- 2 species in subSaharan Africa
- DR personal total: 2 species (100%), 2 photo'd
Ground-Hornbills are huge prehistoric-appearing birds of open grasslands and savanna in sub-Saharan Africa. Watching a Southern Ground-Hornbill
foraging at roadside in Kruger NP, South Africa (left), or in a
Tanzania reserve (below), is a highlight of any visit. Note the
dexterity with which the huge adult picks up a tiny insect (left).
the Ground-Hornbills are considered just a subfamily of the typical
Hornbills [Bucerotidae]. However, unlike all other hornbills,
ground-hornbills do not seal the female inside a nest cavity, they walk
instead of hop, they lack a carotid artery (unique among all birds),
and they have 15 instead of 14 neck vertebrae (Kemp 1995). Even Alan
Kemp himself appears to have changed his mind recently about family
status for these birds. The Birds of Africa series followed
Kemp & Crowe (1985) by including them within the Bucerotidae but
Kemp (1995), referring to a cladistic figure derived from his prior
work, stated that the “two species of Bucorvus emerge as the
earliest surviving offshoot within the order, sufficiently distinct and
long separated to be placed in their own family, the Bucorvidae. They
were already evident as a mid-Miocene fossil from Morocco some 15
million years ago.” By the time he wrote the chapter in Handbook of the Birds of the World (Kemp
2001) he was firmly in the pro-Family camp, stating that "modern
molecular studies suggest that the difference between the
[ground-hornbills and hornbills] are so profound that each should be
elevated to the status of a full family."
decision to separate the Ground-Hornbills into a separate Family makes
eminent sense to me (from a field ornithologists’ perspective) because
of the profound behavioral and breeding biology differences between
them and the mostly tree-loving “typical” hornbills. Ground-hornbills
were of ancient lineage. If you have any doubt that birds are descended
from dinosaurs, check out a young ground-hornbill (above, following the
adult, and right) and become a believer! "Ontogeny recapitulates
phylogeny" indeed. Yes, I know this a disproven biological hypothesis
[to wit, that in developing from embryo to adult, animals go through
stages resembling or representing successive stages in the evolution of
their remote ancestors] .... but still: Look at that face — do you not
see the Velociraptor there?
al. (2011) undertook an extensive molecular evaluation of hornbill
evolution. They found that the ancestor of ground-hornbill diverged
about 54 million years ago as the earliest lineage. So these are very
much "ancient" birds and well deserving of family status.
are two species of ground-hornbill. Southern Ground-Hornbill (photos
above) ranges widely through east and south Africa. The Abyssinian Ground-Hornbill
(left) exists in the arid sahel region on the southern edge of the
Sahara Desert, east to Uganda (where this pair was blocking our route).
Note the blue neck and eye wattle on the front left bird (a female)
that separate it easy from the red-wattled southern species (above).
Male Abyssinian has a blue eye wattle but red neck wattle.
neck wattles on both species can be inflated and are used to make
booming or grunting sounds, often just before dawn. That of Southern
Ground-Hornbill can be called "lion-like," while the higher-pitched
call of Abyssinian recalls the grunt of a leopard.
species of ground-hornbill are omnivorous, spending much of the day
foraging on the ground for lizards, snakes, and a wide variety of live
prey, plus fruits. They nest in crevices, but the female is not
sealed-in like the typical hornbills.
Photos: Most of the photos of Southern Ground-Hornbill Bucorvus leadbeateri
(e.g., the adult and juv, the head close-up) were taken in Kruger NP,
South Africa, in July 2006. The additional photo of that species (2d on
the page) was in Tarangire NP, Tanzania, on 6 Aug 2002. The pair of Abyssinian Ground-Hornbill B. abyssinicus were blocking the road to Murchison Falls Nat'l Park, Uganda, in July 2002. Photos © Don Roberson; all rights reserved.
Kemp, A. C. 1995. The Hornbills. Oxford Univ. Press, Oxford.
Written by one of the world’s authorities on this family, this is a strong addition to Oxford’s “Bird Families of the World”
series. It covers both the typical Hornbills Bucerotidae and the
Ground-Hornbills Bucorvidae. It appears to be authoritative on breeding
biology & behavior (with lots of good line drawings). Taxonomic
decisions appear quite reasonable (54 species) and I appreciate the
detailed biometric tables. The plates by Martin Woodcock are quite good
but in “field guide” style without background (except some branches for
some to sit on). The plates are grouped together near the front
opposite facing text highlighting i.d. points and ranges. Species
accounts and range maps contained no errors obvious to me. Highly
Kemp, A. 1995. Bird Families of the World: The Hornbills (Bucerotiformes). Oxford Univ. Press, Oxford.
Kemp, A.C. 2001. Family Bucerotidae (Hornbills), pp. 436 –526 in Handbook of the Birds of the World (del Hoyo, J., A. Elliott & J. Sargatal, eds). Vol. 6. Lynx Edicions, Barcelona, Spain.
Kemp, A.C., and T.M. Crowe. 1985. The systematics and zoogeography of Afrotropical hornbills, pp. 279-324 in
Proceeding of the International Symposium on African Vertebrates (K. L.
Schuschmann, ed.). Zoologische Forschungsinstitut und Museum Alexander
Viseshakul, N., W. Charoennitikul, S.
Kitamura, A. Kemp, S. Thong-Aree, Y. Surapunpitak, P. Poonswad, and M.
Ponglikitmongkol. 2011. A phylogeny of frugivorous hornbills linked to
the evolution of Indian plants within Asian rainforests, J. Evol. Biol.