Model projections reveal a recent decrease in a yellow‑legged gull population after landfill closure /
Sergio Delgado, Giacomo Tavecchia, Alfredo Herrero, Asier Aldalur, Juan Arizaga.
-- [S.l.] : Springer Verlag, 2023.
Restringido
The food available in open-air landfills, one of the most common predictable anthropogenic food subsidies (PAFS), can have a profound impact on animal biodiversity. Understanding how and to what extent PAFS affect wildlife is crucial for a sustainable management of resources. Most large gulls behave as opportunistic foragers and constitute a good avian model
to analyze the effect of PAFS reduction on animal populations. Using individual data from a yellow-legged gull population
of the Basque coast (northern Iberia) collected over a 15-year period, we estimated survival and reproductive parameters
and used them to parameterize an age-structured population model to explore the effects of the local landfill closure. Local
survival probability declined with time as a consequence of the progressive closure of the local landfill sites. The top-ranked
models included a quadratic function of time, suggesting an acceleration of mortality during the later years, especially in
juveniles, while survival in adults was linear. An effect more pronounced in first year birds than in older birds. Population
models predict a decrease of the population and confirmed a greater sensitivity of the population growth rate to adult survival
probability. Overall, our results suggest that the reduced carrying capacity of the system resulted after landfill closures have
caused a population decline which is expected to continue in the near future.
Demography
Breeding output
Food subsidies
Population dynamics
Landfill
Seabirds
Survival
Artículo científico
Restringido
The food available in open-air landfills, one of the most common predictable anthropogenic food subsidies (PAFS), can have a profound impact on animal biodiversity. Understanding how and to what extent PAFS affect wildlife is crucial for a sustainable management of resources. Most large gulls behave as opportunistic foragers and constitute a good avian model
to analyze the effect of PAFS reduction on animal populations. Using individual data from a yellow-legged gull population
of the Basque coast (northern Iberia) collected over a 15-year period, we estimated survival and reproductive parameters
and used them to parameterize an age-structured population model to explore the effects of the local landfill closure. Local
survival probability declined with time as a consequence of the progressive closure of the local landfill sites. The top-ranked
models included a quadratic function of time, suggesting an acceleration of mortality during the later years, especially in
juveniles, while survival in adults was linear. An effect more pronounced in first year birds than in older birds. Population
models predict a decrease of the population and confirmed a greater sensitivity of the population growth rate to adult survival
probability. Overall, our results suggest that the reduced carrying capacity of the system resulted after landfill closures have
caused a population decline which is expected to continue in the near future.
Demography
Breeding output
Food subsidies
Population dynamics
Landfill
Seabirds
Survival
Artículo científico