Just as people make seasonal wardrobe changes, many birds are beginning a transformation of their own, losing and replacing their feathers in a process known as molting. Molting is when a bird replaces some (partial molt) or all (full molt) of its feathers. This complicated process requires a lot of energy and may take up to eight weeks to complete. Distinguishing birds that are molting from those that are not can be difficult. Though some birds may lose patches of feathers and appear “balding,” most birds’ feather loss and replacement are far less noticeable However, molting is so physically demanding for most ducks and geese that they can’t fly and will molt in seclusion to avoid predators.
For many birds, the color and brightness of their feathers play a very important role in their breeding success. The more brightly colored a bird is, the more likely it is to attract a mate. Bright, vibrant plumage signals that the bird, usually the male, can be a good provider and successfully obtain a sufficient amount of quality food.
Feathers are made of more than 90% protein, primarily keratins, so every molting bird needs extra proteins to grow strong feathers for proper flight and effective insulation. Though feathers are mostly protein, fats are essential for developing the best feather coloration. In many bird species, carotenoids (from fats) are used much like the pigment dyes that color clothing. Carotenoids provide red, orange and yellow to violet colors in feathers. Without fats and proteins, birds such as House Finches, Northern Cardinals, American Goldfinches would appear less bright.
Molting season varies by species and time of year. Right now many birds are beginning their main molt of the year; however, American Goldfinches are one of the last to molt. Due to their late nesting period, they won’t start their molt until late August.
By providing foods that are loaded with fats and proteins in your birdfeeders, you will help your colorful birds maintain their vibrancy. Peanuts are the best single source of protein and fat for your birds and attract woodpeckers, titmice, nuthatches, chickadees, jays and more. Mealworms are a good protein source. Suet is a high-fat food that also contributes protein if nuts and/or bugs are mixed into it. Birdfoods, such as niger/thistle, sunflower, and safflower all contain oils that help to meet the nutritional needs of molting birds that are not peanut eaters. These high-fat, high protein foods are good to feed throughout the winter, too. They provide energy to help birds survive the cold.