American Woodcock (Scolopax minor)

Photo by Gary ZimmerAmerican Woodcock by Gary ZimmerAmerican Woodcock distribution map

Status/Protection

Population Information

The Federal BBS information can be obtained at http://www.mbr-pwrc.usgs.gov/bbs/bbs.html by clicking on Trend Estimates and selecting the species in question. All estimates are for time period (1966-2005).

USFWS Singing-ground surveys and Wing-collection surveys are most reliable monitoring methods for woodcock (Kelly 2003).

*Note: There are important deficiencies with these data. These results may be compromised by small sample size, low relative abundance on survey route, imprecise trends, and/or missing data. Caution should be used when evaluating this trend.

Life History

Habitat Selection

Habitats used by woodcock vary with activity, time of day, and season (Dessecker and McAuley 2001). During the breeding season, woodcock require three distinct types of habitat (Sepik et al. 1996); clearings for singing grounds and roosting, young second-growth hardwoods for nesting and brood rearing, and moist shrubby sites for feeding. Clearings such as clearcuts or old-fields provide spring courtship areas or singing grounds for males (Sepik et al. 1996). Roth (pers. comm.) reported that male woodcock preferred roads rather than tall, dense vegetation for courtship displays in North Central Wisconsin. Aspen clearcuts were found to be highly attractive to woodcock for feeding and night roosting (Hale and Gregg 1976). Nesting sites in Northern Wisconsin were found most frequently in pole-sized (5-11 inches dbh) aspen stands within 0-30 feet of an opening (Gregg and Hale 1977). On average, nests in Dewey Marsh (Portage Co.) were found 121 m from the nearest singing ground (Haasch 1979). Hazel, especially beaked hazel (Corylus cornuta), was the most abundant shrub near nests and nests were often found at the base of a small conifer (Gregg and Hale 1977). Aspen (Populus spp.) was the most abundant species in the sapling and tree size classes (Gregg and Hale 1977). The presence of a shrub component, such as alder (Alnus spp.) and hazel, is a requirement for woodcock use of aspen stands that are in large sapling or older age classes (10 + years) (Gregg 1984). Prior to migration, woodcock were found most frequently in young or poorly stocked aspen stands and alder cover (Gregg 1984). Moist soils are an important component of quality woodcock habitat as they ensure that earthworms, which comprise nearly 80% of their diet, are at or near the soil surface and available to foraging woodcock (Dessecker and McAuley 2001).

Habitat Availability

Woodcock breed where appropriate habitat is found throughout Wisconsin with highest concentrations found during the Breeding Bird Atlas project in the Central Sand Plains, Northwest Lowlands, North Central Forest, Northern Highland, and Southeast Glacial Plains Ecological Units. Within these units, the Chequamegon/Nicolet National Forest, Northern Highland/American Legion State Forest, Black River State Forest, Kettle Moraine State Forest, Necedah National Wildlife Refuge, Wood County Wildlife Areas, Douglas, Jackson, Lincoln, Price and Washburn County Forests appear to be important breeding areas. Industrial lands, especially in Northern Wisconsin, with an emphasis on early successional deciduous species also provide important habitat for this species.

Large rivers such as the St. Croix, Mississippi and Wisconsin provide important migratory corridors for the woodcock in Wisconsin. The mouths of the Amnicon, Brule and Poplar Rivers appear to be important stopover sites for woodcock and other migrating species that traverse Lake Superior.

Young forest or shrubland habitats, critical to woodcock, are declining throughout Wisconsin. Recent forest inventories conducted in Wisconsin (1983 and 1996) showed an 8% decline in the aspen-birch forest type across the state and a 36% decline in Central Wisconsin alone during this period. In Northern Wisconsin, aspen-birch forest type is the most common early successional community; however from 1936 to 1996, aspen-birch types declined from 5.2 million acres to 3.2 million, a 40% decline (WDNR 1997). The quality of this habitat for woodcock is also a concern. Woodcock typically are found where the number of trees >7.6 cm in diameter are low, and density of saplings <7.6 cm diameter and shrubs is high (13,500 – 49,250/ha) (Dessecker and McAuley 2001). Gregg (1984) reported a 20% decrease in important seedling-sapling habitat between 1956 and 1968 in Wisconsin.

