Doortrek van Rode Wouwen Milvus milvus in Midden-Frankrijk in najaar 2022

In autumn 2022, during systematic counts between 16 September and 14 November, visible bird migration was registered in Central France (La Sallandrouze, St. Maurice près Crocq, 45.50.52.01 N, 02.18.35.79 E). Counts started half an hour before sunrise and daily lasted 7-9 hours for the duration of 60 days in total. For this station, 2049 Red Kites were recorded heading in a general SW direction. This number is standardized to a flow of at least 3650 birds crossing a front with a width of 1 km. Red Kite migration started early October, reached the median date of passage around mid-October and tailed off in early November. Migration started in the early morning and lasted till late afternoon with the peak shortly after noon. This pattern was repeated throughout the season. In early morning the birds used the lower air layers. Flying height increased in late morning and reached its maximum in the early and late afternoon. With tail wind birds flew higher compared to opposite winds. During head-on winds flying height declined with increasing wind force. In the early morning birds used flapping flight followed by gliding, later on in the early morning shifting to circling followed by gliding as well. In the afternoon flapping flight was never seen, only circling followed by gliding. The average migration direction had a strong southwesterly component with SW as the main direction of migration. During the day the proportion heading WSW declined in favour of a SSW direction. Average flock size was between 3 and 4 birds. Most flocks were smaller than 10 birds. The largest flock was composed of 58 kites. After correction for the number recorded in different parts of the day, flock size in early morning was much larger compared to later in the morning and afternoon.