First evidence of sex differences in the duration of avian embryonic period

G Blanco, Jesus Martinez-Padilla, J A Davila, D Serrano, J Vinuela

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Parental favoritism in birds would be enhanced if parents can control any egg feature influencing the ontogeny of the embryo during incubation. Egg size and composition may influence the duration of incubation and hatching periods, and eggs bearing embryos of different sex may differ in size and composition. Therefore, the sex of the embryo could also influence its ontogeny before hatching. We tested this prediction by investigating the duration of the embryonic period of different-sex embryos in the Eurasian kestrel (Falco tinnunculus), a sexually dimorphic raptor in which adult females are approximately 20% heavier than are adult males. We found the first evidence of sex differences in the duration of the embryonic period in avian eggs. Female embryos had a shorter embryonic period than did male embryos, which allowed females to hatch earlier in the hatching sequence and assume a higher rank than that of males in the intrabrood size hierarchy. Embryos with a fast growth and development resulted in hatchlings with greater residual reserves and thus larger mass, which suggests that a shorter embryonic period requires less maintenance metabolism relative to growth. Our results also indicated that early hatching may be advantageous to gain a high rank in the size hierarchy within the brood independently of the effect of sex on fledgling mass. Sex differences in avian egg ontogeny may therefore be a factor shaping life-history traits associated with parental control of sibling competition, which should be addressed in any future work on optimal reproductive investment.

Original languageEnglish
Pages (from-to)702-706
Number of pages5
JournalBehavioral Ecology
Volume14
Issue number5
DOIs
Publication statusPublished - Sep 2003

Keywords

  • avian egg
  • embryo ontogeny
  • parental favoritism
  • sex differences
  • HATCHING ASYNCHRONY
  • PARENTAL INVESTMENT
  • INCUBATION PERIOD
  • NESTLING GROWTH
  • SURVIVAL
  • RATIO
  • EGGS
  • ANDROGENS
  • KESTRELS
  • MAMMALS
  • parental favoritism

Cite this

Blanco, G., Martinez-Padilla, J., Davila, J. A., Serrano, D., & Vinuela, J. (2003). First evidence of sex differences in the duration of avian embryonic period. Behavioral Ecology, 14(5), 702-706. https://doi.org/10.1093/beheco/arg049

First evidence of sex differences in the duration of avian embryonic period. / Blanco, G ; Martinez-Padilla, Jesus; Davila, J A ; Serrano, D ; Vinuela, J .

In: Behavioral Ecology, Vol. 14, No. 5, 09.2003, p. 702-706.

Research output: Contribution to journalArticle

Blanco, G, Martinez-Padilla, J, Davila, JA, Serrano, D & Vinuela, J 2003, 'First evidence of sex differences in the duration of avian embryonic period', Behavioral Ecology, vol. 14, no. 5, pp. 702-706. https://doi.org/10.1093/beheco/arg049
Blanco G, Martinez-Padilla J, Davila JA, Serrano D, Vinuela J. First evidence of sex differences in the duration of avian embryonic period. Behavioral Ecology. 2003 Sep;14(5):702-706. https://doi.org/10.1093/beheco/arg049
Blanco, G ; Martinez-Padilla, Jesus ; Davila, J A ; Serrano, D ; Vinuela, J . / First evidence of sex differences in the duration of avian embryonic period. In: Behavioral Ecology. 2003 ; Vol. 14, No. 5. pp. 702-706.
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