Threat Classification

The following classifications were used to define threats for listed species. Taken from: Lawler, J.J. et. al. 2002. The scope and treatment of threats in endangered species recovery plans. Ecological Applications 12(3):663-667.

Resource Use

arrowtimber, ore, oil and gas, grazing, fishing and hunting, collection, other resource use

Exotic Species

arrowcompetition, predation, parasitism, pathogens, disease vector, habitat modification, other effects of exotic species


arrowcommercial, urban/suburban, rural, utilities, roads, other construction

Altered Habitat Dynamics

arrowsuccessional change, fire regimes, hydrodynamic regimes, agricultural regimes, other altered habitat dynamics


arrowdryland herbaceous, irrigated herbaceous, dryland woody plants, irrigated woody plants, silviculture, aquaculture, other agriculture

Species Interaction (non-exotics)

arrowcompetition, predation, parasitism, prey, pathogen, other species interactions


arrowwater point souces, water nonpoint source, air point sources, air nonpoint source, deposition, solid waste, toxins, acid precipitation, other pollution

Water Diversions

arrowdams, irrigation, flood control, groundwater extraction, wetland fill, dredging, other water diversions

Other Factors

arrowinbreeding depression, climate change, weather extremes, catastrophes, all other threats