........taccuini di birdwatching di Claudio
Chiossi.......
SIGHT OF A WHITE-BILLED DIVER (Gavia adamsii) by the CASSA DI ESPANSIONE OF RIVER SECCHIA NEAR CAMPOGALLIANO (MODENA)
On May 7th, 1989, while observing the attempts of nest building made by a colony of common terns by one of the lakes of the Cassa di Espansione of the river Secchia, next to Campogalliano, I had the opportunity to observe and take pictures of a White-billed Diver. In spite of unfavourable weather conditions, with a strong wind causing waves, the bird was noticeable for its jiz, similar to the one of the Cormorant, and for its tendency to hold his bill upwards. A closer look allowed me to notice that it still had winter plumage, and a thick ivory-yellow bill with the upper part straight and the lower part curved, which distinguishes the rare White-billed Diver. The diver was in the widest part of the lake, going round in closed circles starting in both directions, sometimes dipping, and also getting closer to the shore. In the afternoon it stopped in the centre of the lake, by some dry shrubs emerging from the water, for a long time. Around 4:30 p.m. it flew away leaving the Cassa quickly.
The White-billed Diver (length 76-91 cm, 137-152 with open wings) is the rarest diver and the least known one because of the inaccessibility of its nesting places. In fact, its breeding habitat is the lakes of the Artic tundra along the Russian coasts and islands as well as those of northern Asia and North America. It lays two eggs in a nest made of a heap of vegetation or a mud platform near the water. It is also found along the coasts of Norway in the Palaearctic winters, and accidentally in the rest of Europe. This is the third record of the species in Italy, after the 1902 “observation” by Lakes Montepulciano and Trasimeno, with samples kept in the Museum of Florence.
BRICHETTI P., DE FRANCESCHI P., BACCETTI N., 1992 - Fauna d'Italia Aves. I Gaviidae -Phasianidae. Calderini, Bologna.
CHIOSSI C., 1990 - Avvistamento di una Strolaga beccogiallo. Picus, 16: 85-86.
APPLEBY R.H., MADGE S.C. & MULLARNEY K., 1986 - Identification of divers in immature and winter plumage. Brit. Birds 79 (8): 365-391.
ARRIGONI DEGLI ODDI E., 1984 - Ornitologia Italiana. Cisalpino-Goliardica, Milano.
CRAMP S. & SIMMONS K.E.L., 1977 - The Birds of the Western Paleartic Vol. I. Oxford Univ. Press. Oxford.
HARRISON P.,1985 - Seabirds, an identification guide Croom Helm, Londra.Acknowledgements
Thank to Annamaria Arlotta for the translation from italian
