The relationship between urban refuse with fecundity and nestlings' success of a generalist seabird in the Rio de la Plata Estuary-Uruguay

Resource acquisition and allocation impacts individual fitness. Using pellet analysis of breeding adults and stable isotopes of carbon and nitrogen of down feathers of Kelp Gull (Larus dominicanus) nestlings, we evaluated the relationship between urban refuse (beef and chicken) and natural food (fish) consumption of individual females during the pre-incubation period, with fecundity and young nesting's success in the Rio de la Plata Estuary in Uruguay. Assimilated urban refuse positively correlated with egg weight and negatively with young nestling's success. This suggests a possible impact of urban refuse foraged by females during the pre-incubation period on their immediate fecundity (positively) and young nestling's survival (negatively). Differences between studies at the individual and colony levels are also discussed in light of an ecological fallacy of interpretation and we thus argue for the need of additional research to evaluate this relationship further, considering potential confounding factors.

Automated summary

The study shows a relationship between the consumption of urban refuse by female Kelp Gulls during the pre-incubation period and their fecundity and nestling's survival in the Rio de la Plata Estuary in Uruguay. Further research is needed to evaluate this relationship considering potential confounding factors.