Amphibia-Reptilia 37 (2016): 331-334 Intraspecific variation in opportunistic use of trophic resources by the lizard Ameiva corax (Squamata: Teiidae) Grace Garrison 1 , Mia Phillips 2 , Maria Eifler 3,∗ , Douglas Eifler 3 Abstract. Ameiva corax is restricted to a small island (<2 ha), off the coast Anguilla. We present information on intraspecific variation in its diet, based on observations of 190 marked individuals. Larger individual were more likely to attempt to enter active seabird nests and only large males were observed to successfully enter a nest and break open an egg. Flower eating was commonly observed and its occurrence was not related to lizard size or sex. More than half the population was observed visiting areas where fisherman mixed their bait, a foraging strategy also unrelated to lizard size or sex. Ameiva corax is known to socially feed at large food items such as seabird eggs. The individuals that can initially access these food items may occupy key roles in the social network. Keywords: diet, flower-eating, foraging, natural history, ovivory, seabird. The lizard Ameiva corax (Censky and Paulson, 1992) is a diurnal, terrestrial, active forager en- demic to a small island off the coast of Anguilla, British West Indies. Their diet includes a wide range of food types including seabird eggs, fish scraps, prickly pear fruit, invertebrates, and the leaves and flowers of a variety of plants (Hodge, 2000; Censky and Powell, 2001; Hodge et al., 2003; Eifler and Eifler, 2011). Social foraging has been observed at larger food items such as bird eggs and prickly pear fruit, where multiple lizards may feed simultaneously (Eifler and Ei- fler, 2014). The larger food items may be physi- cally difficult for a lone individual to open, as efforts by a single lizard to bite into seabird eggs or break them open by rolling them into rocks usually fail; eggs are also defended by nesting birds (Eifler and Eifler, 2014). Feeding on, or the initial access to, eggs and prickly pear fruit could be limited to a subset of foraging A. 1 - Department of Mathematics, University of Kansas, 405 Snow Hall, 1460 Jayhawk Blvd., Lawrence, KS 66045, USA 2 - Department of Ecology & Evolutionary Biology, Uni- versity of Kansas, 2041 Haworth Hall, 1200 Sunnyside Ave., Lawrence, KS 66045, USA 3 - Erell Institute, 2808 Meadow Dr., Lawrence, KS 66047, USA ∗ Corresponding author; e-mail: maria.eifler@gmail.com corax (Eifler and Eifler, 2014). We investigated whether A. corax exhibited intraspecific varia- tion in its use of key food sources, particularly the larger diet items associated with social for- aging. From 2-29 June 2014 we conducted a study of space use patterns for Ameiva corax on Little Scrub Island (18.30833°N, 62.9667°W), situated approximately 1.3 km NE of Anguilla in the British West Indies. Little Scrub is a small island (1.2 ha) and consists of approximately 60% bare rock; the remaining 40% is vegetated by moon- vine (Ipomoea violacea), prickly pear cactus (Opuntia dil- lenii), various grasses and succulents, and a small amount of rabbit-bush (Portulaca oleracea). We captured lizards oc- cupying the vegetated portion of the island by noosing, and then measured (SVL and mass), sexed by probing, and in- dividually marked them with unique combinations of col- ored beads (Fisher and Muth, 1989). We determined lizard locations using Cartesian coordinates based on lizard dis- tance and compass direction relative to a system of refer- ence points. During the course of the study, we repeatedly traversed the study area as we surveyed for marked individu- als and conducted focal observations. We recorded instances of resource use whenever they were encountered. Three po- tential food sources dominated our records: 1) bird eggs, 2) rabbit-bush flowers, and 3) fish scraps left by fishermen mixing chum. Four bird species nested in our study area: Zenaida doves (Zenaida aurita), Brown Noddies (Anous stolidus), Bridled Terns (Sterna anaethetus), and Laughing Gulls (Larus atri- cilla). As we located bird nests, we recorded their position relative to our spatial reference system. Once located, we marked the nest, identified the bird species using it either by observing the attending adults, or by inspection of the eggs present, and recorded the status of the nest (active, egg(s) present, egg hatched, chick present, abandoned nest, © Koninklijke Brill NV, Leiden, 2016. DOI:10.1163/15685381-00003060