The Effect of Experimental Removal of Single Breeding Pairs of Resident Canada Geese
Published Web Locationhttps://doi.org/10.5070/V425110587
Resident Canada geese cause substantial economic losses to agriculture and personal property and compromise air traffic safety throughout the U.S. Destroying eggs of Canada geese nesting in the contiguous U.S. is a primary component of the integrated management regime to reduce damage caused by the species. This requires regular searches to destroy eggs throughout nesting season, which may be laborious and costly. Much of the breeding by resident Canada geese occurs on small ponds (≤5 acres). Anecdotal observations suggested that social pressure among breeding pairs of Canada geese typically dictates that only one aggressive breeding pair establishes a territory on small ponds. Using this logic, managers allow a single nesting pair on small ponds and destroy their eggs, while deriving the perceived benefits of the sentinel geese excluding other nesting geese. However, a single pair of geese may also cause damage, decimating plants and depositing accumulations of feces in the localized area. We hypothesized that removal of single nesting pairs of Canada geese on small ponds after the onset of breeding activity would result in a void of geese for the remainder of the reproductive season, thus providing an alternate lower-cost management strategy. We further hypothesized that if the male goose was not removed, he would continue to defend the territory, excluding other nesting geese. Our study was conducted on 22 independent sites with small ponds in Bucks County, southeastern Pennsylvania. Each site held historically one nesting pair of Canada geese. To test our hypotheses, breeding pairs of Canada geese were assigned to one of three experimental groups: 1) control neither female nor male goose was removed, the eggs were treated under normal protocols to prevent hatching, and the nest and eggs were removed after the 28-day incubation period; 2) after nest initiation, only the female goose was removed, and the nest and eggs were removed; and 3) both the female and male goose were removed and the nest and eggs were removed. We determined that targeted removal of a nesting pair or only the female of a nesting pair of Canada geese could be effective in eliminating breeding on a small pond for the entire nesting season. Likewise, the traditional approach of allowing a single aggressive nesting pair on small ponds reliably excluded additional nesting pairs.