Saturday, 26 September 2020

Small Cats: Almost a Puma and Not Quite a Lynx

Jaguarundi (grey morph)
As I mentioned at the start of this series, the cat family can be divided into two living subfamilies. The "roaring cats" are all large animals: lions, tigers, leopards and jaguars. The "purring cats", however, are typically much smaller... but there are exceptions. Marginally the largest member of this subfamily is the animal variously known as a puma, cougar, or mountain lion (Puma concolor). These are all the same animal, although the term "puma" is sometimes reserved for the southern subspecies and "cougar" for the northern one(s). They were once found through essentially the whole of the Americas apart from Alaska and central/northern Canada, but, aside from a population of 200 or so "Florida panthers", are now absent from much of eastern North America.

Despite its unusually large size, however, the puma does not represent some early offshoot of the main feline lineage. Indeed, it is more closely related to the domestic cat than it is to, say, the ocelot. The cheetah (Acinonyx jubatus), the only other "purring cat" that comes close to it in size (the females are roughly similar in weight, but male pumas are larger), turns out to be a fairly close relative, despite the cheetah's remarkable specialisations for speed. The closest relative of the puma, however, is a somewhat less well-known animal: the jaguarundi (Puma yagouaroundi).

I should say at the outset that there is some dispute as to the scientific name of the jaguarundi. Its ancestors diverged from those of the pumas around 3 million years ago and, when added to the fact of its much smaller size, this is enough for many scientists to place it in a separate genus, Herpailurus, rather than lump it in with the pumas. Both versions of the name are used in the literature, including in papers published in just the last two or three years... but a quick search confirms that Puma is slightly more common, so that's the one I've chosen.

The name Herpailurus, however, translates as something like "mongoose cat", and one can see the point. Jaguarundis are about twice the weight of a domestic cat and average around 65 cm (2 feet) in length, excluding the tail. Even so, that is much, much smaller than a puma, and the two animals don't look all that similar. Jaguarundis have a slender body, relatively short limbs and, perhaps most distinctively, unusually small ears for a cat. This perhaps makes them look more like some sort of mustelid than a mongoose, but the resemblance is undeniably there.

Although the kittens have spotted underparts, adult jaguarundis have very few markings, and their coat is usually a solid grizzled grey. A significant minority, however, have a reddish coat, with some variation in the exact shade. Despite the radical difference in these two coat colours, they don't represent different subspecies, or anything of that sort, and instances of kittens of both colours being born in a single litter are known. Having said which, red jaguarundis are noticeably more common in dry habitats, perhaps finding the colour a more effective camouflage there.

Indeed, jaguarundis do seem to be generalists when it comes to habitat, living everywhere from dry scrubland and open grassland to marshes and forests. They are even found in low-density urban areas and close to roads. This likely explains why they live across so much of the Americas, being found east of the Andes from northern Argentina to Panama, along the Pacific coast in Colombia and Ecuador, and throughout most of Central America and coastal Mexico. Up to eight subspecies are recognised across this range, although a 2013 study failed to find good evidence for the existence of any of them.

Sightings of jaguarundis have been reported from both Arizona and Texas, close to the Mexican border, but there is a distinct lack of any physical or photographic evidence. While the Texan sightings are apparently at least somewhat credible, that leaves open the possibility of mistaken identity and they may well be locally extinct.

Jaguarundis, like most cats of their size, feed primarily on small mammals, mostly mice and rats, but they also catch a significant number of birds, which may even be the main food source in some areas. Given their broad habitat preferences and wide geographic range, there are naturally a number of places where they live close to ocelots. The two species seem to give one another a wide berth when they can, but it helps that jaguarundis are, unusually for cats, diurnal, so at least the two species don't hunt at the same time of day. They are also less likely to hunt in the trees than margays, although they are capable of climbing if they have to.

For much of the 20th century, jaguarundis, like pumas, were placed in the genus Felis along with most other "purring cats". If any purring cats, other than the cheetah, were placed in a separate genus (and they often weren't), they were the lynxes. There were thought to be three species of lynx: the common lynx, the bobcat, and the caracal. Genetic studies eventually showed that the common lynx represented three different species but they also showed that the caracal (Caracal caracal)... wasn't a lynx at all.

This was quite surprising, because the caracal certainly looks like a lynx. It is roughly half way between a Eurasian lynx and a bobcat in size, has similarly long legs and short body, and the same "bobbed" tail. It even has the long ear tufts that lynxes have. True, it doesn't have the "mutton chops" of true lynxes, and is a mostly bland sandy colour, rather than being spotted, but these were thought to be minor considerations, due to a different habitat and much shorter fur.

Nonetheless, the caracal does not share its immediate ancestors with "other" lynxes, instead being descended from a group of purely African species of cat. Which is ironic, because the caracal is probably the animal that the ancient Greeks named "lynx" in the first place, not knowing about the more northerly animals that have since co-opted the term. The word "caracal" is instead Turkish, being used by Johann Schreber (who was also the first to describe the bobcat) to refer to an animal living all the way down in what is now South Africa. 

But Schreber was right; not only do present-day caracals live anywhere in Africa that has a suitable habitat, but also across the Middle East from southern Turkey to Rajasthan in India. Anything from three to eight subspecies are recognised across this wide area, but the existing evidence for many of them seems weak, so the exact number may be more a matter of guesswork than anything else.

That there are nonetheless large areas of Africa where caracals are not found is down to their habitat preferences, specifically that they don't live in either deserts or jungles. Instead, they live in open woodland, scrub, and dry savannah, extending into semi-desert and rocky hills at the margins. In general, they hunt in open country, such as grassland, but shelter among trees or rocks when they sleep, so that they can, like many generalist predators, be common along the edges of woodland where they can exploit a good mix of terrain.

The reason that caracals so closely resemble lynxes is at least partly because they have adapted to eating a similar diet. Rabbits and hares are perhaps the most popular food items, along with the springhaas, a long-tailed, rabbit-sized hopping rodent common in eastern and southern Africa. Depending on what's available locally, though, almost any animal smaller than about 5 kg (11 lbs) will do, with, for example, rock hyrax or vlei rats being the most common prey in some areas. They also eat birds, which they are agile enough to catch mid-flight, leaping up to 3 metres (10 feet) into the air to do so.

On occasion, however, caracals will take down much larger prey. Since an antelope will last much longer than a rabbit, small antelopes such as reedbuck, steenbok, duikers, and bushbuck can form 10-20% of their diet by weight without them having to hunt such animals very often. They have even been known to kill and eat jackals although analysis of their dung suggests that they eat fewer sheep than would be expected from the kinds of area in which we know they hunt.

Caracals are primarily nocturnal, but seem more concerned with daytime heat than with how bright it happens to be, so that they are more likely to be active during the day in winter. Breeding takes place throughout the year, with an average little having just two kittens, although larger ones are known.

But, if the caracal is not a lynx, what are its closest relatives? That is a question I will answer next time...

[Photos by Fábio Manfredini and Derek Keats, from Wikimedia Commons.]

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