera Common bull kelp Durvillaea antarctica SEAWEEDS Seaweed (algae) comes in a wide range of forms, colours and sizes. Seaweed can be divided into three main groups — green (chlorophytal), browns (phacophyta) and reds (rhodophyta), they all possess chlorophyll and photosynthesis; the variation in colour is obtained from various pigments. They are generally zoned down the shoreline with greens near the top (uppertidal level), reds around the middle (intertidal) and browns near the bottom (subtidal). However there is considerable overlap. e.g. sea lettuce, karengo, neptune’s necklace. Other brown alga includes bull kelp and bladder kelp. Bladder kelp is the fastest growing plant in the world, growing up to 50 centimetres per day. Gigartina (red algae), are commonly found in large numbers all around New Zealand’s coastline. Most species are probably endemic to New Zealand. There are two main groups — those with large flat blades that can be up to one meter long; and smaller, branched ones, normally up to twenty centimeters high. Several are used commercially for the production of carrageenan (a clear, jellylike substance). Paua live beneath stones and ledges at low tide mark. They browse on red and brown seaweed and coralline. The blue-greens of paua shells are influenced by a diet of mostly brown algae, while the deep reds and browns of paua shells are influenced by a diet of mostly red algae and bladder kelp. Animals in Seaweed Living in seaweed has several advantages. They are usually continually moist, dense enough to provide protection, but open enough to venture to and fro and a supply of algal tissue on hand. Many seaweed dwellers are tiny gastropods and crustaceans. Top shells feed by scraping up little plants and debris thct settle on the surface of the seaweed. Carpophyllum (brown algae) is an endemic genus Catseye are found in neptune’s necklace and to New Zealand with four species. Plants are up to Corralina. Cooks turban graze on fronds of flaptwo meters long and form a very distinctive brown jack and kelp. to black band at the low tide level. They possess a 180 degree twist at the base of the stalk — a fea- The hairy seaweed crab camouflages itself by ture only found in Carpophyllum species — which attaching seaweed and other various flora and enhances the plant’s ability to stay attached during fauna to its shell. During the day they hide amongst extreme wave action. All species possess rounded seaweed, rocks and bury themselves in sand. air filled bladders that assist in keeping the plant buoyant e.g. flapjack. The kina is a type of sea urchin. Its usual food is seaweed. 35 Natural History Flying fish Maroro Cypselurus lineatus Sunfish Ratahuihui Mola mola Yellowfin tuna Thunnus maccoyii Broadbill swordfish Paea Xiphias gladius Black marlin Makaira indica Offshore Fish Imagine the ocean as a multi-storey hotel. The fish that live in the top stories (near the surface) are called pelagic species. Those that live on the lower floors (in deep water) are demersal species. Then there are some that live in the basement (near the ocean floor). A huge variety of species inhabit this oceanic hotel but many share some common feaAdaptations help organisms avoid predators, tures: they range widely, are often large and are obtain food, produce more healthy young and an important catch for commercial and recreationwithstand different environmental conditions. These al fishers. special characteristics have allowed different types of organisms to inhabit every possible living Among the residents are the worlds fastest fish — space in the seas. the sail fish; the largest bony fish — the sunfish and the acrobatic flying fish. Sub Tidal Cliff Wherever land and oceans meet abruptly a “wall Tuna are swift surface fish of tropical and temperof mouths” can be found — an environment teem- ate waters. They migrate in large schools and are ing with creatures. The Poor Knights Islands marine common around New Zealand. There are six reserve, remenents of a series of extinct volcanoes species found in New Zealand e.g. yellow fin tuna. off the continental shelf of New Zealands northern They are economically important. east coast, is a good example. The upper jaw of a billfish is shaped like a long Here mixtures of currents, temperatures, nutrient spear. This group of fish includes marlin, broadbill flows and diminishing levels of sunlight with depth, swordfish, sailfish and spearfish. They are wide provide the ecological “seabed" for a profusion of ranging surface fish that feed on other fish and plant, sponge, coral, shell, and fish life. Diverse and squid. About five species of billfish occur seasonalcolourful life forms can be found between depths ly in New Zealands offshore waters, commonly of 30–70 metres. Every piece of the wall is occu- around the northern part of the country. They are pied with creatures crowding and encrusting one important recreational and commercial fish, and another in astonishing displays of community life. average 2–3.5 metres in length. THE UNDERWATER WORLD Marine organisms continually battle for survival in the harsh world under the sea. Few marine animals die of old age because most are victims of predation. These organisms have had to adapt to all the different conditions that can be found in the sea; it is a case of adapt or die. Auckland Museum 36 Kahawai Arripis trutta Fins: power, keel and brakes Fish control their movements with fins — much like a yacht uses it sail, keel and rudder. The tail fin pushes against the water, providing much of the forward power. Dorsal and anal fins act as keels to prevent the fish from