mikeb@uhccux.uhcc.Hawaii.Edu (Mike Burger) (08/07/90)
The idea of visual pigment bleaching is interesting. Maybe the bird is trying to keep its head stationary on purpose to promote bleaching. In the frog, for instance, it uses an apparent visual bleaching as a protection. It goes blind sitting still and only notices things which move. One can imagine anything that moved in his visual field standing out against a black background. Perhaps birds sometimes make use of this idea. When walking on the ground, using head bobbing to keep the world stationary, only things changing their perspective significantly as the bird moves would be "seen". The background clutter would vanish, perhaps revealing the cat which just moved closer. Then again maybe birds just bob their heads because it feels good :-) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Mike Burger Department of Chemistry | 2545 The Mall | BITNET: MIKEB@UHCCUX.bitnet | University of Hawaii | INTERNET: mike@helium.chem.hawaii.edu | Honolulu, Hawaii, 96822 |
bluejay@feathr.enet.dec.com (Bluejay Adametz) (08/08/90)
In article <8886@uhccux.uhcc.Hawaii.Edu>, mikeb@uhccux.uhcc.Hawaii.Edu (Mike Burger) writes: |> Then again maybe birds just bob their heads because it feels |> good :-) Now y'all are getting on the right track! BTW - Why do humans swing their arms when they run? Is it because without doing this their hearts can't pump enough blood around to support running? Personally, I think they do it because it makes them look like they're doing more than they really are, to look more threatening to a potential predator. Or should I take this to rec.humans? - Bluejay Adametz AA-5B/A N45210