Abstract
The Red-necked Grebe is a regular spring migrant on the Great Lakes and occasionally observed in very large numbers, particularly along the northwestern shore of Lake Ontario. Aerial surveys were flown to document abundance, distribution and habitat use of waterfowl and conspicuous waterbirds along the Ontario shorelines of the lower Great Lakes. On 7 April 2019, we observed a very large number of Red-necked Grebes, estimated at 12,395 individuals, concentrated in western Lake Ontario. The majority of these birds were located offshore along a 20 km span of shoreline between Frenchman’s Bay (Pickering, Ontario) and Bluffer’s Beach (Scarborough, Ontario). However, an exceptional number of Red-necked Grebes, estimated at about 11,000 birds, was observed along an approximately 2 km span of shoreline near the Scarborough Bluffs. Red-necked Grebes also were observed on two subsequent surveys in western Lake Ontario, but their estimated total numbers were considerably lower on 28 April (1,326 birds) and 8 May (32 birds). Given that the largest published minimum continental population estimate for this species is 45,000 birds, the 12,395 estimated birds we observed represents slightly more than 25% of that number. This sighting, along with several others over the past several years, represents a significant proportion of the North American population and highlights the importance of western Lake Ontario for spring migrant Red-necked Grebes.
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Recommended Citation
Wood, Ross W.; Badzinski, Shannon S.; Campbell, Barbara A.; Collins, Brigitte; Meyer, Shawn W.; and Sadler, Denby
(2021)
"Abundance and Distribution of an Exceptional Number of
Red-necked Grebes in Western Lake Ontario during Spring 2019,"
Ontario Birds: Vol. 39
:
Iss.
1
, Article 6.
Available at:
https://digitalcommons.usf.edu/ontario_birds/vol39/iss1/6