Control of cats on mountain “islands”, Stewart Island, New Zealand

The southern subspecies of the New Zealand dotterel (Charadrius obscurus) is currently restricted to nesting areas on the bleak alpine mountaintops of Stewart Island. By the early 1990s the species had declined to a total population of 65 individuals. The principal cause of the decline was attributed to predation by feral cats (Felis catus). A cat control programme was initiated in 1992. The programme involved a perimeter of bait stations set up at the bushline. Poison baits for cats were presented in these stations during spring and summer, when dotterels were nesting. Research suggests that cats are not resident year-round in the sub-alpine scrub. They generally stray into the sub-alpine scrub and above the bushline during the summer “low” in abundances of rats, their principal prey on Stewart Island. Little alternative prey is available during summer. The cat control appears to have been successful, as the population of dotterels has expanded to 170 individuals by April 2000. Research into the habitat preference of cats is continuing with a view to more efficient use of resources for ongoing cat control.

Author Harper, G. A. and Dobbins, M.
Year 2002
Secondary title International Conference on Eradication of Island Invasives
Publisher IUCN Invasive Species Specialist Group
Pages 408-408
Control method Baiting
Region NZ