• Publications
  • Influence
Yolk is a source of maternal testosterone for developing birds.
  • H. Schwabl
  • Biology
    Proceedings of the National Academy of Sciences…
  • 15 December 1993
TLDR
These findings indicate that female songbirds can bestow upon their eggs a dose of hormone that modifies the behavior of offspring, suggesting that variable doses of these hormones might explain some of the individual variation in offspring behavior.
Maternal testosterone in the avian egg enhances postnatal growth.
  • H. Schwabl
  • Biology
    Comparative biochemistry and physiology. Part A…
  • 1 July 1996
Hormone-mediated maternal effects in birds: mechanisms matter but what do we know of them?
TLDR
This work discusses mechanisms underlying the pleiotropic actions of maternal steroids, since linked effects may influence the coevolution of parent and offspring traits, owing to their role in the mediation of physiological trade-offs.
Environment modifies the testosterone levels of a female bird and its eggs.
  • H. Schwabl
  • Biology
    The Journal of experimental zoology
  • 1 October 1996
TLDR
It is concluded that here the authors have a mechanism which communicates environmental conditions from the mother to the offspring, and that this mechanism serves to optimize reproduction and/or modify offspring traits.
Yolk androgens reduce offspring survival
TLDR
Additional studies are necessary in order to determine whether the deposition of yolk androgens is an adaptive form of parental favouritism or an adverse by–product of endocrine processes during egg formation, despite its adaptive significance.
Maternal androgens in black-headed gull (Larus ridibundus) eggs: consequences for chick development
We tested the hypothesis that mother birds counterbalance the negative effects of hatching asynchrony for later–hatched chicks by increasing the yolk androgen concentrations in consecutive eggs of
Yolk testosterone organizes behavior and male plumage coloration in house sparrows (Passer domesticus)
TLDR
The results suggest that variable concentrations of maternal testosterone in the eggs of the house sparrow organize the expression of a plumage trait in males and behavior in both sexes.
Determinants of within‐ and among‐clutch variation in levels of maternal hormones in Black‐Headed Gull eggs
TLDR
The level of yolk androgen reflects the hormonal condition of the female, that in turn is influenced by her characteristics such as her age and aggressiveness, and the level of social stimulation, which may facilitate growth and motor development of the chicks.
The Contents of Maternal Testosterone in House Sparrow Passer domesticusEggs Vary with Breeding Conditions
  • H. Schwabl
  • Biology
    Naturwissenschaften
  • 1 September 1997
TLDR
A chronology of key events, books and articles related to pottery analysis, written by R.P. Evershed and R.C. Rottlander between 1989 and 1995.
Female collared flycatchers adjust yolk testosterone to male age, but not to attractiveness
TLDR
It is shown that free-living females of the collared flycatcher (Ficedula albicollis), a small passerine bird, do not produce larger eggs or deposit more testosterone into eggs when mating with attractive males, contrary to the prediction of the differential allocation hypothesis, and higher yolk testosterone concentrations in eggs laid for young than older males are found.
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