Does Inter-age Class Competition Influence Habitat Use in a Territorial Lizard


Meeting Abstract

19.2  Sunday, Jan. 4 10:30  Does Inter-age Class Competition Influence Habitat Use in a Territorial Lizard? DELANEY, D.M.*; WARNER, D.A.; Univ. of Alabama, Birmingham; Univ. of Alabama, Birmingham dmdelane@uab.edu

All organisms have specific habitat requirements that allow them to properly function in their environment. For many organisms, optimal habitats differ across age classes, and individuals shift habitat choice as they age. Field observations of the brown anole lizard (Anolis sagrei) suggest that juveniles perch in open-canopy areas on shorter vegetation whereas adults reside in forested areas on higher vegetation. We manipulated adult densities in mesh enclosures with artificial trees to examine the response of juvenile habitat choice. We found that juveniles chose lower perches when adults were present, suggesting that adults force juveniles to less preferred habitat and that inter-age class competition contributes to the observed ontogenetic differences in habitat choice in the field. Perch width, substrate use, and orientation were all affected by time of day. Lizards perched on leaves much more frequently at night than during the day, which is consistent with observations of other Anolis species. Lizards had no preference in orientation when perched on horizontal branches during the day. However, lizards strongly preferred to face the trunk of the tree at night. This study suggests that adult A. sagrei may drive ontogenetic variation in habitat use in this species, and that time of day affects how A. sagrei uses its habitat.

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