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Habitats
ZLY 103
Olalere Shitttu
Dept. of Zoology,
University of Ilorin
Introduction
The area or natural environment in which an
organism or population normally lives is called its
habitat.
A habitat is made up of physical factors such as soil,
moisture, temperature range, light as well as biotic
factors (food and predators).
A habitat is a specific set of physical and chemical
conditions (space, substratum, and climate, etc.)
that surrounds a single species, a group of species
or a large community.
Habitat Definitions
 An area of land or water occupied by an organism,
single specie, biocenosis or synousia and possessing
all conditions for its existence.
The total area within the species’ range of
distribution that satisfies the species’ ecological
requirements.
The part of the species’ habitat that will guarantee
the existence of a population.
The actual area occupied by a given individual in all
phases of its development
Types of Habitats
Habitats
Aquatic
Terrestrial
Arboreal
Forest
Savannah
Desert
Fresh water
Estuaries
Marine
Terrestrial habitats
They include the following:
 forests,
 grasslands,
 deserts and
 rainforests.
They are typically defined by
factors such as
 plant structure (trees and
grasses),
 leaf types (e.g. broad leaf and
needle leaf),
 plant spacing (forest, wood
land, savanna) and
 climate.
Distribution of the major Terrestrial Biomes
Major Biomes in the Sub-Tropics
Forest Habitats
• It accounts for over one-third of the earth’s land
area and covers over two-thirds of the leaf area
of land plants,
• It contains about 70% of carbon present in
livingthings.
• About 420 million years ago (Silurian period),
ancient plants and arthropods began to occupy
the land.
• Millions of years after land colonizers developed
and adapted to the new habitat.
Forest Habitats
• The first forests were dominated by Giant
horsetails, club mosses, and ferns that stood up to
40 feet tall.
• In the late Paleozoic, gymnosperms appeared by
the Triassic period (245-208 myrs) and dominated
the earth’s forests.
• In the Cretaceous period (144-208 myrs), the first
flowering plants (angiosperms), insects, birds and
mammals appeared.
• A major change in landscape occurred during the
Pleistocene Ice Ages by the arrival of temperate
forests which spread in the northern hemisphere.
Forest Habitats
• Forests are characterized by seasonality and
distinguished by:
• tropical,
• temperate and
• boreal (Taiga) forests.
Tropical forests
• Characterized by the greatest diversity of species.
• Occurs near the equator (latitudes 23.5 degrees
North and 23.5 degrees South).
• Only two seasons are present, viz; rainy and dry
seasons respectively.
•
•
•
•
•
Tropical forests
Length of daylight is 12hours and varies a little
depending on the time of the year.
Averagely, temperature ranges between 20-250C,
with little variation throughout the year.
Average temperatures of the 3 warmest and 3
coldest months do not defer by ≥50.
Precipitation is evenly distributed throughout the
year (annual rainfall exceeding 2000mm).
The soil is nutrient-poor and acidic. The rate of
decomposition is fast and leaching in the soils is
heavy.
The Earth as a Heat Engine
• Air warmed at the
equator rises and moves
toward the poles.
• Replaced by cold air
moving away from the
poles at lower levels.
• Earth’s
rotation,
produces a Coriolis
effect
that
deflects
moving air to the right
in
the
Northern
Hemisphere and to the
left in the Southern
Hemisphere.
• Air circulation in each hemisphere is
broken into three latitudinal zones,
called cells
Tropical forests
• The canopy is multi-layered and continuous and
allows little light to penetrate.
• 12 Km may contain as many as 100 different tree
species. Trees are 25-35m tall, with buttressed
trunks and shallow roots, mostly evergreen, with
large dark green leaves.
• Plants such as orchids, bromeliads, vines (lianas),
ferns, mosses, and palms are present in tropical
forests.
• Fauna include numerous birds, bats, small
mammals, and insects. It is alarming that more
Sub-divisions of Tropical Forests
Tropical forests are further sub-divided on the basis of
seasonal distribution of rainfall:
• Evergreen rainforest: No dry season,
• Seasonal rainforest: It has short dry period in a very
wet tropical region (It exhibits definite seasonal
changes), but retains the general character of
evergreen rainforests).
• Semi-evergreen forest: It has longer dry seasons (the
upper tree story consists of deciduous trees, while
the lower story is still evergreen).
• Moist/dry deciduous forest (monsoon): The length of
the dry season increases further as rainfall decreases
(all tall trees are deciduous).
