(noun) A state of extreme increased appetite and nearly continual eating. Many migratory bird species enter hyperphagia several days or weeks before beginning migration in order to store excess fat to serve as energy during the journey. The fat is stored principally along the breast and flanks, and birds often increase their body mass by 30-50 percent during this time. While hyperphagia has not been extensively studied, it is believed to be triggered by the same factors that birds use to know when to migrate, including changing daylight levels.
Backyard birders can assist birds in hyperphagia by ensuring feeders are filled with foods high in calories and fat such as suet, peanut butter, nuts, Nyjer, black oil sunflower seeds and nectar. Just before migration begins, birds will visit feeders more frequently and will feed for longer periods of time, and it is essential to keep feeders refilled so birds have the opportunity to build their fat reserves or they may not have enough energy to complete their migration successfully.
Photo – Feeding Hummingbird © Larry1732