Ptarmigan Toenail length
I was fortunate to see (and kill) my first two winter ptarmigan yesterday. I've attached a picture of their feet next to one another. At first glance there isn't that big of a difference but when you look at where the cuticle (proper term?) ends on each you can see that the foot on the left has much longer toenails. That bird was also much better conditioned with greater fat reserves. Any hunches as to why one bird would have monster toenails and the other wouldn't? I doubled on this pair and neither dog nor human saw any trace of any other birds nearby. They each had a comb but I didn't see anything different about one than the other.
I could only hazard some guesses, like different age birds? Different sex (smaller)? One scratches more, and harder than the other? I dunno, can't imagine every ptarmigan is a carbon copy of another. But now you'll have me looking. Just got home with a pile of willow ptarmigan and after I relax and finish this fine glass of Merlot I'll check them out when cleaning them.
On another note...After hunting most of the day with the gun, I went back up into the higher elevations with just a camera. The dogs found some rock ptarmigan grouping up on their breeding ground and I took some photos. Some of them had obvious blueberry stains on their face and head. They love those over-winter blueberries this time of year. The willows were, of course, bobbing for buds up in the branches of willow trees.
Congratulations on taking those first winter ptarmigan PG13! There's no stopping you now!
I think it's probably something simple like "all birds are not created equal" as you mentioned. I'm curious though and thought maybe someone else has seen something similar. For all I know the two birds were different species.