Profile of tropical forest, showing stratification of
animal and plant life into six strata.
• Animal biomass is
small compared with
the biomass of the
trees.
• The enormous
expanse centered in
the Amazon Basin,
are the most
seriously threatened
of forest ecosystems.
• Large areas are being
cleared for
agriculture
•
•
•
•
Distribution of Fauna in Tropical Forests
Insectivorous birds and bats occupy the air above
the canopy; below it birds, fruit bats, and
mammals feed on leaves and fruits.
In the middle zones are arboreal mammals
(monkeys and tree sloths), numerous birds,
insectivorous bats, insects, and amphibians.
A middle zone of climbing animals (squirrels and
civets), range up and down the trunks, feeding
from all strata.
On the ground are large mammals lacking
climbing ability (large rodents; capybara, paca,
and agouti) and members of the pig family.
Distribution of Fauna in
Tropical Forests
• A mixed group of small
insectivorous, carnivorous, and
herbivorous animals searches the
litter and lower tree trunks for
food.
• No other biome can match tropical
forests in incredible variety of
animal species.
• Food webs are intricate and
notoriously difficult for ecologists
to unravel.
Shelter
Adaptation
Adaptation can be defined as any body structure or behavior that
enables an animal to find food, protect itself from extreme
conditions, or escape predators.
• Structural: Physical attributes that help an animal to survive
• Behavioural: Activities performed by an animal that help it
survive
Adaptation
Camouflage
Migrate
Mimicry
Nocturnal
Hibernate
Adaptation of fauna to Tropical Forest
• Rainforest mammals have strong limbs and
prehensile tails that enable them to climb trees to
reach their food sources.
• Birds in the rainforest have reduced wings
shaped that enable them for easy maneuvering
around trees and plants as there is not a lot of
flying space.
• Gliders use their skin membranes to glide
between trees without descending to the forest
floor where predators may lurk.
• Birds of the rainforest have specially shaped
beaks and bills to help them find food.
•
•
•
•
Adaptation of fauna to Tropical Forest
Some species of parrots have strong, curved
beaks to help them crack hard nuts and seeds.
Possession of strong claws on the feet adapted for
climbing.
Other birds have a long, slim, straight bill which
they use to get nectar from within flowers, to
pick berries or to grab hold of snails to crush
and eat them.
The glowworm has a unique adaptation of using
its bioluminescence to lures prey into its special
snares.
Adaptation of Fauna to Tropical Forests
Camouflage
“Animals hide by blending in their environment”
 Many animals adapt to live in their
environment by “camouflage”.
 They hide & protect themselves
from being eaten by other animals
by blending in their environment .
 Other animals use camouflage to
help them not to be noticed so that
they can hunt their preys easily.
•
•
•
•
Adaptation of Fauna to Tropical Forests
Brightly coloured birds are surprisingly well
camouflaged against the bright colours of the fruit
and flowers on which they feed.
Most animals have darker colours to help them
hide from their predators.
Small mammals can be camouflaged against tree
trunks and among the leaf litter of the rainforest
floor.
Some toads and lizards are amazingly
camouflaged to look identical to the leaves among
which
they
rest.
•
•
•
•
•
Crafty Camouflage
The tree sloth combines expert cover with slowmotion movement to dodge predators such as the
jaguar.
A sloth's fur is covered with green algae so it
blends with the environment.
The sloth is the world's slowest moving animal
and takes up to a month to digest its food, so it
doesn't need many resources to survive.
The boa constrictor uses its camouflaged
invisibility to sneak up on prey.
Tiny rain forest grasshoppers have developed
near-transparent coloring to blend in with leaves.
•
•
•
•
Picky Eaters
Some animals have adapted to a limited diet so
they don't face competition for food.
Toucans snag hard-to-reach fruit -inaccessible
to other feathered flyers -with their long, narrow
beaks.
Parrots have incredibly sturdy bills to crack nuts
and dig out hidden food.
Leaf cutter ants put in a hard day's work for a
meal. They carry bits of leaves 50 times their
weight from high branches to the ground. They
bury the leaves and eat the fungus that grows as
the plant matter decomposes.
Mimicry
• Poison dart frogs have brightly colored skin to
warn predators that they would make a deadly
meal.
Size and Stature
• Large animals, like lions and elephants, live on
the plains for good reason. Size is no advantage
in the rain forest where a dense understory
makes movement difficult. Jaguars adapted with
a small but stocky build that makes them speedy
hunters and small enough to sleep in trees.
