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FLYING SQUIRRELS!



And such...

FLIGHTLESS BIRDS

Ron gave a list of flightless recent birds. I have the idea that the Madagascan
blue coucal, a bird that was killed off in the 1700s I think, was flightless.
Any input appreciated. Incidentally, there were flightless owls on Mediterranean
islands till recent times too. Plotopterids are the things you were thinking of,
northern hemisphere penguin-type birds related to pelicans et al, some were as
big as the biggest penguins (I hear). As an interesting side-line (not another
one!), plotopterids and giant penguins might have lost out to competition with
marine mammals, and conversely small penguins may be winning over on small
seals. That's presently unknowable, and very complex. 

Oh yeah, there's an illustration in The Encyclopedia of Vanished Species of
Steven Island wren - one is flying to alight on a perch. Ooops.

FLYING SQUIRRELS.

Ok - there are 43 known species of flying squirrel in 14 genera, they are very
diverse in anatomy and ecology, and almost certainly represent numerous
independent radiations from various non-flying lineages. This has mostly
occurred in the tropical forests of SE Asia, with a couple of species spreading
west towards Europe (only one species there, _Pteromys volans_) and 2 living in
the Americas (the _Glaucomys_ sp.). They range from the 40 or so grams of the
smallest to the 8 species of giant _Petauristus_, the biggest of which can be
over 1.2 metres long, and with a mass of over 2.9 kg. That's a big squirrel.

Behaviourally and ecologically, flying squirrels (f-s) are particularly
interesting. For one thing, they're all nocturnal, which is most odd when all
other squirrels, and therefore presumably f-s ancestors, are diurnal. It has
been suggested that the gliders are, because of their wing membranes, more
susceptible to diurnal predation! This is obviously a conclusion at odds with
hypotheses stating that gliding evolved as a means of predator escape - however,
it's unprovable, as we don't have diurnal f-s to test it. Moreover (-;) known
diurnal gliders, like colugo, _Draco_, rhacophorid frogs and gliding snakes, do
just fine at evading predators, probably with less mortality than non-gliders
(but data needed). Some studies have concluded that - get this - the gliding
habit of these animals means that they 'waste' more energy than do normal
arboreal squirrels, it probably being inefficient, and the animals operate on
an energy deficit! (Sounds like my bank balance). In an article published
earlier this year, an f-s worker disregarded these data, and thought the
conclusions ridiculous.

Ecological studies have turned up other amazing facets of flying squirrel
ecology, including the idea that one species of _Glaucomys_ uses its gut
parasites as a 'weapon' to deter the other, more susceptible _G_ species! 

Enough already!! Anyway, work that into your flight-origin hypotheses and I'll
be very impressed..

"Looks like a airplane, but wi'out wings"
"That ain't no airplane.. look!"

DARREN 'I notice that your overdraft exceeds your present limit' NAISH