Changes in spring arrival date and timing of breeding of Ring-billed Gulls in southern Québec over four decades

Abstract

Understanding how birds cope with climate change has received much attention in recent years. So far, more emphasis has been given to passerine species than to any other groups of birds, possibly because of the availability of long-term data sets. Our objective was to study the effect of climate change on spring arrival date and breeding chronology of Ring-billed Gulls (Larus delawarensis), a short-distance migrant with a diverse diet. Based on Étude des Populations d'Oiseaux du Québec (EPOQ) checklists, we found that gulls arrived in southern Québec five days earlier in 2012 than in 1971. Sporadic observations in three nearby colonies indicated that Ring-billed gulls laid eggs eight days earlier in 2012 than they did in 1978. Both arrival and laying dates closely fit temperature warming. Because of their diverse diet, Ring-billed Gulls always have access to some food resources during the breeding period making a mismatch between phenology and food abundance unlikely. Continuous warming may enhance the use of agricultural lands by gulls before and during the breeding period. However, this may not be sufficient to compensate for a reduction of refuse accessibility at landfills that have implemented deterrence programs.

Keywords

• climate change
• Larus delawarensis%22%2C%22default_operator%22%3A%22AND%22%7D%7D%7D"> <span style="font-style: normal">Larus delawarensis</span>
• migration
• phenology
• population dynamics
• rainfall
• reproduction
• temperature
• warming