Population Concerns

Declines in young forest habitats and the isolation of these habitats in some landscapes may be limiting woodcock recruitment and therefore population densities (Dessecker and McAuley 2001). In Wisconsin, these habitat declines correspond to a decline in woodcock populations, down 39% in the state since 1968 (Roth 2001). Kelly (2003) reported an annual long-term 1.8% decline in Wisconsin based on results from singing ground and wing-collection surveys. The woodcock population continues to decline throughout its range due to forest maturation, intensive agriculture, urbanization (WBBA unpubl data), potential impacts of lead toxicity (Scheuhammer et al. 1999), and predation on wintering (Krememtz et al. 1994) and breeding grounds, on which Gregg (1984) reported a 36% mortality. Guidelines to manage forested riparian areas often preclude the removal of substantial overstory vegetation and may unnecessarily limit development of important early successional habitat important to woodcock populations (Dessecker and McAuley 2001). Declines in abundance of woodcock have led the U.S. Fish & Wildlife Service to impose more restrictive hunting regulation. However, McCauley et al (1999) found no difference in survival rates of woodcock on hunted and non-hunted populations in Maine.

Recommended Management

Specific woodcock management techniques, including clear cutting, burning, mowing, and herbicide applications, where appropriate, can be used to create singing grounds and roosting areas and rejuvenate feeding grounds (Gregg 1984). Sepik et al. (1996) recommended several management techniques including: 1) improving feeding cover by clear cutting alder in narrow strips over a 20 year cutting cycle, 2) singing grounds can be created by clear cutting strips through aspen stands or by constructing ¼ to ½ acre openings throughout those stands, 3) singing grounds and roosting areas can be maintained by periodic burning or applying herbicide, and 4) create large openings, at least 3 acres in size to provide nighttime roosting areas. Periodic rejuvenation of habitat is necessary as cover is at its best for about 10 years (Sepik et al. 1996). To provide quality habitat for woodcock, timber harvest and other forest disturbances should remove sufficient basal area and stems from a stand to allow understory development (Dessecker and McAuley 2001). Roth (2001) documented the importance of large blocks of early successional aspen forests to breeding woodcock.

Because woodcock feed primarily on earthworms and other invertebrates, soil moisture and fertility, slope, aspect, and other site factors must be considered. Habitat management in valleys and lower slopes is more beneficial to woodcock than management on dry upper and middle slopes (Dessecker and McAuley 2001). McAuley et al. (1996) recommended maintaining > 25% of a unit in early successional habitat through clearcutting blocks > 2 ha or 30-m-wide strips in mature forest on a 40-year rotation. Stands of alders and similar moist-soil shrub species should be encouraged and maintained by cutting strips on a 20-year rotation across moisture gradients.

Research Needs

Keppie and Whiting (1994) listed several research needs: 1) understanding of the functional interrelationships between habitat structure and breeding success of individual birds, 2) local and large scale population dynamics, 3) research needed to evaluate how habitat effects population dynamics, 4) improve monitoring systems, and 5) more research on the effect of predation. A. Roth (pers. comm.) suggested: 1) migratory habitat and survival, 2) identify migratory stop over sites, 3) research the effects of human development and associated predators on breeding habitat and productivity, 4) the positive/negative effects of an earthworm dominated diet and 5) the impact of elevated lead levels in woodcock. Also, Sepik et al. (1993) adds: 1) habitat selection of woodcock under a variety of weather conditions, 2) the effects of weather conditions on survival and productivity, 3) develop and test other techniques in managing of habitat, and 4) a better understanding of the effects of hunting on local populations. Continue to monitor population trends by using singing ground surveys, wing collection surveys, and the Harvest Information Program (HIP). Roth (2001) recommends monitoring woodcock populations according to floristically similar regions rather than by political boundaries.

Information Sources

References

Contact Information

Kreitinger, K., Y. Steele and A. Paulios, editors. 2013.
The Wisconsin All-bird Conservation Plan, Version 2.0. Wisconsin Bird Conservation Initiative.
Wisconsin Department of Natural Resources. Madison, WI.

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