Synthèse de la migration des Grues cendrées 2007/08

2007 POSTNUPTIAL MIGRATION
	Apart from several nesting sites in the Lorraine, it was in the Nièvre (as is often the case) and the Cher that cranes were seen: no less than 5 birds spent the whole of the Spring and Summer there, covering 5 different sites. In fact, several observations were made as early as June. At the end of July, the first cranes were seen on the Der lake (51/52) and 1 bird was spotted on the Momas lake (64) on August 1^st. Apart from these arrivals, other birds were seen in flight, as, for instance, 8 in the Allier on August 12^th. Numbers continued to increase on the Der lake (51/52) amounting to 23 birds at the end of August. During this period, 16 flew over the Aube. During the night of August 24^th, a group of cranes was heard over the Pyrénées-Atlantiques. On the following day, birds were seen flying over the Gironde, while 7 landed in Le Teich several days later. During the month of September, 10 departments witnessed small migratory flights: the Vienne, Nièvre, Charente, Charente Maritime, Landes, Côte d’Or, Ardennes, Seine-et-Marne, Allier and the Aube. On September 9^th, the first two cranes arrived on the Gallocanta site in Spain (an unusually early occurrence) and on the 16^th, the first bird landed on a lake in the Aube. Between October 1^st and 5^th, flights arrived in 8 departments. For example, the Haute-Vienne, Corrèze and in the Dordogne. Meanwhile, the cranes in Germany had started to form groups in preparation for their departure. For example, on the Rügen site, 48,000 individuals were counted. These initial movements concerned about 700 birds.
FIRST SMALL WAVE (06/10/07 – 09/10/07)	The first noticeable movements took place on October 6^th and 7^th. Birds were seen leaving Germany on October 6^th at the end of the day. In France, the first birds arrived on the Arjuzanx site (40), while 9 departments witnessed flights. The following day, numbers increased and more than 1,300 cranes left Germany, heading for France. By the end of the day, they were seen over the north-east (the Moselle, Meuse etc.) while other flights were observed between Champagne and Aquitaine. The first 3 birds arrived on the Puydarrieux site (65) on the same day. On the 8^th, flights continued throughout the day with more than 4,700 birds in the Hesse region between 1500 and 1800hrs. At the same time, more than 1,000 cranes were observed in the Nièvre, one of the first departments frequented by the birds. Only a few birds remained on the Hornborga site in Sweden, a seasonal record! During this first wave 7,500 cranes migrated!
DEPARTURES FROM THE DER LAKE (11/10/07)	Throughout this day, numerous flights were seen on the traditional migratory route. These birds had stopped over on the Der lake (51/52) and were continuing their journey towards the south-west. More than 1,000 cranes were observed both in the Nièvre and the Creuse. One flight was seen in the Aude.
LARGE MIGRATORY WAVE (13/10/07 – 15/10/07)	After several quiet days, flights increased in Germany: about 24,000 cranes left in just one day (13^th). This movement became visible in France at 18hrs. when the birds began to fly over the Moselle. In close succession, other departments were concerned, such as the Meurthe-et-Moselle and a large part of the Champagne-Ardenne region. In fact, some flights continued their migration without stopping in this region. Consequently, birds flying in the direction of the Yonne and the Loiret, were heard well after midnight in the Aube. The numerous departures on October 13^th began to be really noticeable in France on the following day. While on October 14^th, a further 25,000 cranes took off in the direction of France. Flights were observed in 26 departments, in most cases, comprising several thousands of birds. In the Nièvre, where the observation network is particularly efficient, at least 5,000 birds were counted. In some cases, a number of birds veered slightly to the west, flying over the Seine-et-Marne, the Loiret, Loir-et-Cher and the Eure-et-Loir, whereas some birds landed in the Var. Belgium and Luxemburg also had their fair share of migratory flights. Towards the end of this first wave, the following counts were made: 25,000-30,000 cranes on the Der lake (51/52), 870 on the Arjuzanx site (40), 46 on the Puydarrieux site (65) and more than 1,600 in Extrémadure (Spain). During this wave, some 50,000 birds were involved.
	Map no. 1 Total number of cranes counted between 13^th and 15^th October 2007
MAIN DEPARTURES FROM NORTH-EAST FRANCE (18/10/07)	Shortly after daybreak, a large number of cranes left the Der lake (51/52) and more than 8,000 flew over the Aube at about 1130 hrs. These birds were subsequently seen over at least 12 departments. Once again, the largest number was seen over the Nièvre at the beginning of the afternoon with 1,900 cranes. Highest bird counts were made in the Haute-Vienne between 1800 and 1900 hrs when more than 10,000 cranes were seen. Then, between 1830 and 2000 hrs, 12,500 birds were counted before nightfall halted the sightings. On the east European migratory route, the record was broken on the Hortobagy site (Hungary) with a count of more than 100,000 birds.
