With Stuart Blackman Email your questions to wildquestions@immediate.co.uk
What is a rainbow squirrel?
Squirrels don’t come much bigger than the Malabar giant variety. Weighing four times as much as a grey squirrel, this robust rodent is about the size of a domestic cat. But it’s not the Malabar giant’s size that turns heads and drops jaws.
Endemic to India, where it is the state animal of Maharashtra in the west of the country, it has become quite a hit on social media in recent years thanks to its exquisite pelage, which will leave you in no doubt as to why it has come to be known colloquially as the rainbow squirrel.
While its undercarriage is a fairly standard beige, its back and flanks are adorned with bands of deep, rich reds and blues which, combined, give an overall impression of purple. The precise function of this remarkable colouration, however, is not yet known. One possibility is that, like many colour displays, it’s involved in mate attraction. Or perhaps it’s a counterintuitive form of camouflage. The squirrel spends most of its time in the treetops, where it is safe from predatory leopards but less so from eagles. It may be that, from above, the combination of lights and darks in its pelt mimics the patches of sun and shadow in the forest canopy.
How do birds mate?
Stumble upon a moment of sexual intimacy between a pair of wood pigeons in a tree or gulls atop a lamp post, and you might get the impression that birds mate in pretty much the same way that mammals do. But there are some major differences that go beyond the fact that it is feathers that are ruffled rather than fur.
The reproductive anatomy of birds is quite different from that of mammals. For a start, it’s not easy to tell from the outside which parts of their anatomy serve a reproductive function. That’s because birds have stuck with a system they have inherited from their reptilian ancestors, in which faeces, urine, eggs and sperm are all ejected through a single orifice, called the cloaca or vent.
In some birds, the cloaca has other additional functions. Overheated Inca doves, for example, can cool themselves down by exposing the moist lining of their cloaca to the air to encourage evaporation. And among reptiles, spiny softshell turtles can stay submerged in water for long periods by sucking water in and out of their cloaca and extracting the dissolved oxygen.
Another striking characteristic of birds – 97 per cent of species, at least – is that
