Behavioural Ecology

Question 1

Principle of Animal Colouration

Answer 1

Expect predator/prey to evolve least detectable color
Warning colours
Colours for signalling
Minimize colouration contrast on background
Minimize during predation, maximize during display

Question 2

Pigments

Answer 2

Melanin produced by fish
Carotenoids obtained from the diet
Pigments stored in chromatophores

Question 3

Structural colours

Answer 3

Guanine crystals (reflective) sheets of crystals (stratum argentum) – manipulate reflectance

Question 4

Nerve endings in chromatophores

Answer 4

Chromatophores – epinephrine for contraction and acetylcholine for dispersion

Question 5

Countershading

Answer 5

Dark dorsal, light ventral
Evens out higher downwelling light, and underside shadow

Question 6

Disruptive colouration

Answer 6

Recognize object by continuity of surface
On a heterogenous background, the disruptive colouration draws attention away from outline – contrasting patterns or bars

Question 7

Camoflage

Answer 7

Resemble whole animal profile to background
Change color to match background

Question 8

Acuity disc

Answer 8

Minimum angle within which different hues or patches can be resolved by the eye
Objects or patches smaller than the acuity disc is averaged

Question 9

Red Colouration

Answer 9

Often nocturnal/low light
Hues do not resemble substrate
Melanin has high toxicity – high cost
Red colour has lower cost – still appears black

Question 10

Advertisement

Answer 10

Red colour short ranges signal
distinct facial patterns under UV light – species individuals

Question 11

Bioflurencese

Answer 11

Absorb high energy photons (blue,UV), emission of low energy photons (red, green)
Important at low light levels