SPEZZANO JR., L.C.*; CLAUSSEN, D.L.; Miami University; Miami University: The fast and the furious: Using simulated habitats to study locomotor behavior during agonism in juvenile freshwater turtles Chrysemys picta

One-year old painted turtles Chrysemys picta select significantly shallower freshwater habitats than older age classes suggesting juvenile-juvenile interactions are frequent and ecologically relevant. Unfortunately, field studies of undisturbed behavior are sparse and methodologically challenging, yet simulated habitats provide a useful controlled system. Recent data demonstrate a high frequency of both size- and density-dependent aggression among 1-year olds, though large turtles sustained substantially more than smaller size classes. Here, we quantify the size-dependency of locomotor response during agonism for same-age, painted turtles housed in 3 group densities (6, 12 & 24 turtles), at 4 ambient temperatures (10, 15, 20 & 30 &degC) and 3 nutritional states (0, 4 & 8 days without food). Terrestrial and aquatic movements (bottom crawling, surface and submerged swimming) were recorded during diurnal activity and speed, distance and orientation (relative to conspecifics) of steady speed movement were compared. Preliminary results suggest directed (“beeline”) movements toward conspecifics are common and often exceed several body lengths in distance. Interestingly, large turtles may utilize bottom movement more frequently than smaller individuals suggesting a potential energetic economy. Though speeds generally increase with size, small individuals appear to most often use maximal speeds during undisturbed and escape locomotion suggesting a strong dependency on burst movements in aquatic systems. Given the habitat separation (relative to adults), a growing body of evidence suggests the presence of distinct dominance hierarchies within juvenile populations driven by size and affected by a host of ecological factors.