Hivernada de Làrids "(Aves: Laridae)" al litoral del Principat i del País Valencià (1980 i 1981)

The results of two winter censuses of gulls, performed on the Spanish Mediterranean coast, in the provinces of Girona, Barcelona, Tarragona, Castelló and Valencià in 1980 and 1981, are given  The results obtained were: Species 1980 1981 Estimated minimum Larus fuscus 5,401 4,807 6,000 Larus argentatus 27,616 21,591 30,000 Larus melanocephalus 15,593 12,571 18,000 Larus minutus 501,000 852,000 1,000 Larus ridibundus 59,321 54,961 75,000 Total: 108,432 94,781 130,000   The main concentrations of gulls were observed in Roses bay (\simeq 15,000 individuals), Medes Islands (\simeq 15-17,000), Barcelona-Llobregat Delta (\simeq 8-9,000), L'Ametlla-Ebre Delta (\simeq 22,00), Vinaròs-Castelló (\simeq 20,000), Albufera and surroundings (\simeq 15,000). The most important novelties observed between this and another census realized in the same area in the 1977 and 1979 winters (CARRERA et al., 1981a), are: Larus fuscus: A remarkable increase in the censed figure, due to a better census of the Castelló province fishing harbours (Benicarló-Grau), where the 50 % of the total censed on the coast was found. Larus argentatus: An increase of the censed figure due to a better counting of the Medes Islands sleeping place and other littoral coast points. By checking the ratio adults/ subadults-immatures by province, we find that the percentage becomes more equal as we move farther from the principal reproduction centres (province of Girona). Two new winter recoveries of birds born in the Medes Islands, one in the Camargue and the other in Castelló, are commented. Larus melanocephalus: An increase of the censed figure due to a better census of the fishing harbours of the province of Castelló, that had been subestimated in previous census. Larus minutus: The concentration of about 1,000 individuals at the Llobregat Delta is mantained. Sporadic observations in other places of Catalonia are performed. Larus ridibundus: The main reasons for the traditional low estimation of this species are commented. A minimum estimated figure per province is given. No observation of Rissa tridactyla, Larus canus, Larus marinus, Larus adouinii, is performed

Salutación

La Cátedra UNESCO de Sostenibilidad de la Universitat Politécnica de Catalunya http://www.catunesco.upc.edu se creó en mayo de 1996 con el objetivo de desarrollar un sistema integrado de actividades de investigación, formación, información y documentación centradas principalmente en el análisis de las relaciones múltiples entre la sostenibilidad, la tecnología y el humanismo. Sus actividades se centran en cuatro grandes ejes: docencia, investigación, cooperación y publicaciones

Nova colònia de gavina corsa ("Larus audouinii" Payr.) a l'estat espanyol

In this article a new colony of Adouin's Gull on the Catalan coast (NE Spain) is described. This is the only known colony in the continent and in a sandy beach. The breeding site, founded in 1981, is located in a flat zone almost without vegetation. The nests are placed mainly over small dunes, covered by a mosaic of psammophi- Ilus communities of dune and back of the dune. This vegetation belongs to the Ammophiletum Mediterraneum and Crucianelletum maritimum communities, with some scattered shrubs of Arthrocnemum fruticosum in the lower places. The colony is composed by at least 36 pairs and is placed in one of the ends of a Herring Gull colony. The mean sizes of 6 eggs are: 63.56x44.53 mm, and the mean sizes of 4 nests are: outer diameter: 25.50 cm; inner diameter: 15.25 cm. This site is also an important place for the post-nuptial moult of the Audouin's Gull. In that same place we have verified the breeding of 200 couples in May 1982, which means a considerable increase as well as a consolidation of the colony

Anellament d'ocells poc comuns a Catalunya (1957-1983)

Aquest article aporta 140 dades d'anellament de 18 espècies les quals es consideren rares a Catalunya. La informació procedeix dels balanços de 26 anelladors en actiu a Catalunya durant el període 1957-1983. Aquests registres fan referència a un total de 72.000 ocells, dels quals el 93% van ser anellats a Catalunya en aquest mateix període

Resum de les activitats del Grup Català d'Anellament (1978-1979)

This summary is a continuation of the first publication of the «Grup Catala d'Anellament», which appears in this Bulletin too, and refers to years 1978-1979. The variations that have taken place in the ringing campaings of the last years are briefly commented. A list of our most interesting recoveries, controls and selfcontrols, posteriors to the precedent summary is included, as well as a list of species in systematic order, together with the total ringed birds of each one, and the total of the period 1975-1979 which is of 21.986 birds

Comentaris sobre els desplaçaments erràtics de la població catalana de gavià argentat "(Larus argentatus michahellis)"

The erratical displacements of the Catalan population of the Herring gull (Larus argentatus michahellis) are analysed and discussed, using country observations and 44 recoveries of the 3,104 pulls ringed in the Medes Islands (Girona) and the Ebre delta (Tarragona) colonies. The seven colonies that constitute this population, which is of about 8. 140 couples, are described. It is exposed that a sizable number of the juveniles (22 % according to our recoveries) travels to the French Atlantic Ocean, between the Spanish Basque Country and the Loire delta, from July to November. The farthest recovery occurs 750 km NW from the birth locality. The rest of the juveniles remains near the breeding colonies, entering in the continent and following rivers over a maximum of 160 km from the coast. These movements show a clear parallelism, in space and time, with those of the French Mediterranean population, which make us consider the Franco-catalan mediterranean population, as an homogeneous dispersions nucleus. Although ringing shows the existence of a native population crearly sedentary, on the other side it hasn't been proved that the juveniles gone to the French Atlantic return to the birth areas. The possible penetration routes to the Atlantic of the Franco-catalan population, Ere discussed, the most apropiated, seems the course of the Aude-Canal du Midi-Garonne, probably also used by other sea species (Gavia sp.). Important post-nuptial concentrations are seen out of the Medes Islands breeding area, which seems to indicate that the Franco-catalan population performs moulting migrations. The invernal bird counts of the French and Catalan-levantine Mediterranean Sea are compared, observing that although both breeding populations are quite similar, the invernal populations are very different. The typology and motivation of these movements are discussed, indicating that they don't always have to be considered as erratic

Resum de les activitats del Grup Català d'Anellament (1975-1977)

The present communication gives information about the initiation of the organised bird-ringing in Catalonia, which began with the union of two groups which, together with some independent ringers, constituted the actual «Grup Catala d'Anellament». There is a commentary on the most important ringing campaigns performed during the years 1975-1977: those of migrant passerines, wintering and mountain birds, white storks, colonial birds (gulls, terns, waders, herons) and bee-eaters mainly. There is, too, a quantitative and qualitative systematic list of all the ringed birds from 1975 to 1977, being on the whole 12.167; and also a short commentary about the controls, our recuperations and those of other ringers of whole Europe. Of special interest is the publicitary campaign organised to inform about our ringing activities, and thus obtain a greater number of recuperations