Missatges autoreferencials dels actors del ritual de l'Id-al-ad·ha

L'article analitza la celebració de l'Id-al-ad·ha o "festa del sacrifici", ritual protagonitzat per la comunitat de musulmans el desè dia del mes de dhu-al-hijja. Es parteix d'exemples etnogràfics procedents del context de la diàspora musulmana al Tarragonès i de la societat emiral mauritana. El fenomen s'analitza des dels rols que els actors exerceixen en el ritual. L'argumentació vol subratllar la idea que tot ritual s'inscriu en un context social específic del qual n'és producte alhora que modulador, per mitjà del que Roy Rappaport anomena "missatges autoreferencials". Això no exclou l'existència d'un conjunt de denominadors comuns o "missatges canònics" entre les diverses pràctiques rituals referides.

Impact of fisheries on activity, diet and predatory interactions between yellow-legged and Audouin's gulls breeding at the Chafarinas Is.

Interactions between yellow-legged Larus cachinnans and Audouin´s Larus audouinii gulls and fisheries operating around the Chafarinas Islands, located 4.5 km off the Moroccan Mediterranean coast, are reviewed. At the Chafarinas archipelago two distinct types of fisheries operate: trawlers and purse seines. Gulls take advantage of both fisheries. They scavenge trawler discards and congregate around shoals of fish attracted to the surface by the purse-seine lamps. When both trawlers and purse-seine boats are in operation, the diet of both gull species is similar, with epipelagic fish accounting for over 60% of the biomass, partially collected in association with the purse-seine fishery. When only trawlers operated yellow-legged gulls, but not Audouin´s gulls, augmented their diet mainly with human waste from refuse dumps, suggesting that competition for food between the two species is mainly limited to the periods when resources made available by fishery activities are abundant. Likewise, when only trawlers operated, there was an increase in the predation pressure on eggs and chicks of Audouin´s gulls. In particular, during the week of celebrations for the holy lamb festival when neither fishery operated, egg losses of Audouin´s gull increased dramatically, suggesting that severe food shortage caused by the cessation of fishing can result in an increased predation pressure by yellow-legged gulls, affecting Audouin´s gull productivity. These results suggest a novel socio-ecological link between gulls, fisheries and local feasts.