The seasonal change of bird populations in a modified South Island habitat

[First paragraphs...]
Since September, 1958, a study of bird populations has been made in Dunedin in order to determine the pattern of ecological distribution and the population structure of native and introduced species of birds in a modified South Island habitat.
Acknowledgement is made to the Botanic Gardens authority in Dunedin for making accessible to me the upper part of the Gardens in which this work was undertaken, and to the staff of the Botany Department of Otago University for help with the identification of the plants.
The following is the result of the reconnaissance work by which the assessment of an avian habitat of modified conditions was made. The study area was 12 acres in size and consisted of regenerating woodland mixed with a few introduced trees and patches of flower gardens and lawn. This area was visited 97 times during a period of 12 months for estimating the size of the population, recording the nesting and feeding activities of every species, and ringing nestlings and adults of the key species. The early morning counts of the total population were made weekly in the area and they showed the highest number of 229 in spring and the lowest of 43 in winter with a total of 63 pairs in the breeding season and an average of 73.2 individuals in winter. The house sparrow was excluded from the above counts.