FURTHER DEPARTURES FROM GERMANY (19/10/07 – 23/10/07)	On October 19^th between 1400 and1700 hrs, 40,000 cranes took off in the direction of France. As is often the case, these birds arrived via the Lorraine in the early evening. Once again, some birds elected not to stop, neither in the Lorraine nor in Champagne. A good example of this phenomenon, are the large flights seen in Burgundy and in central France from 2200 hrs onwards. During the same night, many flights came up against poor weather conditions over the Pyrénées, making it impossible to continue. Their calls were heard throughout the night before they flew over the mountains at daybreak. October 20^th and 21^st turned out to be the principal dates for migration in France. Part of the birds coming from Germany the previous day continued their flight towards the south-west. Numbers are sometimes unbelievably high: 10,000 in the Limousin , 9,000 in the Nièvre, 7,200 in the Dordogne between 1700 and 1940 hrs and another 6,500 for the Allier. Eighty birds were seen in the Aiguillon bay (85). Large numbers of cranes flew over the Pyrenean barrier throughout the day. On October 21^st, counts carried out on certain Pyrenean peaks revealed that more than 50,000 birds had already arrived in Spain, where numbers amounted to 6,000 individuals in Extrémadure and 9,500 in Gallocanta. During this time, a total of at least 55,000 cranes left Germany.
	MAP no. 2 Total number of cranes counted between 19th and 23rd October 2007
THE CRANES LEAVE CHAMPAGNE (01/11/07)	After a relatively quiet period, large numbers of birds were observed leaving the Champagne wetlands. Numbers were fairly high: 5,600 cranes were seen in the Nièvre and 2,000 in the Corrèze. The arrival of birds on the Captieux site (33) and that of Arjuzanx (40) increased numbers considerably.
UNUSUALLY LARGE-SCALE MOVEMENTS ON THE MEDITERRANEAN COAST (02 and 03/11/07)	These two days were noteworthy for the sizeable movements in this part of France. The majority of departments in the far south and south-east witnessed flights of cranes. Initially, 5 departments were concerned on November 2^nd: the Alpes-de-Haute Provence, Vaucluse, Gard, Hérault and the Pyrénées-Orientales. In the latter department, 850 birds were counted by just one observer between 1200 and 1800 hrs. On the following day, the phenomenon had become even more remarkable with 2,300 cranes spotted in the same department between 0730 and 1530 hrs! The Aude, Bouches-du-Rhône and the Lozère were equally concerned, with birds probably flying over the Rhône valley and in some cases, carrying on via the migratory route linking up with Switzerland and northern Italy and Spain.
A PROLONGED PERIOD WITH INTERMITTENT DEPARTURES FROM GERMANY (4/11/07 – 17/12/07)	During this period, several departures followed on one after the other but of short duration. Between these two migratory periods from Germany, there was a comparative lull. On the 4^th and 5^th November, two flights were observed, respectively 10,000 and 7,300 individuals were seen over the Hesse region in Germany. In France, between the arrival of these birds and the departure of others on the Der lake, many departments witnesses flights. The highest numbers of birds were seen on the 5^th: 4,400 in the Nièvre, 2,150 in the Allier and more than 2,000 in the Creuse. Thus, throughout these two days, 18,000 additional cranes had rejoined France. On November 10^th, more than 2,000 were counted on the various sites in Lorraine. New arrivals from Germany were observed on November 14^th and 15^th, estimated at about 6,000 birds. A case in point is the fact that one observer in the Nièvre, counted 40 flights in the space of only 15 minutes. In the Dordogne, 4,200 migrated in the space of one-and-a-half hours and 1,000 in 1 hour in the Allier. On November 19^th and 20^th, a further 2,000 cranes left Germany. During this period, a solitary crane landed in the Ille-et-Vilaine. Birds were also observed leaving Champagne. Consequently, between 2,000 and 3,000 individuals were recorded in 1 hour in the Cher and 3,500 in the Nièvre. A simultaneous count carried out in 5 departments in central France on November 25^th, revealed that about 2,500 cranes had arrived. At the same time, numbers on the Der lake (51/52) had dwindled considerably (9,500 on the 25^th) thus boosting others such as those on the Arjunzanx site (40) where 22,500 birds were observed on the 26^th and 640 at Puydarrieux (65). On November 28^th, a thick fog caused many victims among the cranes in Champagne. At the end of the month, 11 birds were recorded in Dombes (01) and on December 1^st, large numbers of birds were seen flying over the Aude and the Pyrénées-Orientales and on the same day, about 100 individuals over the Hautes-Alpes. Between December 15^th and 18^th, more than 3,000 cranes left Germany, heading for France. In Spain, numbers had noticeably increased, particularly in Extémadure with 36,000 birds. At least 30,000 cranes left Germany during this period.
LATE MOVEMENTS (02/01/08 – 06/01/08)	Most of us were surprised by the fact that cranes were still moving south in January, despite the fact that late movements are quite commonplace and fairly regular. This was the case during January 2008, when 3,000 birds arrived from Germany between the 2^nd and 6^th.
2007 POSTNUPTIAL MIGRATION OVERVIEW	During the 2007 postnuptial migration period, 146,630 cranes (figures for Germany only) were reported on active migration in France. This number is much less than those of the two previous seasons, which illustrates once again the difficulty in making accurate counts. In fact, many birds passed without being seen (nocturnal flights). It must also be said that the larger and more compact the flights are, the more it is difficult to make accurate assessments.

2007 postnuptial migration Wintering 2007-2008 2008 prenuptial migration