Contamination from agricultural pesticides is highest in wintering areas where woodcock feed in farm fields. Earthworms are resistant to many chemicals, so they can carry toxins. Since woodcocks are predators of earthworms, there's a chance they'll accumulate persistent toxic chemicals found in worms. That compares to a two percent average annual decrease over the same period throughout its North American range. Most biologists attribute this decline to loss of habitat quantity and quality.
Development also destroys or fragments existing woodcock habitat.
Habitat Habitat requirements for woodcock change throughout the year. Food must be available during all seasons. Woodcock are attracted to moist forestland in early stages of succession. They tend to use edges rather than interiors of big, even-aged thickets. These species can be planted, or, if they already grow in a given area, encouraged by cutting down large trees which may be shading them and stunting their growth.