title: A long-term increase in eggshell thickness of Greenlandic Peregrine Falcons Falco peregrinus tundrius.
abstract: Thickness of eggshell fragments and whole eggs from the Peregrine Falcon Falco peregrinus collected in South and West Greenland between 1972 and 2003 was measured and compared to shell thickness of pre-DDT eggs, also collected in Greenland. Linear regression yields a significant increase in the average thickness of eggshells over the period of 0.19% per year, corresponding to a change in eggshell thinning from 13.9% in 1972 to 7.8% in 2003. Backwards extrapolation of the data, suggests that the Greenlandic Peregrine population probably was never critically affected by DDT-induced eggshell thinning. By sampling eggshell fragments in many nests the spatial and temporal sample distribution was enlarged, allowing the detection of a significant long-term decrease in pollutant-induced eggshell thinning--a trend that could not have been identified if only the rarer whole, addled eggs had been sampled.
authors.affiliation: Teglstrupvej 6a, DK-2100 Copenhagen, Denmark. kf@vandrefalk.dk
authors.forename: Knud
authors.initials: K
authors.lastname: Falk
authors.forename: Søren
authors.initials: S
authors.lastname: Møller
authors.forename: William G
authors.initials: WG
authors.lastname: Mattox
mesh_terms: D000818:Animals; D003634:DDT / Q000633:toxicity; D004528:Egg Shell; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000633:toxicity; D046093:Falconiformes; D006116:Greenland
chemical_list: D004785:Environmental Pollutants; D003634:DDT