Genetic advantage of single over pea comb

[Auntiejessi3]

28°C today. The highest temperature I've not seen my pea combed birds panting

It was 105°F here, 40.5°C, it's the first time this summer I've seen my brahma panting (nothing a cool mud puddle couldn't fix)

 

[fluffycrow]

It was 105°F here, 40.5°C, it's the first time this summer I've seen my brahma panting (nothing a cool mud puddle couldn't fix)

I'm honestly shocked by this. 35°C and they're panting like crazy. 46°C and 44°C (which we did have this summer) and they're flatter than a pancake

 

[RobG7aChattTN]

I'd love to read that study, could you link it?

I’ve been looking for it. There were a few articles with free abstract summaries but you had to pay to read the article. I found several articles that referenced other studies that said the same but I distinctly remember reading an article where they affixed fake combs to roosters and measured their mating activity and I can’t seem to find that one in particular. I did find a study that linked comb size to factors regarding health, sperm quality and bone density.
Here’s an article specifically about research into waddles that makes reference to hens self-selecting for comb size:
https://www.smithsonianmag.com/science-nature/why-roosters-have-wattles-19276697/

 

[RobG7aChattTN]

I’ve been looking for it. There were a few articles with free abstract summaries but you had to pay to read the article. I found several articles that referenced other studies that said the same but I distinctly remember reading an article where they affixed fake combs to roosters and measured their mating activity and I can’t seem to find that one in particular. I did find a study that linked comb size to factors regarding health, sperm quality and bone density.
Here’s an article specifically about research into waddles that makes reference to hens self-selecting for comb size:
https://www.smithsonianmag.com/science-nature/why-roosters-have-wattles-19276697/

And not a research paper but this article talks about how hens look at several factors not just comb size:
https://www.storey.com/storey/laws-chicken-attraction/

 

[Shadrach]

And not a research paper but this article talks about how hens look at several factors not just comb size:
https://www.storey.com/storey/laws-chicken-attraction/

One needs to be very carefull when one takes information from such articles and try to apply it to "normal" behaviour.
I can state without a shadow of a doubt that behviour exhibted under test/experiment conditions will not be the behaviour seen under different conditions.

 

[RobG7aChattTN]

Lots of mutations occur as an accident. The harmful ones die out quickly, the helpful ones get spread, and the ones that people specially select will become common in captive chickens.

Things like crest, muff/beard, silkie feathers, and frizzle feathers would all be disadvantages in wild chickens. But people like them, so the people keep breeding them.

The pea comb mutation happened at some point, and some people kept breeding it, so it is still around in domestic chickens.




People in cold climates have been more likely to select for pea combs, but they are also more likely to select for chickens with large amounts of feathers (like Brahmas and Orpingtons.) To see if pea comb is a problem in hot weather, I would look at pea comb chickens from hotter places (examples: Cubalaya, Sumatra, Aseel). I would also look at some of the Easter Eggers that have large amounts of Leghorn in their heritage (example: Whiting True Blue from McMurray hatchery.) That should make it a comb difference only, not a comb + feathers difference.

Your point about cockfighters removing single combs (dubbing) is interesting, because some of them are in hot places. If the dubbed birds fare poorly and the un-dubbed birds are fine, it would be pretty good evidence that comb type matters in the heat. If all the birds do equally well, it would strongly suggest that a small comb (dubbed or pea) is just as good as a normal single comb in hot weather.

I have never lived in a place that gets very hot, so I don't have any personal observations of pea comb vs. single comb chickens in hot places.



I know of at least three points against pea combs:

--Pea combs are smaller, so it is harder for people to recognize male chicks when they are young. This does not hurt the chicken, but is a point that matters to some people. (I read of one breed-in-development that has single combs for exactly this reason.)

--The pea comb gene also causes a strip along the breastbone that has no feathers. This does not seem to bother the chicken, but does affect how it looks after butchering (different texture to the skin there.) This matters to some people raising chickens for meat (especially commercial meat-producers.) I can't remember whether this happens only in chickens homozygous (pure) for pea comb, or if it happens in the heterozygotes (split) as well.

--I have noticed that roosters seem more attracted to hens with single combs rather than pea combs, probably because the single comb is larger and more obvious. Roosters tend to mate with the laying hens (big red combs) and not with immature pullets (small combs). If the rooster considers the pea comb hens to be less desireable, this could potentially be an issue in a flock with mixed comb types. In practice, it does not seem to be a big deal in most flocks, because most roosters end up mating with all the hens often enough and with their favorite hens more often than that. I would not expect it to be a problem in flocks with only pea combs.

Personally, I like pea combs better than any other comb type, and I do not see them causing harm to chickens (but I'm not in a very hot climate). But any person can have different preferences about what comb looks best to them, and the points I listed can be important to some people.

Here’s some info about roosters picking hens with big straight combs: https://scienceblog.com/56408/big-comb-gets-the-rooster-and-sperm/

 

[RobG7aChattTN]

One needs to be very carefull when one takes information from such articles and try to apply it to "normal" behaviour.
I can state without a shadow of a doubt that behviour exhibted under test/experiment conditions will not be the behaviour seen under different conditions.

Usually researchers do a pretty good job of replicating normal conditions but I’d be happy to read any research you know of that disputes this. One thing is for sure though one person’s personal experience is often flawed as well with no attempt at adjusting or measuring all the factors that contribute to behavior.

 

[Shadrach]

one person’s personal experience is often flawed

True. However, when one has a lot of anecdotal evidence from people who keep chickens that goes against a study which by it's very nature has to set a limited number of parameters one is wise to study the study conditions rather than assume the behaviour reported covers all keepinng conditions.
Some studies are better than others, but when it comes to behaviour, genetics can't and don't take into account changes in environment. Many of these studies are carried out by students in a very limited time frame as part of a wider reaching degree profile.

 

[Red Mangrove]

I can’t see where the heat exchange aspect could mean much, unless roosters have some different need for heat regulation that a hen does not. As straight combed hens generally won’t come close to matching a rooster comb’s surface area, and where in nature RJF hens have hardly a comb at all.

This is a very obvious point that everyone else, including myself, missed. My RJF hens have barely any comb at all. You're probably correct that large combs are merely sexual selection from females

If they were genuinely needed in India for heat discharge then hens would have them also. So logically we can conclude it's not heat

 

[Auntiejessi3]

I'm honestly shocked by this. 35°C and they're panting like crazy. 46°C and 44°C (which we did have this summer) and they're flatter than a pancake

She's a little over 3, so I figure as she's grown she's adapted. My WTB has a modified pea and she doesn't seem bothered at all, but she is a small bird (4lbs ish)