作者: Morten Frederiksen , Thomas Bregnballe , Mennobart R. van Eerden , Stef van Rijn , Jean-Dominique Lebreton
DOI: 10.2981/WLB.2002.021
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摘要: The breeding population of cormorants Phalacrocorax carbo sinensis has expanded more than twenty-fold in continental Europe since 1970, and these large piscivorous birds cause conflicts with human fishery interests parts Europe, including areas outside their range. Culling aimed at reducing local size takes place some wintering areas, particularly France Switzerland. effectiveness such management actions is unknown depends on how high cormorant site fidelity is. We use winter resightings from the period 1980–2000 24,000 colour-ringed Denmark Netherlands to estimate fidelity. Year-to-year single sites (typically lakes) was 85–90%. For that changed mean distances moved year were typically between 10 50 km, depending geographical location. However, long-distance movements (maximum observed 1,891 km) also occurred regularly. larger range, exemplified by France, about 3% all left area year. A mathematical model showed levels movement among sufficiently sustain a culling which would drive it extinction absence immigration. Although are not nomadic season, as previously believed, low must be taken into account programmes.