[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Archaeopteryx with bird book, was Re: Archaeopteryx flight



A naked head is also useful for scavenging -
prevents fouling of the plumage
while the scavenger is immersing itself in a rotting
carcass.  I'm not
saying that _Archaeopteryx_ was a scavenger - but
the head (and neck) may be
naked for purposes other than display.

In total, maybe 1% of living birds have bald heads. Scavenging birds are much bigger than A., possibly because carrion is scarce resource and they need passive flight to cover vast areas to locate it.

Where is the evidence of selection for baldness in scavenging birds? Other than vultures, I can't think of any other type of scavenging bird that is bald (crows, ravens, magpies, gulls as well as some types of owls, herons and raptors). And several of these types of scavenging birds are not much bigger than Archie. The absence of head feathers in Archie is far more likely an artifact of preservation than evidence of baldness. Flight feathers, which are anchored to bone, are more likely to remain affixed during preservation than contour feathers.


PTN