Our department undertook collaborative research with the Maria Mitchell Association to gain a better understanding of what animals utilize and feed on carrion (dead animals) on Nantucket. Carrion is an obligate food source for the federally-endangered American burying beetle (Nicrophorus americanus), which was re-introduced to the island beginning in 1994 with a goal of establishing a self-sustaining population. Carrion resources and the scavenger community that feed on carrion are not well studied, and Nantucket is a particularly interesting case because there are no typical mammalian scavengers such as skunks, raccoons and opossums.
We set camera traps baited with carrion at multiple sites on Foundation-owned property across the island and documented the scavenger species that were attracted to the bait and frequency of visits by individual animals. Results indicate that the scavenger community on Nantucket is comprised of common avian and rodent species such as those generally found scavenging small and medium-sized carcasses on the mainland, including several species of small mammals, American crows, northern harriers, turkey vultures, red-tailed hawks, Norway rats and domestic cats. However, with no large mammalian scavengers on Nantucket, rodents were observed taking a greater percentage of carcasses than reported elsewhere.
It appears that on Nantucket, avian and rodent species together fill the role of larger mammalian scavengers and maintain an equal rate of carrion consumption across grassland and shrubland vegetation types. Despite the lack of large mammalian scavenger species, the American burying beetle on Nantucket faces similar levels of competition for resources to what it might face on the mainland. This finding suggests that efforts to establish a self-sustaining population of beetles on Nantucket will have to account for this effective scavenger community.
Vertebrate Scavenger Species Composition on Nantucket Island, MA and Implications for American Burying Beetle (Nicrophorus americanus) Reintroduction; A. Mckenna-Foster, D.O'Dell, E. Sorrows and J. Laurenzano; Northeastern Naturalist 2019 in press.