Flight of picids is often undulating, but the largest woodpeckers tend toward less undulation and more level flight. Pi-cid wings tend to be relatively short and rounded, providing better control for maneuvering in forest habitats. Some species, such as the yellow-bellied sapsucker (Sphyrapicus var-ius) and northern flicker (Colaptes auratus) in North America are migrant (at least in northern populations). The yellow-bellied sapsucker shows a distinct pattern of differential migration by the sexes, females going farther south. Others such as the three-toed woodpecker (Picoides tridactylus) are somewhat irruptive, departing areas when food supplies are low and moving to areas of food concentration such as epidemic beetle outbreaks. Most occupy similar habitats year round, but some can make drastic seasonal shifts. The red-headed woodpecker (Melanerpes erythrocephalus), for example, is generally a bird of very open habitats where it feeds on beetles, grasshoppers, other arthropods, and some fruit during summer, but in winter it often moves to bottomland forest and focuses its foraging on acorns and other mast (nuts found on the forest floor).

Vocalizations are often simple, with single notes often used as contact calls between mates and "whinny" or "rattle" calls found with some variation across the family. In social species such as the California woodpecker (Melanerpes formicivorus) and red-cockaded woodpecker, the vocal repertoire can be more complex. Communication by production of mechanical sounds through tapping on resonant wood is

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