Anthropogenic lead (Pb) exposure in populations of a wild parrot (kea Nestor notabilis)
- Research and Development Group, Department of Conservation, PO Box 10420, Wellington 6143, New Zealand
- New Zealand Wildlife Health Centre, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand
Kea (Nestor notabilis), large parrots endemic to hill country areas of the South Island, New Zealand, are subject to anthropogenic lead (Pb) exposure in their environment. Between April 2006 and June 2009 kea were captured in various parts of their range and samples of their blood were taken for blood lead analysis. All kea (n = 88) had been exposed to lead, with a range in blood lead concentrations of 0.014 – 16.55 ìmol L–1 (mean ± SE, 1.11 – 0.220 ìmol L–1). A retrospective analysis of necropsy reports from 30 kea was also carried out. Of these, tissue lead levels were available for 20 birds, and 11 of those had liver and/or kidney lead levels reported to cause lead poisoning in other avian species. Blood lead levels for kea sampled in populated areas (with permanent human settlements) were significantly higher (P < 0.001) than those in remote areas. Sixty-four percent of kea sampled in populated areas had elevated blood lead levels (> 0.97 ìmol L–1, the level suggestive of lead poisoning in parrots), and 22% had levels > 1.93 ìmol L–1 – the level diagnostic of lead poisoning in parrots. No kea from remote areas had levels > 0.97 ìmol L–1. The kea is a long-lived, slow-reproducing species at a high risk of decline from even a small reduction in its survival rate. Based on our findings, we conclude there is an urgent need to implement lead abatement strategies in areas of the kea range that overlap with permanent human settlement.