Affiliation:
1. Department of Geography, Planning and Environment, Concordia University , Montréal, QC , Canada
2. Department of Biology, Concordia University , Montréal, QC , Canada
Abstract
Abstract
Most experimental tests of mating systems theory have been conducted in the laboratory, using operational sex ratios (ratio of ready-to-mate male to ready-to-mate female) that are often not representative of natural conditions. Here, we first measured the range of adult sex ratio (proportion of adult males to adult females; ASR) in two populations of Trinidadian guppies (Poecilia reticulata) differing in ambient predation risk (high vs. low). We then explored, under semi-wild conditions, the effect of ASR (i.e., 0.17, 0.50, 0.83) on mating competition patterns in these populations. ASR in the wild was female-biased and did not significantly differ between the two populations. The range of ASR in our experiment was representative of natural ASRs. As expected, we observed an increase in intrasexual aggression rates in both sexes as the relative abundance of competitors increased. In support of the risky competition hypothesis, all measured behaviors had lower rates in a high versus low predation-risk population, likely due to the costs of predation. In terms of mating tactics, a male-biased ASR did not lead males to favor forced mating over courtship, indicating that males did not compensate for the cost of competition by switching to a less costly alternative mating tactic. Overall, this study highlights the need for field experiments using natural ranges of ASRs to test the validity of mating systems theory in a more complex, ecologically relevant context.
Funder
National Research Council of Canada
Publisher
Oxford University Press (OUP)
Subject
Animal Science and Zoology,Ecology, Evolution, Behavior and Systematics
Reference78 articles.
1. Estimating adult sex ratios in nature.;Ancona;Philos Trans R Soc Lond B Biol Sci,2017
2. Individual variation in reproductive behaviour is linked to temporal heterogeneity in predation risk.;Barbosa;P R Soc B Biol Sci,2018
3. Guppies control offspring size at birth in response to differences in population sex ratio;Barbosa;Biol J Linn Soc,2010
4. Risk-sensitive antipredator behavior in the Trinidadian guppy, Poecilia reticulata;Botham;Ecology,2008
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献