Spatial Dynamics of Vernal Pool Amphibians: Using Translocations to Determine Spatial Scales of Habitat Selection
Vernal pool restoration is increasing due in part to their contribution of critical habitat for amphibians. Discerning spatial patterns of amphibian use of these landscapes is critical to successful restoration. Individual-level habitat selection of a vernal pool facultative species, green frogs (Rana clamitans), was investigated in an experimental forest consisting of thirty-nine constructed pools. Movement parameters and habitat selection were measured using local translocations (n=146) across different types and scales of habitat and tracking movements using fluorescent powder. Pools are arranged in clusters of one, three, or nine. At each density, translocations were performed at three spatial scales: pool (avg = 13 m), intra-cluster (avg = 57 m), and inter-cluster (avg = 344 m). Translocation scale was found to influence movement parameters (step lengths and turning angles) but not the spatial setting of selected pools. This suggests that design of pool networks should consider species dispersal characteristics for how animals might encounter pools, but that specific design criteria for increasing or decreasing selection of pools in particular spatial settings may be difficult to obtain. This work has implications for how vernal pool networks are designed and managed; it helps guide an explicit spatial focus and can recommend pool spatial arrangements and associations with existing source populations.