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How Birds Use Wildlife Tree Patches

Wildlife tree patches --- areas of forest left throughout a logged area to provide habitat for birds and other animals --- may mimic a similar forest structure created after natural wildfires, which clear some areas of trees but leave others intact. Bird species that use wildlife tree patches include cavity nesters, open nesters and ground dwellers. In addition, some birds may use these areas for rest during fall or spring migration, especially if the trees are located near water sources such as streams or lakes.

Cavity Nesters
- Eastern screech owls inhabit natural cavities in trees for roosting and nesting.
  
  Primary excavators like woodpeckers dig holes in trees for their own nests; these same cavities may be used by secondary nesters, including swallows and bluebirds. Owls and ducks may use naturally occurring tree cavities. Forest managers creating wildlife tree patches in logged areas consider the needs of cavity nesters by leaving untouched some mature dead and live trees that have abandoned nesting sites, display natural holes or show signs of decay.
Open Nesters
- Herons build heavy nests that need the structural support of large tree branches.
  
  Mature trees with strong branches --- even those with open, broken tops --- are ideal nesting sites for large birds such as bald eagles, osprey, ferruginous hawks, great-horned owls and great-blue herons. Because of the value to these bird species, successful wildlife tree patches contain some of these trees, including ones perhaps damaged by wind or lightning. Nests of this type may be constructed in either coniferous or deciduous tree species that are targets of timber harvesting.
Ground Dwellers
- Mourning doves and other bird species nest in trees and forage on forest floors.
  
  Doves, wrens, juncos and sparrows not only nest at intermediate heights in trees, but also depend on forest floors as foraging sites for food. Although smaller in area, wildlife tree patches are intended to maintain the structural complexity of the forest, with high canopies and mid-level heights, in addition to low understory. Birds that nest on the ground, such as grouse, towhees and even some warbler species, benefit from brush cover and fallen foliage left underneath trees or at patch edges.
Wildlife Corridors
- Birds like northern spotted owls could be adversely affected by fragmented habitat.
  
  Some bird species may easily create corridor routes from patch to patch or use wildlife tree patches and adjacent rock and water features as resting areas during a larger migratory route, such as the Pacific migratory flyway, which links southern wintering grounds with northern breeding sites. However, this forest management technique also may negatively affect others that prefer deeply forested areas to fragmented habitat. Forest managers give special attention to ensure that adequate connections exist between habitat blocks that may support threatened northern spotted owls, and forestry regulations also protect their nesting areas.

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