Terrestrial mammal diversity at Hansen Dam (Los Angeles, California, USA): Flood control area acts as habitat in a human-dominated landscape

Urban expansion is a prominent threat to biodiversity, particularly for terrestrial mammals, which are significantly impacted by disruptions in habitat connectivity and loss. It can also lead to increased human‑wildlife conflicts that contribute to species decline. Urban public works projects, such as flood control areas, may coincidentally preserve significant habitat, but their potential for conservation remains understudied. Hansen Dam, located in the city of Los Angeles, California, USA, is one of these flood control areas, hosting some of the last remaining riparian habitat in the greater Los Angeles area. We deployed motion‑triggered camera traps at 36 stratified random locations and completed small mammal trapping at 20 sites at Hansen Dam. We detected a total of 15 species, not including domesticated animals, but there is potential that additional species inhabit the area. All species detected were common and expected but demonstrate that the Hansen Dam flood control basin has a terrestrial mammal community similar to that reported for other urban habitats. These results suggest incidental habitat conservation could play a significant role in future conservation planning efforts.