Popis: |
We examined the diet of New Mexico Ridge-nosed Rattlesnakes (Crotalus willardi obscurus) from the Sierra San Luis and the Sierra Pan Duro in the northern Sierra Madre Occidental, Mexico. All snakes included in this study were encountered during August, September, and October in 2003 and 2004. Including recaptures of previously captured individuals, 107 of 199 snakes contained at least one prey item. We examined 103 prey items from 92 of these snakes; some snakes contained multiple prey items. Approximately two-thirds of prey items were ectotherms (54.4% lizards and 13.6% scolopendromorph centipedes); birds (21.4%) and mammals (10.7%) were also taken. The diet of juvenile snakes (n = 32) consisted primarily of lizards (62.5%) and centipedes (25.8%), although large juveniles also consumed mammals (6.3%) and passerine birds (6.3%). Adult snakes (n = 71) fed primarily on lizards (50.7%) and passerine birds (28.2%) but also consumed mammals (12.7%) and centipedes (8.4%). Crotalus willardi in the Sierr... |