On a farm in the southeast corner of Arkansas, between Eudora and Lake Village and not far from the Mississippi River, Andrew Vaughn is raising a large community of digger bees. The bees reappear every year in the sandy soil beneath his farm shop. In spite of compaction due to heavy equipment, the bees have no trouble digging down to make their nests.
Andrew is not sure what the bees are foraging on. He says the only things in bloom are patches of winter grasses, such as ryegrass, and trees in a heavily wooded area that’s perhaps a hundred yards from the shop.
Although he wasn’t able to get a photo of a bee, Andrew sent pictures of tumuli the bees left behind. A tumulus is a mound of dirt that builds up at the entrance to a burrow. Some bees just dump the particles in a pile, but others sculpt the dirt into elaborate entranceways. A tumulus can help divert heavy rains from seeping into the tunnel, and some speculate they many also inhibit certain predators.
If I were to speculate, I would say these bees could be a type of Anthophora. The tumuli you see here lay parallel to the ground with the opening at one end. With so many random cylinders lying this way and that, the area has the look of a heavily-used dog park.
Other species build tumuli that are upright, and some build them so they stick out from vertical walls, as shown in these photos of chimney bees in neighboring Louisiana. People familiar with these bees can often identify the species based on the shape of the tumulus.
Honey Bee Suite