This calculation does not fall from the sky. If it has been possible to process this data, it is thanks to a GPS beacon – firmly attached to a leg – which has followed this bird from a very young age. “He was ringed on June 8, 2018, near the town of Gniezno”, adds Sophie Laugareil, director of the Arjuzanx reserve, where Arcadio spent several weeks after this European trip. A goldmine for all scientists studying the species. Because in addition to the recorded distances, this little technological pearl (1), worth about 6,000 euros (including satellite data), also provides information on improvised stops, flight speeds, occupied migration corridors and many other valuable elements (2).
A seventeen hour flight
So much so that we can follow this male – who started a family in the spring of 2022 – on the trail. “The family departed from Poland, for migration after marriage, on October 5. After a stopover in an assembly area in Germany, she headed southwest on the morning of October 19. The cranes will arrive in the Verdun region the next day in the middle of the night”, analyzes Sophie Laugareil thanks to the information from the beacon.
We can even calculate its average: 58 km/h in flight and its maximum height is over 1,500 meters
On 20 October, Arcadio landed 40 km further on in the sector of the dams of Belval-en-Argonne and as far as Lac du Der (Marne). He will remain there until October 30, when he will leave at 10:41 a.m. very sharp. “On October 31 at 03:10, after 747 km and seventeen direct flights, Arcadio and his family flew over the surroundings of Luglon (40). We can even calculate its average: 58 km/h and its maximum altitude is over 1,500 meters, ” she adds.
A week ago, Arcadio was still in Landes. No one can say whether he will continue the holiday route to Spain – the border is only 80 km away – or to North Africa. For now, site officials are scrutinizing his every move. We know where he sleeps – sometimes in the northern dormitories (command sector), sometimes in the southern part of the reserve (Lac des Armayans) – and when he eats. “It feeds in what are called feeding areas. With 97%, it is maize that remains in the fields after harvest – cranes consume 300 grams of it per day – but also worms or larvae. »
Two migration corridors
Through Arcadio, of course, it is the story of this bird that we follow. Majestic, it can reach 1.30 meters in height and a wingspan of up to 2.40 meters. The common cranes – whose world population is 700,000 and have a life expectancy of 25 years – borrow two migratory corridors shortly before winter to head south. “Simply surviving. Looking for warmth and food,” adds Sophie Laugareil.
The first goes through the center of Europe via the Czech Republic and then Hungary with the Middle East as its destination. The second corridor, further west, branches off via Germany and then arrives in France. Some choose to settle for the winter and others continue their way to Spain. It all depends on the state of fatigue of each individual, the weather conditions. The crane is an opportunistic species and does not seek to migrate at all costs. If the winter is mild enough, she does not feel the need to go further south.
In the spring, it will go up to Northern Europe. And since the bird has been used to it since its earliest childhood, Arcadio will – for sure – return to Arjuzanx for its next winter holiday.
(1) This beacon was funded thanks to the support of Ornitella, a group of Lithuanian biologists who manufacture these transmitters. The aim is to follow the cranes’ movements, understand the migration and know the wintering places.