The Auk.: Socially induced synchronization of every-other-day egg laying in a seabird colony.
Article Type: Brief article
Subject: Breeding colonies (Research)
Birds (Eggs and nests)
Birds (Research)
Authors: Henson, S.M.
Hayward, J.L.
Cushing, J.M.
Pub Date: 12/01/2010
Publication: Name: Journal of Avian Medicine and Surgery Publisher: Association of Avian Veterinarians Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2010 Association of Avian Veterinarians ISSN: 1082-6742
Issue: Date: Dec, 2010 Source Volume: 24 Source Issue: 4
Topic: Event Code: 310 Science & research
Accession Number: 252005127
Full Text: Spontaneous oscillator synchrony has been documented in a wide variety of electrical, mechanical, chemical, and biological systems, including the menstrual cycles of women and estrous cycles of Norway rats (Rattus norvegicus). In temperate regions, many colonial birds breed seasonally in a time window set by photoperiod; some studies have suggested that heightened social stimulation in denser colonies can lead to a tightened annual reproductive pulse. It has been unknown, however, whether the analog of menstrual synchrony occurs in birds--that is, whether avian ovulation cycles can synchronize on a daily timescale within the annual breeding pulse. We report everyother-day clutch-initiation and egg-laying synchrony in a breeding colony of glaucous-winged gulls (Larus glaucescens) and show that the level of synchrony declined with decreasing colony density. We also pose a mathematical model based on the hypothesis that preovulatory luteinizing hormone surges synchronize through social stimulation. Model predictions are consistent with observations. Finally, we suggest a procedure for identifying synchronous egg laying in other colonies and species.

2010;127:571-580.
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