Factors Influencing Reporting and Harvest Probabilities in North American Geese

ABSTRACT We assessed variation in reporting probabilities of standard bands among species, populations, harvest locations, and size classes of North American geese to enable estimation of unbiased harvest probabilities. We included reward (US$10, $20, $30, $50, or $100) and control ($0) banded geese from 16 recognized goose populations of 4 species: Canada (Branta canadensis), cackling (B. hutchinsii), Ross's (Chen rossii), and snow geese (C. caerulescens). We incorporated spatially explicit direct recoveries and live recaptures into a multinomial model to estimate reporting, harvest, and band-retention probabilities. We compared various models for estimating harvest probabilities at country (United States vs. Canada), flyway (5 administrative regions), and harvest area (i.e., flyways divided into northern and southern sections) scales. Mean reporting probability of standard bands was 0.73 (95% CI = 0.69–0.77). Point estimates of reporting probabilities for goose populations or spatial units varied from 0.52 to 0.93, but confidence intervals for individual estimates overlapped and model selection indicated that models with species, population, or spatial effects were less parsimonious than those without these effects. Our estimates were similar to recently reported estimates for mallards (Anas platyrhynchos). We provide current harvest probability estimates for these populations using our direct measures of reporting probability, improving the accuracy of previous estimates obtained from recovery probabilities alone. Goose managers and researchers throughout North America can use our reporting probabilities to correct recovery probabilities estimated from standard banding operations for deriving spatially explicit harvest probabilities.     

The Control of Color in Mammals

SYNOPSIS. Recent advances in the biology of mammalian pigmentationare reviewed.Particular attention is given to emerging informationon the integration of pigmentary events occurring at differentlevels of biological organization within mammalian skin andhair. The structural and functional significance of keratinocytesand melanocytes as components of mammalian epidermal melaninunits is viewed from this perspective. New evidence on the natureof genetic, developmental, endocrine, and radiation influenceson performance of melanocytes and the establishment of pigmentarypatterns is summarized.