Adaptation of Fauna to Tropical Forests
Nocturnal
“Some animals are active only at night”
• When the sun goes down, some animals bed
down. Others including the flying fox bat, the
leopard cat and Wallace's flying frog are brighteyed and on the lookout for a meal. The
adaptation to night hunting gives nocturnal
animals the benefit of reduced competition for
food.
Adaptation of Fauna to Tropical Forests
• Animals which displays darker colours
Adaptation of flora to the Tropical forests
• Tropical rainforests get much rain all the year,
this enormous rain can damage the leaves, so
there is a drip tip at the end of each leaf to
help rain water to fall off quickly.
Adaptation of flora to the Tropical forests
• In the tropical rainforest, there are many trees &
leaves growing next to each other, so they can
block ‘prevent” the sun light from reaching to the
plants at the bottom.
- So plants at the bottom adapt by having large
leaves to catch the sun light.
Flora Adaptation to Tropical Forests
Lianas
These are thick, twisted vines
which loop around tree trunks to
reach the sunlight. It is constantly
moving from tree to tree while
growing. This enable them achieve
more sunlight and grow better.
Epiphytes
Also called air plants, small plants
which grow on tree branches,
rather than in the soil. They have
special roots to help them grow on
the trees.
Flora Adaptation to Tropical Forests
Buttress Roots
• The trees in the Rainforest
weigh hundreds of tonnes and
are some of the tallest living
structures on earth but they
have roots in very thin soil.
• To anchor the tree and prevent
it falling over, they have huge
buttresses roots that spread to a
distance of 30ft.
• They come in various shapes
and sizes but all have the same
purpose, which is to stabilize
the tree.
Temperate Forests
• Otherwise called mid-latitude forest biome is one
of the most altered biomes on our planet.
• Over exploitation of this forest by humans for
logging, firewood, construction and art projects
etc. have led to the decline or loss of this biome.
• Occurs in eastern North America, Northeastern
Asia, and western and central Europe.
• It has well defined seasons with a distinct winter
characterize these forest biomes and only
scattered remnants of original temperature forest
remain.
Temperate Forests
• Moderate climate and a growing season of 140 – 200
days during 4-6 frost-free months distinguish
temperate forests.
• The temperature ranges from -300C to 300C and
precipitation (75 – 150cm) is distributed evenly
throughout the year (next slide).
• The soil is fertile, enriched with decaying litter.
• The canopy is moderately dense and allows light to
penetrate, resulting in well-developed and richly
diversified understorey vegetation and stratification of
animals.
• The flora is characterized by 3-4 species per square
kilometres.
Distribution of Habitation Types in Relation to
Precipitation and Temperature
Temperate Forests
• Trees are distinguished by broad leaves.
• They lost their leaves annually e.g. species of oak,
hickory, beech, hemlock, maple, basswood,
cottonwood, elm, willow, and spring-flowering
herbs.
• The fauna is dominated by squirrels, rabbits,
skunks, birds, deer, mountain lion, bobcat, timber
wolf, fox and bear etc.
Temperate Forests
Such forests are sub-divided on the basis of seasonal
distribution of rainfall:
• Moist conifer and evergreen broad-leaved forests:
Wet winters and dry summers (rainfall is
concentrated in the winter months and winters are
relatively mild).
• Dry conifer forests: Dominate higher elevation zones;
low precipitation.
• Mediterranean forests: Precipitation is concentrated
in winter, less than 1000mm per year.
• Temperate coniferous: Mild winters, high annual
precipitation (>2000mm).
Illustration of altitude & latitude influence on biomes
Coniferous forests
• Found in North America, form a broad, continuous,
continent wide belt stretching across Canada and Alaska,
south and the rocky mountains into Mexico.
• This biome continues across northern Eurasia, making it
one of the largest plant formations on earth.
• It is dominated by evergreens: pine, fir, spruce, and cedar
which are adapted to withstand freezing and take full
advantage of short summer growing seasons.
• Conical trees with their flexible branches shed snow
easily.
• The northern area is the boreal (northern) forest, often
called taiga (a Russian word, pronounced “tie-ga”).
Coniferous forests
• The taiga is dominated by white and black spruce,
balsam, subalpine fir, larch, and birch.
• Mean annual precipitation is less than 100 cm (40
In) and the average temperature ranges from -5° to
+3° C (23° to 37° F).
• In the central region of North America, the taiga
merges into lake forest, dominated by white pine, red
pine, and eastern hemlock.
