A Model for Management of Diurnal Habitat for American Woodcock in Pennsylvania

Publisher Website
Google Scholar
Abstract
We examined selection by American woodcock (Scolopax minor) for structure of diurnal habitat during spring in central Pennsylvania and developed a model for use in habitat evaluation and management. Habitat preference and avoidance (defined as nonrandom use of habitat) were determined by comparing vegetative structure at 93 woodcock flush sites and 196 random sites. Frequency distributions of values measured at flush sites differed significantly (P < 0.05) from those at random sites for 7 habitat variables: coverage of moss, bare ground, and small and large shrubs; sapling density; basal area; and canopy closure. Woodcock preferred areas with 12-17% bare ground, .gtoreq. 32% coverage of large shrubs, 5,200-7,400 saplings/ha, and 75-84% canopy closure and avoided areas with < 2% bare gound, < 12% coverage of small or large shrubs, < 1,500 saplings/ha, .gtoreq. 20 m2/ha basal area, and < 50 or .gtoreq. 90% canopy closure. We used logistic regression with 2nd- and 3rd-order terms to develop a model for assessing the relative quality of diurnal habitats and validated that model with an independent set of habitat measurements. Optimum levels of basal area and sapling density were estimated to be 14.3 m2/ha and 4,900 stems/ha, respectively. There was no evidence that optimum large-shrub cover occurred within the range of values observed (0-75%). The model suggests that uneven-aged forest management may be appropriate for maintaining diurnal habitat for woodcock in Pennsylvania.