Antlers and Ageing

Ageing is an inevitable fact of life. Without it, populations would rapidly expand to the point that insufficient resources existed to maintain them, unless we also do away with reproduction. And, if we do that, then the creature in question will never be very numerous, and will be wiped out by the first accident, natural disaster, or change in climate conditions to come along. This is something that has been the case since well before mammals existed, even if the nature and pace of ageing might be different for, say, an oak tree or a coral colony, or conceptually vague, as in a mycelial network.

When it comes to reproductive senescence, however, there is a difference in the way this affects male and female mammals. Females are born with a finite supply of eggs, although, in practice, this is far more than they will need, so they don't cease to be fertile simply because they run out. What actually triggers the menopause in humans is complex, even assuming no confounding health conditions, but the number of remaining egg follicles falling below a required level and thereby lowering the production of certain hormones is thought to be key.

All the World's Deer: The Largest Deer and Other Oddities

Moose

It will probably come as no surprise that the largest species of deer alive today is the moose (Alces alces), confusingly known as the "elk" in some parts of Europe. The latter is, of course, the original English name for the animal, and remains, more or less, the name for it in languages such as German and Swedish today. The word "moose" comes from one or more of the Algonquian languages and entered English no later than the 17th century, although why Europeans chose to rename the animal they already knew about rather than come up with a new name for the novel American beast that looked like a red deer is unclear.

At any rate, moose are undeniably large, considerably larger than the American elk. They typically stand around 200 cm (6' 6") at the shoulder, with females not much shorter than males. The males are, however, significantly bulkier and more muscular, with a full-grown bull typically weighing between 300 and 600 kg (660 to 1300 lbs) and females around 25% less. The occasional exceptional individual can, of course, be much larger than this but, even ignoring those, that's pretty big for a deer.

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.

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.

All the World's Deer: Endangered and Beyond

Eld's deer

A significant number of deer species are endangered. As primarily forest-dwelling animals they are particularly vulnerable to habitat loss, especially in those parts of the world with high human population density and intensive agriculture. Indeed, of the species of deer formally listed as endangered by the IUCN, all but one live in southern and eastern Asia.

Among these is Eld's deer (Panolia eldii), first described by Percy Eld, a British officer working for the Commissioner of Assam, and then more formally written up by army doctor John McClelland in 1842. There is some dispute about the correct scientific name of the animal, due to a number of conflicting studies about where exactly it fits in the deer family tree. It was originally placed in the genus Cervus, along with red deer, but that didn't mean much at the time, since it was 17 years before the theory of natural selection, let alone modern phylogeny. 

All the World's Deer: Deer With Spots

Fallow deer

The fawns of most (but not all) deer species are born with spotted coats, which likely help to camouflage them among the dappled light of a forest. In some species, the spots disappear shortly after birth, while others retain them for a while longer. In five species, however, they keep them all the way into adulthood. I've covered two of these species already: the sika deer of Japan and the um... spotted deer of the Philippines. 

To Europeans, however, the best-known is surely the fallow deer (Dama dama). This is Europe's medium-sized deer, and one of the six original species of deer identified as such in the first list of scientific names in 1758. It lives in woodland areas across most of western and central Europe, preferring broadleaf forests but happy enough with conifers or Mediterranean scrubland. They don't like deep snow, and so aren't found in the Alps or all but the most southerly parts of Scandinavia, but otherwise, they seem pretty adaptable and widespread. Yet, despite being such a familiar animal, they're arguably not really native to the continent.

All the World's Deer: The Red Deer Species Complex

Red deer

When the first list of scientific animal names was drawn up in 1758, all six known species of deer were placed in the genus Cervus - which is, of course, simply the Latin word for "deer". Over the following decades, as taxonomy became more refined, all but one of those species were moved to other genera, and when the deer family, Cervidae, was named in 1810, it had roughly the same meaning that the genus had had so many years before. As its name implies, though, Cervus was selected as the type genus of the family - the one that defines the archetypal group against which all others are compared. Although newly described species had been added since, the one species that was so obviously deer-like it had never been moved anywhere else thus became, in a sense, the defining species of its family.

The Deer Family

Doe (a deer, a female deer)

A little over eight years ago (blimey...) I began a series on members of the goat subfamily, and started it off with a discussion of the difference between horns and antlers. In short, horns are permanent structures, comprised of a central bony core surrounded by a sheath of um... horny material. Antlers, on the other hand, are regrown every year, and once they reach full size and shed the velvet on their outer surface, they consist solely of dead bone, with no sheath of any kind. Antlers are also often branched, whereas 'true' horns never are.

Antlers are, of course, the key defining feature of the deer family, the Cervidae. They are found on (almost) every species in the family, although (almost) only on the males. A large stag with branching antlers is instantly identifiable as a deer, but it may be fair to say that some of the species with unbranched antlers do have a certain resemblance to some of the smaller species of antelope.

The Antlers of Early Deer

Dromomeryx, a palaeomerycid

Probably the most distinctive thing about deer is that they have antlers (and not horns). However, especially when we're looking at fossil species, it's important to remember that not all deer have antlers. Granted, the enormous majority do, and those that don't have lost them during their evolutionary history, rather than being holdovers from some ancient form that never had antlers in the first place. (This isn't true of musk deer, but that's partly why they aren't considered to be true members of the deer family).

And even that's assuming your fossil belongs to a male. (Or a female reindeer, oddly enough).

Antlers first appear on deer fossils in the early Miocene, on the general order of 20 million years ago. Still, in the grand scheme of the Age of Mammals, which has so far lasted 66 million years, that isn't all that long. It's a lot closer to us than it is to the dinosaurs, at any rate. So we ought to have a reasonable idea of what some of these first antlered forms look like.

Caprines: Goats, Horns, and Antlers

Over the last year, I completed a survey of the weasel family, the largest, and most diverse, family of carnivoran mammals. When it comes to the big herbivores, the largest and most diverse family is the Bovidae - the cattle family. This includes a wide range of animals, from the true bovines (that is, bison, yak, and so forth) to slender gazelles. In fact, there are well over a hundred species in the cattle family, and covering them in the same way that I covered the weasels would take me a couple of years or so.

So, instead, I am going to look at just one subfamily within the group. After the gazelles, it's the second largest cattle subfamily, with the bovines down in third place. These, as you'll have guessed from the title of the post, are the goats.

Or, more accurately, "caprines". Just as many members of the weasel family aren't literally weasels, many members of the goat subfamily aren't goats in the usual sense of the word. If you've never really looked at mammalian taxonomy, there will probably be at least a couple of species I'm going to cover over the coming months that will surprise you, and likely a few you've never heard of. One collective term for all of these animals is "goat-antelopes", but it's hardly common usage, and I don't actually find it very useful - not least because most of them don't look much like the regular image of an antelope, either. So I'll stick with the technical term of "caprines", or sometimes just call them goats, and you'll have to accept that I mean that in an unusually broad sense.