About hyenas - March 31

Let us talk briefly about hyenas. PBS Eons have recently released yet another one of their YouTube videos, this time about the hyena evolution, but somehow I do not think that they have done those animals justice. Therefore, let us talk.

For a start, people tend to get an incorrect idea about the modern hyenas because of the reasons listed below.

To begin, we must put all of the four modern and existing hyena species into a row, from the biggest to the smallest: we got the spotted, the striped, the brown and the aardwolf. Though we have not professional biologists, but if we look at this quartet, we get to see that the spotted hyena stands out from the rest of its’ kin. Why and how?

First, because it is spotted, while the other hyena species have stripes. Seriously, the striped hyena is named after its’ coloration pattern, while the aardwolf looks like a miniature version of the striped hyena, and the brown hyena may be mostly brown, but it still has some stripes, albeit mostly on its’ legs; still, they’re stripes, not spots.

Second, the spotted hyena has a differently shaped jaws and muzzle from the other three species: it is shorter and broader than in the other three species. This is more than justified: the structure of the spotted hyena’s jaws and skull, as well as its’ postcranial skeleton is what gives it strength and power to crush bones and to get through flesh so easily; the spotted hyena is the stereotypical bone crusher, put otherwise.

The other hyenas, conversely, well… The aardwolf has become an obligate insectivore instead: it feeds only on insects, mostly social insects such as ants and termites; it has lost most of its’ teeth, though its’ canines are still large and formidable for its’ size – the aardwolf uses them for defence.

…Yes, this is a reference to the Thylacosmilus, the marsupial sabretooth. Initially it was thought to be a marsupial counterpart to the better-known sabretooth cats such as Smilodon, but now it is known that Thylacosmilus led a very different life-style, which just do not know which one. Maybe it was an atypical insectivore such as the modern aardwolf…or the bat-eared fox – more about that below.

Anyways, the striped and the brown hyenas are more formidable than the aardwolf is, but they still fall short to their spotted cousin – and they look much more canine, or maybe lupine, than the spotted hyena does, (whose appearance is pretty unique in the mammal kingdom). The same can be also said for the aardwolf, who is called a ‘wolf’ for that reason: it does look like a wild dog of some sorts on the surface. More succinctly, while the spotted hyena does not look anything like a wild dog, the other three species do.

In behavior, however, the situation appears to be reversed: the spotted hyena is a pack hunter, just as the wild dog species are, while the other three hyena species are not. Fair enough, but how do they live?

In family groups – small in the case of the aardwolf, larger in the case of the striped and the brown hyena, but whereas the spotted hyena is loud and brash and in your face, the other hyena species are shyer and more retiring and aren’t encountered by humans very often. (Especially the aardwolf, for the obvious reason). Consequently, while most people know of the spotted hyena, (especially thanks to Disney’s Lion King Movie from the 1990s and beyond); the other three species of hyena tend to be more overlooked, especially by the non-scientific crowd. What next?

…The hyenas are accused of having lost to the dogs in the evolutionary race. There’s some justification there, as only the striped hyena occurs outside of Africa; the brown hyena in particular is restricted to the countries in the African south, and is a rather shy animal when compared to its’ spotted cousin, but…

However, what an evolutionary win is? From a human point of view, (and we don’t have anyone else’s, ‘cause we’re still the only sentient species on planet Earth, regardless of what the Yetis and co. think), this means that your species continues to thrive, if not outright flourish, on the face of the planet, and here the hyenas…well, make do – they might not be as widespread as the wolves are, but…

However, if we look at the wild dogs, which have supposedly beaten the hyenas, then we see a picture that is not too different from the hyenas. The pack-forming canines are not all that numerous: we got the wolf, (whose main success is in the north, where there are few other large carnivores, save for bears, and the bears are more omnivorous instead). There is the African wild dog that is not found outside of Africa, the dhole, which lives mostly in Southeast Asia, and the Australian dingo, which is found only in Australia, and whose taxonomic status is still debated – is it a wild dog or merely a ‘feral’ one? The rest of the wild canids, including the jackals of the Old World, the coyote of the Americas, and the singing dog of Papua New Guinea tend to live in much smaller family groups – just as the non-spotted hyenas do. So, what does prevent the hyenas from leaving Africa and succeeding elsewhere?

…Because they have already succeeded in Africa, that is why. The non-human mammals, as well as the other animals, tend to lack ambition, especially in human terms; whereas humans often cannot be sated until they have it all, the other mammals can get along with each other under the sun; yes, the prehistoric hyenas have existed outside of Africa and now they’re gone, but so’s their world; the prehistoric wild dogs might’ve displaced them at one point, but now they’re also largely gone; all that’s left are the people, (and the domestic dogs, but they’re something else), and they’re the ones keeping the hyenas, well, subdued, and the same goes for the wild dogs.

The bat-eared fox, incidentally, is the canine counterpart to the aardwolf: it is bigger than fennec, (made famous by the Zootopia movie), but not unlike the aardwolf it lacks most specialized adaptations of a ‘professional’ insectivore, save for teeth and extra-large ears. It lives… alongside the aardwolf, actually, but it does not outcompete the hyena, cough. Therefore, I feel safe to say that the concepts of the canine success and hyena failure are coined human terms and thus should be treated with a grain of doubt when applied to the actual animals.

End