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Abstract. -
Alimentary habits are critical to the ecology of all animals. They reflect resource availability and are correlated with important life history traits such as reproductive output and body size. We analyzed the diet of the previously unstudied Mexican mud turtle Kinosternon integrum at Tonatico, Estado de México, during 2003 and 2004. Analysis was conducted separately by sex and age (immature vs. adults) and seasons (rainy vs. dry). Gastric contents and fecal samples were used in combination for more complete results. Based on 57 samples (32 stomach flushes and 25 from feces), K. integrum is a generalist-opportunist in alimentary habits, feeding on 27 categories of food. Plant material, Coleoptera, Odonata, Diptera, and mixed animal matter were the most important components. Overall dietary diversity was similar between adults and juveniles and between the two sexes, but juveniles differed between seasons. In similarity analysis we found a shift in diet between seasons. Females shifted from being primarily carnivorous during the rainy season to being primarily herbivorous during the dry season, while males were carnivorous during both seasons. The data suggest that this turtle feeds opportunistically on available prey items rather than on a few preferred food items.
KEY WORDS. - Reptilia; Testudines; Kinosternidae; Kinosternon integrum; turtle; diet; food; omnivorous; generalist; sex; age; dry and rainy season; Mexico
The feeding habits of turtles are diverse and range from strict herbivory to strict carnivory (Wilbur and Morin 1988). However, freshwater turtles are generally omnivorous (Burke et al. 2000). Typically the alimentary habits of turtles are determined by prey availability and abundance, with diets structured by higher frequency of animal than plant material, or vice versa (Bjorndal 1991). Sex and age have also been considered important determinants of the alimentary habits of turtles, with juveniles eating a higher proportion of animal matter than adults (Ernst et al. 1994) to allow more rapid growth (Lindeman 1996), and females sometimes consume relatively more animal matter than males (presumably to support reproductive expenditures; Ford and Moll 2004). Diet composition is a very important aspect of the local life-history of a turtle species; it reflects the resources provided by the environment toward the energetic needs of the individual during its lifetime (Pincheira-Donoso 2008), including reproduction (Hume 2005).
Kinosternid turtles are characterized by...