Density and extra-pair fertilizations in birds: a comparative analysis

Westneat, David F.; Sherman, Paul W.

doi:10.1007/s002650050381

Cited by 396 publications

(343 citation statements)

References 138 publications

Supporting

Mentioning

321

Contrasting

Unclassified

Order By: Relevance

“…Because species living at high group densities may be adapted to cope with higher frequencies of malemale interactions, the challenge hypothesis would predict higher basal androgen levels throughout the breeding phases and hence, smaller androgen increases in response to an additional social challenge as compared with solitary males (Beletsky et al, 1992;Pankhurst and Barnett, 1993;Wada et al, 1999;Wingfield et al, 1999a). Among the species included in the present study there was no effect either of the breeding dispersal (i.e., species with dispersed or aggregated nesting; Westneat and Sherman, 1997;Searcy et al, 1999) or of group living outside of the breeding season (i.e., species with solitary males or species with multimale groups; Moller and Birkhead, 1993) on the flexibility of AR to social challenges. This does not exclude the possibility that breeding dispersal and group composition still remain secondarily involved parameters by being related with male-male aggressiveness and mating strategy, which were shown to modulate the androgen response rates.…”

Section: Discussionmentioning

confidence: 82%

“…The mode of group living that males of different species were coping with during the breeding season was qualitatively determined [i.e., breeding density: dispersed (N ϭ 42), or aggregated nesting (N ϭ 30), Westneat and Sherman, 1997;Searcy et al, 1999], as well as group living outside of the breeding season [species with solitary males (N ϭ 26) or species with multimale groups (N ϭ 52), Møller and Birkhead, 1993]. The effect of the pairbond type on the specific androgen response rates was also qualitatively determined as "no pairbond" (N ϭ 7), "seasonal bond" (N ϭ 32), or "longterm bond" (N ϭ 39) and was coded with dummy variables as the degree of paternal care.…”

Section: Social Environmentmentioning

confidence: 99%

See 1 more Smart Citation

Comparative analysis of male androgen responsiveness to social environment in birds: the effects of mating system and paternal incubation

Hirschenhauser¹,

Winkler²,

Oliveira³

2003

Hormones and Behavior

138

View full text Add to dashboard Cite

Male androgen responses to social challenges have been predicted to vary with mating system, male-male aggressiveness, and the degree of paternal investment in birds ("challenge hypothesis," Am. Nat. 136 (1990), 829). This study focused on the interspecific predictions of the challenge hypothesis. Comparative methods were used to control for effects of the phylogenetic relatedness among the sampled species. Male androgen data of 84 bird species were collected from literature records on seasonal androgen patterns. From these, the androgen responsiveness (AR) was calculated as described in the original challenge hypothesis (i.e., maximum physiological level/breeding baseline). Scatterplots of AR versus mating strategy, male-male aggressiveness, and the degree of paternal care confirmed the expected interspecific patterns. When phylogenetic analyses were performed among all of the sampled species, the effects of paternal investment disappeared while the AR remained covarying to a high degree with mating system and male-male aggressiveness. Although these mechanisms may be different at the intraspecific level, this suggests that interspecific differences of AR in male birds may have evolved in response to changes of mating strategies, rather than in response to altered paternal duties. However, control for phylogeny among the subsample of 32 passerine species revealed that if any paternal investment contributed to the observed variance in AR, then the change from "no male incubation" to "male shares incubation duties" represented the most effective, whereas the male's contribution to feeding offspring did not explain the observed variation of AR.

show abstract

Section: Discussionmentioning

confidence: 82%

Section: Social Environmentmentioning

confidence: 99%

Comparative analysis of male androgen responsiveness to social environment in birds: the effects of mating system and paternal incubation

Hirschenhauser¹,

Winkler²,

Oliveira³

2003

Hormones and Behavior

138

View full text Add to dashboard Cite

show abstract

“…However, in passerine birds, where sperm competition is common (Westneat & Sherman 1997) and frequent copulation appears to leave males' sperm depleted (Birkhead 1991;Westneat et al 1998;Nicholls 2000), there is no evidence so far that males strategically allocate sperm. This may be because few tests of strategic allocation have been possible because (i) there is great natural variation in the number of sperm per ejaculate (Amann 1981), and (ii) natural ejaculates are di¤cult to collect from birds (MÖller 1988).…”

Section: Introductionmentioning

confidence: 99%

Ejaculate allocation by male sand martins,Riparia riparia

Nicholls

Burke

Birkhead

2001

Proc. R. Soc. Lond. B

View full text Add to dashboard Cite

Males of many species allocate sperm to ejaculates strategically in response to variation in the risk and intensity of sperm competition. The notable exception is passerine birds, in which evidence for strategic allocation is absent. Here we report the results of a study testing for strategic ejaculate allocation in a passerine bird, the sand martin (Riparia riparia). Natural ejaculates were collected from males copulating with a model female. Ejaculates transferred in the presence of a rival male contained signi¢cantly more sperm than ejaculates transferred in the absence of a rival male. There was no evidence that this di¡er-ence was due to the confounding e¡ects of the year of ejaculate collection, the identity of the model female, the colony, the stage of season or the period of the day in which ejaculates were collected. A more detailed examination of the ejaculate patterns of individual males, achieved by the DNA pro¢ling of ejaculates, provided additional evidence for strategic allocation of sperm.

show abstract

“…Most studies have examined how variation in EPP is related to socio-ecological factors, such as local breeding synchrony and density, that affect opportunities for individuals to encounter and evaluate potential extrapair mates [6][7][8]. Some studies have found empirical support for the influence of these factors on the frequency of EPP [9,10], but the results are inconsistent among species and populations [2,7,11,12].…”

Section: Introductionmentioning

confidence: 99%

Experimental food supplementation reveals habitat-dependent male reproductive investment in a migratory bird

et al. 2015

View full text Add to dashboard Cite

Environmental factors can shape reproductive investment strategies and influence the variance in male mating success. Environmental effects on extrapair paternity have traditionally been ascribed to aspects of the social environment, such as breeding density and synchrony. However, social factors are often confounded with habitat quality and are challenging to disentangle. We used both natural variation in habitat quality and a food supplementation experiment to separate the effects of food availability-one key aspect of habitat quality-on extrapair paternity (EPP) and reproductive success in the black-throated blue warbler, Setophaga caerulescens. High natural food availability was associated with higher within-pair paternity (WPP) and fledging two broods late in the breeding season, but lower EPP. Food-supplemented males had higher WPP leading to higher reproductive success relative to controls, and when in low-quality habitat, food-supplemented males were more likely to fledge two broods but less likely to gain EPP. Our results demonstrate that food availability affects trade-offs in reproductive activities. When food constraints are reduced, males invest in WPP at the expense of EPP. These findings imply that environmental change could alter how individuals allocate their resources and affect the selective environment that drives variation in male mating success.

show abstract

Density and extra-pair fertilizations in birds: a comparative analysis

Cited by 396 publications

References 138 publications

Comparative analysis of male androgen responsiveness to social environment in birds: the effects of mating system and paternal incubation

Comparative analysis of male androgen responsiveness to social environment in birds: the effects of mating system and paternal incubation

Ejaculate allocation by male sand martins,Riparia riparia

Experimental food supplementation reveals habitat-dependent male reproductive investment in a migratory bird

Contact Info

Product

Resources

About