Strange Carnivores of Madagascar

Madagascar is the fourth-largest island in the world, almost three times the size of Great Britain, or half again the size of California. We should not be surprised, therefore, that it has a considerable amount of native wildlife. However, it's also noteworthy that it has been an island for a very long time - certainly for far longer than Britain has been.

In fact, Madagascar became an island around 91 million years ago, over 20 million years before even the likes of Tyrannosaurus appeared on the scene. Moreover, this was when it split away from what was then the island of India, with its break from Africa being almost twice as far back in time. But, even if we take that younger date for the beginning of its isolation from any sort of 'mainland', it's well before any of the sort of mammals we would recognise today had evolved. There's no equivalent here of mammoths nipping across the English Channel.

All the World's Deer: Deer from the Ganges and Beyond

Barasingha

At least before the rise of intensive agriculture, India, with its lush vegetation, was prime habitat for deer. The constraints of geography - the Himalayas to the north and deserts to the west - keep it separate from Europe and central/northern Asia at least, but it's a very large place, able to support a number of local species. When it comes to deer, there are no less than seven species native to the country, although four of those are only found in the north. Across the great bulk of the country, two medium to large species are common: the sambar and the chital. But there used to be three.

That third one was the barasingha (Rucervus duvaucelii). Fortunately, while I say 'used to be', I don't mean that it's extinct, as its closest relative, Schomburgk's deer is. Just that it's no longer common and widespread. It's primarily a grazing species, feeding in long grasslands and on forest edges and there used to be many of these on the Indian subcontinent. As recently as the 19th century, barasingha were found across almost the whole of central and northern India (aside, of course, from the Rajasthan desert) as well as in neighbouring parts of Pakistan, Bangladesh, and Nepal. They were especially common along the great floodplains of the Ganges and Indus Rivers.

All the World's Deer: Sambar and Rusa

Sambar

Deer are predominantly woodland animals, so it's no surprise that the extensive warm forests of Southeast Asia, with their many isolated islands, are home to a number of different species. Some of these are closely related to the red deer that live in cooler environments further north, so much so that some authors have recommended moving them back into the genus Cervus to join the red deer and their immediate kin. 

Nonetheless, they do seem to form a distinct branch on the deer family tree - although how many species might be in that branch, and even which ones they might be, is debated. For much of the 20th century, just two or three species were recognised, but genetic evidence gathered in the 21st century has made it more obvious that some of the island forms have been isolated from their mainland relatives for long enough to become clearly distinct.

Small British Mammals: Common and Field Voles

Field vole

In many respects, voles are extremely similar to mice. In many languages, the local word for 'mouse' also describes voles, and this was even the case in English prior to around the 19th century, when the term "vole-mouse" was borrowed from a now-extinct Scandinavian tongue, and shortly thereafter abbreviated to simply "vole". In its original language, it literally meant "field", and a similar etymology can be seen in languages such as German (Feldmaus) and French (campagnol) among many others.

Scientifically, voles have also been mixed in with the mice at different times. While they have recognised as a distinct group with their own scientific name since 1821, for much of the 20th century they were considered a subgroup within the wider mouse family. That's really only changed in the last 20 years or so, as genetic and biochemical evidence has shown that the two groups, while related, have distinct evolutionary histories.

Endangered Mammals of the Caribbean

Mammals are found on every major land mass on Earth, except for Antarctica. The same is, however, much less true for 'minor' land masses. Here, isolation from the mainland means that, in most cases, there are less mammal species on islands than there are on neighbouring bits of continent. There are bound to be at least some, in other words, that didn't make it across, or that, if they did, didn't survive and where never replenished. This is even true, albeit to a lesser extent, on some (but by no means all) peninsulas, with fewer species towards the tip than at the connection with the mainland - there are, for example, fewer terrestrial mammal species in South Korea than, say, Manchuria.

There are a couple of important exceptions here. For one thing, the rule doesn't really apply to bats, unless the islands are really remote (such as Hawaii, for example), and we're obviously not talking about marine mammals that use the shoreline, such as seals. Secondly, particularly large islands, especially those in the tropics, don't have this effect at all, being able to provide a perfectly adequate base to evolve a large profusion of unique animals. Madagascar, New Guinea, and Borneo are just, perhaps, the most obvious examples of this. It's probably also worth noting that many islands, even if they don't have very many species in total, often have ones that aren't found anywhere else on Earth, the separation from the mainland working in both directions.

Mammals of a Tropical Island Chain

Insular flying fox,
native to the Solomon Islands and Polynesia

There are, at last count, well over 5,000 known species of mammal on the Earth. Many of these inhabit large regions, or particular patches within continents or large islands. Visit even one of the more desolate reaches of land on a major continent (unless it's Antarctica), and there will probably be quite a few species of mammal that live there - although, certainly, you'll find more in a tropical rainforest than the depths of the Sahara.

But smaller islands are a somewhat different matter. Islands tend to have less land-dwelling species than areas of equivalent size on the mainland, due to the difficulty of crossing the water to get there. Obviously, this is less true of things like dolphins or seals, for which almost any coast will do, should they bother to approach one at all, and it can also be affected by how long humans have lived on the island, and what animals of their own they have brought with them - intentionally or otherwise.

France, for example, has something like 90 species of wild land-dwelling mammal. Yet, nip across the English Channel, and Great Britain - ninth-largest island in the world - has only 52. And that's including things like grey squirrels, which do live wild, but are nonetheless a relatively recent human introduction. To be fair, there used to be more before hunters killed them and cities and farmland expanded to cover pretty much the whole of England, since we used, for example, to have wolves. And, yes, Britain is physically smaller than France, but even so, it's a noticeable difference.