|Abstract or Summary
- Stakeholders in the southern Blue Mountains have reported a need for a scientific review of the northern goshawk (Accipiter gentilis atricapillus; hereafter, goshawk) in relation to dry forest restoration and management activities. Here, we provide a compilation of relevant synthesis papers, existing peer-reviewed research, and goshawk monitoring efforts in the region to assist stakeholder discussions regarding restoration planning and implementation.
The goshawk is not currently considered a species of special conservation status in North America, and as such is afforded the same legal protection as other non-priority forest raptors by regulatory entities (USFWS, CITES, IUCN), including the land management agencies within the southern Blue Mountains region (BLM, USFS). However, starting in the early 1990s, there were multiple petitions to list the goshawk under the Endangered Species Act. In response, the US Forest Service Region 6 implemented interim wildlife standards (Eastside Screens) in 1994, which included specific guidelines for the protection of active goshawk nests on National Forests on the eastside of Oregon and Washington. This was intended to secure protections until further information was available.
A review of scientific literature on the goshawk shows the species nests across a broad gradient of forest types throughout the western US, and in more diverse habitat types (e.g., contiguous hardwood forests, open tundra) throughout North America. The Forest Service proposed nine goshawk bioregions along geographical areas of similar ecological conditions across the continental US. Four of those bioregions occur in Oregon, speaking to the diverse forests the goshawk inhabits in this state alone.
While early research appeared uncertain, a series of long-term, rigorous studies in dry forest systems have now markedly improved our understanding of goshawk ecology. The legacy of contentious litigation should not cloud stakeholder understanding of the species’ conservation status. Rather the volume and breadth of published literature helps to clarify the status of the goshawk in the western US and the dry forests of the Blue Mountains.
Recent advances in our understanding of goshawk status and ecology indicate:
1. Goshawk populations appear stable and/or no decline has been measured.
2. The goshawk occupies territories in more diverse forest types than previously understood.
3. While foraging and post-fledging habitat is highly variable, the goshawk selects nest sites in mid to late structural stands with high canopy closure.
4. Standard survey techniques still in use by most land managers may significantly underestimate goshawk occupancy.
We recognize that the Eastside Screens have created an expectation that the goshawk will be protected and managed for, and thus PFAs would be retained during restoration and management activities. While that has not been successful in all projects, it is a requirement counted on by some stakeholders. Under our proposed approach, more wildlife habitat would be retained. Still, we understand that mangers and stakeholders will need assurances that this will work to meet their outlined social and ecological goals. Some stakeholders may need assurances of new wildlife habitat areas being required similar to what PFAs were under the old model.
We recommend the creation of new selection criteria for wildlife habitat in the different dry forest types found on the Malheur National Forest. This strategic placement of wildlife habitat areas (for the goshawk and other species) in forest management planning will require close working relationships and trust between each National Forest, stakeholders, and placed-based collaborative groups. We suggest groups of land managers, stakeholders, and trusted scientists work together to develop the new model of wildlife habitat areas within each of the dry forest types.
Key Management Considerations
1) The goshawk is not a species with population viability concerns, and thus prioritizing its specific habitat needs on a multi-spatial scale is not warranted.
2) The goshawk occupies varied forest types and does not appear to reliably indicate species composition, diversity and abundance in forest communities; suggesting it may be an inappropriate focal species intended to guide dry forest restoration.
3) New research demonstrates goshawks may be more tolerant of limited timber harvest (in nest stands and post-fledgling areas) than previously assumed.
4) The seasonal restrictions required by the Eastside Screens need not be based on decades old management guides, and instead could be modified to either match the dates proposed in the new Forest Plan or the research contained within this review.
1) Modify goshawk management under the Eastside Screens to better suite diverse wildlife habitat needs in associated forest types (ponderosa, dry mixed conifer, lodgepole pine, moist mixed conifer).
2) Alter timber harvest and seasonal restrictions adopted by the Malheur National Forest from Reynolds et al. (1992) to better reflect the current science on such impacts.
3) Consider alternatives to the goshawk for the new Forest Plan that will better meet current and future wildlife habitat needs.
4) Create a working group of managers, stakeholders, and scientists to explore the creation and protection of wildlife habitat areas in lieu of goshawk habitat areas.
5) Work with current science to create new models for selecting wildlife habitat areas based on biophysical characteristics such as soil type, overstory structure, ability to persist in future drought and disturbances, and spatial analysis to surrounding protected areas and planned management activities.