Does Reduced Perch Availability Affect Reproduction in the Brown Anole? An Experimental Test in the Laboratory
The availability of preferred habitat can have numerous effects on an individual's behavior and physiology and, in turn, can affect fitness. In Anolis lizards, different species have evolved specific limb lengths that enable them to perform well in habitats with specific perch characteristics. Indeed, perch width and height have been major drivers in the morphological diversification in this genus. Despite the extensive work on Anolis limb length/perch width relationships, however, the availability of perches (a preferred habitat characteristic) influences aspects of fitness is poorly known. In this study, we housed captive male/female pairs of Brown Anoles (Anolis sagrei) in cages with high and low availabilities of perches and quantified the effect of perch availability on perch use and reproductive variables (egg production, egg mass, interegg interval, yolk steroids, egg hatching success). In the low-perch availability treatment, females spent less time on perches than did females in the high-perch availability treatment. Despite this effect on perch use, however, perch availability had little to no effect on reproduction. Egg mass and yolk testosterone concentrations increased over the reproductive season, but perch availability had no effect on any temporal changes in reproductive variables over time. Despite the importance of perch characteristics in shaping the evolution of Anolis lizards, we found little evidence that perch availability affects maternal reproductive investment in A. sagrei under controlled laboratory conditions.Abstract
Line drawings of perch arrangement in cages in the high- and low-perch availability treatments.
Effect of perch treatment on (A) latency to reproduce and (B) yolk corticosterone. Data are summarized as means 6 SD. Results were not statistically significant (see Table 1).
Percentage of observations that male and female Brown Anoles (Anolis sagrei) were using perches under high-perch availability and low-perch availability. Data are summarized as means 6 SE.
Relationship between oviposition date and (A) yolk testosterone (linear regression: r2 = 0.08, P = 0.018) and (B) egg mass (linear regression: r2 = 0.041, P = 0.002). Open circles and dashed regression lines represent the low-perch availability treatment. Solid circles and solid regression lines represent the high-perch availability treatment.
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