Sunday, 12 August 2018

The Pig Family: The Strange Case of the Sulawesi Pig-Deer

Sulawesi babirusa
Warthogs are fairly odd-looking animals, as are forest hogs, among others. But, at least to my mind, when it comes to wild pigs, nothing quite beats the babirusas.

These strange looking pigs inhabit the island of Sulawesi in Indonesia. Unlike most of the others in the group, this has been an island for far longer than pigs have been in existence - when sea levels were lower, most islands to the west were joined with Asia, and those to the east with Australia, but the waters around Sulawesi are so deep that it remained isolated. I've mentioned this before, in the context of warty pigs, so it's interesting to note that those channels must have been crossed by wild pigs on no less than three occasions (the third sort of Sulawesian pig, Celebochoerus, died out in the Ice Ages).

Sunday, 5 August 2018

False Deer-Llamas of Bolivia

Theosodon
(the nasal bones are that 'bump' on the forehead
just forward of the eyes)
Australia is an island continent, separated from the rest of the world's landmass for millions of years, allowing it to develop its own unique wildlife, from kangaroos and wombats to bandicoots and emus. The only other island continent we have today is Antarctica, which has no native land mammals at all (or emus, obviously).

In geological terms, however, South America was also an island continent until relatively recently, only joining North America three million years ago, towards the end of the Pliocene epoch. Even today, the strip of land connecting the two is only 35 miles (60 km) or so wide at the narrowest point, both narrower and longer than that connecting Eurasia to Africa. This means that, like Australia, South America had a long history of so-called "splendid isolation", and it evolved a number of unique animals in the process.

Saturday, 28 July 2018

Monkeys, Apes, and Simians


Is this an ape or a monkey? Or both?
(Answer at the bottom)
There is, it seems to me, quite a lot of confusion among the general public about the term "monkey", and exactly which species of animal it might cover. Some people refer to chimpanzees as monkeys, while others reserve it for animals with tails, such as macaques and spider monkeys. And what about baboons or gibbons? Come to that, aren't there other kinds of primate? Where do they fit in?

Or us? Are we monkeys? Are we descended from monkeys? Or neither?

In short, what precisely is a "monkey" in scientific terms? About three-and-a-half years ago, I blogged about the definition of "primate", so perhaps now I'll look at some broad types of primate, and how they fit together.

Sunday, 15 July 2018

The Pig Family: Warthogs

Common warthog
Warthogs are, quite possibly, the best known species of wild pig after the wild boat itself. They are relatively common animals, readily observed in the habitats where they live (rather than hiding in dense thickets, say) and, perhaps above all, they have a striking and distinctive appearance.

The common warthog (Phacochoerus africanus) is widespread across sub-Saharan Africa, and is currently thought to have four different subspecies. Unlike other African hogs, they inhabit lush grasslands and open savanna, country dotted with trees and waterways, but neither densely forested nor the truly arid terrain of veldt or desert. Two subspecies live in the north, in the Sahel belt that separates the Congo rainforest from the Sahara, and are found right from the Atlantic coast of Mauritania to the shores of the Red Sea in Eritrea. The others are found across East Africa and pretty much the entire south of the continent outside the deserts, reaching as far as South Africa.

Sunday, 8 July 2018

Miocene (Pt 8): Giant Honey Badgers and European Pandas

Indarctos
A great many predators lived in Europe in the glorious warmth of the Mid Miocene, when the continent was lush with subtropical vegetation and the herbivores that fed on it. As the climate began to turn, and the forests gave way to more open terrain, both the herbivores and the animals that preyed on them underwent a number of changes, with the latter in particular suffering some loss of diversity. (At least, so far as we can tell from the incomplete fossil record).

This affected the full gamut of mammalian carnivores, including many of the smaller, less obvious, ones. The boundary between the Middle and Late Miocene is an arbitrary one that isn't really marked by anything much in Europe, so that, to begin with, these were as numerous as ever. There were badgers, such as Sabadellictis, and even skunks, which today are not found outside the Americas.

Sunday, 1 July 2018

Fishing in the Ganges

The most spectacular cetaceans are, arguably, the really big ones - sperm whales, blue whales, and so on. However, while our knowledge of the exact numbers is a little hazy, somewhere around half of the cetacean species alive today represent much smaller animals. The majority of these belong to just two taxonomic families.

By far the most numerous are the "true" or "oceanic" dolphins, a family that also includes killer whales and pilot whales - small in comparison with the like of humpbacks, but fairly large by most standards. The second family are the porpoises, which are exclusively small, by cetacean standards, and usually slightly smaller than dolphins.

But there are a few small-sized cetacean species that fall into neither group. These oddities share one thing in common: they don't live in the sea. While they are, of course, just as fully aquatic as their better-known kin, this has lead to them receiving the common collective name of "river dolphin", thus distinguishing them from the "oceanic" sort that most people are more familiar with.

Sunday, 24 June 2018

What is a Marsupial?

A possum
In America, the word "possum" is usually used to describe a moderately-sized, somewhat rat-like, animal that has grey fur, sometimes pretends to be dead, and has far too many teeth for any self-respecting land-based mammal. Officially, this creature is an "opossum", and more specifically, the Virginia opossum (Didelphis virginiana). The word comes from the language of the Powhatan people of Virginia, and has been in use in English since at least the 17th century.

Over on the other side of the world, in Australia, the word "possum" is, however, used to refer to an entirely different animal. These are nocturnal, tree-dwelling creatures, typically with large eyes and long tails, and the majority of the seventy or so species are herbivorous. Early settlers, who had probably only vaguely heard of the American animal, nonetheless decided to give it the same name. Like the Americans, over time they confused "opossum" with "a possum", and shortened the word. Unlike the Americans, their shortened word became not merely colloquial, but the one formally used in zoological texts.