Increasing refuse and poor management of landfills in the 20th century and the habit of people to feed gulls have contributed to the exponential growth of several populations of larids both in Europe and North America. In the Montreal region, over 75,000 pairs of Ring-billed gulls (Larus delawarensis) nest on islands located in the St. Lawrence River, on Rivière des Prairies and more recently on building roofs in industrial sectors. Gulls are attracted at landfills where costly scaring programs must be maintained to reduce the presence of birds.

When traveling back and forth from the colonies to the feeding sites, gulls often fly over residential areas where they may let droppings down causing some disagreements for citizens who ask for control measures. After the breeding season, gulls disperse over large areas where they are often observed on lakes where water contamination is considered a potential health hazard by citizens. Proper management of a species like the Ring-billed gull requires adequate knowledge about its ecology. Until recently, there was little information available on the distribution, movements, habitat use, and the population dynamics of Ring-billed gulls in southern Quebec. The general objective of our project was therefore to study the foraging behavior and population dynamics of gulls living in urban and peri-urban settings within an integrated management framework. Several aspects of the research have been completed whereas others are still being conducted. We concentrate our study on Île Deslauriers in the St. Lawrence River where 45,000 pairs of gulls are nesting but we are also visiting other nearby colonies. The results of this research contribute to a better understanding of the biology of an opportunistic species and are used to make management recommendations that aim at reducing the problems associated with the presence of gulls.

Main results

On-going and future projects