Why is the black-backed jackal the only carnivore marked like a gazelle?

The black-backed jackal (Lupulella mesomelas) differs from jackals in the genus Canis, as well as all other Carnivora, in possessing a gazelle-like pattern of colouration on the flanks (see https://f.hubspotusercontent30.net/hubfs/8820531/Imported_Blog_Media/jackal-springbuck-throat-web-3.jpg and https://www.flickr.com/photos/77236126@N00/48051508477/ and https://www.flickr.com/photos/bwildlife/17167029101). Why is it unique in this way?

The important point about this pattern is its relative conspicuousness. Most carnivores have inconspicuous colouration (e.g. see Canis anthus https://www.istockphoto.com/photo/golden-jackal-gm494430463-40577222), which makes sense because they hide not only from their prey but also from more powerful carnivores. In canids, the usual pattern is cryptic, i.e. plain-coloured with countershading. Any markings tend to be disruptive in the sense of camouflaging the figure. However, in the black-backed jackal the banding on the side of the body is stark enough, in some illuminations, to make the whole figure stand out from its background.

Among all canids worldwide, the black-backed jackal is the species living in the most intensely predatory regime. It coexists, and to a remarkable extent competes, with the full spectrum of large carnivores in the environments richest in prey antelopes on Earth, those of acacia savanna in eastern and southern Africa.

The black-backed jackal is inferior in the predatory/scavenging hierarchy to lion, spotted hyena, leopard, cheetah, African hunting dog, and brown hyena/striped hyena; and the leopard kills it not for spite but for food (see https://i.redd.it/bezcb4s8d0s41.jpg). Yet it manages to be a considerable predator of antelopes in its own right (e.g. see https://www.youtube.com/watch?v=nD9MkAbgl-o and https://www.earthtouchnews.com/natural-world/predator-vs-prey/watch-antelope-flees-hunting-jackals-while-an-eagle-attacks-from-the-air/), and even more remarkably is the most diurnal of jackals with the exception of the Ethiopian wolf (Canis simensis). Daytime activity makes hiding difficult but compensates to some degree for the extreme risk of victimisation, because the leopard in particular tends to rest at the bright, warm time of day. At the same time, the black-backed jackal is, among all these carnivores, the one most reliant for hunting and self-defence on close cooperation of monogamous partners.

What this suggests is that the black-backed jackal has adopted conditionally conspicuous colouration according to the same adaptive trade-off as the gazelles it hunts. It compromises between the ability to hide and the ability to monitor the location and activity of group-members at the briefest glance, in a strategy of extreme cooperative vigilance and social coordination, rather than merely keeping a low profile.

The black-backed jackal and the Ethiopian wolf are similarly diurnal, and both have conspicuous aspects to their colouration. So why do they accentuate different parts of their bodies (see my Journal Post of July 23)? Whereas the former species signs its torso, the latter signs its hindquarters and forefeet. One difference is that the Ethiopian wolf hunts its rodent staples alone, whereas the black-backed jackal depends on pairwork to overcome its favourite prey, namely antelopes. Another difference is in the respective predatory regimes, the high-altitude meadows of Ethiopia being beyond the range of most species of large carnivores - as well as gazelles or any other antelopes more gregarious than the plain-coloured bohor reedbuck (Redunca redunca).

Posted on 24 de julho de 2021, 07:18 AM by

milewski

Why is the black-backed jackal the only carnivore marked like a gazelle?

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