Low food abundance prior to breeding results in female-biased sex allocation in Tengmalm’s Owl (Aegolius funerus)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00027014%3A_____%2F20%3AN0000005" target="_blank" >RIV/00027014:_____/20:N0000005 - isvavai.cz</a>

Alternative codes found

RIV/60460709:41210/20:79741 RIV/60460709:41330/20:79741

Result on the web

<a href="https://link.springer.com/content/pdf/10.1007/s10336-019-01707-1.pdf" target="_blank" >https://link.springer.com/content/pdf/10.1007/s10336-019-01707-1.pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s10336-019-01707-1" target="_blank" >10.1007/s10336-019-01707-1</a>

Result language

angličtina

Original language name

Low food abundance prior to breeding results in female-biased sex allocation in Tengmalm’s Owl (Aegolius funerus)

Original language description

Parents can enhance their fitness by favouring that sex whose reproductive value is expected to be highest. In species in which females are the larger sex with potentially greater fitness returns, one can assume that parents should bias their investment toward daughters to increase their daughters’ reproductive value (i.e. age-specific expectation of all present and future offspring) and, thereby, indirectly increase their own inclusive fitness. In the study reported here, we investigated sex allocation in Tengmalm’s Owl (Aegolius funereus), a bird species with a pronounced female-biased sexual size dimorphism in which females are larger than the males. Assuming that parental investment would have the greatest effect on the fitness of larger daughters, we hypothesized that daughters should be favoured in good conditions and sons in poor conditions. Our study was conducted in the Czech Republic over seven breeding seasons (2006–2012). In total, 205 nestlings from 52 nests were sexed. The mean nestling sex ratio, 48.5 ± 4.6% (± standard error), did not depart from parity, and we did not identify any variable to be related to it. However, we did find that at fledging (1) the body mass of female offspring was approximately 8% heavier than that of male offspring, and (2) surprisingly, the body mass of female offspring tended to increase with decreasing prey abundance in the autumn, i.e. prior to breeding. One possible explanation of this “carry-over effect” is that parents increased their investment toward daughters to maximize their daughters’ survival and reproductive value in a poor environment. This explanation could be supported by the sex-specific effect of the adult’s condition on reproductive success. Whereas the number of fledglings tended to increase with increasing age of the mother, it also increased with decreasing wing length of the father. These results indicate that in the Tengmalm’s Owl large body size may be mainly important for female reproduction, while male reproductive success is independent of body size or is even associated with small body size. To the best of our knowledge, our study is the first to have found such a positive, relatively long-lasting, sex-specific carry-over effect of pre-breeding prey abundance on the condition of female offspring in a bird of prey species.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10614 - Behavioral sciences biology

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Ornithology

ISSN

0021-8375

e-ISSN

—

Volume of the periodical

161

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

12

Pages from-to

159-170

UT code for WoS article

000511854700014

EID of the result in the Scopus database

2-s2.0-85071746658