The Der–Chantecoq lake, in Champagne-Ardenne, northeastern France, is the largest reservoir in the country, built in the 1970s. Since the early 1980s it has become one of the most important stopover and wintering sites for the Common Crane (Grus grus) in Europe. On 11th November 2014, over 206,000 birds were counted there as they left the lake to continue their migration or to feed in the nearby fields. This is the highest count recorded here so far and probably represents about half of the global population of the species (Delany & Scott 2006). On 4th January 2015, 42,200 wintering cranes were counted leaving the lake in the morning.
The census work at this site is carried out by the LPO (Ligue pour la Protection des Oiseaux) on a weekly basis from mid-October to the end of November and again during February–March, and every second week in December–January. The birds are counted when leaving the lake early in the morning, by volunteers posted at 11 locations around the lake.
The two previous records were established on 27th October 2013, with 83,100 cranes, and on 9th November 2014, with 93,089 cranes. The wintering of the Common Crane in France is however relatively recent, dating back to 1976/77 when 40 individuals spent the winter in the Champagne wetlands, rising to 300–6000 birds in the 1990s and 8000–20,000 in the 2000s (Dubois et al. 2008). The number of wintering cranes in the area remained stable, at 15,000–25,000 birds, during 2000–2013. However, it increased to around 40,000 birds in 2013/14 and 2014/15, probably due to very mild weather conditions but also, to a lesser extent, to the continuing destruction of the bocage, which is replaced by corn fields where the cranes can find abundant food.
References
Delany, S. & Scott, D. (2006). Waterbird population estimates. Fourth Edition. Wetlands International, Wageningen, The Netherlands.
Dubois, P.J., Le Maréchal, P., Olioso, G. & Yésou, P. (2008) . Nouvel inventaire des oiseaux de France. Delachaux et Niestlé, Paris