The secret life of oilbirds: new insights into the movement ecology of a unique avian frugivore.
BACKGROUND
Steatornis caripensis (the oilbird) is a very unusual bird. It supposedly never sees daylight, roosting in huge aggregations in caves during the day and bringing back fruit to the cave at night. As a consequence a large number of the seeds from the fruit they feed upon germinate in the cave and spoil.


RESULTS
Here we use newly developed GPS/acceleration loggers with remote UHF readout to show that several assumptions about the behaviour of Steatornis caripensis need to be revised. On average, they spend only every 3(rd) day in a cave, individuals spent most days sitting quietly in trees in the rainforest where they regurgitate seeds.


CONCLUSIONS
This provides new data on the extent of seed dispersal and the movement ecology of Steatornis caripensis. It suggests that Steatornis caripensis is perhaps the most important long-distance seed disperser in Neotropical forests. We also show that colony-living comes with high activity costs to individuals.
Holland
Richard A
RA
Department of Migration and Immuno-Ecology, Max-Planck Institute for Ornithology, Radolfzell, Germany. rholland@orn.mpg.de
Wikelski
Martin
M
Kümmeth
Franz
F
Bosque
Carlos
C
D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001717:Birds / Q000502:physiology*; D055669:Ecological and Environmental Phenomena; D017753:Ecosystem; D005247:Feeding Behavior / Q000502:physiology*; D005426:Flight, Animal / Q000502:physiology; D005638:Fruit; D040362:Geographic Information Systems; D009425:Nesting Behavior / Q000502:physiology