Download Beginners Guides to the EnviroZone

Contents
Biomes of the Northern Cape Page
3
Abiotic Factors
Water 4
5
Grassveld
9
Karoo 12
Kalahari
17
Nocturnal Animals
25
Ecology
32
Introduction
TheMcGregorMuseumwasestablishedin1907,forthecitizensofKimberley.
Expandinginscopeandfunctionbeyond thedreamsofitsfounders,itis
todaytheprincipalmuseumintheNorthernCapeProvince.
Vision
To know and conserve our past
and present for the future.
Mission
To research and conserve the natural
and cultural history and diversity of
the Northern Cape, and promote an
awareness thereof through service
excellence.
Forfurtherinformation,consultthemuseum’swebsitewww.museumsnc.co.za.
TheEnviroZoneillustratesaspectsofthediverseecologyofthearidNorthern
CapeProvince,thelargestinSouthAfrica.
M.Jonk
Thespringbokfeaturesprominentlyinthefolkloreofthe/XamSanoftheKaroo
butissurprisinglyrareinrockart.ThisexamplecomesfromasitenearKimberley
andwaschosenasthelogofortheEnviroZone.Rockartisanimportantpart
ofourculturalheritage.Tolearnmoreaboutthisfascinatingsubject,visitthe
AncestorsGalleryoftheMcGregorMuseumorWildebeestKuilRockArtCentre,
acommunityrockartprojectontheR31betweenKimberleyandBarklyWest
(www.wildebeestkuil.itgo.comorwww.museumsnc.co.za/wildebeestkuil).
BIOMES OF THE NORTHERN CAPE
Abiomeisalargeecologicalsystemwhichcanbefurthersubdivided
intomanyvegetationunits.ThemapattheentrancetotheEnviroZone
depictsthesixbiomesthatarefoundintheNorthernCapeProvince,
namelytheNama-Karoo,SucculentKaroo,KalahariSavanna,Desert,
FynbosandGrassland.
TheEnviroZoneillustratesthreeofthebiomesfoundnearKimberleyinthe
NorthernCape:TheNama-KarooBiomewhichcovers54%oftheareaof
ourprovince,theKalahariSavannawhichcovers29%andtheGrassland
Biome(alsoknownlocallyasGrassveld)whichcoverslessthan1%.
Thisisanolddisplaywhichwasoriginallydesignedtopresentthe
vegetationunitsaroundKimberley.TheGrassvelddisplaywilleventually
bereplacedbyadepictionoftheSucculentKarooBiomeofNamaqualand
andtheRichtersveld,whichcovers14%oftheNorthernCapeProvince.
The Grassveld:
TheGrassveldisfoundmainlyonthehighcentralplateauofSouthAfrica.
Thealtitudeisupto2850m,whichishigherthantheotherbiomes.The
topography is flat and undulating. Generally the soils are deep, fertile clays
or loams. The temperatures are cooler because of the high altitude and
varybetween-11°Cand41°C,withanaverageof18°C.Frostoccursonan
averageof120daysperyear.Althoughthesummerrainfalliserratic,itis
relativelyhigh,around500mmperyear,withanevaporationrateofaround
1780mmperyear.
The Karoo:
The Nama Karoo Biome occurs in some of the most arid parts of South
Africa,onthewesternhalfofthecentralplateau.Mostofthebiomefalls
between1000and1400mabovesealevel.Thetopographyisgenerally
extensive flat and stony plains, dotted in places with mountains and the
characteristic flat-topped Karoo koppies (hills). The area is covered by poor,
shallow,lime-richsoil.Thetemperaturesareextremeandrangefrom8°C
to45°C,withanaverageof21°C.Thetemperaturerangeincreaseswith
elevation.Frostoccursonabout150daysperyear.Rainfallsinsummer
andautumn.Itisverylowinthewest(100mmperyear)andincreases
towardstheeast(500mmperyear),withanaverageofaround250mm.
Therateofevaporationishigh,around2200mmperyear.
The Kalahari:
The Savanna Biome covers over one-third of South Africa and is well
developedovertheLowveldofMpumalangaandtheKalahariregion,north
of the Orange River in the Northern Cape. The altitude ranges from sea
level to about 1 000 m. The topography is mainly flat with windblown sand
dunesinthesouth-west.Thesoilsaregenerallydeep,porousredsands.
Thetemperaturesareextremeandvarybetween-8°Cand42°C,withan
averageof20°C.Frostoccursonapproximately60daysperyear.The
rainfallsinsummerandisverylow,from175to300mm,withanaverage
ofaround250mmperyear.Theevaporationrateishigh,morethan2500
mmperyear.
ABIOTICFACTORS
Anecologicalsystemorecosystemconsistsofabiotic(non-living)andbiotic
(living)things.Thelivingthings(thebioticcomponent)inanecosystemare
dependentonandhavetoadapttotheabioticfactors.
The mural at the entrance illustrates the abiotic factors of the 3 biomes.
It shows a cross-section through the biome, depicting the altitude (height
abovesealevel),topography(typeofterrain)andthesoiltypes.Summer
and winter temperatures, annual rainfall and rate of evaporation are also
pictured.
WATER
WaterisapreciousandscarceresourceinthearidNorthernCapeProvince,
duetotheunreliableanderraticrainfall.TheOrangeandVaalRivers,the
largestriversinSouthAfrica,arethelifebloodofthisarea.Unfortunately
theseriversandthevegetationalongtheirbankshavebeenseverelyaltered
byhumanactivitiessuchasdamconstruction,miningandagriculture.Other
riverssuchastheMolopo,AuobandNossobaredrymostofthetime.There
areafewman-madedamsintheProvince,butnon-permanentandseasonal
pansaremorewidespread.KamfersDam,nearKimberley,oneofthefew
perennial wetlands in the Province, supports a large resident population
of flamingos and many other water birds. In many parts of our Province
peopleareentirelydependentonundergroundwaterfromboreholes,and
plants and animals have had to adapt to life without a reliable supply of
drinkingwater.
Water,whereandwhenitdoesoccur,supportsmanyimportantlifeprocesses
andmanyanimalsarefoundonlyinornearwater.
1.
Platanna (Segwagwa)
Xenopus laevis
Unlikeotherfrogstheplatannaorclawedfrogisalmostcompletelywaterliving and only occasionally migrates overland on rainy nights to other
suitable still or stagnant waters. It has many unique features, including
three noticeable claws on its back feet (Xenopus means “strange foot”). It
eats animal matter. As it has no tongue, it uses its front legs during feeding. Large food items are torn up with the sharp claws. It also has no eardrums,
vocal cords or vocal sacks and produces soft buzzing sounds underwater
instead of croaking. Its bulging, lidless eyes are on the top of its head and,
like a fish, it has two rows of sense organs along the sides of its body which
detect vibrations in the water. 2.
Cape River Frog (Kaapse Rivierpadda, Segwagwa)
Rana fuscigula
River frogs are found in many parts of the world. As the name suggests they
are usually found on river banks and readily leap into the water if disturbed. They have long powerful legs and are excellent jumpers. They breed in
large bodies of still water, or permanent streams or rivers. Males produce a
two-part call, consisting of a grunting croak, followed by a series of clicks,
most months of the year.
