During 1971-76 the world population of the Dark-bellied Brent Goose Branta bernicla bemicla has more than trebled, while in the period since the first attempt at assessing the size of the population (1955-57) it has increased nearly sixfold. It has managed this at a time when biologists were predicting that food supplies were holding its numbers at the earlier low level, when conservationists were

...

Stay at the forefront of British birding by taking out a subscription to British Birds.

Subscribe Now