Effects of Helicopter Noise on Mexican Spotted Owls

Dose-response relationships of harlequin duck behaviour to noise from low-level military jet over-flights in central Labrador

“…Effects of military aircraft noise on wildlife have been reported for other species such as increasing flushing frequency in Mexican spotted owls Strix occidentalis lucida with increasing noise level from helicopters (Delaney et al 1999). In general, it is known that birds respond to aircraft noise (Burger 1981;Trimper et al 1998;Hunsaker 2001;Murphy et al 2001), as do caribou Rangifer tarandus (Harrington & Veitch 1991;Jung & Jones 2001;Maier et al 2001).…”

Ecological Risk Assessment Framework for Low-Altitude Overflights by Fixed-Wing and Rotary-Wing Military Aircraft

“…A possible exception is the threshold for effects on the Mexican spotted owl. Because the helicopter was not very visible to the owl in the study by Delaney et al (1999), the slant distance could be converted to a sound exposure without losing much precision. Based on a study with osprey, the appropriate sound measure to use would be the maximum sound level (Trimper et al 1998).…”

“…Because the A-weighted scale represents a simplification of the acoustic response in humans, this adjustment is not entirely appropriate for wildlife (EPA 1980). Occasionally, researchers estimate appropriate decibel-weighting for other species (e.g., owls, Delaney et al 1999). However, acoustic responses are unknown for most wildlife species, and many animals are assumed to have a similar sensitivities to the frequencies of aircraft sound as humans (e.g., caribou, Maier et al 1998).…”

Status assessment and conservation plan for the yellow-billed loon (Gavia adamsii)

“…Relevant parameters to quantify include time and energy expended fleeing or alert, foraging efficiency, possible avoidance of otherwise favorable nesting or foraging habitat, prey delivery to young, incubation constancy, and physiological indicators of stress (Knight et al 1991, Delaney et al 1999, Thorson et al 2002, Washburn et al 2003. A typical approach is to measure an individualʼs response to a well-quantified disturbance event (e.g., a 70 decibel noise at 500 m lasting for 5 minutes) using either "naturally" occurring or experimentally introduced disturbance events.…”