UNH News Service: Researchers at the University of New Hampshire have documented the farthest trek of a young female fisher (Pekania pennanti) moving 118 kilometers (over 73 miles) from Durham to the outskirts of Lincoln, a small town in New Hampshire’s White Mountains. This trip marks the longest known recorded dispersal for the species.
“This is exciting because even though fishers are a significant species and play a key role in the ecosystem of the northeast, relatively few field studies have documented their dispersal, or journey away from their birth home, especially over long distances,” said Remington Moll, associate professor in natural resources and environment. “What makes it even more unique is that the journey was documented over a winter with relatively deep snow, which typically is thought to limit their mobility and dispersal movements.”
In the study, published in the journal Northeastern Naturalist, researchers describe the relatively straight-line distance of the female fisher, identified as F003. Initially outfitted with a GPS tracker, researchers monitored her location each week and obtained snow-depth estimates relevant to the dispersal area from the National Centers for Environmental Information (NOAA 2025). After several months of tracking, she was traced 118 kilometers away in the White Mountains.
Dispersal, or the relocation of a young animal to secure their own home range, plays a crucial role in the survival and genetic diversity of wildlife populations. For fishers, medium-sized carnivores native to North American forests, such movements are essential for maintaining populations that in turn support healthy ecosystems. However, field studies documenting fisher dispersal, especially over long distances, have been scarce.
Fisher populations have been on an apparent decline in last two decades in New Hampshire, with potential contributing factors including rodenticide poisoning, novel diseases, historic harvest, an increase in bobcat population — a known predator — vehicle collisions and ongoing habitat fragmentation.
“Conserving fishers not only supports biodiversity but also helps ensure that New Hampshire’s forests remain resilient and sustainable,” said Moll. “Fishers are important for rodent control, help with dispersing fungal spores and are one of the few predators that hunt porcupines that can cause major damage to timber and harvestable trees.”
Researchers say this type of long-distance journey could occur more frequently given fishers’ abilities to roam freely. It is hard to know why this young female fisher traveled so far. They speculate that ultimately the animal is looking for a suitable habitat with access to mates so they can reproduce and persist as a species. Female fishers tend to prefer areas without other female competition so this animal could have been encountering other females along the way and needed to keep traveling.
Researchers stress that this unprecedented dispersal event underscores the fisher’s adaptability and the need for further research into the species’ movement patterns. This is especially important for preserving connected habitats at a regional scale for management and conservation.
The research was supported by the New Hampshire Fish and Game Department,
the U.S. Fish and Wildlife Service and the University of New Hampshire Agricultural Experiment Station under the USDA National Institute of Food and Agriculture.
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