Much of the natural history of the endangered crawling water beetle, Brychius hungerfordi, is unknown. Population estimates have only been surmised. We have measured, using a mark and recapture technique, a localize population of the beetle in a pool on the East Branch of the Maple River, Emmet County, Michigan. The average population during July 2001 was found to be 1052 individuals with a range of 43 (highest estimate – lowest estimate). A three-year study of the relative abundance of the beetle in the same pool suggests that the population has remained relatively constant.
Grant, Michael; Scholtens, Brian; Kopple, Robert Vande; and Ebbers, Bert
"Size Estimate of a Local Population of Brychius Hungerfordi (Coleoptera: Haliplidae),"
The Great Lakes Entomologist, vol 35
Available at: https://scholar.valpo.edu/tgle/vol35/iss1/4