Landscape modification (loss, fragmentation, and degradation of habitat) is a universal form of human-induced rapid environmental change that creates strong spatial variation in environmental conditions. Behaviorally mediated responses to landscape modification may generate behavioral divergence among populations along environmental gradients. We tested whether movement behavior of red-backed salamanders (Plethodon cinereus) was repeatable and varied within and among forest stands of different ages in a fragmented landscape in New York, USA. Water loss is a major constraint on P. cinereus mobility, and forest fragmentation creates spatial variation in desiccation risk. We quantified multiple components of individual movement behavior in an unfamiliar environment in the laboratory, and we used ordination to identify behavioral variation among individuals in multivariate space. We tested for repeatability of individual behavior and then examined behavioral differences between individuals captured from populations at two spatial scales where desiccation risk was expected to vary: a) between edge and interior locations within forest stands, and b) between forest stands varying in time since agricultural abandonment.
Results/Conclusions
Movement behavior of individuals varied within populations and was characterized by three components: total movement activity (e.g., surface activity, distance moved, boundary crossings), substrate use (time on moist soil vs. dry sand), and latency to initial movement. Each behavioral component was significantly repeatable. At the population level, individuals from old forest stands (≥77 yrs) exhibited greater movement activity than individuals from young stands. Movement behavior did not differ between individuals from edge and interior locations within forest stands. Our results demonstrate that P. cinereus individuals show consistent differences in movement behavior in an unfamiliar environment. Moreover, we show that movement behavior can be spatially structured within fragmented landscapes, but that behavioral divergence among populations depends on spatial scale. Geographic variation in movement behavior may be an important consideration for models of animal movement used for conservation applications.