Consequences of Neckband and Legband Loss from Giant Canada Geese

Abstract

Researchers often assume band loss is negligible when resightings (i.e., any observations subsequent to banding) of neckbanded birds and recoveries of legbanded birds are used to estimate population parameters. We used recapture, harvest, and observation data from giant Canada geese (Branta canadensis maxima) banded in central Missouri, USA, 1989-1999, to estimate neckband and legband retention. We used accelerated failure time models to estimate neckband and legband retention rates and to evaluate sources of variation in neckband and legband loss. We observed considerable neckband and legband loss that varied by sex, year of banding (for neckbands only), and band age. We estimated that 34% of male and 16% of female giant Canada geese had lost their neckbands, and 15% of male and 8% of female giant Canada geese had lost their legbands within 6 years of banding. Neckband-loss rates in our study were lower than those reported for other geese. Conversely, legband-loss rates in our study were higher than those reported for other geese. Neckband and legband loss should be accounted for when estimating population parameters from these types of data.