|A scruffy Northern Mockingbird in molt. Photo by J. J. Meyer|
By the end of August, many songbirds have started to molt. Every bird has a complete molt once a year. Most birds molt in late summer and early fall, but the way birds molt differs among species. Some have a partial molt, then migrate. But they’re not normally in a full molt when flying long distances. Molting generally occurs after breeding because it requires a lot of energy.
Birds tend to become secretive while molting, vocalizing infrequently and hiding in the vegetation. That’s because they’re more vulnerable to predators during molt, especially when growing new flight feathers. It may take weeks or months for them to complete the molting cycle.
With adult birds in molt and juveniles in the midst of developing adult plumage, bird identification can be a challenge this time of year.