A tale of two birds

Posted by Renee Magyar on June 28, 2016

Landscape restoration can benefit sensitive wildlife species habitats including the northern goshawk and white-headed woodpecker

The Northern Goshawk (left) and the White-headed Woodpecker (right) have differing needs for forest habitat.

When looking at a vegetation management project, it is easy to focus solely on what the trees need and how restoration can reduce the amount of overcrowded forest stands on the landscape. But forest ecosystems are far more complex, serving as home to many different wildlife species. Overcrowded forest conditions alter wildlife habitat, but landscape-scale restoration presents an opportunity to be thoughtful about where we create or enhance critical wildlife habitat.

Different wildlife species prefer different habitats, and their responses to environmental change differs. Two wildlife species that are great examples of this are the Northern Goshawk and the White-headed Woodpecker. 

The Northern Goshawk is a management indicator species under current Forest Plans (see the Ochoco NF Forest Plan, and the Umatilla and Wallowa-Whitman Forest Plans), which means that its behavior/presence provides specific information on the effects of management activities by representing groups of other species with similar habitat requirements. This large migratory forest raptor is a powerful hunter capable of killing a variety of prey, including tree squirrels, hares, grouse, corvids, woodpeckers, and large passerines such as American Robins. The Goshawk prefers mature forests with large trees for nest stands and a surrounding landscape of closed forest with small to moderate gaps of open forest. Important habitat qualities of goshawk prey species include snags, down logs, woody debris, large trees, openings, herbaceous and shrubby understories and an intermixture of various forest structural stages (Wisdom et al. 2000). 

In contrast, the White-headed Woodpecker is a non-migratory bird that feeds on pine cone seeds during the winter, and forages by gleaning insects off foliage and outer layers of bark the rest of the year. It is the only North American bird that has a white head and a black body. The White-headed Woodpecker prefers nest sites that consist of open forest with small to moderate patches of scattered closed forest, however, these birds use a mosaic of closed and open forest within their home range. Important habitat components include large ponderosa pine and snags. The White-headed Woodpecker is a focal species under the Draft Blue Mountains Forest Plan Revision, serving as an indicator of ecosystem sustainability for dry forests. Activities that improve habitat conditions for these birds should benefit other species associated with the same forest types.

So here we have two birds with differing needs for forest pattern habitat conditions. The White-headed woodpecker prefers landscapes with a higher proportion of open habitat than does the Goshawk. In a very general sense, forest restoration that reduces the density of trees on the landscape has the potential to reduce Goshawk habitat of dense closed canopied forests. However, these same forest restoration treatments could increase habitat for the White-headed Woodpecker. 

The Northern Goshawk prefers a closed forest pattern (left) and the White-headed Woodpecker prefers an open forest pattern (right).
The Northern Goshawk prefers a closed forest pattern (left) and the White-headed Woodpecker prefers an open forest pattern (right).

These conflicting needs raise the question of how can we restore more than a half million acres of overstocked conditions while maintaining a diversity of habitats for important species like these. How can we manage for both species on the landscape? Can we optimize the landscape for both species? The Forest Resiliency Project provides an opportunity for land managers to take a landscape-approach when deciding where to create or enhance such critical habitats. Modeling habitat distributions is an important tool the Forest Service uses to evaluate current conditions and potential effects of proposed treatments.

Recently, the Pacific Northwest Regional Wildlife Ecologist Kim Mellen-McLean, Regional Analyst Max Wahlberg, and Blue Mountains Restoration Strategy Team member Barbara Wales took the lead on developing a habitat model for both Goshawks and White-headed Woodpeckers across the Blue Mountains. This modeling effort compares White-headed Woodpecker habitat to Northern Goshawk habitat at both the stand and landscape-scales in the Blue Mountains. The model demonstrates the importance of landscape pattern, where on the landscape there is opportunity to create or enhance habitat conditions for each species, and how managing for these species can be compatible with restoring resiliency and natural disturbance processes across the landscape. The modeling indicated that there is a “sweet spot” in terms of the percent of open versus closed forest where habitat preference for both species overlaps. Both species find suitable habitat when about 45 to 70% of the landscape is in open habitat, and when the open and closed forest patterns are properly located. 

With tools like this, the planning team can design treatments that will consider natural landscape patterns that ensure suitable habitat is available for the wildlife that depend on them, while still accelerating the pace of restoration in the Blue Mountains. 

Do you want to know what others are saying about this project? Find out more by visiting the public reading room. Additionally, you can find notes from recent public engagement sessions on the project public engagement website.

This is the sixth of twelve issues of Features from the Blue Mountains Restoration Strategy brought to you by Sustainable Northwest and the U.S. Forest Service Blue Mountains Restoration Strategy Team. This monthly series highlights the environmental and economic challenges and opportunities present in the Blue Mountains region, and includes updates from the Blue Mountains Forest Resiliency Project.