American Burying Beetle

Nicrophorus americanus is one of the largest burying beetle species in North America and one of a small number of insects worldwide that practice biparental care. The breeding cycle is extraordinary: a male and female pair locate a small dead vertebrate (mouse, songbird, snake), assess its size, dig a chamber beneath it, drag the carcass into the chamber, and bury it. They strip the fur and form the carcass into a 'brood ball' coated in antimicrobial secretions that prevent decay. The female lays eggs nearby; both parents stay with the developing larvae for 5-7 days, regurgitating partially-digested carcass to feed them. Genetic studies have shown that fathers contribute substantially to chick survival — pairs with both parents have higher offspring success than single-parent broods. The American burying beetle was added to the US federal endangered species list in 1989 due to habitat loss and shifts in carrion availability (smaller mammals declined as larger predators were extirpated). Conservation programs at the St. Louis Zoo and Roger Williams Park Zoo have produced thousands of captive-bred individuals released into restored habitats. The species was downlisted to 'threatened' in 2020 — one of the few US Endangered Species Act success stories for an insect.