New Zealand Journal of Ecology (1978) 1: 118- 125

Organochlorine residues in New Zealand birds of prey

Research Article
N. C. Fox 1
J. W. Lock 2
  1. Department of Zoology, University of Canterbury, Christchurch, New Zealand
  2. Wallaceville Animal Research Centre, Research Division, Ministry of Agriculture and Fisheries, Private Bag, Upper Hutt, New Zealand

Pectoral muscle samples from 13 New Zealand falcons, 3 Australasian harriers, 7 little owls, 7 moreporks, one long-tailed cuckoo and one New Zealand pigeon were analysed for organochlorine pesticide and polychlorinated biphenyls. Five juvenile falcons had a mean level of 2.6 mg total DDT per kg wet weight, and six adult falcons had an equivalent value of 11.7 mg/kg. Total DDT levels in harrier muscles ranged from 2.0 to 64.9 mg/kg. Levels in other species were probably too low to have detectable biological effects. There was no correlation between falcon eggshell thinning and residues in two eggs and two chicks