At least among mammals, there are two primary modes of communication that are generally studied by researchers. Perhaps the more obvious of these to we humans is vocal communication, since that's the main one we used in pre-literate societies. Not all species are especially vocal, but many are, and some are using sound outside of the human hearing range - such as the ultrasound squeaks of many small rodents such as mice. One estimate suggests that around 95% of mammal species use acoustic communication and this may be on the low side (it's 100% in birds and 90% in amphibians, but apparently less than 5% in reptiles, suggesting that it has evolved at least three times).
Synapsida
A random wander through the world of mammals
Sunday, 4 June 2023
Social Posting - Bear Style
Saturday, 27 May 2023
When the Desert is Too Dry
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The round-tailed ground squirrel lives further east, and is not threatened |
The size and relative location of such territories naturally vary between species, but also depend on the local conditions of terrain, climate and so on. The harder it is to find food, for instance, the larger your territory will need to be. As young animals grow up and leave home, they will need to find unoccupied territories to inhabit, or else somehow drive an existing resident out and take over. Males commonly travel further than females so that they don't end up with only their sisters or close cousins as potential mating partners, although there are a few species where it works the opposite way around.
Sunday, 21 May 2023
The Raccoon Family: Kinkajous - the primate-like "raccoons"
Perhaps the most distinctive, and certainly the most studied, of these is a genus with just one species: the kinkajou (Potos flavus). It was first scientifically described by Johann Schreber in 1774, in an earlier volume of the book in which he would later describe (among other things) cheetahs, snow leopards, and bobcats. While he was understandably clear those were all cats, the identity of the kinkajou was not so obvious. In the days before Darwin, this may not have held any deep meaning for him, but his conclusion was that his new animal was a kind of lemur.
Sunday, 14 May 2023
Oligocene (Pt 2): Europe's Big Break
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Eomys |
Prior to the Oligocene, it would have been possible for a hypothetical traveller to sail from what is now the eastern Mediterranean, through the Paratethys Sea (now the Black and Caspian Seas) due north and into the Arctic Ocean. The body of water that made this possible, the Turgai Strait, was already becoming shallower and narrower as the Oligocene approached, and the sudden dip in sea level finished it off altogether, closing off the sea route that had once run along the eastern flank of the Ural Mountains.
Sunday, 7 May 2023
Cheetahs and Wild Sheep
This does, however, disguise some significant regional variation.
How we should divide the cheetah into subspecies is not absolutely clear. From at least the 1970s, five subspecies were recognised, Two of those were merged in 2017, on the grounds that the East African form could not be reliably separated from its southern relative genetically. Even then, cheetahs have so little genetic variation across their range - due to an apparent population bottleneck when they almost died out at the end of the Last Ice Age - that support for the existence of two of the other subspecies remains a little shaky. Still, four subspecies is, for the time being, the general consensus.
Sunday, 30 April 2023
The Pandas of Bulgaria
This, of course, is the subfamily of the pandas, the Ailuropodinae. Pandas are sufficiently odd that it was unclear for a time whether they were really bears, or something else, although their status hasn't really been in doubt since the 1980s when genetic evidence proved what had, even then, been suspected for a couple of decades. Today, only one species of ailuropodine exists, the giant panda (Ailuropoda melanoleuca), and it is found only in China. The same evidence used to estimate the split between the other living subfamilies puts the date of the split between pandas and other bears much further back, to around 20 million years ago, not long after the dawn of the Miocene.
Sunday, 23 April 2023
The Raccoon Family: Cacomistles
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Ringtail |
The scientific name didn't stand, because it turned out that the first part of it had already been used for a kind of butterfly. Furthermore, while he originally referred to the animal by its Spanish name "cacomixtle", since the specimen he knew of came from somewhere near Mexico City, in English we now call it a ringtail (Bassariscus astutus) or, less accurately, a "ring-tailed cat". Even so, in many parts of the US, an Anglicised form of the Spanish name is still in wide use.