Full life-cycle research reveals forest birds require multiple-aged landscapes

Habitat requirements of birds have, until recently, been based exclusively on breeding season behaviors. We present three examples of birds shifting their activities to forests of different ages and structures after breeding. Cerulean Warblers (Setophaga cerulea) breed exclusively in open, mature deciduous forests. Radio tracking of fledglings revealed they preferentially move to areas of younger forests with dense midstories. Conversely, the Golden-winged Warbler (Vermivora chrysoptera) inhabits early-successional openings in forest to nest, but in one of two populations parents led their young into late-successional forests shortly after they fledged. Mistnetting in young regenerating stands and mature forest understories suggested that these habitats shifts are the norm for breeding birds of late-successional forests. We suggest that a mosaic of multiple age classes be maintained in forests to fulfill avian habitat needs.