Sens Of Life was commissioned by Ailes Marines to set up two one-week monitoring sessions per year, the first between February and May, then the second between July and October. The objective is to define migratory flows, migration phenology and flight paths and altitudes of the different species on the coast near the wind farm project, for 4 years, from 2020 to 2023.
The area to study is particularly large, so it was decided to carry out these monitoring sessions using radars, coupled with field observations conducted by an ornithologist.
Two radars were therefore positioned on the Tour Vauban, the oldest lighthouse in France, located at Cap Fréhel, in order to carry out this monitoring in April and in October 2020. For 7 days, they collected trajectories of migratory birds, day and night. The large S-band radar, installed in vertical mode, tracks gull-sized birds within 10 km. The small X-band radar makes it possible to know birds’ flight altitude.
Radars can be used to analyse groups of species based on the size of birds but cannot identify species precisely. An ornithologist therefore visited the site throughout the monitoring session to recognize species. The data is currently being processed. At the end of the study, the evolution of data between each monitoring year will be analysed to better understand the evolution of migratory flows, trajectories and populations of the different species frequenting the Bay of Saint Brieuc.