3.
Giant Kingfisher (Reuse Visvanger, Mmatlhapi)
Ceryle maxima
This is the largest kingfisher species in the world. It is always seen near
water, sitting on an overhanging branch or hovering over the water, keeping
a lookout for food. It dives into the water, spearing the prey with its sharp
beak. Fresh-water crabs, its favourite food, are beaten on a rock to remove
the pincers before swallowing, while fish and frogs are swallowed head first.
The nest is made in a tunnel dug in a riverbank over running water.
4.
Smallmouth Yellowfish (Kleinbek-geelvis, Thlapi)
Barbus aeneus
This yellowfish prefers clear-flowing waters of large rivers, with sandy or
rocky bottoms, or large dams, where it is an important angling species. It
is usually a golden olive-brown in colour. Its mouth is situated towards the
underside of the head and its lips may be thin and firm, forming a scraping
edge, or very thick and fleshy. It is an omnivore, eating small water animals
such as snails and mussels and water plants such as algae, found on or
near the river bottom.
5.
Sharptooth Catfish (Skerptand Baber, Thlapi)
Clarias gariepinus
The catfish or barbel is probably the most widely distributed fish in Africa
and is an important angling and food species. It is easily recognised by
its flat bony head, long fin on its back and pectoral (“shoulder”) fins each
with a sharp spine. It has a large mouth with four pairs of barbels or cat-
like whiskers, hence the common name. The barbel lives in slow-flowing
rivers, lakes and dams. Behind its gills it has a lung-like organ, which it uses
to breathe air. It can thus survive in muddy water with very low oxygen
content and even in drying ponds. Catfish are known to migrate overland
under damp conditions, if necessary crawling with the fin spines. They are
completely omnivorous, hunting and scavenging virtually any small animal,
eating plant matter and even straining fine plankton.
6.
Orange River Mudfish (Oranjerivier-moddervis, Thlapi)
Labeo capensis
This fish is a strong swimmer, found in the running waters of the large
Orange and Vaal rivers. It has a large mouth on the underside of the head,
with well-developed, complex lips and grinding teeth. It is a bottom feeder,
eating algae and other plant matter off the rocks and plants on the river
bottom.
7.
Hamerkop (Mamasilanoka)
Scopus umbretta
This is a unique African species, which is held in great respect by rural
people and is the subject of many legends. The common name comes from
its hammer-like head with the crest of feathers at the back and the heavy
beak in front. It feeds in shallow water, where it either remains very still,
looking out for passing prey, or walks around, shuffling its feet and flapping
its wings to chase up the prey. Its narrow, deep beak is well adapted for
grasping slippery frogs and for carrying large and heavy twigs to its nest. This huge dome-shaped structure is built of sticks and rubbish in a tree or
on a rock ledge and can be used for many years. The nest is also often
used by African Fish-eagles (Haliaeetus vocifer).
8.
Blackheaded Heron (Swartkopreier, Mogolodi)
Ardea melanocephala
This heron is usually seen away from water on open grassland, farmlands
and golf courses, walking along, carefully looking for food. The eyes focus
on the prey along the beak, the head is moved back and forth to check the
range before striking and the sharp beak is used to spear the prey, such as
moles, mice, birds, frogs and insects. Like all herons, it prefers to roost
in water or in trees over water and will fly up to 30 km to this roost, which
it shares with many other birds. It also builds its nest, a large platform of
sticks, in one of these trees. These colonies of breeding herons are called
heronries.
9.
Yellowbilled Duck (Geelbekeend, Pidipidi)
Anas undulata
This is the best-known and most common duck in our country and it is found
in flocks in almost all kinds of water habitats. It is easily recognised by its
yellow beak, which is used for filtering the water for food, mainly water plants
and animal matter. It will upend and even dive for its food and sometimes
grazes grass on dry land. It nests in marshy areas, building a carefully
hidden bowl of grass lined with down. The chicks are active and leave the
nest immediately. 10.
South African Shelduck (Kopereend, Sehudi)
Tadorna cana
These ducks live in large flocks on dams or pans with shallow water and wet
mud. They are recognised by their bright coppery chestnut colour (hence the
Afrikaans name). The male (right) has a grey head, while the female (left)
has a white face and grey neck. They are territorial, defending a section of
water. The female does most of the courting and the male chooses a mate. The nest is usually built in an aardvark burrow, quite a distance from the
water. These ducks breed in the dry winter months, when the pans dry up,
exposing the special water plants along the pan edges for food for the newly
hatched chicks. 11.
Blacksmith Lapwing [Plover] (Bontkiewietjie, Mathutatshipi)
Vanellus armatus
The name of this bird comes from its loud metallic alarm call, which sounds
like a blacksmith’s hammer striking an anvil. They are usually seen in pairs
or small groups near water, on the muddy edges of dams, pans and rivers
and sometimes on farmlands. They eat insects, worms and snails. The
eggs are laid on bare ground in a slight hollow near the water. The parents
will dive-bomb an intruder coming too close to the nest, swooping and
screaming continuously. The downy chicks are well camouflaged and leave
the nest within hours. Redknobbed Coot (Bleshoender, Kgogonoka)
Fulica cristata
This is one of the most common waterbirds in our country and is usually
the first species to appear after the rains have formed a new pan. The
red knobs, which give this bird its name, are not always easily seen, but
becomelargerduringbreeding.However,thewhiteshieldonthefaceis
unmistakable,hencetheAfrikaansname.Theyeatmainlywaterplantsand
swim, upend and dive, tearing the food off with their sharp-edged beaks.
The nest is a large pile of plant matter, floating on open water.
12.
GRASSVELD
TheGrassveldhashighaltitude,moderaterainfallandloamysoils.Itis
dominatedbyasinglelayeroffairlytallgrassspecies,suchasRedGrass
(Themeda triandra).Treesarelargelyabsent,exceptalongtheriverbeds
and on koppies. Frosts, fire and grazing maintain the grass dominance and
thebiomesupportsavarietyofgrazinganimals.
Black Wildebeest (Swartwildebees, Pudumo / Kgokong)
Connochaetes gnou
This animal appears on our five rand coin. It prefers the open grasslands
of central South Africa and was almost hunted to extinction in the past.
Usuallydarkbrownincolour,malesbecomealmostblackwithage,hence
thecommonname.Also,atadistancetheblackwildebeestappearsdarker
thanitscloserelative,theBlueWildebeest(Connochaetes taurinus),which
1.
is a silvery blue-grey in colour. The white tail, which nearly reaches the
ground,isverycharacteristicandthisanimalissometimescalledtheWhitetailedGnu.GnuisaKhoiword,referringtothebellowingsnortmadeby
territorialmalesorasanalarmcall.Theygrazemainlyonshortgrass,but
alsobrowseonKarooshrubsduringthecoldwintermonthswhenthefood
valueofthegrassislow.
0
2.
Blue Crane (Bloukraanvoël, Kokolohutwe)
Anthropoides paradiseus
The Blue Crane is our national bird and is depicted on our five cent coin.
