At MNA, our Mission is to protect special natural areas and the rare species that live there. The goals of our blog are to cover the latest environmental issues affecting these areas and provide information about the efforts of our volunteers. Our weekly “ENDANGERED!” column serves to inform you about the endangered and threatened plant and animal species found in and around these special natural areas, and how you can contribute to conservation efforts before it is too late.
American Burying Beetle
By Yang Zhang
American burying beetles, also known as carrion beetles, are known for burying the carcasses of small animals, such as moles, birds, and snakes. They rely on carrion as a food source and for reproduction purposes. Thus, they are regarded by nature enthusiasts as master scavengers and one of nature’s most efficient and fascinating recyclers that return valuable nutrients back to the soil.
Identifying an American burying beetle is easy; it is about one-and-a-half inches long with a shiny black body and bright orange markings. A large shield-like area, called the pronotum, connects its head and wings. A large orange marking on the pronotum is the beetle’s most distinctive feature shared with other beetles. It also has an orange marking on its head (triangular on females and rectangular on males) and scallop-shaped orange markings on its wing covers. A club-like antennae with notable orange tips can detect a dead animal from up to two miles away.
Understanding what habitat the American burying beetle prefers is quite tricky. As reported by the U.S. Fish and Wildlife Service, the beetle has been found in various types of habitats including oak-pine woodlands, open fields, oak-hickory forests, open grasslands and edge habitats. The beetle’s habitat preference, especially reproductive habitat, is still not fully understood. However, research indicates that because the beetles require rotting bodies of small animals to feed on and reproduce, carrion availability may be the greatest factor in determining where the species survives.
American burying beetles are usually active at night, live for only one year and typically reproduce once. They bury themselves in the soil to overwinter when the temperature is below 60 degrees Fahrenheit. When the temperature gets warmer, male beetles look for carcasses in which to mate and reproduce.
After finding a carcass, the male releases pheromone from the tip of its abdomen to attract mates. Beetles often fight among themselves over the carcass (males fighting males and females fighting females) until one pair wins. The pair buries the carcass, mates and the female lays eggs on the carcass. The larvae feed on the carcass for about a week, and sometimes both parents digest the flesh and regurgitate liquid food for the larvae to consume. The larvae crawl into the soil to develop, and then emerge 45-to-60 days later.
Historically, American burying beetles existed in the eastern half of North America from southern Ontario, Canada and the northern peninsula of Michigan to the southern Atlantic coastal plain. The number and range of the species has declined so drastically that the beetle is only known to be present in four states: Nebraska, Rhode Island, Oklahoma and Arkansas.
The reason the American burying beetle has disappeared from many areas remains a mystery. However, declines could be attributed to habitat fragmentation and loss, carcass limitation, pesticide use and disease. Increased lighting at night due to human development is also plausible because it could disrupt the beetle’s night activities, thus possibly interfering with reproduction.
Although presumed extirpated in Michigan until rediscovered, the beetle has been known to inhabit areas near Kalamazoo, Detroit and Marquette. MNA has ideal habitat for this species at Dowagiac Woods Nature Sanctuary, Wilcox Warnes Nature Sanctuary and Echo Lake Nature Sanctuary, among others.
The American burying beetle plays an important role in the environment. It recycles carcasses and returns valuable nutrients to the soil, and it is also an indicator species of a healthy environment.
The U.S. Fish and Wildlife Service has an established recovery plan prioritizes tasks necessary in saving the beetle. These priorities include protecting and monitoring existing population, maintaining captive populations and conducting ecological studies.
How You Can Help:
Open your eyes while walking in nature. The Michigan Department of Natural Resources is trying to identify possible populations of the beetles in the state. If you think you spot an American burying beetle, take a photo and note the date and location of the sighting including the county, township, section and the nearest road intersection, and draw a map indicating the directions. Please send the information to the Michigan Department of Natural Resources, Wildlife Division, Natural Heritage Program, PO Box 30180, Lansing MI 48909-7680.
MNA volunteers are currently working to protect this and other endangered and threatened species, and you can help too. Join our efforts as a volunteer removing invasive plants in the special natural areas where this species lives. Or, become a steward and take responsibility for planning efforts to maintain a specific MNA sanctuary. To find out how to get involved, visit our website.