bird vision Flashcards
1
Q
colour production consists of…
A
pigments, interference, scattering
2
Q
pigment
A
- material that absorbs some wavelengths of light, those reflected are what we see
- amount of colour=how healthy they are
- ie. carotenoids produced by plants and eaten by animals
3
Q
interference
A
- structural color produced by birds (and soap bubbles) via the combination of two or more electromagnetic waves in which their addition or subtraction negates (descructive) or combines (constructive interference) their waves, forming a colour
- SIMPLE= light you see is the combination of waves, some reflect off outer surface, some inner surface, and when they reach your eye you see the combination
- only used if posssess carotenods
4
Q
Rayleigh scattering
A
-combination of deflecting some light and defusing/absorbing other parts of light
5
Q
high energy light=
A
low wavelength, high freq
6
Q
low energy light
A
high wavelength, low freq
7
Q
why do some species have more colour patches than others?
A
ambient light influences optimal visual signals, so birds with less available light compensate with more colour
8
Q
visual reception
A
- birds have 4 or 5 cone pigments, where as we only have 3
- extra cones means better wavelength discrimination; they can see more colours than us
- thus some differences, such as colour differences of some males and females are indistinguishable to the human eye
- furthermore sibling species are more different when seen under ultraviolet
