Responses of wintering Brent Geese to human disturbance

Abstract

An assessment is given of the effects of human disturbance on the distribution and behaviour of Dark-bellied Brent Geese Branta bernicla bernicla wintering in Essex. Disturbed areas and places with poor visibility were avoided in early winter, but were used later when other areas became depleted of food. Geese became partially habituated to the proximity of people and to some loud noises, but not to small low-flying aircraft. The areas which contained the most geese apart from Foulness, namely Leigh Marsh and the Blackwater estuary, were also the most disturbed. Here, disturbance at weekends prevented geese from feeding for up to 11.7% of their time, and caused the time spent in flight to increase as much as sevenfold. Overall levels of disturbance were much lower than this, and would probably have been unimportant so long as adequate food was available on which geese could feed in undisturbed times, and at night. However, a shortage of food probably prevented complete compensation for the effects of disturbance. Disturbances could be greatly reduced by restricting access to the sea wall in certain areas around high tide, and by controlling the numbers of low-flying aircraft.