I have just written a new post comparing the ‘jackals’ of North and South America — the coyote (Canis latrans) and the culpeo (Lycalopex culpaeus). Much assisted by AI, I could complete it in perhaps five hours of work, where previously it might have taken five days. A satisfying process — and here I highlight the main findings that surprised me along the way.
THE CULPEO IS THE MORE SEXUALLY DIMORPHIC
The South American form, Lycalopex culpaeus, is much more sexually dimorphic than the coyote, with males up to one and a half times more massive than females. That is partly because its society differs: it is more solitary. This may be counterintuitive, because normally we associate sexual dimorphism with gregariousness. But bear in mind that in the coyote, the more sociable nature is associated with a pattern of monogamy and helpers at the nest — juveniles sticking around to help their parents raise another litter. So it does make sense within the context of Canidae.
DURING THE PLEISTOCENE, THERE WAS NO JACKAL IN NORTH AMERICA
Before the Holocene — before the extinction of the North American megafauna — the coyote did not actually exist as a jackal. This is a complicated thing to realise, which is why it is new to me. Canis latrans existed at the time of the megafauna, but it was about one and a half times more massive than today: somewhere between a jackal and a wolf in body size, presumably because at that time it was mainly a consumer of mammalian meat. Once the megafauna collapsed at the end of the Pleistocene, the coyote shrank to its present jackal-like form of about 10 kilograms. It is fascinating to think that during the Pleistocene there was no jackal in North America.
By contrast, in South America Lycalopex culpaeus, based on fossils, was more or less the same body size as it is today: about six kilograms in females and ten in males, and then, at the far south of the continent — owing to Bergmann’s rule — somewhat larger, about jackal size. The Patagonian populations do not represent the overall pattern, which is that the South American jackal is the smallest of all the jackals of the world. Yet although it hardly qualifies as a jackal in terms of body size, it has been a more permanent jackal in South America than the coyote has been in North America.
THE COYOTE IS ANTHROPOGENIC IN TWO DEEP SENSES
One is that before humans slaughtered the megafauna of North America, there was no jackal there; the North American jackal is a creature of humanity. That is confusing, because the species Canis latrans did exist in the Pleistocene. It is just that, when humans wiped out its prey, it was changed by diminishment of body size to such a degree that it became a new entity ecologically — the first jackal ever to occur in North America.
The other is that although the Pleistocene and the recent Canis latrans are regarded as the same species, the coyote of today is no longer pure Canis latrans: it is an introgressed hybrid with both the wolf and the domestic dog. What most people describe as a coyote today is actually a hybrid, and in that sense also anthropogenic. This commentary stands far enough back to give a perspective on the coyote that almost nobody achieves, despite the extreme familiarity of the animal.
THE FORGOTTEN JACKALS OF THE FAR SOUTH
There was another jackal-like canid in South America, one that I have more or less neglected until now. Admittedly it was found only in the Pampas, Patagonia, and Tierra del Fuego, so it was not particularly widespread. But it was more jackal-like in size than the culpeo: I am talking about Dusicyon avus, which was present in the Holocene in its rather restricted range and seems to have persisted until just a few centuries ago. There is scant palaeontological evidence suggesting that it was kept as a pet by the Native Americans of Patagonia. And on the Falkland Islands there was a canid restricted to those islands, a congener of Dusicyon avus, very poorly known — there is not much material left — which went extinct before science got to grips with it. So you have these two tantalising jackal-like creatures: jackal-like in the sense of being fairly generalised canids of appropriate body mass for a jackal, about 10 kilograms, and both gone.
JACKALS AS BENEFICIARIES OF HUMANITY — AND THE EXCEPTIONS
The extinction of both the mainland and the island forms of Dusicyon goes against the idea of jackals, because most jackals do well under anthropogenic regimes; jackals tend to benefit from human effects on the environment. This is more or less true everywhere else in the world. It is true for the golden jackal in Asia. It is true for the dingo, as long as the dingo evades hybridisation. It is true for both species of Lupulella in Africa — though I am not so sure for the side-striped jackal, which would be the least anthropogenically benefited: it survives humanity mainly by being secretive, as opposed to exploiting resources provided indirectly by humans, as the black-backed jackal does. It is certainly true for the North African jackal, which survives all the way from Senegal through to Ethiopia and up to Egypt and Morocco, largely because it can cope with landscapes devastated by human effects over many centuries. And it is of course true for the coyote, which has invaded the cities of America, albeit in hybridised form.
Against this pattern, the jackals of South America are complicated. The genus Dusicyon, seemingly the most jackal-like of the indigenous canids of South America, perished under human effect — albeit not at the end of the Pleistocene. Whereas in the case of the culpeo there was a modest benefit: what I have established from the literature is that Lycalopex culpaeus has actually spread its range and extended its habitat to some degree in response to farming by Europeans. So it is a bit jackal-like in that way too. And so you can imagine a situation somewhere in the southern part of South America where the culpeo has been subject not only to Bergmann’s rule, bringing it close to jackal size, but is also out on the pastoral lands affected by European farmers, behaving in a jackal-like way. The analogy between the extant South American canid and the jackals of the rest of the world is most closely achieved under those conditions, somewhere in Patagonia.
WHICH, THEN, IS THE JACKAL OF THE AMERICAS?
When you ask which is the North American jackal and which is the South American jackal, it is complicated, and there is a deeper layer of subtlety: you have to think in a certain conceptual framework to frame the animals correctly. In North America, the necessary framing is that the coyote of today is an anthropogenic entity twice over — a jackal made by the megafaunal extinctions, and a hybrid made by introgression with the wolf and the domestic dog. In South America, it is that the truest jackal, Dusicyon, is gone, while the culpeo approaches jackal-hood only at the far south, on farmland. Although the Canidae have been subject to a great deal of zoological interest over the years, I doubt that any author has actually expressed what is said here, because it takes a kind of perspective that is lacking in the zoological community.
The companion post: A comparison of ‘jackals’ between North America (Canis latrans) and South America (Lycalopex culpaeus)