Effects of Spring Grazing By Greater Snow Geese on Hay Production

Abstract

(1) The effects of spring grazing by the greater snow goose (Chen caerulescens altantica, Linnaeus) on hay production were studied in a 283 ha agricultural area at Montmagny, Quebec [Canada]. A flock of 13500 staging birds used the area between 1 April and 19 May 1980. (2) The measurements were obtained at fifty-one sampling stations randomly located in two major habitat types: first-year or new hayfields (sixteen) and older hayfields (thirty-five). Each station contained a fenced and an unfenced plot (1.5 .times. 5.5 m) and a permanent strip transect in which goose utilization was monitored by dropping counts made every 4 days. Grass height and total harvestable biomass (in g of dry matter per square metre, g DM m-2) were measured immediately after goose departure (19 May) and at harvest time (28 June). (3) In all instances, height and total harvestable biomass bore a significant inverse relationship to prior goose utilization. The reduction in yield at the June harvest as a consequence of April and May grazing by staging geese amounted to 47.1 g DM m-2 of total harvestable biomass which represents as estimated 125 t of hay or a 14.3% reduction in potential yield of the first crop of 213 ha of productive areas within the study area.