Luscinia svecica
The bluethroat has many subspecies, distinguished by the size and/or colour of the spot called “mirror” on the throat, which may be white or red. European populations are very sparse and localised. In France, the namnetum subspecies nests on the Atlantic coast between southern Brittany and the Bay of Arcachon. This subspecies has a white mirror on the blue background of its throat.
It frequents coastal wetlands such as the salt marshes in Loire-Atlantique and prefers to nest in bushes and tamarisk trees. South of the Loire, the species nests mainly in rapeseed fields.
The European subspecies migrates and winters in tropical Africa, south of the Sahara. According to ringing records, some of the bluebirds on the French coast winter in Portugal. They are therefore likely to cross the Bay of Biscay during their migration.
To find out more about the migratory routes of the bluethroats and their flight altitudes, particularly over the Bay of Biscay, they are captured at their nesting sites using a vertical net. They are fitted with a 0.5g GLS which records the data (approximate geographical positions and precise atmospheric pressure for altitude). In order to collect the data, the GLS must be recovered the following year by recapturing the birds on their return from wintering.
Breeding in France ; Migrating through France