The importance of marine resources in the diet of urban gulls.

de Faria, J.P., Vaz, P.T., Lopes, C.S., Calado, J.G., Pereira, J.M., Veríssimo, S.N., Paiva, V.H., Gonçalves, A.M. and Ramos, J.A., 2021. The importance of marine resources in the diet of urban gulls. Marine Ecology Progress Series, 660, pp.189-201.

The availability of anthropogenic food subsidies has promoted an increase in generalist opportunistic gull species, which currently breed and forage on predictable anthropogenic resources (e.g. landfills). Here we investigated whether marine resources are still important to urban-dwelling gulls. We studied 4 natural and 2 urban yellow-legged gull Larus michahellis colonies and compared (1) diet composition (through pellet analysis) and (2) isotopic niches of adults and chicks, (3) diet delivered to chicks of different ages, and (4) fatty acid (FA) composition of fledglings, in order to assess diet composition, diversity and quality, and the relevance of marine prey for natural and urban gull populations. Adult urban gulls consumed considerably lower proportions of marine prey when compared to gulls from natural colonies; however, they fed their younger chicks (<20 d old) mostly with fish, representing 61-80% of their chick food deliveries. Refuse items were mostly delivered to chicks older than 20 d. Overall, urban isotopic niches were not completely distinct from those of natural colonies, in some cases sharing ca. 50% of their niche space. Fledglings from the most urbanized colony presented overall higher FA concentrations and diversity, but they were lacking some omega-3 FAs relevant to their physiology. Our results highlight the importance of marine resources in the diet of urban gulls, particularly during early chick rearing, the relevance of food sources in the area around the breeding colonies and the fact that urban gulls benefit from year-round reliable anthropogenic food resources


Nidificación urbana de Gaviota patiamarilla (Larus cachinnans) en Vigo (Galicia)

Mouriño, J., Sierra Abraín, F. & Arcos, F. Nidificación urbana de Gaviota patiamarilla (Larus cachinnans) en Vigo (Galicia). Chioglossa 1, 47–52 (1999).


Entre 90 y 120 parejas de Gaviota Patiamarilla (Larus cachinnans) nidificaron en el casco urbano de Vigo en 1989. La colonia se encuentra en el centro de la ciudad. fundamentalmente en casas bajas y antiguas. donde crían en tejados y chimeneas cerradas. El período de puesta coincide con el conocido para las vecinas islas Cíes. concentrándose a primeros de mayo. Las gaviotas habrían colonizado la ciudad alrededor de 1980 a raíz del incremento de la colonia de Cíes. Se prevé que dado el mantenimiento de las favorables condiciones y la abundancia de recursos tróficos. las gaviotas seguirán expandiéndose por la ciudad.