© Beat Rüegger
Up until a few decades ago, the Grey Partridge inhabited climatically favourable arable regions in Switzerland. In the second half of the 20th century, the population has decreased from 10´000 to only a few individuals. The species recovery programmes in the cantons Geneva and Schaffhausen aim at preserving this species in Switzerland.
The Grey Partridge is a typical breeding species of open agricultural landscapes. Grey Partridges used to be common in Switzerland, but are facing extinction today. The goal of the project, which has been running since 1991, is to promote the remnant populations in the Champagne genevoise, canton Geneva, and in the Klettgau, canton Schaffhausen. For this purpose, habitats of this demanding species have been enhanced since the project start. From 1998 to 2012, the remnant populations have occasionally been sustained by releases and have been scientifically monitored.
In 1991, the Federal Office for the Environment (FOEN) mandated the Swiss Ornithological Institute to launch a recovery project for the Grey Partridge. In close collaboration with farmers and cantonal authorities, new habitats were created in the Klettgau and in the Champagne genevoise. Large parts of the project areas were enhanced with wildflower areas, hedges and extensively managed meadows. In this way, several square-kilometres of optimal partridge habitat were created.
After seven years of thorough habitat improvement, the first partridges were released in the Klettgau in 1998, and settlement behaviour, habitat use and breeding success of these individuals were examined in a PhD thesis. Encouraged by the positive results, the programme was continued and the small population supported by periodic releases of few to maximally 100 individuals from 2004 to 2007. After a crash of the local Grey Patridge partridge population, which was mainly due to unfavourable climatic conditions, no further releases have been done since 2008 in agreement with the cantonal authorities. Activities in the canton Schaffhausen have been restricted to additional habitat improvement and to the population monitoring of the breeding bird species and the brown hare. If and how further activities in relation to Grey Partridge releases are undertaken also depends on the results from the project running in the canton Geneva.
In 2004, partridges were also released in the Champagne genevoise to sustain the remnant population. By releasing numerous autumn coveys, the goal in Geneva from 2008 to 2012 was to increase spring population size to 200 Grey Partridges and to reach a density of 3 breeding pairs per km2. To have enough young partridges available for the releases, the Swiss Ornithological Institute built up a captive breeding programme. From 2008 to 2012, we annually released on average 500 Grey Partridges. The success and suitability of the reintroductions to support the remnant population are being scientifically evaluated.
One of the main causes of the drastic decline of the Grey Partridge is the loss of important habitat structures such as fallow land, hedges, extensively managed meadows, etc. With exemplary habitat improvements in both project areas, which have gained attention well beyond Switzerland, suitable habitat has been created for many threatened bird species of open agricultural landscapes. As a consequence, populations of species such as common quail, whitethroat, European stonechat or corn bunting have strongly increased. In addition, the brown hare has benefitted as well and now reaches densities of up to 15 individuals per km2 in the Champagne genevoise and in the Klettgau, respectively, representing currently the highest values in Switzerland.
The recovery programme for the partridge in Switzerland has had ups and downs. The population in the Klettgau showed a positive trend from 2002 to 2004 and stabilised at 15 to 20 breeding pairs. In the Champagne genevoise, 32 breeding pairs were counted in 2006. However, the snow-rich winters of 2005/2006 in the Klettgau and 2006/2007 in the Champagne genevoise, respectively, resulted in population collapses. As no releases have been done in the Klettgau since 2008, Grey Partridges are now only irregularly observed there. It has to be assumed that the local population will soon vanish.
Population size in Geneva continuously increased with the releases of autumn coveys. In spring 2012, we counted 60 breeding pairs, the highest number since the project started in 1991. Our analyses show that Grey Partridges born in the wild have better survival and reproductive rates than released birds. However, it is unclear how the population in Geneva will evolve without further releases. Apart from adequate survival rates, which in Geneva attain values comparable to other countries, a good reproductive success will be key. Therefore, we will continue optimising the breeding habitat.
Dr. Bertold Suhner-Stiftung für Natur-, Tier- und Landschaftsschutz
CIC, Internationaler Jagdrat zur Erhaltung des Wildes
Fondation pour les animaux du monde, Vaduz
Groupe de Jeunes de Nos Oiseaux
Groupe Perdrix Romande
Pro Natura Genève
Société zoologique de Genève
TURDUS Vogel- und Naturschutzverein Schaffhausen