Mixed-species Foraging Flock - in The Holarctic

In The Holarctic

In the North Temperate Zone, they are typically led by Paridae (tits and chickadees), often joined by nuthatches (Sitta), treecreepers (Certhia), woodpeckers (Picidae, such as the Downy Woodpecker "Picoides" pubescens and Lesser Spotted Woodpecker "P." minor), kinglets (Regulus), and in North America Parulidae (New World "warblers") – all insect-eating birds. This behavior is particularly common outside the breeding season.

The advantages of this behavior are not certain, but evidence suggests that it confers some safety from predators, especially for the less watchful birds such as Vireonidae (vireos) and woodpeckers, and also improves feeding efficiency, perhaps because arthropod prey that flee one bird may be caught by another.