Colouration of antlers and horns in ruminants, part 2

On the human body, we daily observe that keratin, the substance of horns, can be either pigmented (dark hair) or translucent (fingernails). It should therefore not surprise us to find that bovids show adaptive flexibility in the tone of their horns.

Here I focus on the saiga antelope (Saiga tatarica,, the prime example of a bovid species with pale horns, and on the bontebok/blesbok (Damaliscus pygargus), the prime example of a bovid species in which subspecies vary noticeably in the tone of the horns despite the horns remaining similar in size and shape, and showing minimal sexual dimorphism.

The saiga antelope is closely related to gazelles, but unlike any gazelle has horns so depigmented that they are about as clear as human fingernails. The horns accordingly look 'flesh-coloured'.

This is puzzling in terms of evolutionary adaptation. The saiga antelope is extremely peculiar in its nasal anatomy (uniquely proboscis-like, particularly in males, see and its running gait (camel-like pacing instead of cantering), but it is hard to link these peculiarities rationally to the translucency of its horns.


The bontebok (nominate ssp. pygargus) and the blesbok (ssp. phillipsi) have horns approximately similar in shape to those of the saiga antelope, but in females as well as males. These two subspecies occupied separate parts of South Africa, differing mainly in the boldness of their overall colouration. Who would have predicted that members of a single species would differ so much in the tone of their horns?

As in the saiga antelope, this has yet to be explained in terms of adaptation.

For Damaliscus pygargus pygargus see

For Damaliscus pygargus phillipsi see

Posted on September 02, 2021 03:32 AM by milewski milewski


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