Interactions between lay date, clutch size, and postlaying energetic needs in a capital breeder
The condition-dependent model of optimal clutch size assumes body reserves required to initiate egg production include those for subsequent breeding phases. The threshold is expected to be similar among individuals, and hence postlaying condition should be independent of clutch size and lay date. Alternatively, the cost of incubation hypothesis predicts that females laying larger clutches should secure extra resources for incubation, and the expected fitness hypothesis suggests females adjust their condition according to the anticipated fitness benefits of the clutch. In these 2 cases, postlaying condition is predicted to be positively related to clutch size. We tested these predictions in common eider (Somateria mollissima), a precocial bird that produce eggs mostly from stored lipids and partly from endogenous proteins and rely extensively on reserves to incubate. We collected females at incubation onset and measured body condition indicators. Clutch size (number of eggs laid or number found in the nest at incubation onset) was not related to postlaying fat stores but females that laid fewer eggs maintained extra protein reserves. Timing of breeding was not related to postlaying body mass or protein reserves, whereas lay date's relationship with fat stores varied annually. Our results are generally consistent with the condition-dependent model and indicate variation in postlaying condition is mostly driven by factors other than clutch size and lay date. These data are inconsistent with the cost of incubation and the expected fitness hypotheses and suggest body store differences at incubation onset are mostly caused by environmental conditions encountered by laying females. Copyright 2011, Oxford University Press.
If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.
Volume (Year): 22 (2011)
Issue (Month): 1 ()
|Contact details of provider:|| Postal: Oxford University Press, Great Clarendon Street, Oxford OX2 6DP, UK|
Fax: 01865 267 985
Web page: https://academic.oup.com/beheco
|Order Information:||Web: http://www.oup.co.uk/journals|
When requesting a correction, please mention this item's handle: RePEc:oup:beheco:v:22:y:2011:i:1:p:162-168. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Oxford University Press)or (Christopher F. Baum)
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
If references are entirely missing, you can add them using this form.
If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.
Please note that corrections may take a couple of weeks to filter through the various RePEc services.