Cavity use throughout the annual cycle of a migratory woodpecker revealed by geolocators

The importance of cavities as roost sites in migratory species is often unknown because it is challenging to monitor cavity use during the non-breeding period. We documented cavity use throughout the annual cycle of a woodpecker using light-level geolocators. Northern Flickers Colaptes auratus spent 63-90% of nights roosting in a cavity throughout the year, including during migration. The high frequency of year-round cavity use by Flickers suggests that cavities provide benefits beyond nest-sites. Our work highlights the potential use of geolocators to examine cavity use.