Salamanders in a Changing Environment on Hemlock Hill

in the environment is by monitoring animal populations over long periods. Over the past five years, for example, Robert G. Mayer has documented 126 bird species at the Arnold Arboretum, including 46 confirmed breeders and another five probable breeders. Using data from several earlier studies, Mayer was able to document the absence of at least 27 species that had once bred successfully at the Arboretum over the past century and the occurrence of seven new breeding species. In 2004 researchers at the Harvard Forest extended their studies of salamander populations in New England to the Arboretum’s Hemlock Hill. No studies of salamanders at the Arboretum existed, but we have now compiled baseline data on species composition and abundance for use in future monitoring of this ecologically important group.