New Zealand Journal of Ecology (1998) 22(1): 11- 16

Sex ratio of North Island kaka (Nestor meridionalis septentrionalis), Waihaha Ecological Area, Pureora Forest Park

Research Article
Terry C. Greene  
James R. Fraser  
  1. Department of Conservation, Private Bag 68-908, Auckland, New Zealand
  2. Department of Conservation, P.O. Box 134, Russell, New Zealand

The sex ratio of the kaka population inhabiting the Waihaha Ecological Area, Pureora Forest Park was estimated between late October 1994 and January 1995. The observed sex ratio estimate was three males to one female compared to a capture rate (using mist nets) of six to one in the same area between January and June 1994. Females appeared to be less susceptible to capture than males. The skewed sex ratio toward male kaka was significant and suggests that female kaka suffer higher mortality (probably due to predation at the nest) than males. The slow breeding rate of kaka combined with a high loss of breeding females is a serious threat to the long term survival of the kaka population within the Waihaha Ecological Area.