ABSTRACT
Fewer species of land birds breed on islands than on comparable areas of mainland. Often the habitat is different in the two regions. The two main methods of censusing are mist netting and observation. The alternative method is to use observations of birds, either along transects or in an area repeatedly surveyed. When birds are not restricted to territories, their numbers may be estimated by the recapture method applied to the results of visual censuses, providing the assumptions of the method are not violated. Visual censuses were conducted at the end of these 2 years, when the finches were mobile and not breeding. In the breeding season when the birds are restricted to territories, a map is then compiled of all the territories.
