Cooperative Fish and Wildlife Research Units Program: Pennsylvania
Education, Research and Technical Assistance for Managing Our Natural Resources

An effective surveillance strategy and estimate of population size is necessary to better understand river otter distribution and abundance in northeastern Pennsylvania and to develop methods to estimate and monitor river otter populations statewide. Non-invasive genetic sampling is feasible and efficient method to estimate population size of elusive species such as river otter. Although the condition of fecal DNA is of great importance, collection methods and season (i.e., fresh samples collected in winter) can improve quality of DNA used in population identification. Using the proper number of microsatellite loci (i.e., 8–10) can also enable identification of individual otter use of each latrine. Identification of individual otters will enable a genetic mark-recapture estimate of population size from scat sampling provided a thorough survey of latrines in a define area is conducted.