Giraffa
camelopardalis (Giraffe)
Order: Artiodactyla
Suborder: Ruminantia
Superfamily:
Family: Giraffidae
Subfamily:
Genus: Giraffa
Species: camelopardalis
Sub-species: congoensis
General Description/Adaptations:
Another animal
not needing a general description.
The horns begin
as cartilaginous “buds” that eventually fuse to the skull and become bony. These horns are covered with skin and hair
throughout the life of the giraffe. They
are cud-chewing ruminants, but rely more on efficient digestive system – they
have the largest stomach surface area of any ruminant due to tongue-like
papillae in the stomach. (Kingdon, p.340)
Their long legs
allow them to cover ground quickly, and their Arabic-derived name means “fast
walker”. They can run at 60 km/h. At speed, their hoof pivots forward so that
the animal’s weight is borne directly by the hock. The tongue is 45 cm long and is used to grab
browse. There is wide variation in
markings. (Kingdon, p. 341)
It has the same
seven vertebrae as other mammals, so each is very long. (Walker, p. 142)
Main pair of
horns is already present in the embryonic stage. They lie flat and do not present an obstacle
to birth. Within a few days of birth
they are erect and tufted.
Bone-ification starts at the end and works towards the skull, where they
become fused at 4 – 4.5 years in males and 7 years in females. Bone development in males continues
throughout life in the dermal layer, and becomes deposited around the head and
face except where muscles attach. The
head, therefore, develops into a large club used in battle. (Estes, p. 202)
Size: (Kingdon, p. 341)
Head and body
length: 3.5 – 4.8 meters
Tail length: 76 – 110 cm
Total height up
to 5.2 meters
Weight: Female
450 – 1,180 kg; Male 1,800 – 1,930 kg
Habitat:
Savannahs, open
woodlands, seasonal floodplains. Most
common where rainfall, soils, wind, fire, elephants, or flooding favor low and
medium-height woody growth. (Kingdon, p. 342)
Are thought to
greatly affect their habitat, causing their food trees to select for thorns,
galls and the shapes of branches. Heavy
browsing shapes the forms of trees and limits growth. (did they cause the flattened-top of acacias?) (Kingdon, p. 342)
Range/Parks:
Used to be
extremely wide-ranging throughout Africa, even
in the Sahara about 7,000 years ago when it
was wetter. Now limited to parks south of the Sahara.
(Kingdon, p. 343)
Home Range:
Male core areas
may be up to 80 sq. km., but they may range up to 654 sq. km. over the course
of the year. (Kingdon, p. 343)
Young males have
the largest ranges, indicating a tendency to disperse before settling down,
after which time they have smaller ranges than females, likely due to their
different feeding opportunities. (Estes, p. 204)
Food/Water:
They feed on
high-quality browse between 2 and 5.5 meters.
Lower food is only emergency food, partly due to their clumsiness at
that height, but there is also huge competition from the antelopes for those
food sources. Females are shorter, and
so feed from a narrower band of vegetation.
To make up for this, they feed on a wider variety of sources over a
larger space. This ability to specialize
may have contributed to several species sharing ranges in the past. (Kingdon,
p. 340)
Known to feed
from over 100 species. Main staples are Acacia, Commiphora and Terminalia. (Kingdon, p. 342)
Not
water-dependent. (Walker,
p. 142)
Can often tell
gender from a distance by whether they are feeding high (male) or bending down
to feed (female). (Estes, p. 203)
Breeding:
Gestation lasts
14 months. Newborns can stand within 5
minutes, join a crèche in a week, lactate for 6-12 months and after 6 months is
moving independently with the herd. (Kingdon, p. 343)
Females will
return to one place to have their young year after year. (Estes, p. 204)
Breeding happens
year-round, but peaks during the rainy
season. Cows conceive just a few months
after giving birth. Females become
sexually mature at 4 years, males cannot compete for breeding rights until at
least 7 years. (Estes, p. 205)
After giving
birth, the mother will remain in isolation for up to one week, keeping away
both predators and other giraffes. The
calf spends half the day and most of the night lying in hiding. The mother may leave it alone for up to 4.5
hours to go to water. They gradually
spend more time standing.
