Use of farmland in spring by migrating Canada geese in the St Lawrence valley, Quebec.
Abstract
During their spring stop-offs in Lake St. Peter, which averaged 32 days (1974-5), migrating Canada geese (Branta canadensis) flew twice daily to feed on agricultural land up to 13 km from the Lake. About 6 h/day were spent feeding on farmland. About 60% of goose feeding on farmland in spring occurred on grassland, 16% on fields of last-yr maize (standing and stubble), 12% on ploughed grass and 12% on ploughed maize. When compared with the availability of the different field types, the data indicate equal preferences for fields of grass and maize, and avoidance of ploughed areas. Differences in usage and preferences were recorded in relation to field location, time of season and severity of flooding. Foods consumed by Canada geese on agricultural land included a wide variety of native and cultivated grasses (foliage, roots and seeds), waste grains and weeds. Grass foliage was by far the most important item and was consumed in all field types, followed by waste maize kernels. Clover and lucerne, often readily available in grass fields, were rarely taken. Even heavy grazing by geese in spring did not result in a reduction of the yield of fodder at harvest 2-3 months later. A few farmers may have suffered minor economic losses when exceptionally severe grazing occurred. Present evidence indicates that in those rare situations where warranted concern for crop yields exists, the problem could be remedied by simple changes in farm husbandry and by the use of scaring devices.