Perch width, what’s the science?

[lazy gardener]

Just FYI: The action of gripping a perch is called tenodesis. You can see it in yourself by holding your arm with elbow bent 90*, forearm parallel to the floor, and wrist dropping down in a natural resting position. Note that your fingers are flexed a little bit. Now, extend your wrist back, and note that your fingers have a natural tendency to curl.

Birds were created to maximize their functional use of tenodesis. When a bird rests on a perch, the weight through her shanks causes the toes to curl around the roost. This allows her to sleep without falling off her perch. Of course she also has voluntary control of those foot muscles.

 

[Henrik Petersson]

Fair point, but compared to griping a perch........

Yes, maybe they curl them less.

It could also be that the ability to curve the toes well is to enable them to perch on tiny branches during brief intervals throughout the day, but that they are better off sleeping on wide roosts.

Consider the red junglefowl, the wild chicken ancestor. What if they do sleep on tiny branches? Maybe their breast bones do bend, but maybe it's not affecting their ability to reproduce, so maybe there are a lot of red junglefowl out there walking around with deformed breastbones, all happy and successful?

Those red junglefowl probably sleep on different branches almost every night, or at the very least, on different places on the same branch, or turned in a different direction (they don't exactly have to worry about facing a wall or not...), so maybe their breast bones recieve pressure evenly from a lot of directions throughout their lives, so they effectively don't bend. Kind of like how it's better for humans to jog on natural paths than on asphalt; both of them wear down our knee joints, but the paths wear them down from a hundred directions, whereas the asphalt roads wear them down from one single direction, so that the knees get a lot more injured from the latter.

Also, most modern chickens are heavier than red junglefowl. Red junglefowl are essentially bantam chickens. Hens weigh about two pound, roosters three. Many modern chickens weigh at least double that, which I imagine increases the pressure on their breast bones significantly, forcing responsible chicken keepers to go to some extra lengths to not let those ol' remaining junglefowl instincts dictate where our chickens sleep.

 

[centrarchid]

Just FYI: The action of gripping a perch is called tenodesis. You can see it in yourself by holding your arm with elbow bent 90*, forearm parallel to the floor, and wrist dropping down in a natural resting position. Note that your fingers are flexed a little bit. Now, extend your wrist back, and note that your fingers have a natural tendency to curl.

Birds were created to maximize their functional use of tenodesis. When a bird rests on a perch, the weight through her shanks causes the toes to curl around the roost. This allows her to sleep without falling off her perch. Of course she also has voluntary control of those foot muscles.

Chickens do not have that setup.

 

[lazy gardener]

I beg to differ. Any joint which has an agonist, antagonist muscle set up, with tendons crossing the joint has tenodesis.

ten·od·e·sis
(ten-od'ĕ-sis),
Stabilizing a joint by anchoring the tendons that move that joint, thereby preventing anyfurther excursion of the tendons.
[teno- + G. desis, a binding]

 

[centrarchid]

Yes, maybe they curl them less.

It could also be that the ability to curve the toes well is to enable them to perch on tiny branches during brief intervals throughout the day, but that they are better off sleeping on wide roosts.

Consider the red junglefowl, the wild chicken ancestor. What if they do sleep on tiny branches? Maybe their breast bones do bend, but maybe it's not affecting their ability to reproduce, so maybe there are a lot of red junglefowl out there walking around with deformed breastbones, all happy and successful?

Those red junglefowl probably sleep on different branches almost every night, or at the very least, on different places on the same branch, or turned in a different direction (they don't exactly have to worry about facing a wall or not...), so maybe their breast bones recieve pressure evenly from a lot of directions throughout their lives, so they effectively don't bend. Kind of like how it's better for humans to jog on natural paths than on asphalt; both of them wear down our knee joints, but the paths wear them down from a hundred directions, whereas the asphalt roads wear them down from one single direction, so that the knees get a lot more injured from the latter.

Also, most modern chickens are heavier than red junglefowl. Red junglefowl are essentially bantam chickens. Hens weigh about two pound, roosters three. Many modern chickens weigh at least double that, which I imagine increases the pressure on their breast bones significantly, forcing responsible chicken keepers to go to some extra lengths to not let those ol' remaining junglefowl instincts dictate where our chickens sleep.

My chickens will dispute.

 

[centrarchid]

I beg to differ. Any joint which has an agonist, antagonist muscle set up, with tendons crossing the joint has tenodesis.

ten·od·e·sis
(ten-od'ĕ-sis),
Stabilizing a joint by anchoring the tendons that move that joint, thereby preventing anyfurther excursion of the tendons.
[teno- + G. desis, a binding]

innovation of perching birds

 

[Shadrach]

Interesting points.
I'm going with my instinct on this one and the papers I've read on the subject.
I'm going to try and match the diameter of the Bantam's favorite roosting branch in the magnolia tree. I'm going to have to hack the coop about a bit which is irritating given currently the perch ends are in square sockets that allow the perch ends to be outside the coop and receive daylight in an attempt to discourage mites, but I'll work something out.

 

[OhZark Biddies]

I re-purposed some wooden handrail that I'd taken down.

It's about 2" diameter but has a flat side that made it easy to mount, and is available at any big box home improvement store if you have such a thing where you reside.

Thought I'd mention it in case it helps someone in the future...

btw, I checked the suggestion box that hangs in the coop and there was no complaints about these as roosting bars, so the chickens seem happy with them

 

[Ridgerunner]

For reference this is how I keep my tree branches with the bark on stable. They are very easy to remove, just pop the nail out.

It can be a bit hard to see the actual diameter but the red hen is roosting right at this end, next to the rooster. The far end, where chickens also roost, is close to 4" in diameter.

 

[Evelyn's Mom]

I've been in the woods looking for perch branches. I want some reasonably straight pieces over a metre in length. I've seen a few Holme Oak branches that might do and if it gets cool enough this week I'm going to cut them down and get the bark off.
I'm not going to do any testing; True Patriot has started a thread on testing here.

https://www.backyardchickens.com/articles/the-perch-experiment.74272/

If for some reason the hens refuse to use them then I'll post in the thread above.
It's not very scientific but I can't see a sensibly sized branch being any worse than stock square timber.

I like the upper branches of sycamore.. already smooth but a little "scaly" for gripping. And pretty!