U.S. Department of Agriculture: Animal and Plant Health Inspection Service
Date of this Version
Spring 2000
Abstract
We monitored radio-equipped (n = 50) and neck-collared (n = 205) lesser Canada geese (Branta canadensis parvipes) during August through October 1996 in Anchorage, Alaska, to ascertain local patterns of movement and post-molt dispersal; to identify geese from molting sites that frequent Elmendorf Air Force Base (EAFB); and to evaluate the effectiveness of hazing at EAFB. Telemetry data and visual observations of collared geese indicated 59% of geese observed at EAFB were from molting sites ≤10 km from EAFB. We observed 93 marked geese from 11 molting sites 1 or more times in the EAFB airdrome, and 63% of geese observed >2 times on EAFB were from molting sites ≤10 k m from EAFB. A significant direct relationship was found between proportion of geese invading the EAFB airdrome and the distance molting sites were located from EAFB. After attaining flight, geese from the northeast and northwest quadrants of Anchorage initially moved greater distances from molt sites to feeding sites than geese from other parts of Anchorage. Intensive hazing proved effective in preventing 67% of marked geese from returning to the exclusion zone. However, hazed geese dispersed only 3.53 ± 0.2 k m from the exclusion zone. Most observations of marked geese at EAFB occurred during afternoon from 1200 through 1759 hr. Although hazing efforts provided an increased measure of flying safety, we suggest that managing geese at the spatial level of the entire city will be more successful at reducing danger to aircraft.
Comments
Published in Northwestern Naturalist 81:11-17, Spring 2000.