All the World's Deer: Roe Deer and Reindeer

Roe deer

Of the three species of deer native to Britain, the one that's most often overlooked is probably the roe deer (Capreolus capreolus). In fact, it's a common and widespread animal, being found in every major country in Europe except for Ireland, Iceland, and Malta. It's absent from the other Mediterranean islands, too, and doesn't stray far into Russia, but it is found in northern Turkey, and both the Caucasus and Kurdistan regions further east. 

One of the reasons that roe deer aren't so easily brought to mind as fallow or red deer is probably just that they're so much smaller. In fact, they are smaller than any species of deer native to the US or Canada, and by some margin. A fully grown roe deer buck stands no more than 85 cm (2' 9") high at the shoulder, and most are smaller, as of course, are does. They weigh around 25 kg (55 lbs), and have a graceful and slender body compared with most other small deer. The hind legs are slightly longer than the front ones, a feature that's thought to help them creep through dense undergrowth.

Miocene (Pt 28): Miniature Super-horses and the Dawn of the Guinea Pigs

Thoatherium

For most of the Age of Mammals, South America was an island continent, separated from its northern counterpart by a wide sea. Even at the dawn of the Miocene, 23 million years ago, this isolation had already lasted for a long time, and the seas to the north were already a formidable barrier, with just a few islands where Central America is now. In some respects, the variation in climate across the continent was less extreme, especially because the Andes were not so high as they are today and so cast less of a rain shadow. Even so, there was enough variety that many different kinds of animals lived across its great area.

Indeed, the long separation of the continent from the rest of the world meant that it had had plenty of time to develop its own native animals. Whereas, in most of the rest of the world, animals of broad types we would still recognise were already around (early cats, deer, elephants, and so on), most of the larger animals of Early Miocene South America would have been much harder to place, since most of their descendants died out long before the Ice Ages, let alone the present. 

Life Lessons from Monogamous Mice

As a general rule, male mammals don't have much to do with raising their young. In many cases, that's because the species in question prefers the solitary life, and the two sexes only meet up to mate before parting ways again. In more social species, males and females may still live in different herds for most of the year, often because they have different feeding requirements and want to avoid competition. Even where are there mixed-sex groups, the males often spend more of their time fighting off rivals than they do actually looking after the young they sire - although, in this instance, they may be helping indirectly by protecting the herd from predators or the like.

But there are plenty of exceptions. 

Of Pandas and Bamboo

Today, there are eight living species of bear. Six of these are "ursine bears", members of a subfamily distributed across the northern hemisphere, and including the familiar brown, black, and polar bears, among others. The other two are distinct enough that modern taxonomists place each of them in their own subfamily, representing lineages that diverged from the common ancestor of the ursine bears a long time ago. One of these is the spectacled bear of South America, the last survivor of a group of American "short-faced" bears, some of which were really quite impressive.

The other, of course, is the giant panda (Ailuropoda melanoleuca).

This is a most peculiar bear. So much so, in fact, that for much of the 20th century it was unclear whether it really was a bear at all - a misunderstanding due to its similarity, and presumed close relationship to, the decidedly un-bearlike red panda. However, we now know that the two animals are not particularly close relatives and the resemblances between them are largely due to the fact that they share a similar diet.

Early Ungulates of Southern France

Lophiodon

The majority of hoofed animals living today belong to the artiodactyl order, known as the "even-toed ungulates" or, in plainer English, cloven-footed animals. This order includes such animals as deer, antelope, cattle, and pigs, as well as some of their non-hoofed relatives, such as camels. In comparison, there are relatively few living species of the perissodactyl, or "odd-toed ungulate" order, which today consists only of the horses, rhinos, and tapirs.

Yet, as so often, this group was once more diverse. Not only were there many more kinds of (for example) rhinoceros, but there were entire families of perissodactyl that are no longer with us. It is also an ancient lineage, on a par with other major groups, such as the primates. Molecular studies allow us to make some educated guesses as to when the horse-like and rhino/tapir-like perissodactyls last shared a common ancestor, and this turns out to be around 56 million years ago, at the dawn of the Eocene, not long after the non-avian dinosaurs had gone extinct. While this is just an estimate, it also happens to be not much older than the earliest identifiable fossils of the group, so there's a good chance it's fairly accurate.

All the World's Deer: Deer from the Grasslands, Swamps, and Mountains

Pampas deer

In 1758 Swedish naturalist Carl Linnaeus was able to describe six of the species of deer we know today. Five, of these, perhaps unsurprisingly, were the five species native to Europe. What may be more surprising is that the odd one out isn't the widespread white-tailed deer, or even one of the Asian species, but one from South America. (As an aside, he also identified two species of what he thought were deer living in Africa. One may not even be real, and if it ever was, was probably a misidentified antelope. The other is very definitely real, but is no longer considered to be a 'deer').

That one exception is what we now call the Pampas deer (Ozotoceros bezoarticus). These live, or at least used to, across much of central South America from central Brazil to northern Argentina. Today, they are found primarily in scattered patches of land across the region, although their numbers are just high enough in total to avoid being formally listed as a threatened species (although the same is not true of all the subspecies). The main reason for this is that their preferred habitat, as their common name indicates, is open grassland... and most of that has been converted into farmland, with some estimates suggesting that as little as 1% of the original habitat survives today, as compared with the late 19th century.

A Good Winter's Sleep

Mammals have an advantage over reptiles in that they don't need the weather to be warm in order to stay active. This makes it easier for them to live in parts of the world that have cold winters, but even then, the scarcity of food at such times of the year means that they often need some additional survival strategy. Some, of course, simply migrate somewhere warmer during the winter - which typically means moving downhill from summer grounds on mountainsides, the long-distance migration of birds being less of an option. Others, such as polar bears, are just good at surviving cold weather anyway, and may not need to do anything significantly different in winter.

But, leaving those possibilities aside, three basic options for surviving the winter present themselves. They could do something behavioural, such as storing food during the summer and coming back to their hidden caches later in the year when food is short. Or they could change physically, such as by building up fat over the summer or having an extra-thick winter coat that falls out in the spring. (And these are not, of course, mutually exclusive).