Forest Grouse Monitoring Initiative
There is concern that spruce grouse (Falcipennis canadensis, Canachites canadensis) numbers may be trending lower in some areas of Alberta, although the information to validate this assumption is lacking. Alberta Environment and Protected Areas (EPA) asked Alberta Conservation Association (ACA) to develop an approach for gaining a better understanding of grouse trends over space and time. We began the effort in 2021 with three main tasks: 1) we summarized spruce grouse harvest data from 2015 to 2021 to better understand hunter success spatially and among years; 2) we asked trappers to provide their insight on spruce grouse numbers using a brief survey to help detect problem areas for grouse; and 3) we trialled a methodology to detect occupancy based on the presence/absence of spruce grouse pellets. This method to detect grouse occupancy is viable, although it is very time consuming and logistically expensive. The data derived from voluntary hunter harvest reports are problematic for several reasons, especially for game birds where a specific species licence is not required in Alberta: 1) the total number of hunters pursuing spruce grouse and the total number of harvested birds within Alberta is not known, 2) it appears that at least some hunters struggle to differentiate spruce grouse from other grouse species within Alberta, and 3) it is likely that many hunters that pursue spruce grouse do so while primarily hunting other species, and therefore harvest metrics that factor in hunter effort may not be a reliable means of detecting trends.
From 2015 to 2021, the reported average annual harvest of spruce grouse was 6,127 birds taken by an average of 2,622 hunters, although we do not know the total number of hunters or the total harvest per year. From 2015 to 2019, spruce grouse harvest and hunter numbers were stable to increasing as suggested through voluntary reports; however, in 2020 and 2021, the number of voluntary reports decreased as did the reported number of spruce grouse harvested. It is not clear if these declines represent a decrease in those pursuing spruce grouse, a real decrease in harvest, or simply a decrease in the number of hunters willing to fill out the voluntary report.
Hunter harvest reporting systems can be extremely cost-effective tools for tracking population trends over time. Voluntary‑based harvest reports provide less information compared to mandatory reports, and in the case of voluntary reports for game birds in Alberta, the reported data lacks the utility to detect meaningful trends for spruce grouse spatially and temporally. Mandatory reporting by species would increase the utility of harvest reports for detecting trends with game birds. This approach would track harvest and effort more accurately and provide an early warning indicator if grouse numbers are trending dangerously low over time in a particular geographic area. Moreover, these reports would provide much greater utility if hunters identified each bird harvested to species, as well as to sex and age class (young of year vs. adult).
Alberta Environment and Protected Areas, Alberta Trappers Association
|Forest Grouse Monitoring Initiative||2022-2023||2|