But, for a great many mammal species, we don't. This may be because it's rare, or difficult to observe in the wild, or perhaps that it's a newly discovered species that we can reasonably assume isn't that different from close relatives we already knew about. But, at least when it comes to reproductive behaviour, one of the biggest gaps in our knowledge concerns the bats.
Sunday, 10 January 2021
Sunday, 20 December 2020
|The largest known Oligocene whale was|
moved into the new genus Ankylorhiza
Sunday, 13 December 2020
The sabretooth cats represent an early branch in cat evolution, perhaps splitting off at some point during the Early Miocene, over 20 million years ago. But this means that the cats we are familiar with must have existed - in some form - for equally long, leaving their own fossil history. If you wound back the evolutionary clock on a domestic cat, or even a tiger, you wouldn't find a sabretooth or anything that looked much like one. Exactly what you would find isn't something we can know with certainty, but we do know of a number of fossil species of non-sabretooth cat that at least give us some idea.
Sunday, 6 December 2020
As you'd probably expect, this gets harder the further back you go. Firstly, even animals belonging to familiar groups are getting further away from their present-day forms. There comes a point where whales still walked on land, for instance. Secondly, the further we go back, the more animals we find that didn't leave any modern descendants, and, indeed, weren't even closely related to anything that did (Smilodon, for instance, has no living descendants, but it's still pretty obviously a cat). That can sometimes make it harder to say where such animals fit into the mammalian family tree or, perhaps more importantly, how they lived and behaved.
Saturday, 28 November 2020
|Palaeotragus, a short-necked giraffe|
These changes in climate also affected the animal life on the continent, to the benefit of some and the detriment of others. Pigs are omnivorous animals, and one might expect them to have survived such changes relatively unscathed. In a sense, this is true, since they remained common on the continent, but the nature of particular species living there did change.
Sunday, 22 November 2020
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, 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.