SREL Reprint #2292




Size-Related Habitat Use by Nonbreeding Anolis carolinensis Lizards

Thomas A. Jenssen, Katheryn A. Hovde, and Kendall G. Taney

Studies on sympatric anoline faunas as models of community structure have led to the progressive formulation of the "ecomorph" concept (Williams, 1969, 1972, 1983). Embodied in this term is the view that associated Anolis species, which characteristically partition the habitat (e.g., Haefner, 1988), converge on predictable phenotypes peculiar to each species' particular habitat niche (e.g., crown-anoles, trunkanoles, grass-anoles). Collette (1961) first suggested this ecomorphological correlation between a species' limb and body morphology and its structural habitat niche. Behavioral (e.g., Moermond, 1979; Pounds, 1988) and physiological correlates (e.g., Garland and Losos, 1994) were further incorporated into the ecomorph concept, with Losos (1990a, 1990b, 1990c) testing the concept's robustness across phylogenetic assemblages.

Most of the ecomorphology studies, however, have been based on (1) data from sympatric anoline faunas in which interspecific competition, particularly for food (e.g., Schoener, 1977), was inferred as a prime influence on ecomorph differentiation; (2) data usually from adults; and (3) data collected when proximate mechanisms of sexual selection might influence intraspecific habitat profiles because many anoline species are sexually active for most and sometimes all of the circannual cycle (see review in Ienssen and Nunez, 1994). To avoid some of the above issues and to further expand the ecomorph concept into a different ecological context, we made a simple set of habitat observations during the postbreeding period on all size classes of a habitat generalist with no endemic congeneric competitors. We hypothesized that, if habitat physiognomy is influencing interspecific habitat use, the same phenomenon should apply to different size classes within a species. In accord with this prediction, our data showed a nonrandom connection between the ontogeny of body size and microhabitat utilization. From these data, we suggest that the ecomorph concept may also have a developmental-ecological application within the perspective of' the ontogenetic niche (sensu West and King, 1987).

SREL Reprint #2292

Jenssen, T.A., K.A. Hovde, and K.G. Taney. 1998. Size-related habitat use by non-breeding Anolis carolinensis lizards. Copeia 3:774-779.

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