3.2. Bird and mammal diversity and abundance
Within both of the sample areas described above we
selected four patches of evergreen forest to represent the
range of size and disturbance classes found within each
sanctuary. Within each patch two 500 m transects were
established, one in the edge zone, defined as being
within 100 m from the forest edge (McGarigal and
McComb, 1995), and the other within the interior. Edge
zone transects were further divided into five 100 m lines
and located perpendicular to the patch edge at 200–300
m intervals. These intervals reduce the chance of counting the same birds twice during sampling. Each transect was surveyed seven times during site visits spanning
from September 1997 to June 1998.