These birds prefer to live on open
grassland, where they have a good view
of their surroundings. In many places they
have adapted to foraging on farmlands. They sometimes roost in shallow water,
but can usually be seen walking through
the grass on their long legs, feeding on
seed, insects and other small creatures. Cranes have complicated courtship
rituals, including flights to great heights
and dancing. The eggs are laid on the
bare ground. Unfortunately our cranes
have become very scarce and face many
threats, including the destruction of their
habitat and poisoning by grain farmers.
3.
Doublebanded Courser (Dubbelbanddrawwertjie, Letukubii)
Smutsornis africanus
This plover-like bird is easily overlooked because of its excellent camouflage
and habit of standing quietly in the short grass. It eats mainly insects,
especially termites. It is active at sunset and sunrise and on moonlit nights,
when it is often heard calling. A single egg is laid on the bare ground,
sometimes among small antelope droppings, which hide it well.
4.
Orange River Francolin (Kalaharipatrys, Lesogo)
Francolinus levaillantoides This bird is sometimes called the Kalahari Francolin or Kalahari Partridge. It
occurs on open grassveld. It remains out of sight, depending on its excellent
camouflage, and is even known to hide in holes in the ground. It scratches
11
in the ground, much like a chicken, and eats mainly plant bulbs, corms and
seeds. The nest is a shallow scrape lined with dry grass, under a large tuft
of grass or a low bush. 5.
Cape Hare (Vlakhaas, Matsaatsela)
Lepus capensis
The Cape Hare prefers to live in dry, open grassveld. It is solitary and
nocturnal, lying during the day in a form (temporary shelter) under grass or
bushes, with its ears folded back on its body. It depends on its camouflage
for protection, but if chased, it will run off and sometimes hide in a hole in
the ground. It lives mainly on grass, preferring short green grass, as well
as bushes. Leverets (the young) are born throughout the year, in a form. Unlike the young of rabbits, they are fully haired, with open eyes and can
move around on their own soon after birth.
6.
Sungazer or Giant Girdled Lizard (Ouvolk, Mmamagwai)
Cordylus giganteus
The common name of this lizard comes from its habit of basking on a termite
mound or suitable rock, facing the sun. Unlike other girdled lizards which
live on rocks, it is terrestrial. It digs long burrows of up to 2 m long and 42
cm deep in deep, soft soil. If disturbed it will retreat backwards into this
shelter, lashing its spiny tail from side to side for protection. If it is grabbed,
it anchors itself by jamming the four large head spines into the roof of the
burrow. It eats insects such as beetles and grasshoppers and other small
creatures. Unfortunately this endangered lizard lives in the so-called maize
triangle of the northern Free State and southern Mpumalanga and most of
its natural habitat has been ploughed over. Surviving populations are also
threatened by illegal collection for the pet trade.
7.
Cape Sparrow (Gewone Mossie, Tswere)
Passer melanurus
The sparrow, as a symbol of faith and hope,
has since 1923 been portrayed on South
Africa’s lowest value coin. Are not two sparrows sold for a
farthing? And one of them shall
not fall on the ground without your
Father knowing it.
Matthew10:29 (KJ21).
12
The Cape Sparrow or mossie is a remarkably adaptable bird and occurs
throughoutourcountryandalsointownsandcities.Althoughoftenseen
withtheHouseSparrow(Huismossie-Passer domesticus),thisbirdcanbe
recognisedbytheblackheadwiththewhitec-shapedmarkofthemalebird.
Ithopsontheground,feedingonseedsandgrains.Thisbirdbuildstwo
nests(usinggrass,stringandjustaboutanythingelse),oneforbreedingin
summerandanotherforsleepinginthewinter.
Abdim’s Stork (Kleinswartooievaar, Lekololwane)
Ciconia abdimii
These storks breed in northernAfrica and migrate to our country for the
summer months. They are terrestrial and walk busily around feeding on
locusts and other insects. They are often attracted to veld fires and are
sometimesseenglidingtogreatheightsonhotaircurrents.Theyrooston
thorntreesatnight.
8.
KAROO
TheKaroohasamoderateclimate,lowrainfallandpoorshallowsoils.The
dominantvegetationaregrassesanddwarfdrought-resistantshrubs,such
asthetypicalKaroobushes(Pentzia spp.),doringkapokorthornykapokbush
(Eriocephalus spinescens) and driedoring or threethorn (Rhigozum
trichotomum).Theanimalsgrazeandbrowse.Manyspecies(suchasthe
largeherdsofspringbokofthepast)arenomadicinresponsetorainfall.
1.Springbok (Tshepe) Antidorcas marsupialis
ThishandsomeantelopeisSouthAfrica’snationalanimalandappearson
our one rand coin. It is well known for spectacular ballet-like “pronking”
or stotting displays, hence the common name. The animal performs a
series of stiff-legged bounces, up to 2 m high, erecting the crest of white
hair (the “pronk”) on the back. The scientific name marsupialis refers to
the marsupium or “pouch” of light brown hair which normally hides this fan
of white hair. Both the rams and ewes carry horns, with those of the rams
being thicker and heavier than those of the ewes. Springbok graze in the
summer months when grass is plentiful and browse during the winter when
the grass loses its food value.
2.
Cape Cobra (Kaapse Kobra, Kake)
Naja nivea
This highly poisonous snake does not spit, but is quick to spread its broad
hood at the first sign of danger. The venom attacks the nervous system and
leads to paralysis of the prey. Cape Cobras vary from dark brown to butter
yellow in colour. They are active during the day and early evenings and
eat a variety of small animals, including other snakes. They are also often
found in sociable weaver nests, feeding on the chicks.
3.
Secretarybird (Sekretarisvoël, Thlangwe) Sagittarius serpentarius
This majestic hunting bird features on our national coat of arms, with its
wings spread protectively. It may have been named for the crest of long
feathers on its head, which resemble writing quills tucked behind the ear
of an old-time secretary or clerk. The name could also have been derived
from the Arabic saqr-et-tair, meaning “hunter” or “hawk-bird”. The scientific
name Sagittarius (The Archer) refers to the hunting habit of this bird, while
serpentarius refers to its preferred diet of snakes. This unusual bird of prey
lives largely on the ground. They usually hunt in pairs, striding through the
grass on their long legs, searching for rodents, lizards or any small creature. Snakes are killed with violent blows of its clawed feet, while the wings are
14
held outspread as a shield and for balance. The nest is a large stick platform
built for safety on top of a thorn tree and is also used for sleeping.
4.
Spotted Thick-knee [Dikkop] (Dikkop, Tswang-tswang)
Burhinus capensis
The large yellow eyes of this bird indicate that it is nocturnal or crepuscular
(most active at dawn and dusk). Its mournful call is a familiar sound on
moonlit nights. It prefers to live in open areas with short grass. It is extremely
well camouflaged and spends the day squatting on the ground under a bush
or in the shade. It eats insects, snails, frogs and other small creatures.
5.
Small-spotted Cat (Klein Gekolde Kat, Sebalobolokwane)
Felis nigripes
This is the smallest of our cats and is found in the dry central parts of our
country. It is nocturnal and uses old springhare or aardvark holes or holes in
termite mounds to rest in during the day. The Afrikaans name miershooptier
(“ant heap tiger”) refers to this habit. It is a solitary and secretive little animal,
living mainly on mice, small birds, reptiles and insects.
