摘要
Based on histological analyses and field studies,this research describes the reproductive ecology of a population of Ninia atrata snakes inhabiting an oil palm plantation.Furthermore,through a multivariate approach,we explored the main drivers of reproductive output in N.atrata.Results showed that prey abundance and food intake were crucial variables contributing to reproductive output.Multiple linear regression models showed that neonates had high sensitivity(R2=55.29%)to extreme changes in climate,which was strongly related to slug and snail abundance variability and microhabitat quality.Reproductive cycles were markedly different between the sexes,being continuous in males and cyclical in females.Despite this variation,reproductive cycles at the population level were seasonal semi-synchronous.Constant recruitment of neonates all year,multiple clutches,high mating frequency,and continuous sperm production characterized the reproductive phenology of N.atrata.In addition,a significant number of previtellogenic females presented oviductal sperm as well as uterine scars,suggesting a high precocity in the species.The main drivers of reproductive output also differed between the sexes.In females,clutch size and secondary follicle variability were highly related to stomach bolus volume,fat body area,and body mass.In males,height of piles of palm leaves and body mass,rather than intrinsic reproductive traits,were the main drivers of sperm production.Nevertheless,in both cases,the relationship between body mass,prey abundance,and food intake suggests that N.atrata follows the income breeding strategy to compensate for reproductive costs and to maximize fitness.
Based on histological analyses and field studies, this research describes the reproductive ecology of a population of Ninia atrata snakes inhabiting an oil palm plantation. Furthermore, through a multivariate approach, we explored the main drivers of reproductive output in N. atrata. Results showed that prey abundance and food intake were crucial variables contributing to reproductive output. Multiple linear regression models showed that neonates had high sensitivity(R2=55.29%) to extreme changes in climate, which was strongly related to slug and snail abundance variability and microhabitat quality.Reproductive cycles were markedly different between the sexes, being continuous in males and cyclical in females. Despite this variation,reproductive cycles at the population level were seasonal semi-synchronous. Constant recruitment of neonates all year, multiple clutches, high mating frequency, and continuous sperm production characterized the reproductive phenology of N.atrata. In addition, a significant number of previtellogenic females presented oviductal sperm as well as uterine scars, suggesting a high precocity in the species. The main drivers of reproductive output also differed between the sexes. In females, clutch size and secondary follicle variability were highly related to stomach bolus volume, fat body area, and body mass. In males, height of piles of palm leaves and body mass, rather than intrinsic reproductive traits, were the main drivers of sperm production.Nevertheless, in both cases, the relationship between body mass, prey abundance, and food intake suggests that N. atrata follows the income breeding strategy to compensate for reproductive costs and to maximize fitness.
基金
supported by the Faculty of Sciences and Project Management Program of the Welfare Office of the Universidad Nacional de Colombia under Grant Nos.3733,1150,1302,1567,and 3093
Colciencias Scholarship Doctoral Program under Grant No.6172
Yoluka NGO,Biodiversity and Conservation Research Foundation under Grant No.001-2014
Universidad Manuela Beltran under act 13072019 and Palmasol S.A.Ac001-2014。
