Timing of avian reproduction in unpredictable environments

Jácint Tökölyi, John M. McNamara, Alasdair I. Houston, Z. Barta

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Organisms living in periodically varying environments adjust their life history events to the changes in food availability. When these changes are not entirely predictable animals face a trade-off between maintaining physiological preparedness (which can be costly) and being unprepared (which decreases the chances of successful reproduction). To investigate this problem, we developed an optimal annual routine model of gonad regulation in birds. Most birds regress their reproductive organs during non-breeding periods, but to start breeding again they need to have functional gonads. Maintaining the gonads in this state is costly, but because it takes time to achieve this state, if gonads are not functional the bird may miss a possible breeding opportunity. We explore the resolution of this trade-off in environments where favorable periods can occur at any time of the year and variability in the length of good and bad periods can be altered. Consistent with empirical studies of reproductive behavior in unpredictable environments, we find that birds maintain the gonads partially activated during unfavorable conditions in many cases. However, gonad regulation may differ strikingly depending on the consistency of the good and bad periods. Furthermore, seasonal changes in food availability lead to the entrainment of reproduction and the segregation of the breeding and non-breeding season, even if the magnitude of seasonality is small compared to the degree of environmental fluctuations. These results indicate that several aspects of the environment need to be taken into account to understand reproductive behavior in unpredictable environments. Given that the trade-off between the costs and benefits of maintaining physiological preparedness is not limited to birds, our results have implications for understanding behavioral flexibility in other organisms as well.

Original languageEnglish
Pages (from-to)25-42
Number of pages18
JournalEvolutionary Ecology
Volume26
Issue number1
DOIs
Publication statusPublished - Jan 2012

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gonads
bird
trade-off
reproductive behavior
breeding
birds
food availability
entrainment
seasonality
life history
organisms
animal
cost
animals
regulation
organism

Keywords

  • Annual routine
  • Breeding season
  • Gonadal cycle
  • Opportunism
  • Phenotypic flexibility

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Cite this

Timing of avian reproduction in unpredictable environments. / Tökölyi, Jácint; McNamara, John M.; Houston, Alasdair I.; Barta, Z.

In: Evolutionary Ecology, Vol. 26, No. 1, 01.2012, p. 25-42.

Research output: Contribution to journalArticle

Tökölyi, Jácint ; McNamara, John M. ; Houston, Alasdair I. ; Barta, Z. / Timing of avian reproduction in unpredictable environments. In: Evolutionary Ecology. 2012 ; Vol. 26, No. 1. pp. 25-42.
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