The North American Geese (el. knyga) (skaityta knyga) | knygos.lt

Aprašymas

There are eight currently recognized species of North American geese: emperor, greater white-fronted, snow, Ross's, Canada and cackling, barnacle, and brant geese. This book describes each species' geographic range and subspecies, its identification traits, weights and measurements, and criteria for its age and sex determination. Ecological and behavioral information includes each species' breeding and wintering habitats, its foods and foraging behavior, its local and long distance movements, and its relationships with other species. Reproductive information includes each species' age of maturity, pair-bond pattern, pair-forming behaviors, usual clutch sizes and incubation periods, brooding behavior, and postbreeding behavior. Mortality sources and rates of egg, young, and adult losses are summarized, and the past and current populations of all species are estimated. The book includes 8 maps, 21 line drawings, 28 photographs by the author, and more than 700 literature citations.