Use of crop fields and forest by wintering American Woodcock

摘要

During the 1970s-80s, Scolopax minor (American Woodcock) on wintering grounds in North Carolina generally used bottomland forests diurnally and fed on earthworms in conventionally tilled soybean fields at night. Researchers surmised the ridges and furrows in conventionally tilled fields provided Woodcock protection from predators and winter weather. Since the 1980s, farmers widely adopted no-till practices for soybean agriculture, and this change in field structure may have altered Woodcock crop field use. We returned to the same area as previous research and conducted a study of Woodcock crop field and forest use in a landscape where crop fields are the dominant open-habitat type. During December 2009-March 2010, we captured and radio-tracked 29 Woodcock. Every 24 hours, we located each radio-marked Woodcock during diurnal and nocturnal periods, and verified the habitat type on foot as either crop field or bottomland forest. We recorded 94% of nocturnal locations in forest, 6% of nocturnal locations in crop fields, and 100% of diurnal locations in forest. Percent of an individual Woodcock's nocturnal locations in crop fields ranged from zero to 44%, with a mean of 6% (± 2% SE). The adoption of no-till technology and associated reduction in ridge and furrow micro-habitat available in crop fields may contribute to the low frequency of Woodcock nocturnal field use. Because Woodcock primarily were relocated in bottomland forests diurnally and nocturnally, forest stands should be conserved when managing agricultural landscapes.