There has, historically, been some dispute as to whether bears truly hibernate or not. This is because the sort of undoubted hibernation practised by, say, bats, involves an almost total shutting down of normal metabolic functions with the animal effectively becoming cold-blooded for the duration. Bears do not do this; while they are asleep through the winter, their body temperature drops from a normal level of 37°C (99°F) to a low of 33°C (91°F). Now, this is not insignificant, since a human with a body temperature that low would be suffering from clinical hypothermia and in fairly urgent need of medical treatment. But still, you're not going to be so cold that dew literally starts forming on you, as happens with bats.
Sunday, 22 November 2020
Sunday, 15 November 2020
|Asian golden cat|
The forests of Southeast Asia are particularly good place for such creatures to be found, and, in fact, I've already described a number of small cat species that inhabit the region. Those all belong to the "leopard cat" and "domestic cat" evolutionary lineages, but there are a further three species that occupy yet another branch on the cat family tree. Given what I've said above, it shouldn't be surprising that we don't know very much about them.
Sunday, 8 November 2020
|Today, true seals only live much further south|
For simplicity, I'm going to refer to these two groups as "true seals" and "sea lions" in this post, although you should be aware that the so-called fur seals fall into the latter group. We've long known that "fur seals" aren't really a specific type of animal, but are at least two different kinds of sea lion that coincidentally look a little different from their relatives.
Sunday, 1 November 2020
Fast forward to 1956, and scientific research confirmed another interesting fact about such animals: they can echolocate by sending out sonar pings. In 1968, the two facts were put together when it was demonstrated how the unusual structure of the porpoise's head allows it to transmit the necessary sound pulses, which are initially generated somewhere in the nasal passages.
Sunday, 25 October 2020
Perhaps the most obvious of these are the ground squirrels. Most ground-dwelling squirrels belong to a single evolutionary group, which includes something like a quarter of all known squirrel species. Many of these - the animals most commonly known simply as "ground squirrels" - look much like their tree-dwelling kin, but the group also includes such animals as prairie dogs and marmots as well as the semi-arboreal chipmunks.
Sunday, 18 October 2020
The more familiar of the two is surely the serval (Leptailurus serval), an animal that is not only widespread across Africa, but that happens to be relatively easy to breed in zoos. The name apparently derives from an alternative (and now obsolete) Portuguese name for the lynx that has now replaced variants of the older English name of "tiger cat" in most non-African languages. (It's still tierboskat - literally "tiger-forest-cat" - in Afrikaans, and, unsurprisingly, languages such as Swahili had perfectly good words for it already).
Sunday, 11 October 2020
|The largest predator in Africa today|
For one thing, the cats, hyenas, and so forth, were not the only carnivorous mammals to have made the crossing from Asia. The animals known as bear-dogs, or more technically, amphicyonids, are far better known from Europe, Asia, and North America, but they did reach Africa, too.