rolling and pitching. Unlike the fixed fins of cartilaginous fish, bony fish fins can be unfurled to act as brakes and as paddles for low speed swimming or if treading water. Trevally Araara Pseudocaranx denrex Fins of different shapes have evolved to suit different lifestyles. To reduce drag, fast fish like the yellowtail kingfish and kahawai have “V” shaped tail fins. Oblong sunfish Ranzania laevis Leather-jacket Kokiri Parika scaber Carpet shark Pekapeka Cephaloscyllium isabella Finely scaled kingfish generate speed by rapidly flexing their rigid “V” shaped tail. To fuel the necessary muscles, kingfish have oxygen rich fatty tissue, which readily gives up oxygen when required. Kahawai have large coarse scales that inhibit body flexing, Instead stiff movements of its broad tail produce power and movement. Broad, flat fins give good manoeuvrability and control, but little speed. e.g. the scarlet wrasse is a bottom fossicker which uses its pectoral fins for fine control while feeding. The tail acts as a rudder but is moved for bursts of speed and direction change. Fish needing rapid acceleration, such as predators that lunge at prey, take in the aerodynamic features of a dart, with fins set well back. Slow swimmers like seahorses are often armoured for protection. Elephant fish Reperepe Callorhynchus milii While most fish swim with side to side motions there are other ways of getting about. e.g. flexing large dorsal and anal fins — oblong sunfish; curving entire body in snake-like waves — 37 Natural History snake eel; rippling dorsal and anal fins — rough leather jacket; waves passing along large winglike pectoral fins — smooth skate; ripple body and fins — lemon sole. All cartilaginous fish are carnivores, their teeth adapted for different foods. Predatory sharks like mako or great white have sharp sometimes serrated teeth, like steak knives, for slicing through flesh. Shellfish feeders, like the elephant fish, have stout Cartilaginous fish: Sharks, Rays and Chimaeras flattened teeth to crack open prey. Two of the New Zealand has 61 species of shark of which half world’s largest fish, the whale shark and basking are harmless dogfish. shark, don’t use teeth to feed at all ; instead they use modified gills to filter small animals from the Cat sharks are the largest shark family named for water. their cat-like eyes e.g. carpet shark. When some large predatory sharks (like the great Mackerel sharks include mako and great white white) are attacking, the mouth opens and the sharks. Mako are a popular game fish, putting up lower jaw rolls forward; at the same time it rolls its a strong fight if caught. eyes back and the final strike is made blind. The great white is the largest and most feared of Sharks have evolved special sensors (ampullae of predatory sharks; large individuals will prey on lorenzini), that detect tiny electrical currents promarine mammals. Usually solitary. duced by their prey. Cowshark have 6 or 7 gill slits; most sharks have 5. Electric rays have further developed this sense. Kitefins belong to the large and important group These stout bodied rays have electric organs in of sharks, the dogfish. The pygmy shark at 27 cen- each wing to detect electric fields and stun prey. timetres is one of the smallest sharks. All cartilaginous fish fertilise their eggs internally. New Zealand has 17 species of skates and rays, 9 Males have claspers, used to place sperm in the are endemic. Like many seabed dwellers they have female. flattened bodies. e.g. eagleray. Many produce live young, but some lay eggs. Chimeras are cartilaginous fish with a single pair of gill openings, smooth skin and a large dorsal fin spine. The mouth is small, with teeth fused into plates e.g. elephant fish (makorepe). Mako Isurus oxyrinchus Basking shark Reremai Cetorhinus maximus Great white shark Mango tuatini Carcharodon carcharias Eagle ray Whai manu Myliobatis tenuicaudatus Auckland Museum 38 SPECIES PROFILE: BLUE PENGUIN, KORARA, Eudyptula minor SPECIES PROFILE: NEPTUNES NECKLACE, Homosira banksii • Penguins occur only in the Southern Hemisphere. They are flightless seabirds with non-folding wings. Their food is principally fish, squid and crustaceans. • The little blue penguin is the most common New Zealand penguin occuring form Northland down to Stewart Island. • At 300mm in height, the little blue is the smallest of all penguins. • It is an impressive ocean traveller, having been recorded swimming 113km in 34 hours. • Unlike most other penguin species, the little blue tends to remain in one area, rather than disperse across the Southern Ocean during its non-breeding season. • The little blue has dropped in numbers close to large centres of population. The traditional causes of their decline stoats, dogs and vehicles still exact a toll, although efforts at conservation such as providing nesting boxes have had some success. • Our most common seaweed, a string of olive brown beads, is neptune’s necklace. • The beads vary a lot in shape and size, depending on where they grow, for this plant is extremely adaptable. It may be found on exposed or sheltered rocky shores, or carpeting the floor under mangrove forests. • Each bead of these neptune’s necklace plants is a knobbly bladder filled with water to prevent desiccation between tides. • Plants with the largest bladders live in the mangrove estuaries, lying open to direct sun among the breathing roots. They are exposed for most of each tidal cycle, so their water needs are especially great. These plants have far more branches than usual, and are also peculiar in not being attached to anything. The palisade of mangrove