ENERGETIC COST OF MAN-INDUCED DISTURBANCE TO STAGING SNOW GEESE

For greater snow geese Chen caerulescens atlantica in Quebec, 2 responses of birds to disturbance were considered 1) birds fly away but promptly resume feeding following a disturbance (Response A) and 2) birds interrupt feeding altogether (Response B). Daylight foraging time decreased by 4-51% depending on disturbance levels. Average rate of disturbance (1.46/hr) in Response A resulted in a 5.3% increase in hourly energy expenditure (HEE) combined with a 1.6% reduction of hourly metabolizable energy intake (HMEI). In Response B, HEE increased by 3.4%; HMEI decreased by 2.9 to 19.4%. A 4% increase in night feeding could compensate for energy losses caused solely by disturbance flights (Response A), but a 32% increase in nighttime feeding was required to restore energy losses incurred in Response B. No increase in daily feeding rate was observed between days with different disturbance levels. -from Authors