The Raccoon Family: Coatis

White-nosed coati

The common raccoon is the only member of the family whose scientific name dates back to the official dawn of biological taxonomy in 1758. However, just eight years later, in a later edition of the same work, Linnaeus added two further species (people were, by this point, sending him many samples of new species to catalogue) that we would now place in the raccoon family - albeit, he initially described them as civets.

These two animals were coatis (or "coatimundis"), with one first identified from Mexico, and the other from Brazil. They were given their own genus by Gottlieb Storr in 1780 when he first named the raccoon family. It's probably fair to say that, to modern eyes, Storr's classification seems the more reasonable of the two; coatis look a lot more like raccoons than they do like civets.

Age of Mammals: The Oligocene (Pt 1)

It's been over a decade since I started including bimonthly looks at specific slices of Earth's past in this blog. In that time, I have covered three epochs: the Pleistocene, Pliocene, and Miocene. Together with the current Holocene epoch, these comprise what we currently consider to be two "periods": the Quaternary and Neogene. Both of these are dominated, more or less, by mammals of the sort we'd generally recognise today, even if the details are different. All of the earlier chunks of time since the extinction of the non-avian dinosaurs, however, constitute a different period, the Paleogene, where this was much less true.

When Charles Lyell devised the current system of dividing the "Age of Mammals" into epochs in 1833, he originally defined four. A few years later, he revised this to five, but even then, the entirety of what we'd now call the Paleogene was placed into a single epoch, the Eocene. In 1854, however, German palaeontologist Heinrich Beyrich, split off the later part of the Eocene into a new epoch, which he saw as a distinct period of transition in the development of fossil seashells. He called this the Oligocene, and it proved useful beyond his original mollusc-based definition, and so has remained in use to this day. (Beyrich's wife, incidentally, was a children's author, and made the unusual step of favourably commenting on the work of Charles Darwin in a novel for young girls at a time when it was still controversial).

Fruit Bats of Madagascar

While most attention tends to focus on large charismatic animals such as rhinos and tigers, it will probably come as no surprise to discover that many species of bat are endangered. Here in Britain, all bats are legally protected by the Wildlife and Countryside Act 1981, making it an offence to disturb their roots. That's perhaps an unusually robust example, but other protections and conservation efforts exist across the world.

On the other hand, it is true that the majority of bat species are not especially threatened, at least on a worldwide scale - although things may be different locally. Bearing in mind that around one in six bat species are so recently identified and so little studied that we simply don't know how common they are, only around another one in six are rare enough to be listed as "threatened" by the International Union for the Conservation of Nature. Still, that's not exactly a small proportion, and since there are somewhere around 1,400 named species of bat, it's not small in absolute terms, either.

Tha bats are a highly diverse group, representing no fewer than 21 taxonomic families, none of which are likely as familiar to the layman as terms such as "cat family" or "deer family". Some of these contain very few species, representing oddities that don't quite fit into any of the main subgroups, but there are still five families with over a hundred species each. Of these, the one that contains the highest proportion of threatened species is the fruit bat or "flying fox" family, the Pteropodidae.

Friendship and Fission-Fusion

Mammal species have a wide range od different social systems into which they organise themselves. Many are essentially solitary outside the breeding season, others form long-lasting pair bonds, and others live in larger associations which may themselves have varying different structures. Among the latter, one common pattern is that of the fission-fusion society.

Here, rather than having a long-lasting association, perhaps bonded by ties of family, the animals live in groups but the membership of that group is not constant. New animals are constantly wandering in, while others break off and leave for other groups. On a larger scale, it may be that the individual fission-fusion groups - the actual bands of animals you would see travelling together - are themselves gathered into larger social networks that may have a relatively consistent structure. That is, the new animals joining the group aren't random; they're individuals already known to the group, and rival social networks may exist nearby that do not mix their members.

The Raccoon Family: The True Raccoons

Common raccoon

While the raccoon family contains more species than most people likely realise, by far its best-known example is the animal for which it is named. The common raccoon (Procyon lotor), alternatively known as the "northern raccoon" or simply "the raccoon" was the first species in the family to be scientifically described, no doubt because it's not only common and widespread, but because it's a very distinctive animal. Everyone must surely be familiar with what they look like, and, if you're North American, there's a decent chance that's from first-hand experience.

The common raccoon is found across almost the whole of the contiguous United States, barring only some of the drier parts of the Great Basin, as well as across southern Canada and virtually all of Mexico and Central America. Furthermore, raccoons were introduced to Germany as a hunting animal in 1927 and, with the help of others that escaped from fur farms, since around the 1970s they have been expanding rapidly across Europe. Over the last couple of decades, they have established populations from Spain and France in the west across to Russia and Ukraine in the east. In the 1990s, they were also introduced to Japan and they have also been introduced to Uzbekistan and other parts of Central Asia, probably following escapes from fur farms.

Tree-Dwelling Almost-Lemurs of the Canadian Arctic

Northern Canada, it has sometimes been noted, can get a bit cold. The northern coasts, and the islands beyond them, are covered in treeless tundra, the permanently frozen subsoil preventing anything that needs deep roots from growing there. The interiors of the more northerly islands don't even have that much, just permanent fields of ice and snow. 

The most northerly island in Canada is Ellesmere Island, whose most northerly point is not far from being the most northerly piece of solid land on the planet, only beaten by parts of Greenland. Midsummer temperatures reach a daily high of about 9°C (49°F) in midsummer, and it often snows in July. Winter temperatures regularly drop below -35°C (-31°F) on January nights. So, yeah, that's uncomfortable.

Benefits of a Deadly Predator

A basic concept in ecology is that of the trophic level, a concept that lines up life forms by where they sit in the food chain. Plants are at the bottom level, taking energy directly from the sun, then the next level up are the herbivores, which eat the plants. Above that we have primary predators eating the herbivores, and then secondary predators eating the primary ones. Because the transfer of energy is never perfect, each level will be smaller than the one below it, with fewer individual life forms in it, thus forming a pyramidal pattern.

The reality is more complex than this. Secondary predators also eat herbivores, omnivores are common, really large herbivores aren't likely to be eaten by anything, there may be more than two steps in the chain of carnivores, and we can't forget the detritivores and fungi. And so on. So what we actually have is a "trophic web", a complicated set of interactions where some animals don't fit neatly into a single level on the pyramid. Nonetheless, that doesn't make the basic idea useless and one of the concepts it leads to is the apex predator - the large carnivores that have no predators of their own (at least as adults).