 While working at the museum he, along with his colleague Jean Dorst, who later replaced Berlioz as the head of the ornithology department, helped write the species description for the Djibouti spurfowl, a critically endangered spurfowl endemic to Djibouti whose type specimen was brought to the museum.He also developed a lifelong interest in two distinctly different bird families, the hummingbirds and the petrels.In 1955 Jouanin published his first independent species description after realizing that the new species, named Jouanin's petrel, differed significantly from the Mascarene petrel.