The questionable assumption that reedbucks display the tail in alarm

it is stated repeatedly in the literature that reedbucks (genus Redunca) raise the tail in alarm, this displaying the white underside. I have never observed this in the field for any of the three species and I cannot recall seeing any photo showing this. So I wonder how this apparently misleading information arose.

The white-tailed deer (Odocoileus virginianus) is the wild ruminant most familiar to North Americans, and in summer coat it happens to resemble reedbucks. The tails have similar size and bushiness, and similarly are white underneath. So anyone knowing the white-tailed deer might understandably tend to assume that reedbucks would emulate the deer in displaying the tail.

In fact, the difference could hardly be greater. Firstly, the white-tailed deer not only raises it's tail, it fully erects it and pilo-erects the long white hairs on it's underside, and then waves the upright, fanned tail from side to side as it runs. Secondly and simultaneously, it flares out the white fur on the posteriormost haunch, more than doubling the 'blaze' of extremely conspicuous white on the hindquarters.

Far from having converged evolutionarily with this display, reedbucks do not seem even to possess the anatomical structures needed for it. They do advertise themselves when alarmed, but in a peculiar and poorly-understood way involving the production of popping sounds from hindquarters.

(By the way, the white-tailed deer produces a nasal sound comparable to the whistling of reedbucks, while standing alarmed and watching the intruder. But here again the difference is that the deer flicks its tail up synchronously with each 'sneeze', in this case without any erection of white fur so that the display is one of dramatic motion rather than whiteness.)

To dispel any misconception that reedbucks display the tail in flight, here is a challenge to naturalists. Can anyone show us a video or photo of any reedbuck displaying its tail in any way in alarm? And if not should we begin to write, in field-guides on African wildlife, that a remarkable aspect of reedbucks is the inertness of tails that seem bushy and white enough to be suitable for flagging alarm?

פורסם על-ידי milewski milewski, אוגוסט 25, 2020 12:26 לפנה"צ


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