Originally Posted by MeepBeep
Anyone that says chickens can't perch is just being ignorant... They can perch but not as well as many other perching birds and not was well as their wild counterparts due to their increased body weight and captive behaviors (aka more time spent at roost) and thus the proper sized and shaped perch makes all the difference...
Not saying they can't use a round perch, they can but studies show it's not ideal...
This article gives some good scientific study references and explanations...
In climates that experience freezing temps the compromise of a flat perch seems to be the best compromise option as it allows them to easy cover their toes in cold weather and avoid frostbite... In warmer climates the properly size flat with rounded edges sized to your chickens feet seems to be ideal based on studies for most modern breeds that differ from their wild counterparts...
This is very curious, thanks MeepBeep.
I went out and found a "volunteer" (or as my kids say, "voluntold"). Echo (standard size Black Australorp) volunteered only because I knew if I had some of the ornamental cherries, conveniently ripe right now, she would get in my lap where I could grab her. Tip to tip, she measures ~3" back toe to middle toe. Based on the article:
- The minimum diameter of a round roost would be ~1" (so her toes don't touch).
- But, they said square with rounded edges are better with a minimum of 4 cm (1.58") which happens to be pretty close to a 2x2 and does exceed her 1" minimum diameter for a round roost.
BUT, it also said that they put 5x the weight on their keel bone as they do on their foot pads when they are roosting. So we have to modify our "they sleep flat on their feet" to something like: "they sleep on their keels, with their feet keeping their side to side balance". I'm having trouble figuring out just how much keel they can have on a roost 1.5" wide (*). The 2 Rocks that were on the 1/2" plywood must have been putting a lot more weight on their feet than they would on a "proper roost".
The "standard" 2x4 on the flat roost under Echo's feet (if evenly placed) will have an extra 1/4" in front and behind. Thus she is flat on her feet, toes extended. I wonder if they would be more comfortable with some amount of "toe curl". I guess they could be sleeping forward on the roost with their front toes curled over the edge of the 2x4 so they aren't totally flat footed, but I have no way of knowing that. Obviously the 3" fence rail provides a gentle toe curl, front and rear, but it likely doesn't provide as much keel support since it is a continuous curve and not being made of foam, won't allow the keel to sink in. Their keels are probably point loaded. But then the keel isn't a flat surface, so it might not matter, they are probably point loaded anyway. I've not seen a preference for either roost shape (**) They seem to go for walls and outside corners over roost shape. They do seem to walk more easily on the round fence rail though.
And overthinking this just a bit more, chicken toes are jointed so I would GUESS that the ideal roost wouldn't be such that there is a horizontal to vertical change between joints but right at the joint. Custom made perches for each chicken anyone?? Or, as I suggested above, they might move forward to position their feet so the horizontal to vertical transition IS at a toe joint and only their back toe has to be out flat.
It would seem the ideal shape would be one where their toes can curl over some (still covered in the winter in our colder climates) but there is a perpendicular support for the keel. But the perpendicular part couldn't force their legs out of the natural position. Individual "chicken beds" with a slight up curved 1" wide "keel board" set into a perpendicular 2x2 "foot board" ???? OK, I can't imagine my birds would settle into an "anatomically correct" curved bed.
* I know, I KNOW - 1.5"! But how much is 1.5" as a percentage of how much they would ideally have on the roost??
** Other than my own. I note the fence rail rarely has any poop on it, where as the 2x4s have a fair bit).