• However, most of this forest was destroyed by
exploitive logging and was replaced by shrubby
second growth, which still characterizes much of
Michigan, Wisconsin, southern Ontario, and
Minnesota today
Distribution of Fauna in Coniferous forests
• Mammals of the boreal and lake coniferous forests
g are deer, moose, elk, snowshoe, rodents, carnivores
like wolves, foxes, lynxes, weasels and martins,
d
Omnivorous bears etc.
Distribution of Fauna in Coniferous forests
• They are adapted physiologically or behaviorally for
long, cold, snowy winters.
• Common birds are chickadees, nuthatches, warblers,
and jays. One bird, the red crossbill, has a beak
specialized for picking seeds from cones.
• Mosquitoes and flies are pests to both animals and
humans in this biome.
• Southern coniferous forests lack many mammals
found in the north, but they have more snakes,
lizards, and amphibians.
Adaptation of flora to Temperate
forests
• Temperate forests don’t have much rain as the
tropical rainforest, so trees in the temperate forest
adapt by losing their leaves in the fall to save
water.
Adaptation of fauna to Temperate forests
• Other animals go to a very deep sleep during the
winter, when they couldn’t find their food, like:
Dormouse & Bears.
• Skunks spray a stinky smell when a predator
comes close to them.
Adaptation of fauna to Temperate forests
“Polar bears”
- Polar bear’s white fur
helps it to blend with
the ice & snow to make
it easy for them to hunt
the seal without being
seen.
Grassland (Prairies)
• Prairies are generally humid and covered by tall grasses.
• There are very few trees, most of them usually found on
hill slopes/humid area near springs
• Soil is rich in nutrients and ideal for plants growth.
• The North American prairie biome is one of the most
extensive grasslands in the world extending from the
Rocky Mountain edge on the west to the eastern
deciduous forest on the east, and from northern Mexico
in the south to the Canadian provinces of Alberta,
Saskatchewan, and Manitoba in the north.
• It has been transformed into the most productive
agricultural region in the world, dominated by
monocultures of cereal grains.
Grassland (Prairies)
• Very few animals survive, but
jackrabbits, prairie dogs, ground
squirrels, and antelope remain.
• Mammalian predators include
coyotes, ferrets, and badgers,
although, of these, only coyotes
are common.
• Rainfall on the North American
prairie ranges from about 80 cm
(31 inches) in the east to 40 cm
(16 inches) in the west.
• Average annual temperatures
range between 10° and 20° C
(50° to 68° F).
Tundra
• Tundra is characteristic of
severe, cold climatic regions,
especially
treeless
Arctic
regions
and
high
mountaintops.
• Plant life must adapt itself to a
short growing season of about
60 days and to a soil that • Most tundra regions are
with
bogs,
remains frozen for most of the covered
marshes, ponds, and a
year.
• Average annual precipitation is spongy mat of decayed
usually less than 25 cm (10 vegetation.
inches) and the annual • High tundras may be
temperature averages about covered only with lichens
and grasses.
10° C (14° F).
Tundra
• Despite the thin soil and short growing season,
vegetation of dwarf woody plants, grasses, sedges,
and lichens may be quite profuse.
• Plants of the alpine tundra of high mountains,
such as the Rockies and Sierra Nevada, differ
from the Arctic tundra in some respects.
• Characteristic animals of the Arctic tundra are
the lemming, caribou, musk-ox, arctic fox, arctic
hare, ptarmigan, and (during the summer) many
migratory birds.
Desert
• Deserts are arid regions where rainfall is low (less
than 25 cm [10 inches] a year), and water
evaporation is high.
er,
• The North American desert is of two parts, the hot
deserts of the southwest (Mohave, Sonoran, and
Chihuahuan) and the cool, high desert in the rain
shadow of the High Sierras and the Cascade
mountains.
Desert
• Desert plants, such as thorny shrubs and cacti, have reduced
foliage, drought-resistant seeds, and other adaptations for
conserving water.
• Many large desert animals have developed remarkable
anatomical and physiological adaptations for keeping cool
and conserving water.
• Most smaller animals avoid the most severe conditions by
living in burrows or developing nocturnal habits.
• Mammals include mule deer, peccary, cottontail, jackrabbit,
kangaroo rat, and ground squirrel.
• Typical birds are roadrunner, cactus wren, turkey vulture,
and burrowing owl. Reptiles are numerous, and a few
species of toads are common.
• Arthropods include a great variety of insects and arachnids.
Animals that live in the desert:
End of Part One
Thanks for Listening