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

Re: skin decoration Vs feather decoration in predatory archosaurs



At 03:39 2000-04-13 -0700, Martin Barnett wrote:

The bateleur and the gymnogene among others have bright red skin on their
faces. This is actually not that uncommon among raptors. Certainly there
are raptors with blue (or at least blue-grey) legs, the Gyrfalcon for
example, in old times  was also known as "blåfot" (bluefoot) in Swedish,
brigt yellow skin is much more common though. Furthermore vultures hardly
qualify as raptors, they specialized scavengers and do relatively little
hunting for themselves

I can add a few plumage colors:

blue-gray (fairly common, e g male Harriers)

rufous (also fairly common e g kestrel and related small falcons)

chestnut/orange (breasts of some Accipiters and falcons)

Note that there is one completely and one almost completely white raptor
(light phase of Variable Goshawk (Australia) and White Hawk (Central
America)), some Icelandic and Greenlandic Gyrfalcons are also nearly white.
I've been lucky enough to see all three and they are all extremely striking
birds. How about white theropods in Australia/Antarctica?

There is no green, bright blue, bright red or bright yellow plumage in any
raptor.


Tommy Tyrberg



>     I noticed that all  the birds' feathers (with the possible exception
>of Pernis aviporus, the honey  buzzard) were of the following colours:    
>Black     White     Grey-scale     Anywhere within the brown  spectrum
>between peach and terra-cotta   It was  interesting to note that any with
>bright colour had it in their eyes or on their  skin  The following colours
>were noted on the skin:       Token example Accipiter nissus (sparrowhawk) 
>   with Gyps fulvus (griffon vulture) to more  "mother-of-the-bride"
>shades, ie, Falco vespertinus (red-footed  falcon)      Found in Elanoides
>forficatus (swallow-tailed kite)  among others.     Orange? - Neophron
>percnoterus  (Egyptian vulture) picture is a little unclear, could be a
>solarised  yellow.      I also recall (from memory, so beware!)  seeing a
>raptor with blue feet.       So, the overall trend with at least modern
>feathered archosaurs is for  camouflage colours using pattern for display
>on the plumage and actual vivid  colours when present on the skin.        
>Daspletosaurus with  blue legs)   Sam