Nantucket Island, off the coast of Massachusetts, is home to a thriving population of white-tailed deer. Their presence on this isolated island raises questions about how these typically mainland animals arrived. Understanding their history provides insight into both natural processes and human influence on island ecology.
Early History of Deer on Nantucket
White-tailed deer were once native to the New England region, including Nantucket, but were extirpated from the island before European settlement. Historical and archaeological evidence indicates Native American hunting significantly reduced or eliminated deer populations. By the time English settlers arrived in the early 1600s, no large native mammal species, including deer, were present on the island.
Theories of Deer Arrival
The primary explanation for how deer arrived on Nantucket involves human introduction, although natural migration has been considered. While white-tailed deer are proficient swimmers, capable of covering distances up to 10 miles, the open expanse of Nantucket Sound presents a significant barrier. The sound measures approximately 25 miles wide, with the closest mainland points like Cape Cod’s Monomoy peninsula around 12 miles distant and Chappaquiddick Island about 8 miles away. Researchers suggest that a sustained natural colonization by swimming would be unlikely given the distance and strong currents.
Historical records and genetic studies confirm deliberate human intervention. On June 3, 1922, fishermen rescued an exhausted male deer found swimming in Nantucket Sound and released him onto the island, where he became a local point of interest. This led to a 1926 introduction by summer resident Breckinridge Long, who brought two female deer from Michigan. Mitochondrial DNA analysis confirms these Michigan does are the maternal ancestors of most current deer, illustrating a significant “founder effect.” Further introductions occurred in the mid-1930s, including bucks and does from New Hampshire, intended to enhance the existing stock, but contributing less to overall genetic diversity.
Nantucket’s Current Deer Population
Following these introductions, Nantucket’s deer population experienced substantial growth and are now a firmly established component of the island’s wildlife. A 2013 aerial survey estimated around 2,000 deer, or approximately 40 animals per square mile. More recent 2022 and 2023 assessments suggest the population has increased to between 4,000 and 6,000 deer, with densities of about 50 deer per square mile. As of 2025, a state biologist proposed that the total number of deer could be 10,000 or more, with densities potentially reaching 70 to 100 deer per square mile in areas open to hunting, and considerably higher in unhunted zones.