Raptors are still affected by environmental pollutants: Greenlandic Peregrines will not have normal eggshell thickness until 2034

Knud Falk, Søren Møller, Frank F Rigét, Peter B. Sørensen, Katrin Vorkamp

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

    Abstract

    The DDT-induced effects, eggshell thinning and breeding failure in Peregrine Falcon populations, were reverted with restrictions on the use of the compound from the 1970’ies, and in most studied populations the eggshell thickness is back to normal. In Greenland, a previous study of eggshell thinning in Peregrines found that shells had not yet reached pre-DDT levels. In this study, we extend the time series and reinterpret shell thinning data for 196 clutches covering a 45-year time span (1972-2017). There was a significant (P<0.001) increase in the eggshell thickness of 0.23% per year. This corresponds to a change in eggshell thinning from 14.5% to 5.4% in 2017 compared to the pre-DDT mean. With the current rate of change, pre-DDT shell thickness is predicted to be reached around the year 2034. However, a few clutches are still below the critical limit. The relatively slower recovery of the shell thickness in the Greenland population is likely indicative of the slower phasing out of DDT in the Greenlandic Peregrines’ wintering grounds in Latin America. The shell thinning in the Greenlandic population probably never crossed the 17% threshold associated with population declines, contrary to the populations in many other parts of the world.
    OriginalsprogEngelsk
    TidsskriftOrnis Hungarica
    Vol/bind26
    Udgave nummer2
    Sider (fra-til)171-176
    Antal sider6
    ISSN1215-1610
    DOI
    StatusUdgivet - 1 feb. 2019

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