Foraging habits, population changes, and gull-human interactions in an urban population of Herring Gulls (Larus argentatus) and Lesser Black-backed Gulls (Larus fuscus)

Introduction: There are several species of breeding gull in the UK, many of which live in urban areas. The main urban colonists are Herring gulls (HG; Larus argentatus) and Lesser Black-backed gulls (LB; Larus fuscus). In some urban areas, they are considered a nuisance, although overall gull numbers are declining, and all breeding gulls in Britain are protected by law.
Objectives: To determine how the HG and LB population and gull nuisance events in Bath, Somerset change across the breeding season, and to investigate how humans are contributing to gull nuisance behaviours.
Methods: Field ethological methods were used to study HGs and LBs across six sites in Bath for five months between March and August 2017. Five minute instantaneous scan samples were used to record gull and human abundance. Behavioural data were recorded continuously for 30 minutes at each site. A total of 129 hours of observations were conducted.
Results: Fluctuations in the mean number of gulls could partially be explained by phases in the breeding season. Mean number of gull nuisance events were low and fluctuations were not significantly linked to breeding phase. There was a strong, positive correlation between the number of humans feeding gulls and the number of gull nuisance events recorded.
Conclusion: The urban gull nuisance problem in Bath is less serious than originally thought. Nuisance events occurred infrequently throughout the breeding season and predominantly in areas where humans were feeding the gulls. Measures to avoid nuisance should focus on reducing food availability, but more longitudinal research is needed to determine long-term trends in gull population and nuisance behaviours.

MSc by Research