I promise I won't be long-winded. In response to Dave Cameron, features of
recent captivity for a wild sparrow would include heavily worn plumage
(especially flight feathers), a leg band, and an overgrown beak. The photos
shared on this forum clearly showed the absence of any of these features.
Tony's analysis ignored the possibility that a Rufous-collared Sparrow born
with a genetic makeup that encodes migratory behavior would indeed be
physiologically adept to migrate. I agree that a non-migratory bird that
suddenly decides to fly thousands of miles would be unfathomable. In
migratory species, the phenotype of migratory behavior had to start
sometime. Of course, only those genetic changes that lead to greater fitness
will survive. If the Georgetown sparrow did migrate to Colorado and it
doesn't find a mate, its unique genotype is doomed. However, there are
numerous species with populations divided among migratory and non-migratory
individuals.
Here is yet another scenario for this bird to be wild: A curious
Rufous-collared Sparrow at the airport in Quito, Ecuador, hops into the
cargo hold of an airplane. Well adapted to high elevation, it survives the
4-hr direct flight to Denver, where it deplanes and heads towards its
familiar montane habitat at Georgetown. Human-assisted, yes. Captive, no.
Any progress on obtaining a sonogram?
Nick Komar
Fort Collins CO
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