A Hole the Size of a Quarter

In early May, Xerces Society pollinator specialist Sarah Nizzi was mushroom hunting in a 200-plus-acre park in Boone, Iowa, when a queen bumble bee flew past, inches off the ground. Within seconds she knew: a rusty patched bumble bee (Bombus affinis), a federally endangered species.

The queen landed and crawled into a quarter-sized hole along a deer trail. Nizzi marked the spot. Rusty patched bees nest 18 to 24 inches underground, usually in an old rodent burrow — one reason their nests are almost never found. Only one other rusty patched nest has ever been discovered in Iowa, in Iowa City in 2024.

Workers came and went all summer. By mid-September the nest was quiet. In early October, the Fish and Wildlife Service excavated it with Iowa's natural resources department and Iowa State University. An hour's digging found a large cavity, and the nesting material suggested a rather large colony.

An endangered bee's address can look like nothing — a quarter-sized hole in a city park, between a playground and a disc golf course.

Source: Sarah Nizzi, "Discovering an Endangered Rusty Patched Bumble Bee Nest in Iowa," Xerces Society, October 27, 2026. https://xerces.org/news/organizational-news/discovering-endangered-rusty-patched-bumble-bee-nest-in-iowa

Photo: Rusty patched bumble bee nest entrance in Boone, Iowa, by Sarah Nizzi / Xerces Society.