Subfamily
Cephalophinae
Duikers |
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The duikers are a highly specialized and easily recognizable subfamily.
With the tropical forests of Africa being their main habitat, duikers
fill the same niche as chevrotains and muntjacs in Asia, and brocket deer
and agoutis in the Neotropics. Like these other groups, duikers have
a compact body, relatively short legs, and strong hindquarters - they rely
on short bursts of speed through dense vegetation to escape predators.
Indeed, the name duiker is Afrikaans for "diver", as these antelope
dive straight into cover at the first sign of danger. The entire
evolutionary history of this subfamily is restricted to the African continent.
The fossil record is scarce, beginning approximately 6 million years
ago (although some records indicate that this subfamily may have been present
12 million years ago).
All 18 extant species have the same body plan, but there are wide variations
in size (from the 5 kg Philantomba species to the 80 kg yellow backed
duiker, Cephalophus silvicultor) and extreme variations in colors
and markings (as evidenced by common names: red duiker, blue duiker, black
duiker, gray duiker, white-bellied duiker, yellow-backed duiker . . .).
There is minimal sexual dimorphism, but (unusual in mammals) females
tend to be larger than males. In the majority of species, both males
and females grow horns (except for Philantomba, Sylvicapra,
and Cephalophus rufilatus). The horns are among the smallest
of any bovid; their small size, low angle, and position near the back of
the skull reduces the chance of them becoming caught in jungle underbrush.
A tuft of hair on the forehead often conceals these tiny spikes.
Duikers tend to be territorial - their very large preorbital glands are used
in scent marking. The glands form prominent bulges on either sides
of the nose, opening into a long slit which extends well in front of the
eyes.
Although duikers have a virtual monopoly on frugivory in African rainforests,
several species of duikers have been recorded eating meat. Their brains
are large and complex; since duikers are reliant on fallen fruits, most species
are aware of canopy activity, and will often follow primates in order to
eat dropped leftovers. |
The Cephalophinae Family
Tree
(branch lengths are not proportional to
time)
Click on the species above to learn
more,
or jump to the Cephalophinae
Species List
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Literature Cited
Estes, R. D. 1991. The Behavior Guide to African Mammals: including
hoofed mammals, carnivores, primates. Los Angeles: University of California
Press.
Hernandez-Fernandez, M., and E. S. Vrba. 2005. A complete estimate
of the phylogenetic relationships in Ruminantia: a dated species-level supertree
of the extant ruminants. Biological Review; 80: 269-302.
Kingdon J. 1997. The Kingdon Field Guide to African Mammals. Academic
Press, London and New York: NaturalWorld.
Nowak, R. M. [Editor]. 1991. Walker's Mammals of the World. Fifth Edition.
Johns Hopkins University Press, Baltimore.
van Vuuren, B. J., and T. J. Robinson. 2001. Retrieval of four
adaptive lineages in duiker antelope: Evidence from mitochondrial DNA sequences
and fluorescence in situ hybridization. Molecular Phylogenetics and
Evolution; 20(3): 409-425.
Vrba, E. S., and G. B. Schaller. 2000. Phylogeny of Bovidae based
on behavior, glands, skulls, and postcrania. In Antelopes, Deer,
and Relatives. Edited by E.S.Vrba and G.B.Schaller. New
Haven & London: Yale University Press. pp. 203-222.
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