The Cat Family: Felidae

It is sometimes said, perhaps only half-jokingly, that the growth of the internet has been largely driven by two things: pornography and pictures of cats. I can't do much about the first of those here, but cats are a different matter.

In fact, the reason that I haven't looked at cats so far in my annual surveys of mammal families is precisely because, if there's one group of mammals that has substantial coverage on the internet already, it's cats. Lions, leopards, and so on are also amongst the most popular of subjects for TV wildlife documentaries, and it's hard to see that I have much to add. But, nonetheless, and while I have, of course, covered cats before in individual posts, exploring the family is a gap that I eventually had to fill. So here we go.

Compared with some, more diverse, mammal families, members of the cat family, Felidae, are all readily identifiable as such. Cats have short faces, lacking the long snout of dogs, with large eyes and ears, and prominent whiskers. Their bodies are generally sleek, usually (although not always) with long tails, and they have muscular limbs and sharp claws. Indeed, apart from size and coat colour, most species of cat are remarkably similar in physical appearance. If you removed the skins of a lion and a tiger, only a real expert would have any chance of telling them apart.

Ancient Musk Deer of Barcelona

Micromeryx

The deer constitute the second-largest family of ruminants, in terms of living species, after the huge "cattle family", which includes just about everything with true horns, from bison to goats to impalas. Historically, they have been divided into two main subfamilies: the cervines, which include such things red deer and fallow deer, and the capreolines, which include roe deer, reindeer, and moose, among many others. But there was always one species of deer that just didn't fit, shunted off into a subfamily all by itself because of its many peculiarities.

This was the musk deer (Moschus moschiferus). The most obviously strange thing about, for a deer, is that it doesn't have antlers. Less immediately apparent is the fact that it's the only kind of deer to have a gallbladder, and there are some other anatomical oddities, too. The former could be explained by it having lost them at some point in its evolution - and, indeed, there are other known species of deer where this has quite obviously happened. However, it's a bit trickier to explain why a gallbladder would come back after vanishing, so the assumption was that musk deer were a very primitive form of deer that had never lost it in the first place.

Voyage of the Kinkajous

For much of the time since the extinction of the dinosaurs, South America was an island continent. Developing in isolation, the mammals living there developed a number of unusual forms not seen elsewhere. Around 2.8 million years ago, however, South America became joined to its northern counterpart via the Isthmus of Panama. Northern animals flooded south, and relatively few headed in the opposite direction. As a result, unlike Australia, which remains an island continent today, the mammalian fauna of South America includes many animals at least broadly familiar from elsewhere.

Among the first mammal families to make the crossing was that of the raccoons. Although this had first appeared in Asia, living species are now found only in the Americas (ignoring some recent man-made introductions) with most of them found in tropical habitats. In fact, they reached South America almost ridiculously early, something we know because we have a fossil example that's around 7 million years old... at least 4 million years before the land crossing we'd expect them to have used had formed.

Digging in a Winter Wonderland

Humans have a somewhat ambivalent attitude to snow, greeting it either with joy and wonder or with concern and frustration, in large part depending on how old you happen to be. It decorates Christmas cards, covers the countryside in pristine white, and provides plentiful opportunities for play. On the other hand, it makes travel difficult, and may even interrupt deliveries of food, making our lives awkward. (Plus, if you're in a city, it may not stay white for very long).

If heavy snow makes it difficult for us to get around and obtain sustenance, the same obviously goes for animals that live in the relevant parts of the world. Different species have different strategies for how to cope with its arrival. Some hibernate, while others avoid the problem by migrating somewhere else for the winter, but there are, of course, a number of species that simply have to put up with it. Those that live particularly far north may even have to do so for over half the year, and the difficulty of doing this is probably at least part of the reason why relatively few species do.