Effects of overflights on incubating Wilson's plover behavior and heart rate

Increasing attention is paid to the effects of human activities, including the use of aircraft, on wildlife. However, responses to visual and auditory stimuli associated with aircraft are highly species- and context-dependent and results of existing studies should not be generalized across species, or even across life stages of the same species. We used digital audio recorders, auto-triggered cameras, and heart rate monitors to study the responses of nesting Wilson's plovers ( Charadrius wilsonia) to different types of planes (civilian and military fixed-wing aircraft) and helicopters (civilian and military rotary-wing aircraft) at Cape Lookout National Seashore, North Carolina. We compared vigilance behavior, incubation rate, and heart rate before, during, and after overflights. Wilson's plovers were alert and scanned more during military rotary-wing overflights, and scanned more during both military and civilian fixed-wing overflights than during periods without overflights. Heart rates and incubation rates did not change during any type of overflights. Although we found no direct link between increased vigilance rates and decreased reproductive success, a substantial increase in aircraft traffic at our study site, especially rotary-wing overflights, would merit further investigation.