Post-Breeding Dispersal and Summer Home Range of Female American Toads (Bufo americanus)

• Published in: Northeastern naturalist 2006-01, Vol.13 (1), p.59-72
• Main Authors: Forester, Don C, Snodgrass, Joel W, Marsalek, Katherine, Lanham, Zachary
• Format: Article
• Language: English
• Subjects: Amphibia; Amphibians; Animal behavior; Breeding; Breeding of animals; Breeding sites; Bufo americanus; Conservation biology; Female animals; Forest habitats; Freshwater; Habitat conservation; Habitats; Soil water; Toads; Transmitters
• ISSN: 1092-6194; 1938-5307
• DOI: 10.1656/1092-6194(2006)13[59:PDASHR]2.0.CO;2

While many amphibians have complex life cycles involving a primarily terrestrial adult phase and an aquatic larval phase, use of terrestrial habits by adult forms remains poorly understood. We used radiotelemetry to track the post-breeding dispersals of 16 female Bufo americanus during the summer and fall of 2001 to determine the extent of upland habitat use by females of this species. Female toads dispersed a minimum of 250 m and up to 1000 m from the breeding pond with the majority (97%) of relocations occurring more than 400 m from the breeding site. Typically dispersal paths were non-random and linear, punctuated by periods of sedentary behavior. During periods of sedentary behavior females confined their activities to an area of several m2. Females employed 24-h movements of up to several hundred m when moving between activity centers. For 8 toads with > 22 recaptures, total area of upland habitat utilization ranged from 434 to 1305 m2 (mean = 717.7 m2). All 16 toads were lost prior to entering winter torpor, including 10 confirmed cases of predation. Our study of post-breeding dispersal by female American Toads suggests terrestrial habitat use extending up to 1 km from the breeding site is common, and emphasizes the need for consideration of terrestrial as well as aquatic habitats in the development of conservation plans.