6.
Familiar Chat (Spekvreter, Tswetla)
Cercomela familiaris
Although this bird is usually found near rocks in the veld, it is quite tame and
often lives in built up areas. Its Afrikaans name refers to its cheeky habit
of feeding on the lard used to grease wagon wheels in the past. It is often
seen perching on some look-out post and it flicks its wings a few times every
time it moves. It eats insects such as flies.
15
7.
Yellow Canary (Geelkanarie, Talane)
Serinus flaviventris
These birds are nomadic and occur singly, in pairs or in large flocks, sometimes
with other small birds. They are lively and always active, dropping to the
ground to feed on seeds and flying away again. They are good songsters,
keeping up a sweet-toned twittering from the tops of bushes.
8.
Southern Large-billed [Thickbilled] Lark (Suidelike Dikbeklewerik, Sebotho)
Galerida magnirostris
This lark is common in the agricultural areas in the south-western parts
of our country. They are usually seen in pairs, creeping along the ground
searching for food, such as beetles and other insects and seeds, and
sometimes digging for bulbs with their heavy beaks.
9.
Northern Black Korhaan (Witvlerkswartkorhaan, Tlatlawe)
Eupodotis afraoides
The male birds with their bold colouring are always noticed as they noisily
defend their territories. They often stand on termite mounds or other
prominent positions to proclaim their presence or keep watch. When
disturbed, or as part of its courtship display, a male bird flies into the air,
uttering a loud harsh call. When it comes in to land it falls rapidly, calling
loudly, flapping its wings and dangling its yellow legs. Females are far less
noticeable and more secretive. One to two well camouflaged eggs are laid
in a slight scrape on the ground. They eat plant material and seeds, as well
as insects. 10.
Southern Anteating Chat (Suidelike Swartpiek, Totoma)
Myrmecocichla formicivora
This bird is always seen perching on a termite mound, fence pole or other
suitable look-out point, from where it searches for the termites it likes to
eat. In flight its quick wing beats and the white patches on its wings give it
a butterfly-like appearance. Its cup-shaped nest is built on a ledge in an
aardvark hole, or in other large holes in the ground.
11.
Puff Adder (Pofadder, Lebolobolo)
Bitis arietans
The Puff Adder is a very common snake in this region and is recognised by
its thick body, flat triangular head and beautiful brown and tan markings.
It is extremely well camouflaged and rats, mice and other small creatures
are attacked from where it lies unnoticed. The Puff Adder moves slowly
by caterpillar-like waves of movement of its ribs. If disturbed, it adopts a
16
striking posture and gives a loud warning hiss (hence the common name). It can strike with lightning speed, unfolding its long, hinged poison fangs,
which lie flat against the upper jaw when the mouth is shut. The venom
attacks the cell tissue of the victim, causing extensive swelling, pain and
occasionally death. Litters of 20 - 40 fully developed young are born in late
summer.
Cape Bunting (Rooivlerkstreepkoppie, Mmaborokoane)
Emberiza capensis
These birds are normally found in rocky habitats and are well camouflaged
while perched on rocks. They are recognised by their boldly striped black
and white heads and bright, reddish-brown wings. They spend most of their
time foraging on the ground, with seeds, insects and spiders the main items
on their menu. Very little is known about their movements. A bird ringed
near Kimberley was recovered in Zimbabwe!
12.
Southern Rock Agama (Bloukopkoggelmander, Kodutala)
Agama atra
These agamas live in dense colonies in rocky areas. They have long tails
and long legs with sharp claws, allowing them to run effortlessly over slippery
rocks. They are territorial and breeding males are easily recognised as they
perch on the highest rocks to advertise their status by bobbing their bright
blue heads (hence the Afrikaans name). Because of their bright colours,
some people believe these lizards are poisonous, but this is not true. At the
first sign of danger they can fade these highly visible colours to blend in with
the colour of the rocks. If this fails, they scamper off at top speed to shelter
in a deep crevice. They feed almost exclusively on ants and termites
13.
Rock Hyrax or Dassie (Klipdassie, Pela)
Procavia capensis
Dassies live in colonies on koppies or other rocky areas, where deep
crevices provide the necessary shelter. Scattered throughout the coat are
14.
17
long black whisker-like hairs, which help them to find their way in these
dark shelters. They are diurnal and are often seen sunning themselves
on exposed rocks, their compact, tailless bodies resembling small rocks.
Therearespeciallightshieldsinthedassie’seyes,whichallowittolookup
intothesun,tocheckforitsworstenemy,Verreaux’s[Black]Eagle(Aquila
verreauxii).Thesolesofthefeetarenakedandkeptmoisttoprovideextra
grip on the rocks. The colony uses a latrine situated below overhanging
rocks.Scientistshavefoundthattherearesimilaritiesinthegenesofan
elephantandadassie,whichmakesthemgeneticallycloselyrelated!
KALAHARI
TheKalahariispopularlycalledadesert,becauseofitshotsummers,low
rainfall,almosttotallackofsurfacewaterandsandysoils,butunlikeatrue
deserttheKalahariisgenerallycoveredwithascantlayerofgrassesand
scattered,hardy,thorntrees,suchastheCamelThorn(Acacia erioloba).The
plantsandanimalsaresubjectedtoharshandextremeclimaticconditions
andhaveevolveddifferentwaystosurviveheatanddrought.
Bat-eared Fox (Bakoorvos, Tlhose)
Otocyon megalotis
Althoughitresemblesajackal,thisenchantinglittleanimalisdistinguished
byitsenormousbat-likeears(hencethecommonname),bushyblacktail,
rounded back and much smaller size. While hunting for food during the
dayoratnight,itsearsareheldforwardandusedassuper-sensitivesound
amplifiers to detect the faint sounds made by small creatures in the sand.
Termitesandbeetlelarvaeareitsfavouritefood,butthefoxalsoeatssmall
1.
rodents, scorpions, locusts, adult beetles and even certain plants. It lives in
the old burrows of springhare and aardvark.
2.
Striped Mouse (Streepmuis, Peba)
Rhabdomys pumilio
Although its body colour may vary, the Striped Mouse is distinguished by
the four distinct stripes along the length of its back. It is also the only small
rodent in the Kalahari which is truly diurnal. It survives the intense heat of
the day by eating plant pods, flowers, insects and other food with a high
water content. It also shelters from the extreme climate and predators in a
burrow, which is lined with soft plant matter to maintain the ideal temperature
and humidity.
Yellow Mongoose (Witkwasmuishond, Mosa)
Cynictis penicillata
This small mammal is often seen running across the road and is recognised
by its yellowish-brown colour and white-tipped tail. The Slender Mongoose
(Galerella sanguinea) which is very similar, but is a darker reddish-brown
in colour, with a black-tipped tail, is also frequently seen in the Northern
Cape. These animals live in burrows and hunt mainly insects and other
small creatures during the day.
3.
4.
