Organochlorine Residues in Alaskan Peregrine Falcons (Falco peregrinus Tunstall), Rough-legged Hawks (Buteo lagopus Pontoppidan) and their Prey

Abstract

DDE residues in Alaskan Peregrine Falcons and Rough-legged Hawks were compared with levels in their prey.Based on oven dry (OD) weight, average DDE levels (and standard errors) for Peregrine tissues (N=3) were as follows: egg -131 (+ 53.4) ppm; brain -58.2 (+ 15.5) ppm; fat -752 (+225) ppm: muscle-114 ( +27.6) ppm: liver -398 (+78) ppm.Based on OD weight, DDE levels for Rough-legged Hawk tissues (N = 3 for each tissue) were: egg -7.07 (+ 6.57) ppm; brain -0.67 (+£0.48)ppm; fat-13.3(+7.58) ppm; muscle -1.21 (+ 0.53) ppm.The highest ratio of tissue residues (Peregrine: Roughleg) occurred between brain samples (i.e.86.9) and muscle samples (i.e.94.2).Resident Arctic prey contained less than 1 ppm DDE (OD).Tissues of migrating prey, which constitute the bulk of the Peregrine's diet, were represented by two ducks and contained between ten and twenty times more DDE residue (depending on tissue analyzed) than the roughleg prey.resident small mammals.