Muralidhar P, de Sá F P, Haddad C F B, Zamudio K R
Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA.
Departamento de Zoologia, Instituto de Biociências, Universidade Estadual Paulista - UNESP, Cx, Postal 199, 13506-900, Rio Claro, São Paulo, Brazil.
Mol Ecol. 2014 Feb;23(2):453-63. doi: 10.1111/mec.12592. Epub 2013 Dec 11.
Resource availability influences sexual selection within populations and determines whether behaviours such as territoriality or resource sharing are adaptive. In Thoropa taophora, a frog endemic to the Atlantic Coastal Rainforest of Brazil, males compete for and defend limited breeding sites while females often share breeding sites with other females; however, sharing breeding sites may involve costs due to cannibalism by conspecific tadpoles. We studied a breeding population of T. taophora to determine (i) whether this species exhibits polygynous mating involving female choice for territorial males and limited breeding resources; (ii) whether limited breeding resources create the potential for male-male cooperation in defence of neighbouring territories; and (iii) whether females sharing breeding sites exhibit kin-biased breeding site choice, possibly driven by fitness losses due to cannibalism among offspring of females sharing sites. We used microsatellites to reconstruct parentage and quantify relatedness at eight breeding sites in our focal population, where these sites are scarce, and in a second population, where sites are abundant. We found that at localities where the appropriate sites for reproduction are spatially limited, the mating system for this species is polygynous, with typically two females sharing a breeding site with a male. We also found that females exhibit negative kin-bias in their choice of breeding sites, potentially to maximize their inclusive fitness by avoiding tadpole cannibalism of highly related kin. Our results indicate that male territorial defence and female site sharing are likely important components of this mating system, and we propose that kinship-dependent avoidance in mating strategies may be more general than previously realized.
资源可用性影响种群内的性选择，并决定诸如领地行为或资源共享等行为是否具有适应性。在巴西大西洋沿岸雨林特有的蛙类陶氏雨蛙中，雄性争夺并保卫有限的繁殖地点，而雌性通常与其他雌性共享繁殖地点；然而，由于同种蝌蚪的自相残杀，共享繁殖地点可能会带来代价。我们研究了一个陶氏雨蛙的繁殖种群，以确定：（i）该物种是否表现出一夫多妻制的交配方式，即雌性选择有领地的雄性和有限的繁殖资源；（ii）有限的繁殖资源是否为雄性在保卫相邻领地方面的合作创造了潜力；（iii）共享繁殖地点的雌性是否表现出亲属偏向的繁殖地点选择，这可能是由于共享地点的雌性后代之间的自相残杀导致的适应性损失所驱动。我们使用微卫星来重建我们重点研究种群中八个繁殖地点的亲子关系并量化亲缘关系，这些地点在该种群中很稀缺，同时我们也在另一个繁殖地点丰富的种群中进行了研究。我们发现，在繁殖适宜地点在空间上有限的地区，该物种的交配系统是一夫多妻制，通常有两只雌性与一只雄性共享一个繁殖地点。我们还发现，雌性在选择繁殖地点时表现出负亲属偏向，这可能是为了通过避免高度相关亲属的蝌蚪自相残杀来最大化其广义适合度。我们的结果表明，雄性领地防御和雌性地点共享可能是这种交配系统的重要组成部分，并且我们提出，交配策略中依赖亲属关系的回避可能比之前所认识到的更为普遍。
