Intraspecific variation in the diet of the Mexican garter snake Thamnophis eques
The Mexican Garter Snake (Thamnophis eques) 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 T. eques through analysis of 262 samples of identifiable stomach contents in snakes from 23 location...
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PeerJ Inc.
2017-11-01
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| Online Access: | https://peerj.com/articles/4036.pdf |
| _version_ | 1797424703526141952 |
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| author | Javier Manjarrez Martha Pacheco-Tinoco Crystian S. Venegas-Barrera |
| author_facet | Javier Manjarrez Martha Pacheco-Tinoco Crystian S. Venegas-Barrera |
| author_sort | Javier Manjarrez |
| collection | DOAJ |
| description | The Mexican Garter Snake (Thamnophis eques) 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 T. eques through analysis of 262 samples of identifiable stomach contents in snakes from 23 locations on the Mexican Plateau. The snake T. eques 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 T. eques 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. |
| first_indexed | 2024-03-09T08:04:45Z |
| format | Article |
| id | doaj.art-bc76686157394978bb760717b2caa0e1 |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T08:04:45Z |
| publishDate | 2017-11-01 |
| publisher | PeerJ Inc. |
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| spelling | doaj.art-bc76686157394978bb760717b2caa0e12023-12-03T00:23:49ZengPeerJ Inc.PeerJ2167-83592017-11-015e403610.7717/peerj.4036Intraspecific variation in the diet of the Mexican garter snake Thamnophis equesJavier Manjarrez0Martha Pacheco-Tinoco1Crystian S. Venegas-Barrera2Facultad de Ciencias, Universidad Autónoma del Estado de México, Toluca, Estado de Mexico, MexicoFacultad de Ciencias, Universidad Autónoma del Estado de México, Toluca, Estado de Mexico, MexicoDivisión de Estudios de Posgrado e Investigación, Instituto Tecnológico de Ciudad Victoria, Ciudad Victoria, Tamaulipas, MéxicoThe Mexican Garter Snake (Thamnophis eques) 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 T. eques through analysis of 262 samples of identifiable stomach contents in snakes from 23 locations on the Mexican Plateau. The snake T. eques 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 T. eques 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.https://peerj.com/articles/4036.pdfOntogeneticSizeSexual variationThamnophis |
| spellingShingle | Javier Manjarrez Martha Pacheco-Tinoco Crystian S. Venegas-Barrera Intraspecific variation in the diet of the Mexican garter snake Thamnophis eques PeerJ Ontogenetic Size Sexual variation Thamnophis |
| title | Intraspecific variation in the diet of the Mexican garter snake Thamnophis eques |
| title_full | Intraspecific variation in the diet of the Mexican garter snake Thamnophis eques |
| title_fullStr | Intraspecific variation in the diet of the Mexican garter snake Thamnophis eques |
| title_full_unstemmed | Intraspecific variation in the diet of the Mexican garter snake Thamnophis eques |
| title_short | Intraspecific variation in the diet of the Mexican garter snake Thamnophis eques |
| title_sort | intraspecific variation in the diet of the mexican garter snake thamnophis eques |
| topic | Ontogenetic Size Sexual variation Thamnophis |
| url | https://peerj.com/articles/4036.pdf |
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