Sociable Weaver (Versamelvoël, Thaga)
Philetairus socius
The huge thatched nests of the Sociable Weaver are among the more
19
common and remarkable sights of the Kalahari. These “apartment blocks”
are jointly-built in thorn trees and other structures. They can weigh up to 1 000 kg, contain 50 or more nest chambers and provide a home for up to
400 weavers, as well as many other birds. The nests are constructed to
provide a secure barrier against most intruders and offer excellent insulation
against extreme temperatures. Sociable weavers seldom drink water and
forage together in large flocks in search of seeds and insects.
5.
Pygmy Falcon (Dwergvalkie, Segwetsane)
Polihierax semitorquatus
This is one of the smallest birds of prey in the world. It is one of two South
Africa birds (the other is the Greater [Painted] Snipe (Grootgoudsnip Rostratula benghalensis) where the female is more colourful than the male
and courts the male. It uses the sociable weaver nest for breeding, sleeping
and protection against the harsh climate. The entrance to its nest chamber
is marked by a coating of pinkish-white droppings. Pygmy Falcons are
effective little hunters, catching large insects, lizards, small rodents and
birds. They occasionally seize a weaver chick, but it is not in the hunter’s
interest to destroy the domestic system on which its survival depends.
M. Jonk
6.
African Wildcat (Vaalboskat, Tibe)
Felis lybica
The African Wildcat resembles the domestic tabby (Felis catus) and the
two species do interbreed. It is becoming increasingly difficult to find purebred wildcats anywhere near human settlement and the species may be
vulnerable to extinction. The wildcat is heavier than the domestic cat, with
much longer legs. The backs of its ears are a characteristic rich red colour,
20
while that of the domestic cat are black or dark brown. The wildcat is
nocturnal and solitary. It eats mainly rats and mice, but will also eat larger
prey such as hares and springhares, as well as smaller creatures such as
birds, lizards and even insects. 7.
Leopard or Mountain Tortoise (Bergskilpad, Khudu)
Geochelone pardalis
Both the common and scientific names of this huge tortoise refer to the
leopard-like pattern of black spots on a yellow shell, found in young tortoises.
The shell turns a uniform dark brown with age. Adults normally weigh up
to 15 kg, but may reach 50 kg. They are slow growing and may live for 75
years or even longer. They eat a variety of plants and sometimes gnaw
bones and shells to obtain the calcium needed for the growth of the shell
and developing eggs. Young tortoises have many predators, including ants,
leguaans, storks, cranes and small mammals. Adult tortoises are relatively
safe from predation, but many are killed in veld fires and on roads or are
eaten by people.
Mole Snake (Molslang, Tsosamasigo)
Pseudaspis cana
This is a large snake with a solid, thick body, which may grow to 2 m in length. Young snakes have a blotched colour pattern, while adults are normally
plain red-brown, dark brown or olive in colour. This extremely useful and
harmless snake lives in abandoned animal burrows and feeds on various
small mammals, including moles (hence the common name), rats and mice. It has no poison fangs and is a powerful constrictor, wrapping coils of its
body around its prey and killing it by suffocation.
8.
Kori Bustard (Gompou, Kgori)
Ardeotis kori
With a body mass of up to 19 kg, the Kori Bustard is Africa’s heaviest flying
bird, with a wingspan of up to 280
cm. In display, the male bird strides
about importantly with its tail fanned
and wings pointed downward. The
neck feathers are puffed up and the
throat is filled with air, producing great
booming or drumming calls. The
Afrikaans name refers to the birds’
habit of eating thorn tree gum and the
peacock-like raised and fanned tail
9.
M. Jonk
21
feathers of the courting male. The diet also consists of insects, such as
locusts and crickets.
10.
Cape Ground Squirrel (Kaapse Waaierstertgrondeekhoring, Samane)
Xerus inauris
Unlike their tree-living relatives, these squirrels spend their whole life on the
ground. They live in colonies of up to 30 animals in underground burrow
systems, where they shelter from the extreme temperatures of the Kalahari. They are diurnal and the fan-like bushy tail (hence the Afrikaans name)
comes in handy during hot days, when it is curved over the head to provide
a bit of shade. Sometimes these ground squirrels are incorrectly called
meerkats, but they are true rodents, feeding on roots and bulbs of plants.
11. Southern Pale Chanting Goshawk (Bleeksingvalk,Phakalane)
Melierax canorus
This goshawk is a common sight in the drier western parts of our country,
where it perches on a telephone pole or the top of a thorn tree. Its common
name is derived from its striking pale grey colour and tuneful call uttered
during display flights. It usually catches lizards, mice and insects by gliding
down from its perch. Sometimes it runs on the ground after its prey. It may
catch prey as large as guineafowl.
12.
Ground Agama (Gewone Koggelmander, Kodutala)
Agama aculeata
Ground Agamas can be distinguished by their triangular heads with large
earholes, rough scales, sturdy legs and short tails. They are usually seen
22
in pairs, which shelter in shallow holes dug in the loose soil at the base
of a bush. Although mainly ground-living, these creatures will often climb
into low shrubs to escape the burning sand. If threatened, agamas huddle
close to the ground, relying on the perfect camouflage of their mottled brown
bodies. If this is unsuccessful, they dash for the shelter of a nearby bush
or their burrows. They eat mainly termites and ants.
13.
Suricate (Stokstertmeerkat, Lejara)
Suricata suricatta
Although these delightful, pixie-like animals are commonly called meerkats,
they are not cats but are related to the mongoose. The Afrikaans name
refers to the slender, stick-like tail, which is carried upright like an antenna
when the animal is moving. They are highly social animals, with all the
individuals cooperating to ensure the survival of the group. They live in
burrow systems housing up to 30 animals and regularly shared with ground
squirrels or Yellow Mongoose. They feed during the day, digging furiously
with their sharp front claws for insects, lizards, scorpions and millipedes. A
number of sentinels always stand guard and bark a warning at the approach
of danger, particularly the martial eagle, which is their most feared enemy. 14.
Lanner Falcon (Edelvalk, Segotsane)
Falco biarmicus
These birds are usually seen singly or in breeding pairs, but in dry areas
they may gather in large numbers around waterholes. They perch boldly
on telephone poles or trees, to watch for passing prey, usually flying birds
and termites, but also sometimes small animals on the ground. The Lanner
Falcon can probably fly as fast as the Peregrine Falcon (Swerfvalk - Falco
peregrinus) , which is said to reach speeds of up to 250 km/h. It kills a
bird in full flight with its sharp claws, releasing a great spray of feathers. It
sometimes bites off the head of the prey as it flies back to its perch. Once
there, it plucks out all the feathers, tears the prey apart and swallows the
pieces whole.
15. Kalahari Scrub-Robin (Kalahariwipstert, Pane)
Erythropygia paena
This bird spends most of its life on the ground and its colouring matches the
Kalahari sand. It runs quite fast on its longish legs and often stops, flicking
its tail up and down, hence the Afrikaans name. If disturbed it flies away
and seems to dive into a bush to perch well within the leaves. On landing
it fans its tail, showing a distinctive reddish-brown pattern with a white tip. The robin eats insects, mainly termites.
23
16.
