Wolves, Foxes, and Food

Large scary predators are, by their nature, rare. There simply can't be too many of them, or they would run out of food to eat, something typified by the trophic pyramid often seen in biology textbooks: plants are eaten by herbivores are eaten by carnivores are eaten by bigger carnivores, with each step necessarily having a smaller total mass. The reality is, of course, somewhat more complex than this simple chain would suggest, most obviously because it ignores omnivores and decomposition.

But the basic idea holds, and apex predators - those that are large enough that nothing else normally eats them - exist in much smaller numbers than herbivores or smaller carnivores. This means that, relative to their numbers, they have a disproportionate effect on the ecosystem within which they live. Take away the apex predators and, even though there weren't very many of them to begin with, you will radically change the local ecology.

And, because they are relatively few in number, apex predators tend to be especially vulnerable to being wiped out. That's even assuming that humans don't focus on them deliberately out of fear, whether for their own lives or for the good of their livestock. Globally, apex predators are declining. (On this blog, we're mostly interested in mammals, but consider, for example, that at least eight of the 23 species of crocodile/alligator are currently thought to be endangered).

When Snow Leopards Reached Portugal

While the various species of "roaring cat" all share a great many points of similarity, most are easily distinguished from each other. Arguably, one of the most distinctive is the snow leopard (Panthera uncia). Not only does this have unusually thick fur for a wild cat, but it also has a longer tail than we would expect, and the face is shorter and wider than that of other roaring cats.

The snow leopard was first scientifically described by Johann Schreber in 1775 as a member of the genus Felis. The differences from other cats were sufficient that, in 1854, John Edward Gray proposed that it be given its own genus, Uncia. His original definition of the genus did not stand (it also included at least one species of "purring cat"), but it was resurrected again in the early 20th century, and used solely for snow leopards up until 2006. In that year genetic evidence placed it alongside the other "roaring cats" in Panthera, something that has been amply confirmed since.

Delphinids: Common and Bottlenose Dolphins

Common dolphin

When the genus Delphis was first named in 1758 at the dawn of taxonomy, it included three species of small to medium-sized toothed cetacean. By the time the dolphin family, Delphinidae, was named in 1821, one of those species (the porpoise) had been moved elsewhere, but five new ones had been added. Many more followed, but, from the mid-18th century onwards, naturalists began to notice subtle differences between animals that were probably more mysterious to them than land-dwelling mammals, and many species of dolphin began to be separated out into newly created genera.

So much so in fact, that by the time we reach the 21st century, only one species remains in the genus originally created to contain all dolphins and dolphin-like animals. That species is, of course, the one that we believe Linnaeus happened to be thinking of when he named the genus, and therefore is the defining (or 'type') species not only for its genus but for the dolphin family as a whole. This is the aptly named common dolphin (Delphinus delphis).

Call of the Mole Vole

There are over 170 recognised species of vole. The exact number is hard to determine because new species keep being described and not all will necessarily stand the test of time but we can certainly say that there are a lot. Although we might typically think of voles as being all rather similar to one another - small, mouse-like animals with short tails and rounded snouts - within such a large group there is inevitably some variation.

Most obviously different from regular voles are the giant species. Although genetic data shows us that these are voles, in the sense of being offshoots of the vole family tree rather than something distinct, we don't normally refer to them as such in English. Instead, we call them "lemmings" or, in the case of the very largest species, "muskrats". To avoid potential confusion, in more scientific language we would therefore use the taxonomic name when referring to the subfamily as a whole and say that voles, lemmings, and muskrats collectively are "arvicolines".