Age- and sex-specific variations in microhabitat and macrohabitat use in a territorial lizard

Abstract

Animals should select microhabitats with features that enhance fitness. However, the fitness benefits of different habitats may vary across ages and between sexes. By quantifying microhabitat choice in relation to age or sex, as well as the specific fitness consequences of habitat selection, we can better understand the factors that shape the way organisms distribute themselves across landscapes. Studies of Anolis lizards have provided critical insights into population and community structure, but most studies have focused on interspecific variation in habitat use, rather than intraspecific patterns. We quantified habitat use of Anolis sagrei at two scales (microhabitat and macrohabitat) for males and females of two distinct age classes (juvenile vs adult). We show that age, sex, size, and macrohabitat have significant effects on how A. sagrei utilize available microhabitat and that age, sex, size, and season influence macrohabitat use. In addition, large individuals of both age classes had increased survival during the breeding season. However, body size did not influence overwinter survival, but lizards that used relatively low perches had increased overwinter survival. Overall, this study demonstrates that the complex variation in habitat use by A. sagrei is explained by interactions among age, sex, size, season, and habitat scale. Habitat choice behaviors can have important effects on fitness, yet optimal habitat may vary across ages and between sexes. In this paper, we quantified microhabitat and macrohabitat use of the brown anole lizard (Anolis sagrei) and subsequently estimated selection on these behaviors via mark recapture. We show that the complex variation in habitat use by A. sagrei is explained by interactions among age, sex, size, season, and habitat scale. In addition, body size influenced survival of both age classes during the breeding season but not over winter. However, lizards that used relatively low perches had increased overwinter survival. These findings provide new insights into the factors that shape the way these organisms distribute themselves across landscapes and provide a rare assessment of selection on behavioral traits.