Do birds select habitat or food resources? Nearctic-neotropic migrants in northeastern Costa Rica.
Nearctic-neotropic migrant birds need to replenish energy reserves during stopover periods to successfully complete their semiannual movements. In this study we used linear models to examine the habitat use of 11 migrant species in northeastern Costa Rica to better understand the influence of food and structural resources on the presence of birds during stopover periods. Our models indicated that frugivorous migrants primarily used food abundance, while insectivorous migrants chiefly used vegetation structure as cues for habitat use during stopover. In addition to habitat use models, we documented fruiting plant phenology and found a general relationship between migrant arrival and the timing of ripe fruit availability. Our results suggest that insectivorous migrants probably rely on structural features when using habitat because it may be inherently difficult to assess cryptic-arthropod availability during a short period of time in a novel habitat, such as stopover periods.
School of Renewable Natural Resources, Louisiana State University Agricultural Center and Louisiana State University, Baton Rouge, Louisiana, United States of America ; Department of Wildlife, Humboldt State University, Arcata, California, United States of America.
Jared D
JD
Wolfe
Department of Wildlife, Humboldt State University, Arcata, California, United States of America.
Matthew D
MD
Johnson
Redwood Sciences Laboratory, United States Department of Agriculture Forest Service, Arcata, California, United States of America ; Klamath Bird Observatory, Ashland, Oregon, United States of America.
C John
CJ
Ralph
D025041:Animal Migration / Q000502:physiology; D000818:Animals; D001717:Birds / Q000502:physiology*; D003364:Costa Rica; D017753:Ecosystem; D012621:Seasons