The Status of Breeding Storm Petrels (Hydrobates Pelagicus) on the Mediterranean Coast of France

Abstract

The presence of the Storm petrel Hydrobates pelagicus on islands close by the large Mediterranean port of Marseille is surprising to say the least, and yet the Storm petrel was known as a breeding species on the “Archipel de Riou” during the mid-nineteenth century (Jaubert & Barthélémy-Lapommeraye, 1859). In 1915 a few pairs were reported breeding on the island of Riou (L’Hermitte 1915–16), and by 1918 large breeding colonies were found on “Ile Plane” and the two rocky islets: the “Grand and Petit Congloués” (Lavauden & Mourgue, 1918). In the spring of 1923 Heim de Balsac (1923) visited Riou, but gave no indication that the Storm petrel bred there. However, he did visit Ile Plane and found many petrels “apparently sleeping in recesses in the rocks”. In early April 1924 he visited the “Grand Congloué” and found Cory’s shearwater Calonectris diomedea and the Levantine race of the Manx shearwater Puffinus p. yelkouan occupying nest sites, but the Storm petrel was absent. Heim de Balsac & Mayaud (1932) again visited Ile Plane on 9 May 1931 and counted 40 petrels. The two fresh eggs found indicated that the breeding season had only just begun. Fifteen years later Storm petrels were still breeding on Ile Plane, some even nesting under dense low bushes (A. Rivoire pers. com.).