Barretto Julliana, Baena Martha L, Domínguez Israel Huesca, Escobar Federico
Red de Ecoetología, Instituto de Ecología, Xalapa, C.P. 91073, Mexico.
Instituto de Investigaciones Biológicas, Universidad Veracruzana. Av. Luis Castelazo Ayala s/n Col. Industrial Ánimas, Xalapa, C.P. 91190, Mexico.
Curr Zool. 2021 Dec 25;68(6):635-644. doi: 10.1093/cz/zoab101. eCollection 2022 Dec.
While theory suggests that at conception the sex ratio should be balanced (1:1), this can be variable across space and time in wild populations. Currently, studies of the environmental factors that regulate adult sex ratio (ASR) in species with different life history traits are scarce. Using capture-recapture over a year, we analyzed the influence of habitat type (forest and nonforest) and season (rainy and dry) on variation in ASR, male aggregation and the trajectory movement of 2 dung beetle species with different life history traits: (a hornless roller species) and (a tunneler species with horns on its head and thorax). We found opposite tendencies. The population tends to be female-biased, but the population of tends to be predominantly male, and observed values were not related to habitat type or season. However, the 95% confidence intervals estimated were highly variable between seasons depending on habitat. On examining the monthly variation in ASR for both habitats, we found that it depends on the species. In addition, male aggregation differed between species depending on habitat type and season, and species movement patterns were closely related to their habitat preferences. Based on our results, we argue that comparative population studies of species with different life history traits are necessary to understand the variation in demographic parameters as well as its ecological and evolutionary implications in the face of spatial and climatic environmental variation.
虽然理论表明在受孕时性别比例应是平衡的（1:1），但在野生种群中，这一比例可能会随空间和时间而变化。目前，关于调节具有不同生活史特征物种的成年性别比例（ASR）的环境因素的研究较少。通过为期一年的标记重捕法，我们分析了栖息地类型（森林和非森林）和季节（雨季和旱季）对两种具有不同生活史特征的蜣螂物种的ASR变化、雄性聚集及轨迹移动的影响：（一种无角滚粪球蜣螂物种）和（一种头部和胸部有角的掘洞蜣螂物种）。我们发现了相反的趋势。种群倾向于雌性偏多，但种群则倾向于以雄性为主，且观测值与栖息地类型或季节无关。然而，根据栖息地不同，各季节估计的95%置信区间变化很大。在研究两种栖息地ASR的月度变化时，我们发现这取决于物种。此外，不同物种的雄性聚集情况因栖息地类型和季节而异，且物种的移动模式与其栖息地偏好密切相关。基于我们的研究结果，我们认为，有必要对具有不同生活史特征的物种进行比较种群研究，以了解人口统计学参数的变化及其在面对空间和气候环境变化时的生态和进化意义。