Black-backed Jackal (Rooijakkals, Phokoje)
Canis mesomelas
This jackal is recognised by the dark saddle on its back. This adaptable and
opportunistic creature is active by day or at night. It rests in unused burrows
of aardvark, rock crevices or under bushes. It is a hunter, scavenger, or
even omnivore, as it eats just about anything: rodents, springhares, locusts,
termites and other insects, birds’ eggs and fledglings, reptiles, carrion and
some wild berries. It usually hunts alone, but during the springbok lambing
season they operate in small packs, with some individuals distracting the
mother, while others catch her lamb. Sheep and cattle may be attacked
in the same way and the jackal is considered a problem animal by stock
farmers.
17.
Martial Eagle (Breëkoparend, Ntswi yo motonna)
Polemaetus bellicosus This is the largest eagle in Africa, with a wingspan of 210 to 260 cm and
weight of up to 6,2 kg. Its heavy beak, fierce-looking yellow eyes, broad head
(hence the Afrikaans name) and bold markings contribute to its impressive
image. They are usually seen flying in pairs a few hundred metres above
the ground, in search of their prey. Nothing escapes their incredibly sharp
eyes; the bird is said to be able to pick out a ground squirrel at a distance of
6 km. When it spots a likely meal it dives downwards, gaining speed all the
time. It attacks from close to the ground to remain undetected and breaks
the prey’s body with its weight and sheer speed. Although it is reputed to
kill domestic stock, dassies, hares, other small mammals and birds form the
bulk of this eagle’s diet.
24
18.
Chestnut-vented Titbabbler (Bosveldtjeriktik, Tontobane)
Parisoma subcaeruleum
This titbabbler is distinguished by the reddish-brown patch under its tail. It is
a noisy bird, uttering a loud babbling “cherik-tik-tik” call, hence the Afrikaans
name.
It is usually seen flitting between bushes, actively searching
branches, stems and leaves for insects, spiders and sometimes berries. 19.
Gemsbok (Kukama)
Oryx gazella
It is said that the legend of the unicorn arose from the oryx of Arabia,
closely related to the southern African gemsbok. The gemsbok is certainly
a handsome creature with its eye-catching grey, black and white markings
and slender rapier-like horns, which can measure up to 100 cm. These
horns can be wielded with deadly force and accuracy against predators
such as lions and hyaenas. The gemsbok is superbly adapted to the desert
conditions of the Kalahari. It has an unusually low metabolic rate which
lessens its need for food and water. It is able to live for months without
drinking water and gets vital moisture from the plants that it eats, including
the tsamma melon. Its light-coloured and shiny coat reflects the heat of the
sun and it spends the hottest part of the day in the shade. The gemsbok
does not waste precious water to cool itself by sweating or panting and this
is only done at times of great stress. On especially hot days it allows its
body temperature to rise and gradually loses this stored heat during the
cooler nights. 25
NOCTURNAL ANIMALS
In the arid Northern Cape many creatures hide in underground burrows
orshadysheltersduringtheheatofthedayandonlyemergetohuntand
forageduringthecoolhoursofthenight.Theseanimalsarecallednocturnal
animals. This is an adaptation to save precious moisture that would
otherwise be wasted by panting or on other tactics to keep cool. During
thewintermonthswhenthenighttemperaturesareicy,manyanimalsare
crepuscular,beingactiveatduskanddawn.
Spotted Eagle-Owl (Gevlekte Ooruil, Morubisi)
Bubo africanus
This large owl with its characteristic “ears”, large yellow eyes and dull
brown, finely marked feathers, is commonly found in towns and in the veld
throughout SouthAfrica.The ear-tufts apparently serve no purpose other
1.
than to frighten its enemies. The real ears are flat slits at the sides of the face,
coveredinfeathers.Oneisslightlyhigherthantheothersothattheowlcan
determinethedirectionanddistancetoasound.Astheeyesareplacedat
thefrontoftheface,thevisionislimitedtothefront.Tocompensate,theowl
canturnitsheadrightaroundthrough180°.Duringthedaytheowlroostsin
a tree, under bushes or in an aardvark hole, emerging at night to hunt from a
prominent perch. It glides down silently onto its prey, usually rats and mice,
insects and birds. 2.
Porcupine (Ystervark, Noko)
Hystrix africaeaustralis
The upper parts of the body of the porcupine are armed with long black and
white quills. If threatened it will freeze, standing motionless with its quills
erect to make it appear larger. It can become aggressive, stamping its back
feet, grunting and rattling the hollow quills on its tail and suddenly rushing
backwards to plant its sharp quills in the body of its enemy. Contrary to
popular belief, the quills cannot be shot out and are not poisonous. The
porcupine rests in caves, rock crevices or in holes in the ground during the
day. It is the largest rodent in southern Africa, digging up roots and bulbs,
and sometimes eats wild fruit and tree bark. It can become a pest on farms,
raiding crops and gnawing through plastic water pipes.
3.
South African Hedgehog (Suid-Afrikaanse Krimpvarkie, Tlhong)
Atelerix frontalis
The hedgehog is covered in a coat of short sharp spines. If threatened,
it rolls into a tight ball, with the head, legs and soft belly protected by the
spines. During the day it curls up under tall grass, under a bush or in a hole
in the ground. Hedgehogs are often found in town, under heaps of garden
rubbish. They spend most of the cold winter months in a warm shelter, in a
state of semi-hibernation. They eat a wide variety of food such as insects,
earthworms, frogs and lizards.
27
4.
Pangolin (Ietermagog, Kgaga)
Manis temmincki
The Pangolin is a most unusual mammal as it is covered by armour of
heavy, overlapping brown scales. If threatened it rolls up into a tight ball,
which has to be handled with care, as the slicing movement of the tail can
inflict a nasty cut. The common name is derived from the Malay penggoling, meaning “the roller”, from this habit. It walks on its hind feet, only
occasionally balancing on its front feet or dragging the tail. The front feet
are armed with sharp claws, which are used to dig open ant nests and
sometimes termite mounds. The long sticky tongue is pushed into the nest
and withdrawn covered in ants, pupae and larvae. It has no teeth and the
food is ground up in the muscular stomach.
28
5.
Egyptian Free-tailed Bat (Egiptiese Losstertvlermuis, Mamathwane)
Tadarida aegyptiaca
These bats live in large colonies, roosting in caves, rock crevices, in hollow
trees or under the bark of trees during the day. They rely on echolocation
to find their way in the dark, making high-pitched clicking sounds which are
reflected back to their huge ears. They are insectivorous, catching small
flying insects in the membrane stretched between the back legs.
6.
Smith’s Red Rock Rabbit (Smith se Rooiklipkonyn, Tlholwe)
Pronolagus rupestris
As the name suggests the red rock rabbit is found in rocky areas, where it
rests in deep crevices during the day, emerging at sundown to graze soft
green grass. During the summer months, one or two young are born in
sheltered places under tree roots or rocks, in nests lined with the mother’s
fur. Unlike the young of hares, they are naked at birth and only leave the
nest when well grown.
7.
