(Roller Coracias garrulus Le Rollier d’Europe)
The European Roller is a migratory species spending the winter months south of the Sahara. The first ones to arrive in France are noted at the end of April, but the majority of the birds arrive in May when breeding starts immediately, some years from mid-May, but the peak of egg-laying takes place at the beginning of June, late pairs often lay eggs until June 25.
They are a cavity-dwelling species that often uses the cavities dug by Green Woodpeckers and any others cavities it can find in various trees (plane trees, willows, poplar, pine, oak, almond), at a height that varies between 5 and 10 meters. They sometimes will use holes in walls, sandy banks or can even use old European bee-eater galleries (Tron et al., 2008). They do not bring any nesting material into the chosen cavity. The female lays 4 to 7 eggs there, the incubation of which lasts 18 or 19 days. Breeding success is 73%, i.e. 3.6 fledglings per breeding attempt.
After their emancipation, the young Rollers will disperse outside of the immediate nesting zone in the Mediterranean region where they originated. This dispersion classically takes place in the Rhone Valley and in Occitania. However in 2022 this phenomenon has taken on a quite remarkable magnitude with a dispersal covering a large part of the southern two thirds of France, albeit sporadic and localised a situation that is unparalleled in recent decades. Obviously at this stage the reason for this is speculative but one way or another the heat waves that we experienced this summer in France will have been a significant factor with reduced available water and insects.
NOTE. A single Roller was seen in Lincolnshire, UK, at the end of August this year, (2022)
It's also worth noting that France is one of the few countries witnessing a population increase for this species that is declining elsewhere in Europe.
Chris
