Chaplin Lake is situated in south central Saskatchewan, near the town of Chaplin. It is a large saline lake approximately 35 km in length and up to 10 km wide (after the Quill Lakes, it is the second largest saline lake in Canada). The lake is divided into four sections by a series of dykes and roads that were constructed as part of a sodium sulphate mine development on the north shore. Extensive marshes are located in the southern half of the lake. Water levels fluctuate considerably, with extensive mudflats becoming exposed during the late spring and summer; during some years the lake may become completely dry by mid-summer.
Chaplin Lake supports tremendous numbers of shorebirds, especially during spring migration. One-day aerial surveys in 1987, 1993, and 1994 yielded estimates of 59,773, 73,359, and 55,127 respectively. For 1994, species peak numbers on Chaplin Lake provided a total count of 110,061. One of the most abundant species at this site is Sanderling; although a site specific number is unavailable, (estimates for Chaplin and Old Wives Lake were combined) the average number was 55,471 for both these lakes. This may represent as much as 30% of the estimated North American population. Large numbers of Baird's Sandpipers (29,862 in the spring of 1987 as much as 21% of the world's population), Semipalmated Sandpipers (30,404 in the spring of 1987 and 28,796 in the spring of 1994), and Stilt Sandpiper (4,349 in May, 1993, representing 4.3% of the global population) have also been recorded at Chaplin and Old Wives Lake. Other shorebirds that have been recorded in large numbers at Chaplin Lake include American Avocet (2,685 1994; over 4% of the estimated Canadian population), Red-necked Phalarope (7,755 1994), Wilsons Phalarope (7,100 1984, and 6,192 1994; both approximately 1% of the Canadian population).
Chaplin Lake also supports a significant breeding population of the nationally endangered and globally vulnerable Piping Plover. As many as 205 adults were recorded during the 1996 International Piping Plover Census (about 3.4% of the world's estimated population). Over a three-year period (1996-1998) an average of 169 breeding Piping Plovers were recorded. Burrowing Owls, another nationally endangered species, have also been recorded nesting in the grasslands surrounding the site.
Of additional ornithological interest is the presence of nesting Snowy Plovers in 1987 (2 pairs 1 female appeared to be incubating). Since 1987, this species has been reported on several occasions. This site is one of only three known breeding locations for Snowy Plover in Canada. Also, two species that are nationally vulnerable, the Ferruginous Hawk and the Long-billed Curlew, nest in the surrounding grasslands in small numbers.
BirdLife International (2020) Important Bird Areas factsheet: Chaplin Lake. Downloaded from http://www.birdlife.org on 28/11/2020.