- 1 species in Africa
- DR personal total: 1 species (100%), 1 photo'd
The sight of a male Ostrich
(above) striding across the east African plains is an impressive one.
It is the world's largest bird, standing taller than a man and weighing
up to 150 kg (=330 lbs). It has great legs, and can sustain speeds of
50/km per hour for about half an hour.
territories in the African veldt. In some places they are monogamous,
but in other locales they tend harems of females. These social systems
can be complex, with the "major hen" and the male doing the incubating
and care of the young, while "minor hens" mate with the harem owner or
other males, and lay eggs in the same nest, but do not incubate (Folch
eggs are huge, and weigh about as much as two dozen eggs from your
favorite supermarket. The eggs are laid in very rudimentary scrapes on
the ground, and incubated. One ostrich can incubate up to 25 eggs, but
most nests have even more because of the extra ones laid by "minor
hens." The "major hen" puts her own eggs in the middle but she still
incubates some of the 'extra' eggs. We once found a lone egg on the
open plains of Tanzania (right).
The primary adults
guard the young and protect them from predators as best they can,
including the use of a variety of distraction displays. Yet breeding
success is quite low. Only ~10% of eggs hatch, and then the precocial
young are often taken by predators. Fortunately, Ostriches are
long-lived because in studies in Kenya, for example, only 0.15 young
are raised each year from each adult (Folch 1992). Thus in many years
the effort to raise young to independence will fail.
once roamed throughout open areas of all of Africa and in the Middle
East, but they were hunted for food and plumes in the 19th century and
the world population is much smaller today. The Middle Eastern race syriacus became extinct by about 1966. Today, Ostriches exist in the Western Palearctic only in southeastern Egypt.
are two basic types of Ostrich in Africa: pink-necked, pink-legged
birds of the East African plains (above) and two races of
bluish-necked, bluish-legged birds. The race S. c. molybdophanes
of Somalia to n. Kenya (left; male sitting on a nest) has been
considered by some to be a separate species, but possible sympatry with
S. c. massaicus (above) in northeast Kenya has not yet been adequately studied.
is another blue-necked race in southwestern Africa where the
populations are very fragmented. Ostriches in South Africa — such as
Kruger National Park — are all introduced birds, often of the
pink-necked sub-Saharan nominate race or feral individuals of unknown
Photos: The pink-legged Ostrich Struthio camelus massaicus
were photographed in the Masai Mara, Kenya, in Nov 1981 (top photo) and
Tarangire Nat'l Park, Tanzania, in Aug 2002. Rita is holding the
Ostrich egg found near Ndutu, Tanzania, on 6 Aug 2002. The blue-necked
Ostrich S. c. molybdophanes was photographed by my father,
B.B. Roberson, in Samburu Nat'l Park, Kenya, in Oct 1981. Photos ©
D. Roberson and B.B. Roberson, respectively, used with permission; all rights reserved.
There is no "family book" per se of which I'm aware (there are numerous
coffee-table "survey" books that include Ostrich among other large
flightless birds), but an excellent introduction to the family is in
Folch, A. 1992. Family Struthionidae (Ostrich) in del Hoyo, J., Elliott, A., & Sargatal, J., eds. Handbook of the Birds of the World. Vol. 1. Lynx Edicions, Barcelona.