Little Gulls (Hydrocoloeus minutus) in the Hudson Bay Lowlands, Northern Ontario, Canada 1973–2021

Limited information exists on Little Gulls (Hydrocoloeus minutus) in the Hudson Bay Lowlands, their presumed primary North American breeding site. A 48-year checklist dataset from 1973–2021 in the Ontario portion of the Lowlands combined with a 10-year intensive observation dataset from July to September 2009–2019 in southwestern James Bay, Ontario, reveal key insights. Checklist records consisted primarily of migrants and included 473 Little Gulls (annual mean = 14.8, range = 0–91), with peak numbers (122 individuals) in the third week of May. Intensive observations documented 267 Little Gulls (range = 3–54/year). In the intensive study, adults were first recorded in the third week of July, while second-year birds and juveniles appeared in the first week of August, when all age groups peaked in abundance. The last sightings were juveniles and occurred in the first week of September. This paper advances understanding of Little Gull ecology and migration in North America, emphasizing the necessity for future research. Future studies that employ advanced tracking technology will reveal breeding locations, migration routes, roosting sites, and non-breeding locations, which are vital for the conservation of this enigmatic North American gull species.