Spatial Analysis of Northern Goshawk Territories in the Black Hills, South Dakota

Declining American Goshawk (Accipiter atricapillus) Nest Site Habitat Suitability in a Timber Production Landscape: Effects of Abiotic, Biotic, and Forest Management Factors

“…Therefore, retaining natural stand structure and limiting extensive commercial treatments is important, but pre-commercial thinning could be used to improve structure in nest areas of forest-dwelling raptors (Lõhmus 2005). Ultimately, managing habitat beyond the nest tree itself (Klaver et al 2012) and retaining forest buffers around existing nests, such as the 12-ha area we found to be important for goshawks, seems imperative to encourage raptor reoccupancy of the territory in landscapes where timber harvest is prevalent (Santangeli et al 2012, Bergmanis et al 2019).…”

“…Goshawk use of mature forest stands with greater canopy cover for nesting is well documented across North America (Beier and Drennan 1997, Klaver et al 2012, Byholm et al 2020). We found goshawk habitat suitability was positively and strongly correlated with mean percent canopy cover at a 12-ha scale.…”

“…In addition to canopy cover, the role of forest structure is important for goshawk nesting (Penteriani 2002, McGrath et al 2003, Reich et al 2004, Klaver et al 2012). Canopy base height, one measure of forest structure, is the distance from the forest floor to the bottom of the forest stand's canopy and provides a measure of the space available for goshawks to fly and maneuver beneath the canopy to access and defend nests and forage.…”

“…The isolation of the BHNF relative to the surrounding grassland-dominated Northern Great Plains combined with the extent of recent timber harvest and natural disturbances has left in question the long-term sustainability of a breeding goshawk population in the region (Klaver et al 2012, South Dakota Department of Game, Fish and Parks 2014). We documented that goshawk habitat suitability decreased over time across the BHNF with the highest estimated habitat suitability occurring for the 1990–2001 period and lowest for 2015–2019 (Fig.…”

“…In addition to increased timber harvest volume since the 1990s (Graham et al 2021), wildfire has rendered forest previously used by goshawks for nesting as unsuitable. Widespread mountain pine beetle outbreaks, often occurring in larger trees (>20 cm dbh) indicative of goshawk nesting habitat (Klaver et al 2012), have further contributed to loss of mature forest (Graham et al 2016). Although beyond the scope of USDAFS management, private land in the Black Hills had significantly lower quality of goshawk nesting habitat compared to public land.…”