Journal Article

Determinants of false alarms in staging flocks of semipalmated sandpipers

Guy Beauchamp

in Behavioral Ecology

Published on behalf of International Society for Behavioral Ecology

Volume 21, issue 3, pages 584-587
Published in print January 2010 | ISSN: 1045-2249
Published online March 2010 | e-ISSN: 1465-7279 | DOI: https://dx.doi.org/10.1093/beheco/arq032
Determinants of false alarms in staging flocks of semipalmated sandpipers

More Like This

Show all results sharing these subjects:

  • Evolutionary Biology
  • Ecology and Conservation
  • Zoology and Animal Sciences

GO

Show Summary Details

Preview

False alarms occur when animals flee abruptly upon detection of a threat that subsequently proved harmless. False alarms are common in many species of birds and mammals and account for a surprisingly high proportion of all alarms. False alarms are expected to be more frequent in larger groups, where the odds of misclassifying threats are higher, and under environmental conditions where detection of threats is compromised, such as low light levels. In addition, false alarms should be less frequent when the energetic cost of fleeing increases. I examined these hypotheses in roosting flocks of staging semipalmated sandpipers (Calidris pusilla) over 2 years. False alarms increased with group size but the effect of group size was confounded by the fact that more attacks by falcons (Falco spp.) were directed at larger roosts. False alarms were more frequent at low light levels and later during staging. As individuals double their body mass during staging, the energetic cost of fleeing must greatly increase thus contributing to decreased responsiveness. A simple reduction in responsiveness caused by repeated exposures to harmless signals would also produce a temporal decrease in responsiveness but this hypothesis cannot account for the effect of group size and light level. Study of the determinants of false alarms provides an opportunity to examine adjustments in behavior in relation to changes in perceived predation risk.

Keywords: false alarm; group size; predation risk; roosting; semipalmated sandpiper; stopover ecology

Journal Article.  3430 words. 

Subjects: Evolutionary Biology ; Ecology and Conservation ; Zoology and Animal Sciences

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.