The breeding population of peregrine falcons (Falco peregrinus) in Norway was almost exterminated by the early 1970's. Long-term monitoring of breeding pairs has been conducted since 1976 up to present. Peregrine falcons were first established at breeding sites in coastal habitats, where they remained at stable low numbers until the early 1990's. Starting around 2000, numbers began to increase steadily, and current numbers have now reached historical population levels from the pre-DDT era. We documented a range expansion with increasing numbers of peregrines nesting in the fjords and inland valleys. We found that once a territory was colonized, the probability that a territory remained occupied was high (S > 0.958). During early stages of population recovery, the transitional probabilities of becoming or remaining a breeding territory were high (ψN-B > 0.40, ψB-B > 0.65) but declined over time, especially in coastal habitats. Moreover, the productivity per nest has also decreased over time at sites in coastal habitats in the former stronghold of the population. The levels of environmental pollutants in eggs of the peregrines have dropped sharply over the last few decades, and contaminant levels now seem to be below critical levels. Eggshells were relatively thin throughout the 1970s, 1980s, and 1990s, but have increased to almost normal levels during the last 2 decades. Reductions in levels of organochlorine pollutants, especially DDT, appear to have been the main factor in explaining the population recovery. The territory dynamics are consistent with density-dependence and the low breeding success of the coastal-breeding peregrines is believed to be caused by declining numbers of colonial seabirds and other prey species.

中文翻译：

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自从DDT禁令生效以来的四十年中，挪威中部的游eg猎鹰的种群恢复。

1970年代初期，挪威的游eg（Falco peregrinus）繁殖种群几乎灭绝。自1976年至今，一直对育种对进行长期监测。游eg始建于沿海生境的繁殖地，直到1990年代初一直保持稳定的低位。从2000年左右开始，数字开始稳定增长，而目前的数字已从DDT前时代达到历史人口水平。我们记录了范围的扩大，在峡湾和内陆山谷筑巢的游of越来越多。我们发现，一旦领土被殖民，领土被占领的可能性就很高（S> 0.958）。在人口恢复的初期，成为或保留繁殖区的过渡概率很高（ψN-B> 0.40，ψB-B> 0.65），但随时间下降，特别是在沿海生境中。此外，在过去人口密集的沿海生境中，每个巢的生产率也随着时间的推移而下降。在过去的几十年里，游eg蛋中的环境污染物水平急剧下降，现在污染物水平似乎低于临界水平。整个1970年代，1980年代和1990年代，蛋壳相对较薄，但在过去的20年中，其蛋壳水平已提高到几乎正常水平。降低有机氯污染物，特别是滴滴涕的含量似乎是解释人口恢复的主要因素。