We do not know whether Ring-billed gulls (Larus delawarensis) were common when Montreal was established in 1642. However, we know that at the beginning of the previous century, the birds were rare because their eggs were harvested and their flight feathers served as ornaments on lady’s hats. Protected through the Migratory Bird Treaty Act signed in 1916, the population increased and sightings in the Montreal area became more prevalent around 1930. The first nests were located in 1953 on Île Moffat that was later transformed into Île Notre-Dame for Expo 67. The birds then moved to Île de la Couvée, an island created during the St. Lawrence Seaway construction.
Today, the North American population is estimated at 1.7 million birds with approximately 240,000 in Quebec. In the Montreal area, the main colony with nearly 45,000 pairs is located on Île Deslauriers located on the St. Lawrence River near Varennes. Surveys by the Canadian Wildlife Service show that the population is slightly declining.
Ring-billed Gulls start breeding around 3-years old and can live up to 10-15 years although some individuals have reached 27 years! They nest in colonies of few hundreds to several thousands birds and lay 3 eggs in a simple cup on the ground. Incubation lasts 25-27 days and young leave the nest few hours after hatching but remain in the surroundings to be fed by their parents for 30-35 before fledging. On average, each pair produces 1-2 juveniles.
Gulls can carry fecal coliforms and other pathogens that can infect humans but no case of transmission have been reported. Gull droppings on buildings, cars, patios, etc. are often considered a nuisance that incite citizens to complain. Gulls are significant bird hazards to aircraft near airports according to Transport Canada.
Managing populations considered over-abundant requires detailed knowledge on their ecology in order to implement any management plan. The on-going study about movements, habitat use and population dynamics conducted by UQAM researchers and their partners aims at providing such information. An integrated approach that consists in reducing the amount of residual material, a better management of these residues before and after their removal at individual homes and a comprehensive education program to discourage people of feeding the birds should be promoted.