Striped Polecat (Stinkmuishond, Nakedi)
Ictonyx striatus
The Striped Polecat or skunk is easily recognised by the conspicuous
black and white colouring, which serves as a warning to other animals. If
disturbed, the polecat becomes quite aggressive, raising its hair to appear
larger and curling its tail over the head, ready to release an evil-smelling
fluid from the glands beneath its tail. During the day it shelters in a burrow
or suitable hole in the ground, in rock crevices or under tree roots or fallen
logs. It only emerges late at night to feed on insects, mice and other small
creatures.
29
8.
Springhare (Springhaas, Tshipo)
Pedetes capensis
The Springhare hops on its long, powerful, kangaroo-like hind legs, using
the long tail for balance. Its common name comes from the Afrikaans, and is
unfortunate as the springhare is not closely related to hares. Both front and
hind feet are armed with strong curved claws, which are used for burrowing. Its ears and nostrils can be closed for protection against sand and dust. Springhares live almost entirely on grass, eating the seeds, leaves, stems
and roots. They also dig for other plant roots and bulbs and can become
pests in agricultural areas.
9.
Leopard (Luiperd, Lengau)
Panthera pardus
The Leopard has a striking coat with black spots arranged in rosettes or
circles, unlike the Cheetah (Jagluiperd - Acinonyx jubatus), which has a
coat with single black spots. Like all cats, it is a highly efficient hunter with
adaptations such as a well camouflaged coat, very sharp curved claws
which can be retracted (pulled back), soft cushioned paws for silent stalking,
specialised eyes which can see during the day and at night, long whiskers
to feel obstructions in the dark and long canine teeth to kill the prey. The
leopard hunts alone and prefers to catch smaller buck species of less than
70 kg which it can store in a tree, out of reach of other predators.
10.
Rufouscheeked Nightjar (Rooiwangnaguil, Khoê)
Caprimulgus rufigena
Nightjars get their name from the jarring call that they utter at night. This
species lives in southern Africa during our summer months, where it breeds,
and then migrates northwards to West Africa. The nightjar spends most of
the day resting in the shade on bare ground, preferable near dead leaves
and twigs for camouflage. At dawn and dusk it swoops around, catching
small flying insects. Although its beak is small and weak, it can open very
30
wide and is surrounded by long bristles, which help the bird to catch its
prey. 11.
Aardwolf (Thudukwi)
Proteles cristatus
The Aardwolf is related to the hyaenas, as can be seen from the shorter
back legs. The common name (“earth-wolf”) comes from the Afrikaans
and refers to its habit of sheltering in holes in the ground during the day. Another Afrikaans name, maanhaarjakkals or “maned jackal”, refers to the
crest of long hair on its back which is erected in defence. Unfortunately
many farmers hunt aardwolf because they have the undeserved reputation
of fearsome sheep killers. However, the aardwolf is not a true carnivore,
as it has only tiny peg-like teeth which cannot chew meat. It feeds only on
termites which are licked up as they forage above ground. Research has
shown that a single aardwolf can consume as many as 300 000 termites
per night!
12.
Small-spotted Genet (Kleinkolmuskejaatkat, Tshipa)
Genetta genetta
The genet is related to the civet, mongoose and suricate, as can be seen
from the short legs, long body, long tail and pointed face. As the name
suggests, the Small-spotted Genet can be distinguished from other genets
by its smaller spots. More characteristic is the crest of black hair along its
back, which is raised under stress. It has retractile claws (claws that can
be pulled back) like a cat and climbs into a tree if threatened, to rest during
the day or to hunt. It eats any small creatures such as rats and mice, birds,
reptiles, spiders and insects.
31
13.
Giant Bullfrog (Reuse Brulpadda, Letlametlu)
Pyxicephalus adspersus
Giant bullfrogs are the largest of the South African frogs, reaching 20 cm
in length and 1 kg in weight. The common name refers not only to their
massive size, but also to the breeding call of the male, which sounds like the
bellowing of a bull. They live in the grasslands and dry areas of our country,
feeding and breeding during the summer months and then spending the
winter underground. With a greedy appetite to match their size, bullfrogs
eat anything small enough to swallow, including insects, lizards, mice and
snakes.
14.
Aardvark or Antbear (Erdvark, Thakadu)
Orycteropus afer
The name of the Aardvark (“earth-pig”) comes from the Afrikaans and refers
to its pig-like appearance, with its long snout and ears and sparsely haired
body, and the fact that it digs in the soil for its food and shelter. Using its
muscular legs, armed with long, thick claws, the aardvark digs huge burrow
systems, some with resting chambers and many entrances. Such a burrow
has been found to maintain a temperature of around 10° C, offering excellent
protection against the extreme climate. The very survival of many animal
species depends on the shelter provided by these burrows. The aardvark
cannot see very well, but locates its food by an excellent sense of smell. It
digs open ant and termite nests, pushing its nose and mouth and sometimes
its whole body into the hole, to trap the insects on its sticky tongue.
32
ECOLOGY
Thepostersinthekioskillustratedifferentecologicalprinciples:
1.A.
THE SUN IS THE SOURCE OF LIFE:
Sunlight (light energy) is the main source of energy in most ecosystems.
Throughtheprocessofphotosynthesis,greenchlorophyll-containingplants
produce their own food by capturing the sun’s energy, extracting carbon
from the air and minerals from the soil. This energy is used for the life
processes of plants and is also stored in the plant cells. Plants are thus
calledproducersorautotrophs(“self-nourishing”).Animalscannotmake
theirownfoodanddependonthegreenplantsfortheirenergyandnutrients.
They are thus called consumers or heterotrophs (“nourished by others”).
Herbivores (plant eaters) are primary consumers, while carnivores (meat
eaters)aresecondaryconsumers.
1.B.
THE ECOLOGICAL PYRAMID:
The trophic (feeding) structure and functioning of an ecosystem can be
illustratedintheformofanecologicalpyramid.Thepyramidshapeisvital
fortheecosystemtobeself-sustainingasmuchenergyislostinthetransfer
fromonetrophicleveltothenext.Thelowestlevel,theproducers(usually
greenplants),mustproduceenoughenergytosupportthenextlevel,the
primaryconsumers(herbivores),whichinturncansupportfewersecondary
consumers(carnivores)inthetoplevel.
Exampleillustrated:Anareaofgrasscansupportanumberofspringbok,
whichinturncansupportonlyoneleopard.
2.A.
THE FOOD CHAIN:
Thetransferofenergyfromaproducer throughaseriesofconsumersis
calledafoodchain.
Example illustrated: sunlight -> green plant -> locust -> shrew -> cobra
-> eagle.
Simplefoodchainsandecologicalpyramids,suchasthoseillustrated,are
seldomfoundinnature.Mostorganismseatmanydifferentfooditemsand
are in turn eaten by a range of predators, forming a complex network of
linkedfoodchains,orafoodweb.
2.B.
THE ENERGY CYCLE:
Nutrientsoccurinlimitedquantitiesinanecosystemandmustberecycled
or returned to the system to be used again. In nature there are many
cycles,suchasthecarbon,nitrogenandwatercycles.Thesecyclesare
vital if the ecosystem is to be self‑sustaining and healthy. Scavengers and
decomposers play essential roles in the ecosystem, breaking down dead
organisms and making the nutrients available for use once more.
