Saturday, 25 September 2021

All the World's Deer: Muntjacs

Red muntjac
For many people, the word 'deer' likely conjures up a medium to large animal with large branching antlers in the males. This fits the description of not only red deer and fallow deer in Europe and white-tailed deer in America, but also many species less familiar to those of us in the West, such as barasingha, sambar, and huemul. But there are a number of animals much smaller than these that are nonetheless indisputably deer. The smallest species of deer in Europe is the roe deer, but even smaller species live further east, most of which are collectively described as muntjacs or "barking deer".

Muntjacs were first scientifically described in 1780, from a specimen collected in Java. Muntjacs, of course, live much further afield than this, and, over the years, some of those living elsewhere were split off and given their own species names. As per the standard rules, the one that's found on Java kept the original scientific name, modified only when muntjacs as a whole were given their own genus in 1810. We now call this the red muntjac (Muntiacus muntjak) and it remains one of the best-known species, not least because it's the most widespread.

Sunday, 19 September 2021

Before the Monkeys: Primates in North America

an omomyid from Wyoming

The primates are one of the larger groups of mammals, with literally hundreds of living species known. Naturally, there is a great deal of diversity across the primates but, at the highest level, we can divide them into two main suborders. These used to be referred to as the "lower" and "higher" primates, but that's misleading because the so-called lower primates have been evolving for just as long as the higher ones. It isn't as if they gave up one day and stopped evolving towards some ultimate goal of becoming human. 

So, instead, when we aren't using the technical terms strepsirrhine and haplorrhine, today we tend to call them "wet-nosed" and "dry-nosed" primates, based on whether their nose is moist like that of a dog or not. When most people think of primates, however, it's likely the haplorrhine, or "dry-nosed" primates that they think of first, since this is the group that includes all the monkeys and apes - as opposed to lemurs and the like.

Sunday, 12 September 2021

Hanging Out in the Heliconias

Bats are usually sociable animals. Since large caves are relatively rare, when bats find one, literally millions of individuals can pack themselves into a single one, often comprising several different species. But the shortage of suitably large roosts means that many cave-dwelling bats will roost elsewhere including, in human-dominated landscapes, inside attics or other manmade spaces. Furthermore, of course, many bats don't live in caves at all, spending the day roosting in trees or other suitable sources of shelter.

One might think that these tree-dwelling bats would be less sociable than those forced to cram themselves into caves. But, while it's true that they certainly don't tend to form colonies numbering in the millions, this doesn't mean that they live on their own. In some species, the males do in fact do this, following a pattern that's often seen in other social mammals, while the females gather together in maternity roots or breeding colonies. But very few bat species are entirely solitary, with both sexes living alone and, when bats do gather together, the exact structure of their social groups varies considerably between species.

Sunday, 5 September 2021

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.