Plumage and its Function in birds

Transcription

1 Plumage and its Function in birds

2 Basic distinction between: Molt = feather replacement and Plumage = Feather coat Basic (prebasic molt) - renewed plumage postbreeding Alternate (prealternate molt) - breeding plumage Typically replace all feathers after breeding and, often, before onset of migration Typically partial replacement of feathers in spring

3 Why replace feathers?

4

5 Mite damage can damage an individual's plumage during heavy infestations & result in energy-loss via poor thermoregulation or loss of mates if plumage is involved in mate selection

6 Birds use three general types of pigments: Melanins: are synthesized in animals. These pigments are typically responsible for the blacks, browns, and less striking colors.

7 Porphyrins & Carotenoids: are responsible for the reds and yellows and greens. They are only synthesized by plants, and thus must be consumed in the diet.

8 Great-tailed grackle Barbules are layered with air bubbles that create a diffraction/interference pattern to reinforces selected wavelengths while canceling others The plumage of iridescent birds is caused by reflectance from the sun and amplification of certain wavelengths, rather than using pigments.

9 Sunscreen applied Broods from sunscreen-ed males produce fewer sons UV Many birds have plumage characters that reflect UV light

10 Feather wear, as in this Snow Bunting, which changes from a contrasting black and white in the male to a less contrasting, browner plumage after breeding

11 What is the function of a bird s plumage? - Stream-lining - Thermoregulation - Waterproofing - Protection - Camouflage - Foraging - Anti-predator behavior

12 Detectability (%) What is the function of a bird s plumage? Concealment of the eye - Stream-lining - Thermoregulation a b c d e - Waterproofing - Protection - Camouflage - Foraging - Anti-predator behavior 100% 50% Distance to border

13 What is the function of a bird s plumage? - Stream-lining - Thermoregulation - Waterproofing - Protection American redstart wing-flicking - Camouflage - Foraging - Anti-predator behavior

14 What is the function of a bird s plumage? - Stream-lining - Thermoregulation - Waterproofing Pygmy owls - Protection - Camouflage - Foraging - Anti-predator behavior Sun bittern eyespots

15 What is the function of a bird s plumage? - Stream-lining - Thermoregulation - Waterproofing - Protection - Camouflage - Foraging - Anti-predator behavior MELRYID BEETLE Hooded Pitohui

16 - Stream-lining } - Thermoregulation Color - Waterproofing - Protection - Camouflage - Foraging - Anti-predator behavior Not all color need have a function } Color would have little role in these functions except which? has a behavioral function i.e., within species interaction so does color always have a behavioral function?

17 - Stream-lining - Thermoregulation - Waterproofing - Protection - Camouflage - Foraging - Anti-predator behavior } Color } Color would have little role in these functions except which? has a behavioral function i.e., within species interaction Structural coloration

18 What is the function of a bird s plumage? - Stream-lining - Thermoregulation - Waterproofing - Protection - Camouflage - Foraging/Anti-predator behavior What else? COMMUNICATION This male Lyrebird has something to communicate

19 What do birds have to COMMUNICATION? - Species recognition - Individual identification - Social dominance rank (age) - Fitness (male quality) - Attract mates

20 What do birds have to COMMUNICATION? - Species recognition - Individual identification - Social dominance rank (age) Private - Fitness (male quality) - Attract mates Sergeant Badges of Status The size of the black bib in several species of sparrows signals dominance rank and eliminates undo fighting between males Captain

21 Summary of results from Rohwer and Rohwer (1978) manipulation experiments on subordinate Harris Sparrows Paint black Inject testosterone Both Look dominant Behave dominant Y N N N Y N Y Y Y Change in status Cheating is prevented b/c status is ultimately checked by escalation If birds BOTH look dominant and act dominant they can rise in status, whereas acting w/o looking dominant they can t

22 What do birds have to COMMUNICATION? - Species recognition - Individual identification - Social dominance rank (age) Breeding Female - Fitness (male quality) - Attract mates Non-breeding First Yr Male Breeding Second Yr Male American Redstart

23 What do birds have to COMMUNICATION? - Species recognition - Individual identification - Social dominance rank (age) - Fitness (male quality) - Attract mates

24 Plumage Saturation (%) What do birds have to COMMUNICATION? - Species recognition - Individual identification Red-billed Quelea - Social dominance rank (age) - Fitness (male quality) - Attract mates Northern Cardinal Plumage Hue

25 - Species recognition - Individual identification - Social dominance rank (age) - Fitness (male quality) - Attract mates These two types of traits are not limited to (colorful) plumage what else is there? Displays Vocalizations And in very special cases.bowers