23 August 2020
Many birds look ragged right now because they’re molting. July and August are the perfect time to replace worn feathers because the breeding season is over, food is plentiful and they aren’t traveling on migration. The cardinal below looks moth-eaten because he’s molting his body feathers.
What a red bird eats while he’s molting affects his feathers. Red feathers get their color from carotenoids in food so a diet rich in carotenoids makes a cardinal brighter for the coming year.
Bush honeysuckle, though invasive, is a good source of carotenoids. Unfortunately it’s not as nutritious as our native berries.
This bright red cardinal is eating American beautyberry (Callicarpa americana). The redder he is, the better the ladies like him.
This dull colored cardinal must have missed the red berries last summer.
House finches have a more obvious response to nutrition while molting. Finches without enough carotenoids produce orange feathers instead of red. In Marcy Cunkelman’s photo below there’s an orange house finch on the right, a red one on the left.
You are what you eat.
(photos by Bob Kroeger, Marcy Cunkleman, Kate St. John and from Wikimedia Commons)