Date of this Version
The Prairie Naturalist 44:109-110; 2012.
Collisions with electrical powerlines are a well-known documented cause of avian mortality (Avian Power Line Interaction Committee [APLIC] 1994, Savereno et al. 1996). Mortality caused by collisions with powerlines can be an important concern for many bird species, but is a serious conservation problem for threatened and endangered species because any mortality can have biological and legal ramifications (Janss 2000). Loss of individuals, particularly breeding adults, from an already small population may impede a species’ recovery by reducing reproduction and recruitment into the breeding population. The death of an individual from a threatened or endangered species as a result of a collision may constitute “take” as defined by the federal Endangered Species Act (1973; 16 U.S.C. 1531–1544.) and the federal Migratory Bird Treaty Act (1918; 16 U.S.C. 703–712). Companies and/or individuals may be prosecuted when powerline collisions occur, particularly if recommendations intended to reduce the risk of collision, provided by the United States Fish and Wildlife Service (USFWS) regarding the placement of the powerlines, have not been followed.
The interior least tern (Sternula antillarum athalassos) is a federally endangered species (50 Federal Register 21784–21792) that breeds on and along the Mississippi and Missouri rivers and their tributaries (Thompson et al. 1997). The species’ principal nesting habitat includes sparsely vegetated sandbars within main river channels, but in some cases birds will nest on human-created habitats such as waste sand from dredging or mining operations (Thompson et al. 1997). Interior least terns are small and agile flyers able to readily avoid powerline collisions. In fact, collisions with powerlines were not identified as a potential threat to recovery in the interior least terns’ recovery plan (United States Fish and Wildlife Service [USFWS] 1990). Here, we provide the first documented report of an interior least tern mortality that we are aware of, caused by a collision with a powerline, and comment on the conservation implications of the incident.