PART VIII: Species Management
	WOODLAND BIRDS

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From an overall landscape perspective, many woodland birds survive best in large tracts of forests connected to each other by forested corridors. Therefore, there are many management opportunities for woodland birds in northern Michigan, which is currently more than 70 percent forested. Options within southern Michigan exist in forest areas, and riparian zones. Neighbors who cooperatively manage their woodlands also increase opportunities for woodland bird management. 

Small forested tracts are also very important for some species like the northern cardinal and the great-crested flycatcher. Migrating birds may also use these small forests as stop over sites. 

Forest Types

Michigan is home to many types of woodlands, each of which attracts certain kinds of birds. Therefore, the first step to managing for woodland birds is to determine what type of forest system is dominant on your property and surrounding lands. 

Certain woodland birds are found in only one forest type. Requiring a certain element within the forest, these birds are considered habitat specialists. For example, red-winged crossbills almost exclusively feed on seeds from conifer cones within dry mesic conifer forests. Another example of a specialist species is the Kirtland's warbler. Their survival depends on jack pine stands that are eight to 20 years old. 

On the other hand, some species require a mix of forest types and different ages. For example, the indigo bunting does not require one specific forest type, but rather a mix of forest types to survive. They are located in brushy and weedy habitat along the edges of non-specific deciduous forests, swamps, abandoned farm land, roads, and railways. They prefer the fruits of shrubs, small trees, and vines. 

Edge-sensitivity

Fragmentation occurs when roads, homes, trails, power lines, and other forms of development break up the natural wooded habitat. Some birds are greatly affected by human disturbance to their habitat, while others are less bothered or not impacted at all. 

Edge-sensitive species are those birds with the lowest tolerance for fragmented habitat. Many of these birds seek forest interiors and shun forest edges. Species with moderate to high sensitivity to fragmentation do best at least 100 yards from the edge. Many habitat types create an edge next to woodlands such as grasslands, brushlands, wetlands, and river corridors. Edge-sensitive species prefer forest areas hundreds to thousands of acres in size. These large tracts of forest lessen problems such as nest predation and brood parasitism which is quickly increasing due to the rise in habitat fragmentation.

One of the most common brood parasites is the brown headed cowbird, which is attracted to the forest edge. Cowbirds do not make their own nests, instead they invade the nests of others. Cowbirds remove host eggs before laying one of their own in the host’s nest. Their eggs tend to hatch one to three days earlier than the host’s. Because cowbird nestlings are larger and grow faster than the young of their host, the young cowbird receives more food and parental care than the host’s young. As a result, most of the host’s young do not survive. A female cowbird can lay up to 77 eggs each season if she can find enough host nests in which to deposit them. 

Woodland birds that are edge-sensitive include the broad-winged hawk, pileated woodpecker, wood thrush, yellow-throated vireo, ovenbird, American redstart, veery, and black-and-white, cerulean, and hooded warblers. Many edge-sensitive species are declining in populations as their habitat becomes more fragmented.

Woodland birds with a moderate sensitivity to habitat fragmentation, which can tolerate stands between 40 and 100 acres in size, include the yellow-billed and black-billed cuckoo, hairy woodpecker, acadian flycatcher, scarlet tanager, red-eyed vireo, northern parula, white-breasted nuthatch, tufted titmouse, and blue-gray gnatcatcher. 

Woodland birds that are the most tolerant to an abundance of edge include the indigo bunting, gray catbird, Carolina and house wren, American robin, black-capped chickadee, northern cardinal, rose-breasted grosbeak, rufous-sided towhee, common grackle, northern oriole, brown-headed cowbird (a nest parasite), eastern wood-pewee, great-crested flycatcher, and downy, red-headed, and red-bellied woodpeckers. It is not surprising that many of these species are found in urban areas. 

Management Considerations

The following are options to consider when managing for woodland birds. 

Edge-sensitive considerations:

• Maintain sites larger than 40 acres, and leave woodlands as undisturbed as possible. 
  
  
• Manage your woodland in a circular shape rather than a rectangular or other long, narrow design. This will reduce the amount of edge.
  
  
• Maintain a well-developed understory of woody and herbaceous plants because many species of forest birds need the food, nest sites and cover provided by such low growing plants. Slightly opening the canopy can help maintain the understory. However, be aware that some species require a more sparse understory, such as the red-headed woodpecker. 
  
  
• If you cut, remove only single mature trees. Single-tree selection results in the maintenance of the largest area of contiguous forest without the undesirable fragmentation caused by other types of timber harvest.
  
  
• When single-tree selection is not possible, owners of large forested tracts should adopt a uniform plan of rotation cutting to make sure the oldest sections are next to each other. This same plan of rotation cutting can help a manager to design wooded connections between disturbed areas and to keep gaps to a minimum. This practice is better for woodland birds because it causes the least amount of disturbance.

Edge-tolerant considerations:

• Plant shrubs along woodland edges and in grass openings. 
  
  
• Maintain or create dense thickets or densely growing understories of young trees in mature forests. To provide such habitat, cut groups of mature trees in stands no larger than one acre, or thin the large, mature trees to produce a dense understory. Watch for overbrowsing of new understory growth by white-tailed deer, and take necessary precautions. 

General considerations: 

• Attempt to protect or restore wooded areas along streams, as these areas are of special value to many bird species, and they provide movement between corridors.
  
  
• In areas where mature forests are limited, try to protect one or more mature tracts to serve as repopulation centers. Ideally, the mature tract should be at the center of the area being managed. 
  
  
• Speed up natural succession by planting trees and shrubs in open areas, thereby reducing fragmentation. To provide a diverse habitat remove aggressive, non-native shrubs, and forbs. 
  
  
• Allow large trees that are dead or dying to remain standing as they provide food and homes for many species. You can create these snags by girdling healthy trees (removing the bark in a band around the trunk). 
  
  
• If mature live and dead trees left standing number less than one per acre, erect nest boxes for cavity nest builders such as the wood duck, and members of the woodpecker family. Information is available in the chapter on Homes for Wildlife in the Backyard Management Section. 
  
  
• During the nesting season of late April through early August, keep disturbances such as camping, picnicking, or cutting to a minimum. This "hands-off" practice is especially important in the forest interior. Avoid construction projects such as building roads, trails, ponds, powerlines rights-of-way or other land-clearing practices that fragment forested areas.
  
  
• Reduce brown-headed cowbird feeding opportunities near woodlands. You can accomplish this goal by eliminating mowing and grazing on land next to the forest. If you must mow roadside vegetation, cut it no shorter than six to nine inches to discourage cowbirds from feeding there. Plant bare ground to grass and revegetate logging trails and roads. 

As you can see, even doing nothing to your wooded property will encourage some kinds of birds and discourage others. Specific management prescriptions will have a similar effect. For these reasons, it is important to classify the type of woodland habitat you own as well as properties adjacent to yours. You can then develop goals for the kinds of birds you want to encourage on your land. 

Forming a landowners association with your neighbors is a good way to enhance a larger forested area than your own property. Applying legal restrictions such as a conservation easement to your land is also a good way to eliminate the threat of future development. For information, contact the Michigan United Conservation Clubs.

Last Revised: December 12, 1999

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You can download and print each chapter or section in its original format. The material is NOT copyrighted, however, please use the following citation: Sargent, M.S and Carter, K.S., ed. 1999. Managing Michigan Wildlife: A Landowners Guide.  Michigan United Conservation Clubs, East Lansing, MI. 297pp.