9th International Deer Biology Congress

AUTHORS: Jacob L. Bowman, Department of Entomology and Wildlife Ecology, University of Delaware; David M. Kalb, Virginia Division of Game and Inland Fisheries; Jacob M. Haus, Department of Entomology and Wildlife Ecology, University of Delaware; T. Brian Eyler, Maryland Department of Natural Resources

ABSTRACT: The introduction of sika deer in the United States has occurred several times at different locales and with several different subspecies. The first introduction was onto James Island, Maryland in 1916. Results of genetic analysis found that five sika deer arrived in Maryland from Yakushima Island, Japan via a multigenerational stopover in the United Kingdom [1]. In the 1920’s, a small number of sika deer from the James Island population were transported east to Assateague Island along the Atlantic coast. These deer dispersed onto neighboring Chincoteague Island, and by 1963 the eastern population was estimated to be 1,300 individuals. A population of 10,000 – 12,000 sika deer is presently established on the eastern shores of Maryland (Fig. 1) and is increasing in abundance and expanding in range. Densities can reach as high as 42 deer/km2 in managed areas [2].

Sika deer outcompete native white-tailed deer, resulting in a decrease in the nutritional value of white-tailed deer diet when ranges overlap with sika deer [3]. The presence of white-tailed deer, however, does not affect the diet quality of sika deer. This dietary competition could lead to competitive exclusive of white-tailed deer in areas with high sika densities. While habitat in their native range of Yakushima Island was primarily mountainous, sika deer habitat in Maryland consists of tidal marsh, agricultural fields and thick, forested wetlands. Sika deer in Maryland also maintain larger home ranges (464 – 4121 ha) than both white-tailed deer and native sika populations and occasionally exhibit seasonal migrations and nomadic behaviors [4,5].

Harvest of sika deer began on James Island and mainland Maryland as early as 1938 but was sporadic through the early 1960’s with only a few harvested annually [6]. Sika deer were distinguished from white-tailed deer as a large game animal in 1973 and regulations allowed for greater rates of harvest on sika deer than white-tailed deer [7]. Regulations regarding sika deer harvest have changed several times as hunting has become increasingly popular in the region. Professional guide services are available that cater exclusively to sika deer hunters, and recent survey figures indicate that 3,000 – 5,000 hunters annually pursue sika deer for over 30,000 hunter days per year [8]. Sika deer harvest dates run concurrently with white-tailed deer harvest, typically the first week of September to the end of January with a mix of archery, muzzleloader, and firearms seasons. Current regulations permit the harvest of 3 sika deer, no more than 1 antlered male, per each weapon type. The Maryland Department of Natural Resources manages sika deer as a local economic and social benefit to the region, and recently increased harvest bag limits for the 2014 – 2015 hunting season. Harvest management is the most effective means of controlling population growth, and the spread of sika deer across Maryland and neighboring states has led to efforts to curtail the range expansion.