Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2002 Mar 22;269(1491):647-54.
doi: 10.1098/rspb.2001.1929.

Cyclic variation in seasonal recruitment and the evolution of the seasonal decline in Ural owl clutch size

Affiliations

Cyclic variation in seasonal recruitment and the evolution of the seasonal decline in Ural owl clutch size

Jon E Brommer et al. Proc Biol Sci. .

Abstract

Plastic life-history traits can be viewed as adaptive responses to environmental conditions, described by a reaction norm. In birds, the decline in clutch size with advancing laying date has been viewed as a reaction norm in response to the parent's own (somatic or local environmental) condition and the seasonal decline in its offspring's reproductive value. Theory predicts that differences in the seasonal recruitment are mirrored in the seasonal decrease in clutch size. We tested this prediction in the Ural owl. The owl's main prey, voles, show a cycle of low, increase and peak phases. Recruitment probability had a humped distribution in both increase and peak phases. Average recruitment probability was two to three times higher in the increase phase and declined faster in the latter part of the season when compared with the peak phase. Clutch size decreased twice as steep in the peak (0.1 eggs day-1) as in the increase phase (0.05 eggs day-1). This result appears to refute theoretical predictions of seasonal clutch size declines. However, a re-examination of current theory shows that the predictions of modelling are less robust to details of seasonal condition accumulation in birds than originally thought. The observed pattern can be predicted, assuming specifically shaped seasonal increases in condition across individuals.

PubMed Disclaimer

References

    1. Science. 2001 Mar 30;291(5513):2598-600 - PubMed
    1. Nature. 1996 Mar 21;380(6571):215-21 - PubMed
    1. Biol Rev Camb Philos Soc. 1995 Nov;70(4):621-37 - PubMed
    1. Am Nat. 2000 Apr;155(4):453-472 - PubMed

Publication types

LinkOut - more resources