Example illustrated: nutrients in the soil -> grass -> steenbok -> lynx ->vulture
(a scavenger which also feeds on the steenbok carcass) -> decomposition
bacteria (which break down the remains) -> nutrients are released in the
soil, where they are again available for use by plants.
3.
COLONISATION AND SUCCESSION:
Within an ecosystem, plants and animals are continually dying and being
replaced by others. The new organisms may be the same species or
they may be new species colonising the area. This progressive series of
changes in a plant or animal community is known as ecological succession. It takes place over many years until the abiotic factors such as rainfall, soil
and temperature limit any further changes in the ecosystem. This relatively
stable state is called a climax community. If an ecosystem is disturbed,
for example by fire or human activity such as cultivation, the area recovers
gradually and this process is called secondary succession.
Example illustrated: After a fire only some plant species (mainly the trees)
survive and the ground is bare in patches. The wind blows in seeds and
after 1 to 3 years about 15 hardy pioneer species have colonised the area. It now becomes a better habitat for other plants and different, less tough
species gradually appear, until a subclimax plant community of about 80
species is attained after 5 to 10 years. Most of the pioneers are unable to
compete with the new colonists and will disappear, to be replaced by new
species, better adapted to the modified environment, until a climax stage
with 30 species is reached after 30 - 50 years.
NATURAL SELECTION:
Natural selection or “survival of the fittest” is a complex process whereby the
environment determines which members of a species survive to reproduce
and pass on their genes to the next generation. This need not necessarily
involve a fight between individuals.
Example illustrated: As in many other species, springbok rams maintain
territories in the best pasture during the mating season. Although fighting
does occur, injury or death is rare. The dominant rams mate with the ewes
moving through their territories to feed, thereby passing only the best genes
on to their lambs and ensuring the survival of the species.
COMPETITION:
When animals of the same species live together they compete for the
same food, thus limiting their numbers. When a variety of game species
34
live together, the number of individuals of each species may be lower,
but as each occupies its preferred habitat and eats its preferred food, the
competition between species is reduced and the veld is also better utilised.
Example illustrated: The springbok grazes short green grass in summer and
during the winter months browses on Karoo shrubs. The blue wildebeest
grazes short, green, lawn-like grass. The kudu browses the leaves of shrubs
and trees. The blesbok which is a selective grazer (preferring only certain
grasses) and the red hartebeest which grazes and browses can also be
introduced in this system.
ASSOCIATION:
In an ecosystem many animals and plants live in association with other
species. One such type of association is known as symbiosis and may
benefit one or both species.
Example illustrated: By nesting in the same tree as the secretarybird,
the sparrow-weavers are protected from snakes. There are many other
examples shown in the EnviroZone and mentioned in this booklet.
PEOPLE AND THE ENVIRONMENT:
A natural ecosystem, without the influence of man, is usually in balance.
Human activities can have severe impacts on the environment. Example illustrated: If too many sheep, which all eat the same grass species,
are introduced, overgrazing and trampling takes place. Similarly, human
overpopulation and industrialisation lead to pollution and damage to the
natural ecosystem. Through wise management and sustainable use, man
and nature can live in harmony in a balanced ecosystem.
4. ADAPTATIONS:
Plants and animals show many adaptations to survive in the arid Northern
Cape.
Illustrated examples:
A.
In the Kalahari the deep sand allows easy root penetration and
greater water uptake. Large Acacia trees, which have deep root systems,
are thus found. Other trees and plants have water storage systems in their
roots. On the Ghaap Plateau (and in the Karoo) root growth is retarded in
the shallow, compact and rocky soils. Thus water intake is reduced and
only short, hardy shrubs are found.
B.
Behavioural adaptations allow small animals such as the ground
squirrel to avoid over‑heating and water loss. It rests underground in its
burrow system during the hottest part of the day and if it emerges in the sun,
35
itusesitsbushytailasaprotectivesunumbrella.Manyanimalsarealso
nocturnaltoavoidtheheatoftheday.
C.Thegemsbokdoesnotpantandwastewaterthroughevaporativecooling
likeotheranimals.Insteaditallowsitsbodytemperaturetoriseduringthe
day,uptoanincredible45°C.Asitissuchalargeanimaltheheatingprocess
isfairlyslow.Atnightwhenthetemperaturedrops,theaccumulatedbody
heat is lost again through radiation. A physiological adaptation enables
someevaporativecoolingofbloodtotakeplaceinanintricatenetworkof
bloodvesselsclosetothesurfaceofitsnasalpassages.Thiscoolerblood
ispumpeddirectlytothebrain,keepingitavitalfewdegreescoolerthanthe
restofthebodyandprotectingthekeypartsofthebrainfromwhatwould
otherwisebelethallyhightemperatures.
D.
Plantsinaridareashavevariousstrategiestoreducewaterlossby
transpiration through the stomata (openings) on the leaves. The surface
area of the leaves (and thus the number of stomata) are reduced by
developing compound leaves, folding the leaflets or even losing the leaves
entirelyduringtimesofdrought.Sometimeshairscovertheleaf,andthus
thestomata,tominimisewaterloss.
M.Jonk
Other booklets available at the McGregor Museum:
TaniaAnderson, 2004. A beginner’s guide to the plants of Kimberley
andsurrounds,withspecialreferencetoMagersfonteinBattlefield.
Corné Anderson and Tania Anderson, 2004. A beginner’s guide to
the animals of Kimberley and surrounds, with special reference to
MagersfonteinBattlefield.
TaniaA.Anderson (ed.), 1998. Hidden Splendour – A Guide to the
natural history of the Kalahari and surrounds
Join the Wildlife and Environment Society of South Africa
(WESSA)!
Our mission is to promote public
participation in caring for the earth.
WESSA is a leading environmental organisation in South Africa. For over
80 years, WESSA has been a motivating force behind many significant
environmental actions.
The proclamation of the Kruger National Park, the protection of the St Lucia
Wetlands area, the establishment of the Addo Elephant Park, the protection
of the Brenton Blue butterfly, pioneering of MOSS (Metropolitan Open Space
System) and, more recently, lobbying for the protection of the Pondoland Coast,
are but a few of the successful conservation initiatives undertaken by WESSA.
WESSA is a leader in the field of environmental education and training, with
projects run throughout the SADC Region.
WESSA also plays a important role as an environmental watchdog, ensuring
that developments are not detrimental to the environment.
So, what is WESSA? It is a society of people who believe in a better quality of
life for all. People who speak out, take action, get involved, or simply support
the actions of the organisation by becoming members.
Benefits include the quarterly magasines, African Wildlife and EnviroKids, as
well as Regional newsletters (Griqua Gnus in the Northern Cape), monthly
outings and talks.
Why not join the WESSA Environmental Clubs Scheme?
Amongst other benefits, clubs receive quarterly newsletters which focus on
special environmental days and are packed with ideas for celebrating these
days. Contact us:
WESSA National Office
PO Box 394, Howick 3290 Tel: 033 - 330 3931 Fax: 033 - 330 4576
[email protected] WESSA: Northern Cape
PO Box 316, Kimberley 8300
Tel: 053 - 839 2717
Fax: 053 - 842 1433
[email protected]
www.wessa.org.za
37