Mother-daughter bond can last up to 22 months, and even when young join
crèches at one month, the mother still pays close attention to offspring and
are quick to come to their aid. After
3-4 months, young begin ruminating and will spend up to 63% of their day
browsing. Most become independent at 12
– 16 months. (Estes, p. 206)
Social
Organization:
Social units are
temporary.
Gregarious,
nonterritorial; loose, open herds. (Estes, p. 203)
When gathering as
a herd in open savannah, there is no leader, and their movements are only
coordinated to the extent that it helps avoid predation. Mothers and small calves continue to
associate closely, and young gathering in crèches causes some females to
associate. (Estes, p. 203)
Males join
bachelor herds at puberty (3 years), and emigrate outside their natal
range. They become increasingly solitary
over time. They frequently mingle with
females to check readiness to mate, but these connections are transitory, and
group compositions may change from hour to hour. (Estes, p. 204)
Although not
territorial, a bull attempts to keep other males away from a potential mate
once he has identified her. No bond
after mating. (Estes, p. 206)
Communication:
Mostly silent, calves will occasionally
bleat, mew, moo and make alarm snorts.
Cows seeking straying calves will give a roaring bellow and courting
bulls will sometimes “cough”. Moaning,
snoring, hissing and flutelike sounds are rare but recorded. (Estes, p. 204)
To challenge another male to a duel, one male
will approach another in the erect posture with a raised head and face the
opponent. If the other wants to fight,
they will stalk stiff-legged towards each other and stand parallel. At low-intensity, they may rub heads and
necks gently together and lean heavily against each other. This is probably to assess relative size and
strength. At high-intensity, they will
aim blows at rump, flanks or neck, often standing in reverse-parallel. The striking giraffe will straddle its
forelegs to brace itself, then swing it’s head sideways and upwards over its
shoulder to strike with the horns. A
serious fight usually involves a stranger, as bulls in a common area have
long-since determined their relative status. (Estes, p. 205)
Activity
Patterns:
Wet season:
widely dispersed, feeding on green deciduous growth.
Dry season: concentrate near evergreens.
Males and females
both spend about half their time feeding each day. Males increase their feeding time during the
dry season, and always spend more time walking than females, due to their
search for mates. Peak feeding times are
the first and last 3 hours of daylight.
Hottest hours of the day are spent ruminating. They will also feed during the night,
especially on bright nights. (Estes, p. 204)
Lifespan:
½ to ¾ of young die in their first year due
to predation. (Kingdon, p. 343)
Maximum age in wild is about 25 years.
(Estes, p. 202)
Sign:
Pellets are
similar in size and shape to kudu, but are more scattered due to the drop. They are flattened at one end. (Walker, p. 142)
They have a pacing gate, moving both legs on one
side, then the other. Their long legs
would interfere with each other if they tried a diagonal gait. In a gallop,
the hind feet come down outside of and ahead of the front feet. (Estes, p. 204)
Predators:
Lions, hyenas, leopards, crocodiles, humans.
(Kingdon, p. 343)
Not many predators stand a chance against the
kick of an adult giraffe, but young are quite vulnerable. Young can outrun an adult over short
distances and can often outrun a lion, but lack the endurance to outrun a
hyena. (Estes, p. 207)
Conservation/Commercial
value:
Not currently
endangered as a species, but their range has been extremely reduced and local
populations have become extinct. (Kingdon, p. 344)
References:
Estes, R. (1991).
The Behavior Guide to African Mammals. Berkeley, CA: The University of California
Press.
Kingdon, J.
(1997). The Kingdon Field Guide to
African Mammals. Princeton,
NJ: Princeton
University Press.
Walker, C.
(1996). Signs of the Wild: A Field Guide
to the Spoor & Signs of the Mammals of Southern Africa.
(5th Edition). Cape
Town, South Africa: Struik Publishers Ltd.