Distribution, Identification, Landscape Setting, and Conservation of Rana kauffeldi in the Northeastern U.S.
Biological inventories aimed at enumerating a region’s species, combined with detailed natural history observation, can reveal evidence of cryptic species: overlooked species incorrectly grouped under a single taxonomic name. The identification of cryptic species raises fundamental questions about each species’ distribution, identification, and conservation status. Leopard frogs in the northeastern United States have faced this situation since the recent discovery of Rana (= Lithobates) kauffeldi, the Atlantic Coast leopard frog, as distinct from R. sphenocephala (southern leopard frog) and R. pipiens (northern leopard frog). Following on this discovery, the objectives of our study were to 1) Determine conclusively which leopard frog species occur presently and occurred historically in ten eastern U.S. states; 2) Refine the range of R. kauffeldi relative to the two other leopard frog species; 3) Map new, potentially reduced, ranges for the two congeners; 4) Assess the species’ conservation status, particularly in areas where R. kauffeldi is already known to be of concern; 5) Contrast multi-level habitat associations among the three species; and 6) Improve upon the separation of species using acoustic and morphological field characters to facilitate future inventory, monitoring, and status assessments of the new species.