Seasonal Food Forge National Use by White-Tailed Deer at Valley Historical Park,-Pennsylvania, USA BRIAN L. CYPHER* RICHARD H. YAHNER'I" ELLEN A. CYPHER** School of Forest Resources The Pennsylvania State University University Park, Pennsylvania 16802, USA ABSTRACT / Food habits of white-tailed deer (Odocoileus virginianus) were examined from January to November 1984 via fecal-pellet analysis at Valley Forge National Historical Park (VFNHP), which represents an "island" habitat for deer surrounded by extensive urbanization, in southeastern Penn- sylvania. In addition, use of fields by deer was compared to food habits. Herbaceous vegetation (forbs, leaves of woody plants, and conifer needles) was the predominant food type in all seasons except fall. Acorns and graminoids (grasses and sedges) were important food resources in fall and spring, respectively. Use of woody browse (twigs) was similar among seasons. Field use was relatively high during fall, winter without snow cover (<20 cm), and spring when food resources in fields were readily available. In contrast, use of fields was lowest in summer when preferred woodland foods were available and in winter with snow cover when food in fields was not readily accessible. Patterns of food-type use by deer at VFNHP indicate the year-round importance of nonwoody foods and field habitats to deer populations on public lands such as national parks in the northeastern United States. Food habits of white-tailed deer on public lands such as national parks are poorly understood. Yet, in states like Pennsylvania, deer herds on federal lands may be increasing but harvests are prohibited (Hubley 1985). Thus, food habits and habitat use of these herds on federal lands need to be understood for de- velopment of future management recommendations and policies (Bratton 1980, Scanlon and Vaughan 1983, Cypher and others 1985). Valley Forge National Historical Park (VFNHP) in southeastern Pennsyl- vania contains a diversity of habitats and food types. Although the white-tailed deer population within the park is not regulated and predation pressure is min- imal, the herd has not adversely affected park vegeta- tion (Cypher and others 1985). Because VFNHP con- rains extensive fields, enabling deer to be visible on a year-round basis, probable food use can be related to use of fields by deer among seasons. Moreover, be- cause of extensive urban development along Park boundaries, VFNHP represents an "island" habitat for deer. Therefore, an understanding of food use by deer at VFNHP will give land managers and deer biol- KEY WORDS: White-taileddeer, Odocoileus virginianus; Public lands; National parks; Food habits; Habitat use *Present address: Cooperative Wildlife Research Laboratory, Southern Illinois University, Carbondale, Illinois 62901, USA. **Presentaddress: Departmentof Botany,Southern IllinoisUniver- sity, Carbondale, Illinois62901, USA. tAuthor to whom correspondence should be addressed. ogists important information on deer-habitat relation- ships on public lands, such as national parks sur- rounded by urbanization. The objectives were to de- termine (1) seasonal use of food types by deer at VFNHP and (2) use of food types relative to seasonal use of field habitats. Description of Valley Forge The 972-ha VFNHP is located in Chester and Montgomery Counties, 20 km northwest of Philadel- phia, in southeastern Pennsylvania, USA. Regional temperatures average 23~ in summer and 0~ in winter, with annual temperature extremes ranging from 44 ~ to - 27~ Annual precipitation and snowfall average 117 and 76 cm, respectively. There are 170 to 200 frost-free d/yr (U.S. National Park Service 1980). Land uses adjacent to VFNHP include commercial and high-density residential development to the south and east and medium-density residential development to the north and west, which creates an "island" habitat for deer. Fenced four-lane highways to the north, east, and south enhance the isolation of the park (Cypher 1986). Fields and woodlands are the primary habitats in VFNHP (57% and 38%, respectively). Other habitats (<5%) include developed areas (e.g., buildings), barren areas (e.g., dirt parking areas), and wetlands (small ponds). Field habitats include old fields, fields mowed annually, and fields mowed biweekly. Domi- nant shrubs in fields are ash (Fraxinus spp.), blackberry (Rubus spp.), honeysuckle (Lonicera spp.), and staghorn EnvironmentalManagement Vol. 12, No. 2, pp. 237-242 9 1988 Springer-Verlag New York Inc.