Data from: Kin-bias, breeding site selection, and female fitness in a cannibalistic Neotropical frog

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.

资源可获得性影响种群内的性选择，并决定领域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Thoropa taophora中，雄性竞争并保卫有限的繁殖位点，而雌性常与其他雌性共享繁殖位点；然而，共享繁殖位点可能因同种蝌蚪的同类相食而产生代价。我们研究了T. taophora的一个繁殖种群，旨在确定：（i）该物种是否存在一雄多雌交配系统（polygynous mating），其中雌性选择领域雄性且繁殖资源有限；（ii）有限的繁殖资源是否为雄性间合作保卫邻近领域创造了可能性；（iii）共享繁殖位点的雌性是否表现出亲缘偏爱的繁殖位点选择，这可能由共享位点雌性后代间的同类相食导致的适合度损失所驱动。我们使用微卫星（microsatellites）标记在焦点种群（该种群中繁殖位点稀缺）的8个繁殖位点以及另一个繁殖位点丰富的种群中重建亲子关系并量化亲缘关系。我们发现，在繁殖位点空间有限的区域，该物种的交配系统为一雄多雌制，通常有两名雌性与一名雄性共享一个繁殖位点。我们还发现，雌性在繁殖位点选择中表现出负亲缘偏好，这可能是为了通过避免高亲缘关系的蝌蚪同类相食来最大化其广义适合度（inclusive fitness）。我们的结果表明，雄性领域防御和雌性位点共享可能是该交配系统的重要组成部分，并且我们提出，交配策略中依赖亲缘关系的回避行为可能比之前所认识到的更为普遍。