RESPONSE OF BRANT AND OTHER GEESE TO AIRCRAFT DISTURBANCES AT IZEMBEK LAGOON, ALASKA

Effects of increased aircraft disturbance and other disturbances on Pacific black brant (Branta bernicla nigricans) and other geese were studied at Izembek Lagoon, Alaska. Spatial distribution, foraging ecology, and normal behavior of brant were determined by extensive field observations made each fall from 1985 to 1988. Response to disturbance usually involved alert behaviour followed by flight. After landing, brant remained alert, shifted positions, and engaged in maintenance behavior before they resumed foraging. Of all incidental disturbances, bald eagles and boats elicited the greatest magnitude of response in flocks of brant. The percent response by flocks was least with the Piper Navajo twin-engine aircraft and greatest for the Bell 205 helicopter. In contrast to fixed-wing aircraft, the response of brant to helicopter overflights did not diminish with increasing altitudes up to 610 m (2,000 ft). The threshold noise level would be 49 dB for alert response and 58 dB for flight response. The study provided evidence that noise rather than a visual cues triggered the behavioral response.

• Corporate Authors:

  Alaska Fish and Wildlife Research Center

  Anchorage, AK  United States 
• Authors:
  • Ward, D H
  • Stehn, R A
• Publication Date: 1990-3

Media Info

• Pagination: 206 p.

Subject/Index Terms

• TRT Terms: Aircraft; Aircraft noise; Behavior; Birds; Boats; Field studies; Helicopters; Noise; Sound level; Traffic distribution
• Geographic Terms: Alaska
• Old TRIS Terms: Field observation; Forage
• Subject Areas: Aviation; Environment; Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00607823
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: MMS-90/0046
• Files: TRIS
• Created Date: Apr 30 1991 12:00AM