roots is enough to keep them in place as they rise and fall with the water movements. • The unattached form of this plant reproduces asexually, from broken fragments. • The attached form reproduces sexually, each is distinctly male or female. The sex organs look like tiny goose-pimples scattered all over the bladder. The plant squeeze out their clusters of eggs or sperm in sticky masses which break apart into a cloud. All plants release their eggs and sperm at the same time (when high tide washes over them), to maximise fertilisation. SPECIES PROFILE: ROYAL ALBATROSS, TOROA, Diomeda epomophora • Albatrosses soar over the Southern ocean in search of food. Their streamlined bodies and long slender wings enable them to fly for weeks at a time without landing. • They invest much effort in breeding and raising chicks, so much so that some breed only every 2 years. The royal albatross incubates its eggs for up to 83 days. Once the chick is hatched the adults feed it regurgitated fish and squid gathered during lengthy, long-distance fishing expeditions. • In order to prepare itself for the years it will spend at sea before returning to its birthplace to breed (6–15years), the fledging requires great quantities of food. Between 216 and 303 days hatching, the chick is finally ready to fly. • Albatrosses are monogamous, needing both parents if breeding is to be successful. Eggs are continuously incubated and the chicks fed for a long time. They develop a genuine pair bond over their long lives. • A vital ingredient of the breeding cycle is the courtship ritual. It is very intricate, with much bill snapping and groaning. • Over the past 20 years some species of albatross have declined at a significant rate, unwitting casualties of the bluefin tuna fishing industry. 44 000 albatrosses and petrels were being killed each year in the Japanese fishery which covers huge areas of the Southern ocean. 39 Natural History SPECIES PROFILE: EELGRASS Zostera novazelandica • A flowering plant that iscompletely submerged by the tide. • Vast pastures of eelgrass can be found in all large sheltered harbours and can also be found on rocky coasts in minute havens of shelter, where a suitable bed of sediment has built up. • Stems are completely buried, fibrous roots spread widely and penetrate deep into the black sulphurous mud. All these underground parts of the plants interweave to form a firm sod-like mat, which consolidates the lower shore and extends beyond low tide and across tidal channels. • The leaves have a thick cuticle which seems to be an adaptation against desiccation when the leaves are left exposed to wind and sun. • Eelgrass help to accumulate sediments. It has an important biological role in the productivity of coastal waters beyond low tide mark. It draws out nutrients which would otherwise be bound in the deep airless mud that its roots penetrate. Eelgrass mobilises minerals by drawing them up into tissues, to be dispersed when the plant dies or is eaten. • It secretes considerable amounts of phosphorus, a mineral essential to the growth of planktonic plants. • Eelgrass oxygenates the water which is essential for all life found under the water • Eelgrass plants produce flowers, which are tiny and fertilised underwater, so they are not often seen. SPECIES PROFILE: KINA, SPINY SEA URCHIN, SPECIES PROFILE: COMMON MUD CRAB, Evechinus chloroticus Helice crassa • Have no real brain, or head. Kina may move in any direction. • Snapper, red moki, blue cod and crayfish feed on small urchins. • Lives under ledges and in crevices, clinging with its tube feet. • It is covered with spines, like a small hedgehog; in soft these may wear away a hollow where it is attached. • It does not move fast; in fact it does not have to move at all as it can wait for food to attach itself to its spines. • Where there is abundant seaweed, masses of kina devour large forests. • Some kina may be as old as 15 years, and grow as heavy as 1kg. • For Maori, kina are a delicacy. When the kowhai are in bloom is when the gonads or roe of the kina become bright and swollen. • Kina spawn in spring when eggs and sperm are produced by gonads of sexually mature kina (3–4 years old). A few days before full moon they are released. The eggs and sperm fuse to create minute larvae that float away in the plankton until they settle 2–3 months later. • Crabs are one of the important scavengers of the coastline, cleaning up organic scraps and in turn providing animals such as fish and birds with an important source of protein. • Like all crustaceans, crabs are joint legged, have two pairs of antennae and moult their shells as they grow larger. • Crabs protect themselves in a number of ways. Their shelllike cover or carapace acts like a suit of armour, and they can give a potential predator a painful nip with their powerful claws. • A mudflat at low tide reveals countless tiny burrows, the homes of common mud crabs. • Mud crabs are extremely wary of any large moving object, they scuttle for cover when approached. • Seabirds and kotare are predators of the mud crab, as well as fish. • Outside their burrows are heaps of tailings and tiny dung pellets, which the crab cleans out as the tide goes out. This allows easy access to the burrow when needed. • They feed on the minute particles of organic matter with which the mud is impregnated. Auckland Museum 40 Recorded information: (09) 306 7067 Administration: (09) 309 0443 Fax (09) 379 9956 School Bookings: (09) 306 7040 Fax (09) 306 7075 Email: [email protected] www.aucklandmuseum.com AUCKLAND MUSEUM The Domain Auckland Private Bag 92018 Auckland New Zealand