Manjarrez Javier, Pacheco-Tinoco Martha, Venegas-Barrera Crystian S
Facultad de Ciencias, Universidad Autónoma del Estado de México, Toluca, Estado de Mexico, Mexico.
División de Estudios de Posgrado e Investigación, Instituto Tecnológico de Ciudad Victoria, Ciudad Victoria, Tamaulipas, México.
PeerJ. 2017 Nov 14;5:e4036. doi: 10.7717/peerj.4036. eCollection 2017.
The Mexican Garter Snake ( is a terrestrial-aquatic generalist that feeds on both aquatic and terrestrial prey. We describe size-related variation and sexual variation in the diet of through analysis of 262 samples of identifiable stomach contents in snakes from 23 locations on the Mexican Plateau. The snake we studied consumed mostly fish, followed in lesser amounts by leeches, earthworms, frogs, and tadpoles. Correspondence analysis suggested that the frequency of consumption of various prey items differed between the categories of age but not between sex of snakes, and the general pattern was a reduction of prey item diversity with size of snake. Snake length was correlated positively with mass of ingested prey. Large snakes consumed large prey and continued to consume smaller prey. In general, no differences were found between the prey taxa of male and female snakes, although males ate two times more tadpoles than females. Males and females did not differ in the mass of leeches, earthworms, fishes, frogs and tadpoles that they ate, and males and females that ate each prey taxon were similar in length. We discuss proximate and functional determinants of diet and suggest that the observed intraspecific variation in could be explored by temporal variation in prey availability, proportions of snake size classes and possible sexual dimorphism in head traits and prey dimensions to assess the role of intersexual resource competition.
墨西哥束带蛇是一种水陆两栖的泛食性动物，以水生和陆生猎物为食。我们通过分析墨西哥高原23个地点的262份可识别胃内容物样本，描述了该蛇类饮食中与体型相关的变化和性别差异。我们研究的这种蛇主要以鱼类为食，其次是水蛭、蚯蚓、青蛙和蝌蚪。对应分析表明，不同猎物种类的食用频率在蛇的年龄类别之间存在差异，但在性别之间没有差异，总体模式是猎物种类多样性随蛇体大小而减少。蛇的长度与摄入猎物的质量呈正相关。大蛇捕食大型猎物，也会继续捕食小型猎物。一般来说，雄蛇和雌蛇的猎物种类没有差异，不过雄蛇食用的蝌蚪数量是雌蛇的两倍。雄蛇和雌蛇所食用的水蛭、蚯蚓、鱼类、青蛙和蝌蚪的质量没有差异，而且捕食每种猎物种类的雄蛇和雌蛇在长度上相似。我们讨论了饮食的近端和功能决定因素，并建议可以通过猎物可获得性的时间变化、蛇体型类别的比例以及头部特征和猎物尺寸可能存在的两性异形来探索观察到的种内饮食差异，以评估两性间资源竞争的作用。
