|Visible Male/Female Differences
Females have one pair of nipples
between the hind legs. Mature males are larger than females, and have
much thicker necks with heavier skin folds and larger tusks.
Habitat and Distribution
Hippos need water which is at least 1,5 m deep in but can survive temporarily
in mud holes and need fresh water for
A selective grazer but will take floating water
plants and eat elephant dung in severe food shortages . It can do serious damage to crops and
single calf weighing 30 kg is born every 2-3 years at any time of year after a gestation 225-227
days. Young begin grazing at 6-8 weeks and are weaned at 8-14 months. Females
mature at 5 years and males at 6-8 years with a life expectancy of 35 years.
Crocodiles take young hippos in the water and
lions take young hippo on the shore. Females give birth in dense reed
beds and introduce the calf to the
herd after 2 weeks. Females with young are very aggressive but allow other females
to act as babysitters. Calves suckle under water and come up for breath every few seconds.
Behavior and Habits
spend the day resting in or near water and will leave the water to sunbathe. Hippo sweat contains a
red pigment that will act as a sun screen. Hippos can swim on the surface or run
in slow motion along the bottom. They can remain submerged for up to 6 minutes. Both ears and nostrils
have valves that keep water out. At dusk they move to the bank where it will feed for 7-8 hours.
Hippos will travel up to 30 km to feed.
Hippos live in
pods of up to 30 with
a single dominant bull which will defend the pods' territory which includes only
the water. If frightened on land hippo rush back to the safety of the water and anything in the way
will be trampled.
A bull may hold a
territory for as long as 12 years. Neighbouring bulls meeting on their boundary stare
each other, turn, and spray dung and urine - much like politicians.
Savage fights over territory and females are
savage may leave serious wounds and may be fatal. For some reason hippos wounds
rarely become infected, even in very dirty water. The vanquished bulls are driven out of the territory
while young males are
chased out of the pod
by the dominant bull at about six years old. Dominant bulls
sometimes try to kill the young to force the female into oesterus and mothers
will defend their offspring. The dominance act of yawning displays the large
mouth and tusks and is a warning to keep away.
The most characteristic call is a series of one long roaring grunt up to 120
decibels and several short
ones produced as it surfaces; it also roars, screams, croaks, clicks and whines. Calls
transmit through water as well as through air; underwater croaks are probably a
short-range contact call. Calls probably include sounds
below the frequency limit of human hearing.
Dung and Field sign
Hippo trails wear into two parallel ruts. Dung heaps near paths.