Combs don't help with heat regulation. If a comb turns purple under heat stress, then you're more then likely have one dead due to heart attack.
Combs and wattles engorge with blood in hot weather, and when cooler air or a mist of water hits the comb and wattles, heat is pulled out of the body. It's called evaporative cooling.
Comb, & Wattles don't have the function to cool the body, it's only been theoretical, never actually been proven.
I can actually gut that. I just dubbed cockerel in hot weather a week ago, his comb barely bled. Just a couple drops, & that was it.
Interesting. I've read from several sources (like Storey's guide to chickens) that they do use evaporative cooling. Kalmbach's website also mentions it. They state it as fact rather than theory.
Nope it's only been theorized. I've read stuff too, but rather do my own observations. All my observations through watching the birds it the combs, & Wattles serve more of a target, & something to grip onto during fighting.
I've had roosters with large wattles during the winter dip their wattles, & end up with frostbite. The dipping you see isn't intentional, it's just them going for a sip, & getting too close to the water. Bearded chickens sometimes end up with soggy beards due to this as well. It could be a perception issue to if the water is really clear, they can't tell how far to stick their lower beak into the water for a drink.Evaporative cooling thru comb and wattles as a theory does make sense to me... It's (usually) the only bare skin to air contact a chicken has. Have there been any studies that point to proving or disproving it? Now I'm really curious
One reason why it makes sense to me is because in hot weather, I observe my girls dunking their wattles in cool water as they drink. They don't do it in cool weather. As the cool water evaporates off their wattles, I imagine it does cool them, just like sweat evaporating off our skin cools us. I've also read that when a chicken is under heat stress it can help to get comb and wattles wet with cold water to cool them down. But evaporative cooling can only work if the humidity in the air is low enough for moisture to evaporate (below 75%).
Storey's guide says the 4 ways a chicken regulates temperature are:
– Radiation (heat transfer between chickens and nearby objects)
– Convection (heat transfer between chicken and the air)
– Conduction (heat transfer between a chicken and an object on contact)
– Evaporation (loss of latent body temperature occurs when the environmental temperature approaches a chicken's body temperature and its body heat vaporizes liquid on the body's surface, such as from misting the bird with cool water; OR, respiratory heat transfer when a chicken inhales air cooler than its body temperature and exhales moisture laden air. "The moist air passages in the bird's extensive respiratory system [...] help a bird lose internal body heat.")
So I was mistaken, comb and wattles weren't specifically mentioned in Storey's guide (I must have just mashed Storey's with another source in my head). And for evaporative cooling to work, the air temperature should be approaching the chicken's internal body temp (~104⁰F) and the humidity needs to be less than 75% or the moisture won't evaporate.
Sometimes, but not always, it seems intentional when my girls do it. They just skim their lower beaks on the water's surface normally, so their wattles get a little wet on the tips just from the proximity. But they dip quite deeply and let the water run down their wattles and throats when it's really hot outside. The ones with smaller wattles dip down much deeper to wet them. I have no doubt that it started as an accident but they realized that it felt good and started doing it on purpose.
Mine do it to get more water in their beaks, kinda like a guzzle, but the chicken way.
