DOI: 10.5061/dryad.j9kd51ct3
title: Detection locations of fisher (<em>Pekania pennanti</em>) in Connecticut, USA 2018-2023

description: Many mustelids share a history of population decline in North America
 after European settlement followed by a period of restoration and
 recovery. Relative to their past, mustelids now are perceived to be common
 and widespread. However, the local conservation status of many mustelids
 challenges this perception. Fishers (Pekania pennanti) in Connecticut were
 considered abundant prior to the initiation of an annual trapping season
 in 2005, but indices of relative abundance decreased over the last 18
 years, particularly in western Connecticut. We collected detection data
 from camera surveys in winter (December-April) in 5 km2 units (n = 59
 units, 354 cameras) throughout Connecticut between 2018 and 2023 to verify
 management concerns and contribute to an updated conservation assessment
 of fisher in the state. We applied an occupancy modeling framework to the
 detection data emphasizing regional comparisons in occupancy,
 detection-rate, and model-based density. We detected fishers across
 Connecticut except in the southwestern part of the state, but the area
 occupied was small (88 km2). The model-based density estimate (λ) was much
 lower in Connecticut compared to an abundant fisher population in southern
 Vermont, and lower in western Connecticut compared to east. Region was the
 best-supported covariate on occupancy in our single season model and
 parameter estimates (ψ, p) from top models were greater in eastern
 Connecticut compared to west. Fishers did not show spatial segregation
 from other carnivores in the study but did exhibit temporal separation in
 daily activity patterns with other carnivores. Our results support
 management concerns for the conservation status of fisher in Connecticut,
 particularly in the western part of the state. The relative abundance of
 fisher appears low based on all metrics and a short-term closure or
 reduction in length of the trapping season in western Connecticut could
 benefit the recovery of fisher. Harvest data and other sighting metrics
 may be insufficient to fully assess the conservation status of mustelids
 like fisher. Therefore, we recommend implementing a long-term monitoring
 program to provide current distribution data for fisher. Future studies
 should focus on understanding the impacts of anticoagulant rodenticides
 and canine distemper on the current decline of fisher in Connecticut.
description: # Detection locations of fisher (*Pekania pennanti*) in Connecticut, USA
 2018-2023 Dataset DOI:
 [10.5061/dryad.j9kd51ct3](https://doi.org/10.5061/dryad.j9kd51ct3) ##
 Description of the data and file structure Camera detection data for
 fisher collected during 3, 5-day surveys at sites throughout Connecticut.
 ### Files and variables #### File: Table_S3.xlsx **Description:** Camera
 detection data for fisher collected during 3, 5-day surveys at sites
 throughout Connecticut ##### Variables * Species = fisher (Pekania
 pennanti) * Country = United States * State = Connecticut * UTM = Zone 18
 or 19 * X and Y = coordinates ## Code/software Coordinates can be uploaded
 and visualized in ArcPro (ESRI) or Google Earth as example programs. ##
 Access information Other publicly accessible locations of the data: *
 Source publication Data was derived from the following sources: * N/A