How do hippotragin bovids bite?
We do not normally regard ruminants as biting animals.
However, there is an intriguing possibility that the roan antelope (Hippotragus equinus) bites injuriously in self-defence.
The reasons why ruminants are associated with biting in self-defence are that they
- have horns or antlers, plus hooves, all potentially effective as weapons,
- lack canine teeth in most species, even in males,
- lack upper incisors, which means that any 'bite' by means of the lower incisors would be relatively harmless, and
- in the case of several clades, have gapes so tight that defensive biting by means of the premolars is impossible.
The domestic goat (Capra hircus) is known to bite humans. However, as far as I know it does so by means of its lower incisors, which are limited by the absence of upper incisors.
Hippotragus spp. have a reputation for pugnaciousness, both intraspecifically and anti-predator.
It is usually assumed that this involves only the horns. However, footage of a mature male individual of the sable antelope (Hippotragus niger niger) standing its ground against a group of the African hunting dog (Lycaon pictus) shows that the forehooves are flailed threateningly. And there is mention in the literature of the roan antelope (Hippotragus equinus) biting attackers.
What seems previously to have been overlooked is that hippotragins differ from most other bodies in that they possess a stretchy gape, allowing the biting off of fibrous food items such as grass culms. Unlike alcelaphins (all of which have tight gapes), hippotragins rely on plant matter some distance above the ground, not normally grazing on lawns.
The stretchy gape of hippotragins also allows the abrasion of bones in the mouth in osteophagy, a practice particularly frequent in this tribe owing to its tendency to occur on nutrient-poor substrates.
The stretchy gape of hippotragins is evident as a 'perverse smile' when the animals breathe heavily while running under duress.
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