Grey Partridge Reintroduction
To reintroduce captive-bred grey partridges into their former range in Switzerland
The grey partridge, Perdix perdix, is widely distributed in the western Palearctic from the United Kingdom to Kazakhstan. It has its origin in steppes but, in Europe, has become a typical breeding bird of agricultural areas dominated by arable land. In Switzerland, the grey partridge occurred mainly in the lowlands where climatic conditions were favourable and farmland predominated. Already in the 1970s, as a result of agricultural intensification, the partridge experienced a dramatic decline in numbers from more than 10'000 to only a few individuals. Only small isolated populations remained and dwindled in the 1990s to a few breeding pairs in the canton of Geneva. Only two breeding pairs were observed in 2003. In the northern part of Switzerland, in the canton of Schaffhausen, the last partridge was observed in 1996.
Similar population developments occurred in several European countries, e.g. the population of the United Kingdom dropped of 82% between 1970 and 1998, in the Netherlands only tiny relic population are left, and it is estimated that the population decline in the species' entire range has been about 80 % since the 1950s. Additionally, the distribution area has increasingly become patchy.
This decline has been caused mainly by changing agricultural practices. Intensive farming with large monotonous, drained fields and hard machinery resulted in a loss of suitable breeding habitats. Furthermore, pesticide use affected the survival and breeding success of the grey partridge by reducing the quantity and diversity of invertebrates, either directly with insecticides or indirectly with herbicide destructing their food and habitat resources. It could be demonstrated that, in particular, the use of herbicides for weed control had a detrimental effect on the survical rate of the grey partrige chicks. Predation by an increasing red fox population and by domestic cats may also have contributed to the decline.
In 1991 the federal authorities mandated the Swiss Ornithological Institute of Sempach to develop and implement a species recovery programme for the grey partridge in order to prevent the extinction of the species in Switzerland.
At that time a great effort was undertaken to increase habitat quality in some areas of the cantons of Geneva and Schaffhausen.In particular the number of wild-flower strips was significantly increased. The total surface of ecological compensation areas reached up to 10% of the cultivated area. Several endangered farmland bird species benefited from this restoration. In the study area in the canton of Schaffhausen, hand-reared and wild partridges were released between 1998 and 2002. Their habitat use, home range and survival rates were investigated in a study by F. Buner. This study was the scientific basis for the decision to start a reintroduction programme for grey partridges. In 2002, the Swiss Ornithological Institute released 50 wild partridges from Poland. Since then, about 50 hand-reared chicks have been released every Summer to be adopted by "wild" pairs. Following this method, the institute was able to start the reintroduction programme in the canton of Geneva in 2004. In both cases, the cantons took the political responsibility and financially supported the reintroduction. Langenberg Wildlife Park cared for the quarantine of the imported partridges intended for release. Berne Animal Park have started breeding partridges and donated the chicks to the programme.
The Swiss Ornithological Institute published a 60 pages report under the title "Das Rebhuhn - Symbol für eine artenreiche Kulturlandschaft, Avifauna Report Sempach Nr. 4".
WAZA Conservation Project 05032 is executed by the Swiss Ornithological Institute, Sempach and supported by the Langenberg Wildlife Park Berne Animal Park "Dählhölzli", Animal Park Lange Erlen, Animal Park Seeburg, the Swiss Authority for the Environment, Forests and Landscape, the cantons of Geneva and Schaffhausen, local nature conservation and hunter associations, and the CIC.
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