Fisher Artificial Reproductive Den Box Study
This project’s goals are to: determine the extent that artificial den boxes will be used by reproductive Fishers (or other wildlife); identify the degree to which these devices will mitigate losses of natural denning habitat; provide a science-based mitigation technique to address the loss of Fisher habitat; and engage stakeholders that can influence Fisher habitat in the conservation efforts for this species. Suitable reproductive den trees are generally old, large in diameter, and rare elements in most landscapes. In the short-term, this project is maintaining 57 artificial reproductive den boxes that Fisher will use for resting and reproduction.
The Bridge River landscape has been historically impacted by hydro-electric development, and more recently by large-scale fire and logging, resulting in decreased opportunities for reproductive denning. Maintaining the den boxes will provide reproductive habitat for an estimated 14 Blue-Listed Fisher that reside in the watershed (Davis 2013). In 2015, two female Fisher used the boxes to raise kits, and that number is expected to increase over the next two reproductive seasons.
Final Report: Executive Summary
Fishers (Pekania pennanti) are a threatened species (S2S3) in British Columbia and are a high priority for conservation efforts. Fishers are the largest obligate tree-cavity user in North America and this study seeks to determine if the species will use artificial den boxes for reproduction. Trees with characteristics of natural fisher dens are naturally rare in forested landscape and changes to the forest landbase resulting from hydro-electric development, insect infestations, forest-harvest activities, and large-scale fires are likely to have decreased the supply of these elements. This fourth year of the study continues the monitoring efforts on 53 den boxes installed during this project.
Monitoring during the reproductive season (late March – June) identified four den boxes that were used for reproduction. Three of the structures used were in the Bridge Watershed and one was in the Chilcotin. All 4 den boxes were new, bringing the total number of den boxes used to 6 over the 3 denning seasons we have monitored. An average of 2 kits were observed at the den boxes. We also collected information on fisher prey by observing one female bring several items of prey back to the den box. Modeling of habitat attributes at reproductive den box sites did not produce significant results, although den boxes in forests younger (<80 years) were never used by fisher for reproductive or other uses. Increasing the number of reproductive den boxes may help clarify which variables are important for fisher use. This will be the focus of monitoring during our last field season.
Click the provincial database link below to read the full final report for this project.