Critically Endangered Beetle Making Home On Nantucket

Photography by David Creed

There was a time when the American burying beetle (Nicrophorus americanus) could be found in 35 of the 50 states across the country. At the turn of the 19th century, the beetle's population began to decline. Fast forward to 2022 and the beetle has disappeared from 90 percent of its historic range, the number of states it can be found in has dwindled down to seven, and the species now finds itself on the brink of extinction.

Block Island, Rhode Island is home to the only natural population of these beetles on the east coast. Lou Perrotti, the director of conservation programs for Roger Williams Park Zoo, hopes to make Nantucket the second area where these beetles can prosper.

Perrotti, along with seven volunteers, spent most of their Saturday morning in the Middle Moors placing roughly 70 beetles in prepared, dug up holes that will hopefully allow the beetles to produce offspring that will hatch from eggs into larvae, grow in size to 1-1.5 inches, and pupate into adults. The beetle is a native to the island, but the last record of it prior to Perrotti's venture was in the late 1920s.

“Our effort is to create another population here on Nantucket, which has a very similar environment and ecosystem to that of Block Island,” Perrotti said. “Our hope is that the population here can develop into an insurance colony in case something happened on Block Island and we lost the entire eastern genetic.”

Perrotti released beetles on Nantucket from 1994 through 2006. They stopped releasing beginning in 2007, but continued annual checks up until 2018, when they began releasing beetles again. They lost two more years due to the COVID pandemic. There is no exact estimate on how many of these beetles remain in the world, but Perrotti said it is in the thousands.

33 of the 36 holes have two beetles for mating, along with a dead quail bird. The bird is needed in order for the beetle to reproduce. The other three holes have just one beetle and Perrotti said he is hoping they mate with beetles whose parents of grandparents were brought to the island in past years. These beetles have a life span of just one year.

These beetles will pluck the feathers off the bird, roll it into a ball, and feed it to the larvae, which are the size of a piece of rice when they first hatch.

Perrotti said the extinction of passenger pigeons in 1914 and heath hens in 1932 played a significant role in the deterioration of the beetle’s population. He said they were two animals the beetle would frequently feed on.

“Now that those species are extinct, you have less resource for this beetle within the weight range it needs because it is a specialist. It needs carrion (dead, decaying flesh) between 100 to 180 grams. Now you have less of that and more competition for that,” Perrotti said. “Now you add modern day stressors into that like pesticide use, nighttime lighting, things like that.”

Perrotti said the island’s wet soil is needed in order for this beetle’s population to stabilize. That, along with the lack of predators, makes it the ideal spot to bring along a population. They also feed on quail pheasant that live in this area.

“There are no coyotes, skunks, raccoons on this island which makes it an ideal habitat,” Perrotti said. “These 36 broods could produce hundreds of beetles. We monitor the population annually for things like abundance and distribution. We hope to eventually get the population into the thousands like it is on Block Island.”

The beetle plays a vital role in its environments because of its ability to enrich soil and bury dead organisms underground that would otherwise decay and could produce flies that could become disease vectors.

Groups that have contributed to this project include the U.S. Fish and Wildlife Service, Roger Williams Park Zoo, Nantucket Conservation Foundation, Massachusetts Division of Fisheries and Wildlife, Maria Mitchell Association, Mass Audubon Nantucket, and the Nantucket Land Bank
Next spring, Perrotti said he will have a better idea of how the project is working and whether the population has grown following a minor decline during the COVID years.