Changes in bird numbers on Tiritiri Matangi Island, New Zealand, over the period of rat eradication

Tiritiri Matangi is 25 km north of Auckland City in the Hauraki Gulf, New Zealand. Most of its forest cover was removed during many centuries of Maori and European occupation and farming. Some areas of extant forest canopy remained. Farming ceased in 1971. Since 1984 some 300,000 native trees have been planted. Twenty-seven species of native bird are naturally present and breeding on the island. Twenty-two exotic species introduced to mainland New Zealand have found their way to the island. Nine species of native bird have been translocated to the island. Data from bird counting transects within extant forest areas in spring are considered. The data from a three-year period before eradication of Pacific rats (Rattus exulans) in September 1993 are compared to a three-year period following rat eradication, with a three-year settling period between. A number of significant changes are recorded with both increases and decreases in bird numbers. These are attributed to the direct impact of the rats or changes in forest composition following rat removal, or the data are confused by conservation management actions beyond the immediate count areas.

Author Graham, M. F. and Veitch, C. R.
Year 2002
Secondary title International Conference on Eradication of Island Invasives
Publisher IUCN Invasive Species Specialist Group
Pages 120-123
Region NZ