Distribution and habitat of endangered American burying beetle in northern and southern regions

The American burying beetle, Nicrophorus americanus, is a federally endangered insect that once occurred in 35 US states and 3 Canadian provinces. Today, it remains at the periphery of its former range with the largest populations concentrated in Nebraska and Oklahoma. We assessed beetle occurrence records throughout the western ranges in Nebraska and Oklahoma, but excluded a small eastern population on Block Island, Rhode Island. We compiled more than 2500 presence–absence records and used GIS-based random forest models to create distribution maps throughout the current western range of the American burying beetle based on habitat characteristics within 800 m of each trap. We also used generalized linear models to identify habitat characteristics associated with N. americanus occurrences and to document differences between northern and southern habitat associations. In its northern range, N. americanus was associated with wetter areas while avoiding agricultural and urban areas. In the southern range, N. americanus was associated with sandy soils, hayfields, and native forests and grasslands, while avoiding human population centers and agricultural areas. Our N. americanus distribution maps for the northern and southern regions highlight areas where N. americanus is likely to occur, providing a tool that may improve current management. This first attempt at a range-wide model of American burying beetle occurrences revealed important differences among regions and can improve region-specific management and conservation.