Conservation Planning for Amphibian Species with Complex Habitat Requirements: A Case Study Using Movements and Habitat Selection of the Wood Frog Rana Sylvatica

Abstract

Conservation of fauna breeding in vernal pools is challenging given their complex life histories. Many species, including the widespread North American Wood Frog (Rana sylvatica), require both aquatic and terrestrial habitat, yet insufficient information exists about movements between these environments, nor fine-scale selection patterns within them. To inform conservation planning, we conducted a radio-telemetry study of seasonal patterns of Wood Frog movements and habitat selection in southern Maine. Forty-three frogs were tracked an average of 25.6 days each, April to November 2003. In early spring, Wood Frogs generally selected damp leaf litter retreats on the margins of breeding pools. Following breeding, frogs selected forested wetlands (9.3% of the landscape) over forested uplands (90.7% of the landscape) in 75.3% of radio locations (N = 544). Postbreeding movements from breeding pools to nearby, closed-canopy, forested wetlands ranged from 102–340 m (median 169m, N = 8) and included stopovers in upland forest floors ranging from one to 17 days (median two days, N = 7). Summer refugia were characterized by shady, moist (nonaquatic), and sphagnum-dominated microhabitats. In urbanizing areas, we recommend a shift from a core-habitat conservation model to a spatially explicit approach that considers pool-breeding amphibian habitat as a network of migration-connected habitat elements (e.g., breeding pools, upland forest, nearby forested wetlands). In our study, this approach reduced the amount of land potentially requiring protection by > 2/3 from that of core habitat models. With the rapid dissemination of GIS technology, spatially explicit planning for pool-breeding amphibians is increasingly feasible.