Effects of forest composition on Northern Goshawk nest occurrence and productivity

Research Issue

The Northern Goshawk is a forest raptor found at low densities throughout northern hardwood forests of the Great Lakes region, and is a species of management concern for the Chequamegon-Nicolet National Forest (CNNF), Wisconsin, and Hiawatha National Forests, Michigan.  The species has a circumboreal distribution and appears to be quite flexible in its nesting requirements and prey base, which limits the applicability of literature on nesting and foraging requirements from outside of the Great Lakes region.  Therefore, there is a need for local information on these aspects of Northern Goshawk biology to inform land managers of the most effective means to conserve the species.  In addition, it remains unclear what effect timber harvesting, which influences forest composition, has on goshawks within national forests.  

Our Research

Goshawks are associated with mature forest with large trees and open understories, but they may select nesting locations as close as possible to foraging habitats.  We examined how landscape-scale forest composition and road density at several different distance from nest sites and random locations throughout the CNNF influenced goshawk nesting presence.  The CNNF applies a 30 acre no-cut buffer surrounding nests and a second buffer extending another 330 ft in which only uneven-aged timber management is permitted.  Using 10 years of goshawk monitoring data, we are evaluating how forest type composition as a result of management practices within 3 zones of influence (e.g., 200, 500, and 1000 m) may help explain the occupancy of goshawk nests.  Current efforts are using the same approach on goshawk nest survey data on the HNF to compare across landscapes.

Research Results

Nest survey and monitoring data from 1997-2006 on the CNNF indicate more conifer cover and less aspen-birch cover and fewer primary roads in the surrounding nests.  The key driver of goshawk nest occurrence was the ratio of conifer cover (1000 m) to aspen-birch (500 m) cover surrounding a potential nest site.  These results are useful in sustaining populations throughout the forest and helping managers recognize important factors in goshawk nest occurrence. 

Donner, Deahn M.; Anderson, Dean; Eklund, Daniel; St.Pierre, Matthew. 2013. Large-scale forest composition influences northern goshawk nesting in Wisconsin. Journal of Wildlife Management 77(3): 495-504.

Research Participants 

Principal Investigator

• Deahn M. Donner, US Forest Service, Northern Research Station - Landscape Ecologist

Research Partners

• Dean Anderson, Wildlife Ecology and Epidemiology, Landcare Research, New Zealand
• Matthew St. Pierre, US Forest Service – Wildlife Biologist, Chequamegon-Nicolet National Forest, Rhinelander, WI
• Daniel Eklund, US Forest Service – Forest Biologist, Chequamegon-Nicolet National Forest, Park Falls, WI
• Steve Sjogren, US Forest Service – Wildlife Biologist, Hiawatha National Forest, St. Ignace, MI 

Last Modified: December 9, 2016

For further details log on website :
https://www.nrs.fs.fed.us/sustaining_forests/conserve_enhance/wildlife_fish/goshawk/