Biological purpose of comb/wattles?

I believe they help regulate temperature as well as serve as a sort of attraction for mates. It's been proven that single combs are preferred over any other type by a group of chickens.

 

When I was younger, I was told that the waddles and combs helped with oxygen exchange and recently here on BYC I read that it helps regulate blood and body temperature. Whatever, they are very interesting to puzzle over.

 

Blood and body temp, perhaps.

Oxygen exchange, I doubt.

Fer looking good... yup that's it.

 

Yes. Combs are used to regulate body temperature. In the summer (hotter times of the year) the blood is put throughout the comb. The blood gets closer to the outside air at this area and the heat is exchanged with the outside air.

In the winter, the blood is kept closer to the head and the heat exchange does not happen.

 

Oxygen exchange has to occur across a moist membrane and since the comb is not moist it will not occur. I agree with the female attraction for mating and the temperature regulation (cooling).

Tim

 

Gosh, if those combs are so useful then I want one!

 

Yup - keepin' the bird cool in hot weather, and as a male sexual display thing.

It is likely that there are a couple issues involved in the sexual-display thing. First, they make it real clear who's the guys and who's the girls (always a good starting point for any mating encounter intended to produce offspring ).

Second, the size of the comb may offer some information about how, what would you call it, well-grown and strong and robust and long-term healthy is the male wearing it. Females of many species have been shown to select for male traits that are correlated with individuals who've grown better; which makes sense because there is probably often *some* genetic contribution to those males having done better for themselves.

And third, I do not offhand know of any studies involving chickens, tho I expect they've been done, but it is pretty common for males (in species with female choice AND in species with lots of male-male aggression) to have some body part whose color etc reflects the individual's current health. I would not be surprised if, with chickens, if you artificially reddened a sickly roo's comb or put pale makeup on a healthy roo's comb, it would change the likelihood of physical attack by other males and perhaps affect female chickens' willingness to mate. (In a small enclosure the females may not get lots of choice but in a large space it can be different).


Pat

 

When hens' combs go pale during a molt or non-laying period, is it a sign to the roos that they "have a headache"?