Oral presentation- Open Session 12th International Mammalogical Congress

The cottontail rabbits (Lagomorpha: Leporidae: Sylvilagus) of Costa Rica: a novel taxonomic and systematic perspective. (#236)

Jose M. Mora 1 2 , Lucía I. Lopez 3 , Luis A. Ruedas 4
  1. Instituto Internacional en Conservación y Manejo de Vida Silvestre (ICOMVIS), Universidad Nacional, Campus Omar Dengo, Heredia, Costa Rica
  2. Universidad Nacional de Costa Rica, Universidad Nacional, Campus Omar Dengo, Heredia, Costa Rica
  3. Unidad de Ciencias Básicas , Universidad Técnica Nacional , Atenas , Alajuela , Costa Rica
  4. Department of Biology and Museum of Vertebrate Biology, Portland State University,, Portland , Oregon, United States of America

Costa Rica, despite its size (51,060 km2 or 0.03% of the World’s land area), contains an almost unparalleled mammalian biodiversity; some 250 species (ca. 4% of the World’s total) inhabit the country.  Among the cottontails, Sylvilagus, that diversity is manifested in the presence of one likely endemic, S. dicei, and two widespread species, S. gabbi and S. floridanus.  Or is it?  Detailed cranio-dental inspection of the holotypes of S. f. floridanus and S. f. costaricensis, while confirming a degree of phylogenetic affinity, also point to clear and distinct species–level differences.  A similar situation may exist in S. gabbi, currently considered a polytypic species distributed from the Mexican state of Veracruz to the Colombian Chocó.  Detailed examination of holotypes, together with the recent description of a neotype for S. brasiliensis, are enabling us to begin to appreciate the taxonomic diversity formerly obscured within the morphologically conservative Sylvilagus. In addition to excising S. costaricensis Harris, 1933 from synonymy with S. floridanus, we demonstrate the existence of extensive, undocumented variation in Costa Rica’s cottontails, from both lowland and highland areas.  We hypothesize that the marked topographic relief of Costa Rica results in remarkable plant biodiversity, architecture, and function, in turn leading to the establishment of fine scale allopatric populations distributed both altitudinally as well as within ecologically allopatric redoubts in the apparently homogeneous lowlands.  This concept of the ecological milieu may result in the presence of many more species than have heretofore been appreciated.