|A sika deer feeds on underwater grasses near the |
Chesapeake Bay Foundation’s Karen Noonan Center
in Dorchester County, Maryland, on August 2, 2017.
Native to Japan, Taiwan and eastern Asia, sika deer were first introduced to the United States when four or five of the animals were let loose on James Island in Dorchester County, Maryland, in 1916. Outside of the Chesapeake Bay watershed, sika deer have been introduced in various locations across the United States, including Texas, Oklahoma, Wisconsin and Assateague Island in Virginia.It's hard to imagine that in a landscape practically overrun with White-tailed Deer, that their little Sika cousins are much of a threat.
The introduction of sika deer was mostly overlooked for several decades, until their population began to rapidly increase around the 1950s. Although a popular game animal, sika deer have no natural predators in the Chesapeake Bay region, meaning their growth had gone relatively unchecked. Today, an estimated 12,000 sika deer live on the Delmarva Peninsula.
Previous studies have suggested that, although they are an exotic species, sika dear are not invasive, because they do not directly compete with native wildlife for food and habitat. However, recent research has suggested the increasing number and expanding range of sika deer may threaten the future health of the fragile salt marsh habitats they tend to graze in. Their fondness for crops like corn and soybeans—like their white-tailed cousins—has also made them a pest in some areas.