American burying beetles. Photo © St. Louis Zoo via Cool Green Science

Beetles, apart from being the most numerous type of insect in the world, comprise the largest group of animals in general, with somewhere between three- and four-hundred thousand species described; and that doesn’t even count the presumably undiscovered ones hiding out in some unexplored corner somewhere. We’ve covered dung beetles before, but also mycokleptic species, and now we’re learning about a very important carrion beetle in North America known as the American burying beetle from Ted Williams at The Nature Conservancy’s Cool Green Science blog:

The shiny black, orange-spotted adults can approach two inches in length. Offspring beg both parents for food, inducing regurgitation by stroking their jaws like wolf pups. They’re federally endangered American burying beetles, largest of the 31 species of North American carrion beetles.

Riding on the adults like oxpeckers are orange mites that keep them and their larval food supply free of fly eggs and microbes.

With his orange-tipped antennae the male beetle scents carrion (usually a bird or small mammal) sometimes from two miles away. Often there’s a fight for possession. The winning male attracts a mate by releasing a pheromone from the tip of his abdomen.

After elaborate courtship the couple moves their prize, which may weigh 200 times more than they do, to an appropriate site and buries it. Then they strip feathers or fur, coat the carcass with oral and anal secretions to discourage bacterial and fungal growth and repel any maggots they don’t kill with their mandibles. They stay with the carcass, feeding pieces to 10 to 30 grub young until they pupate in 12 to 14 days.

Historically, the species occupied at least 35 eastern and mid-western states and the southern fringes of Nova Scotia, Quebec and Ontario.

Now natural populations remain only in parts of Arkansas, Kansas, Nebraska, Oklahoma, South Dakota and Rhode Island. Reintroduction, yet to prove successful, is ongoing in Massachusetts, Ohio and Missouri.

Probable causes for the species’ demise are artificial lighting that confuses nocturnal scavenging, proliferation of competitors like raccoons, skunks, opossums and feral cats, and reduction of larval food items — most notably extinctions of the passenger pigeon (thought to have been more numerous than all other North American birds combined) and the heath hen, a subspecies of greater prairie chicken adapted to the Atlantic coastal plain.

Nowhere Near Recovery Goals

The gravest current threat is the gas and oil industry, not so much because of the habitat it degrades (U.S. Fish and Wildlife Service permits require mitigation), but because of the push by the industry and allies to get the species taken off the endangered species list.

Read the entire post here.