Is This Bird Cheating?

Male birds are often flashy looking during mating season. The idea has always been that deep and bright colors let the ladies know these guys are very healthy and would make a good catch. The right diet and overall tiptop health has been believed to enable them to pack loads of carotenoids into their feathers to flash around. Recent research may upend some of that theory though, and put researchers back to wondering if we are looking at birds through our own lens? This latest discovery has a lot more to do with feather construction than diet.  Check out this article in the NYT.
Summer Tanager; Photo Credit: Deborah Rivel