Forest birds select food-rich habitat during migratory stopover

Many species of migrant songbirds require stopover habitat during migration, as places to rest, and gain additional weight prior to proceeding on in migration. For some birds, the amount of time spent at stopover habitat exceeds the amount of time spent in flight during migration.  While the amount of time spent at stopover decreases as habitat quality increases, it is unclear what cues migrant birds use to identify high quality habitat.  A set of thirty sites north of Lake Ontario were surveyed weekly during April and early May for the presence of both migrant songbirds, and the emergence of arthropods, as a potential food source. Neither distance from Lake Ontario nor size of the forest had a significant influence on number of migrants or arthropod biomass observed at each stopover site.  Total arthropod biomass did however have a significant positive influence on the total number of migrants observed over the course of the migration season.  The relationship between arthropod biomass...