[obol] Raptor perception

[Cindy Ashy]

Dan and OBOL:

I have for a long time been fascinated with this topic...that other animals are
seeing patterns invisible to the human eye. We co-exist in the same space yet
live in different perceptive universes. It's also interesting to think about
how this might effect the conclusions we draw from our observations on
wildlife...possible erroneous ones. I have a portable black light that I
sometimes use to explore spider webs, tree lichens, and various invertebrates.
Now Dan has me wanting to get into an ornithology lab with my black
light....better yet, a well-organized avian museum collection.

I have some questions:

How fast does the fluorescence in bird feathers such as you find on Cedar
Waxwings fade on specimens? I know it fades with lichens and invertebrates but
even specimens many years old still seem to lightly fluoresce.

Are there any known examples for fluorescence in egg shells? I'm thinking of
the eggs in colony nesters like Common Murres where it's important for every
egg to look different....maybe they're even more different than those varied
speckly patterns we can see...of course it sounds like patterns visiable in UV
could also attract predators.

How about placement of fluorescent objects in nests? I've watched gulls at
Yaquina Head spend hours putting the finishing touches on a nest, fiddling with
one particular object that doesn't match the other nesting materials....does
this make it more unique and easier to find?

What about fluorescence in the larids? Different species look sort of similar
all gathered up in a mixed species flock (to us anyway) but what are the gulls
actually seeing in the UV range? What about those eye rings....do they show
differently in the UV range?...something that maybe a raptor circling high up
couldn't detect but might be obvious to 2 gulls face to face.

What information is known about how well other groups of birds can see UV?

Any examples of bird photos with UV sensitive film online?

Any other cool examples like the Cedar Waxwings?

Are any of the following species known to use UV (patterns on plumage, locating
certaing food, etc): Western Gull, Common Murre, Pigeon Guillemot, Brandt's
Cormorant, Pelagic Cormorant, Black Oystercatcher, Bald Eagle, Peregrine
Falcon? (species we'll be concentrating on during Birdwatching Spoken Here).

Cindy Ashy


 
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