American Burying Beetle Repopulation Project

American Burying Beetle Repopulation Project

Male and female American burying beetles
The American burying beetle, like other invertebrate species, serves as an “indicator species.” Its decline alerts scientists to dangerous changes in the habitat.

Honors for RWP Zoo’s ABB Project

AZA Top Ten Conservation Success Stories 
AZA Edward H. Bean Award
Selection as leader of the ABB Species Survival Plan

AZA North American Conservation Award


Louis Perrotti
Director, Conservation Programs
(401) 785-3510 ext. 335

National Headquarters for AZA's American Burying Beetle Species Survival Plan

Roger Williams Park Zoo is the national headquarters for the Association of Zoos & Aquariums’(AZA) American Burying Beetle (ABB) Species Survival Plan (SSP). RWP Zoo Director of Conservation Programs, Lou Perrotti, leads the national SSP.

In the early 1990s, the United States Fish and Wildlife Service (USFWS) initiated a project to capture ABB mating pairs from Block Island and attempt to rear them in captivity, with the aim of repopulating them in a former habitat.  Husbandry and breeding techniques for captive ABB were developed at the Boston University by Adrea Kozol. during the first years of the project

We joined the project in 1994 and in 1995 became the sole breeding facility for the American burying beetle recovery program. Since then we have continuously contributed a breeding facility and expert keeper staff, husbandry and breeding data, and field support to the project. We have reared over 5000 ABB’s at our facility and released over 2800 in Nantucket, MA. The ABB population has stabilized and most likely is growing so it appears that our reintroduction efforts have successfully established an ABB population on Nantucket Island. 

In 2006, the Association of Zoos & Aquariums created a Species Survival Plan for the ABB, the first for a terrestrial invertebrate. Lou Perrotti was selected to direct this program which has expanded to 2 other participating Zoos.

Why is this beetle endangered?

There are 15 species of burying beetles in North America, but only the ABB (Nicrophorus americanus), has experienced a drastic decline in population.

In the 19th century, ABB populations covered the entire eastern half of the United States and neighboring Canadian provinces. By the 20th century, spotty populations remained only in Arkansas, Oklahoma, Kansas, Nebraska, extreme southern South Dakota, and north eastern Texas, and in the east only on Block Island off the southern coast of Rhode Island. In 1989 the United States Fish & Wildlife Service declared the ABB endangered.

Human beings are most likely the major cause for the near extinction of the ABB. Hunting and development destroyed and fragmented wildlife habitat, eliminating the top tier of animal predators such as wolves, bears and wild cats.  Scavenger predators like foxes, raccoons, and skunks then multiplied in greater numbers, now competing for and affecting the availability of food for carrion eaters. Passenger pigeons were plentiful in the 19th century, but their numbers declined significantly at about the same time as the American burying beetle. Scientists think that the ABB, because of its relatively large size and the need for carrion weighing between 80 and 180 grams on which to rear its young, depended on the carrion of these larger birds while other carrion beetles can utilize carcasses of smaller birds and mammals.

Our use of night time lighting, bug zappers and pesticides also may have a significant impact on the ABB.

Why does it matter?

When a species is lost, the fragile balance of a habitat is disrupted, sometimes permanently. The American Burying Beetle, like all species, has its own important role in the ecosystem.

All carrion beetle species require a vertebrate carcass to rear their brood. Known as nature's most efficient and fascinating recyclers, these burying beetles are important scavengers that recycle decaying animals back into the ecosystem.  They return nutrients to the earth which in turn stimulates the growth of foliage. By removing carcasses from the ecosystem, the ABB also helps keep fly and ant numbers from reaching epidemic proportions.  

This beetle and other invertebrate species act as “indicator species,” alerting scientists about the health of the environment. If this insect cannot survive it is a sign that the habitat has changed in an unhealthy way. Over time, this can have a ripple effect. According to the USFWS, over 500 species of animals have become extinct, suggesting North American habitats are becoming significantly diminished. We are wise to pay attention.

The Cooperative Conservation Project: Zoos Play an Important Role

The USFWS initiated this project knowing that the cooperation of many partners would be required to make it work.

The population on Block Island is monitored annually by The RI Department of Environmental Management Division of Fish and Wildlife.

Starting in 1990 as a pilot study, Beetles were released by the USFWS and the Boston University on Penikese Island, one of the Elizabeth Islands west of Cape Cod in Massachusetts, and left to survive on their own, without support.  This population was monitored annually until 2005.

Participating Zoos breed and maintain genetically diverse captive populations of the ABB annually.

Participating zoos have released mating pairs in two sites within the beetle’s historic range, one in the West (Ohio) and one in the East (Nantucket Island, MA).

As part of an 18 year project under the supervision of the U.S. Fish and Wildlife Service, the Roger Williams Park Zoo (RWPZ) and the Nantucket Maria Mitchell Association (MMA) have worked to reintroduce the ABB to Nantucket Island, Massachusetts.  This effort is the longest on-going reintroduction program for this species and is probably one of the most intensive endangered insect recovery efforts in the United States. It is one of the few successful invertebrate reintroductions in the world. 

Since 1994, the RWPZ has developed a highly successful captive rearing program that has provided over 2,900 ABBs for the reintroduction effort.  Reintroductions stopped in 2006 and intensive trapping, pairing, and carrion supplementing efforts over the last seven years have shown a steadily increasing total annual capture for new beetles, as well as dispersal from the original release site.  The development of a successful reintroduction methodology is the result of assessing capture rates, winter survival rates, physical beetle measurements, brood sizes, and dispersal patterns over several years. 

The number of individual beetles trapped during 2010 increased 39% over 2009 and based on this success, we shifted to the next phase of the project in 2011 to see  whether the beetles can survive on their own.  In early summer, RWP Zoo and MMA provided carrion to only 25 mating pairs  in order to test the dependency of ABB reproduction on provisioning. Trapping later in the season resulted in lower numbers of  young beetles (tenerals), the lowest since 2008. We believe this drop was due to the reduced provisioning and also to natural dispersal from release sites. However, the number of adult beetles found was higher than in any previous year. We will continue to monitor the population in hopes of seeing a self-sustaining community, much like the one on Block Island, by the end of 2013.

The Nantucket Island reintroduction is an important test of the feasibility of the overall USFWS program which aims toward the restoration of additional populations of the beetle within its historic range in the northeastern, southeastern, mid-western and Great Lakes region of the U.S. Captive rearing and reintroduction of the species appears to be the most readily available means to achieve that end.