A doctoral research project assessing factors that may impact fisher populations in northern New York is being conducted in collaboration with SUNY ESF. One aspect focuses on the reproductive health of fishers. The ovaries and uterus from trapper-harvested female fishers are being examined histologically to identify signs of past reproduction and estimate the number of offspring.
Another aspect of the project is examining exposure to toxic rodenticides. Anticoagulant rodenticides are widely used to control rodent populations. Fishers that eat mice or rats that have eaten these products can develop bleeding disorders. Our prior testing indicates that a large proportion of both free-ranging raptors and fishers have been exposed to these compounds. Livers from trapper-harvested fishers are being screened for 11 of these rodenticides, including products available for purchase by general consumers at hardware stores and compounds restricted to professional pest companies.
In addition, blood samples drawn from live fishers by DEC biologists in the field are being tested by the Comparative Coagulation Section at our Animal Health Diagnostic Center. The tests will measure blood clotting times, which can be used as a potential indicator of rodenticide exposure.
Both projects will provide more information about changes in health and reproduction in fisher populations. The DEC uses this kind of data to develop management strategies for fishers.
