 He has done many major projects in the field, notably with petrels in the Indian Ocean and Madeiras, and has described a number of species.Jouanin began working professionally with birds in 1940 at the age of 15, when he started working for the Muséum national d'histoire naturelle under the tutelage of Jacques Berlioz, then the head of the ornithology department.At the age of 22 he married his wife, Nicole, with whom he has had two daughters.