Sika Deer of Dorchester County

 

   Sika deer are not native to Maryland or any part of North America but actually originate in Japan, Taiwan and eastern Asia. Like most deer species, they have been introduced to numerous locations worldwide and have adapted to a wide variety of habitats. In the U.S., captive sikas have been reported in 34 states and wild populations can be found in Texas and Virginia as well as on the Eastern Shore of Maryland.

Sika deer became established here during the early 1900s when Clemment Henry, an Eastern Shore resident, released five or six deer onto James Island in the Chesapeake Bay. Over the years the population expanded off of the island and onto the mainland, where today they inhabit the marshes and forested wetlands characteristic of the area.

   Sikas from the original Henry stock were also released onto Assateague Island and gradually populated both the Maryland and Virginia portion of the island. Today, sika deer are known to inhabit Dorchester, Somerset, Wicomico, and Worcester counties, with the highest concentrations located in southern Dorchester County and on Assateague Island.

   In an effort to pinpoint the exact origins of the Maryland sikas, researchers with the Smithsonian Institute, in cooperation with local residents and the Maryland Department of Natural Resources (DNR), are in the process of conducting a genetic study of the Dorchester County and Assateague Island populations. Preliminary results suggest that the Maryland sika deer originated on a small island in southern Japan. Exactly how they made their way from that island to Clemment Henry in Dorchester County remains unclear.

What Makes Them Different?
   Sika deer are actually more closely related to the elk than they are to whitetailed deer; thus, their appearance, traits, and general behavior differ somewhat. They are smaller than whitetails, with adult males, called stags, typically weighing about 90 pounds and adult females, or hinds, weighing roughly 70 pounds. Coat color ranges from chestnut brown during winter to reddish-olive during summer. Sikas keep their white spots as adults, which are most visible during the summer months, and tend to have proportionally shorter snouts and smaller ears.       Unlike whitetailed deer that raise their tails like a flag when alarmed, they have a white rump patch that flares outwards.

Sikas are also one of the most vocal members of the deer family with at least five distinct calls. During the fall and early winter breeding season, stags can be heard bugling, best described as a multi-pitched, extended wail.   Hinds use soft bleats and whistles to communicate with other females and offspring, and their alarm call is a short, high-pitched bark.

  Like whitetails, only the males have antlers; however, they are more narrow and erect and resemble miniature elk antlers in form. Stags rarely have more than three points per antler; typically spikes as yearlings, which develop into four or five points as two year olds, and finally six points at three years. Trophy-class antlers are about 13 to 15 inches in length and are shed between February and April of each year.

  While sika deer generally reach sexual maturity at about 16 months and breed during their second year, research has shown that approximately 25 percent of the hinds in Maryland actually bred during their first year of life. The season begins around late September, and the gestation period lasts approximately 30 weeks, with most calves born in May. However evidence based on hunter check station age data suggests that the breeding season may actually span significantly more than several months in length. And unlike whitetailed deer that commonly give birth to twins or even triplets, hinds almost always give birth to a single calve.

  During most of the year, sika hinds generally remain in small family groups with their young, sometimes including offspring from the previous year. Stags are largely solitary during fall and winter, and then form bachelor bands during late spring and summer. With the exception of the breeding season, stags and hinds typically remain segregated.

  Sikas appear to be relatively long-lived and ear-tag studies by DNR combined with age data collected from hunter check stations suggest that it is not uncommon for them to live up to, and probably beyond, 10 years of age in the wild. The combination of their heavy, sometimes impenetrable, habitat and strongly nocturnal nature no doubt enhances their ability to survive.

  Sikas will travel relatively long distances when staking out a new home range or when moving to or from a natal area for calving. Several radio-marked hinds in Dorchester County were known to move several miles each spring to give birth to their calves before then returning later in the year to their fall and winter range. Similarly, yearling stags often disperse over several miles during late summer to set up new home ranges.

  Contrary to popular local belief, sika deer are excellent swimmers and readily take on the many creeks, guts, and rivers that crisscross the lower Eastern Shore. One yearling stag captured and radio-marked near   Blackwater National Wildlife Refuge in Dorchester County swam across the Nanticoke River near Vienna and was monitored near Mardela Springs for a period of time before it moved back across the river. Likewise, several radio-marked hinds regularly swam back and forth across the Chicamacomico and Transquaking rivers during the course of their travels.

  The elusive sika seems to have filled a unique niche on Maryland’s lower Eastern Shore. Their expansion to the north out of southern Dorchester County is probably limited by the lack of significant continuous marshland and forested wetlands, as well as the imposing Choptank River, which is fairly wide at its mouth. However, the population may be growing south of Dorchester in the lowlands of western Wicomico and Somerset counties.        Currently, they do not appear to be competing with native whitetails or other species inhabiting the area but as with any exotic species, they must be monitored carefully to ensure they do not negatively impact native species in the future.