The Kaskattama River Mouth is located on the Hudson Bay Coast, about 75 km west of the Ontario border. The closest community within Manitoba is Gillam, which is located about 290 km southwest of the site. The coast is a narrow sandy beach, bordered by gentle sand dunes. There are no rock outcroppings along this section of the coast. Tundra borders the coastline, gradually grading into taiga then boreal-coniferous forest. The river branches a number of times at its mouth creating numerous islands and extensive sandbars. Since the terrain is flat, the tidal action from Hudson Bay creates large areas of mud flats and supertidal salt marshes.
Due to its isolated location, few detailed surveys have been completed at this site, and none have documented the full magnitude of bird usage. In the fall of 1997, peak one-day counts included over 50,000 Lesser Snow Geese (about 1.5% of the mid-continent population); more than 10,000 Canada Geese (which may be mostly Tall Grass Prairie birds, therefore containing as much as 3% of this population); and greater than 700 Hudsonian Godwits (probably over 1.4% of the world's estimated population of 50,000). Considering the probability of high turnover rates, it is likely that the numbers of these species using this site during the entire season is much larger.
Other species with notable one-day counts during fall migration include Red Knot (100+) and Lesser Yellowlegs (250+). Nesting species include Least Sandpipers (50+), Semipalmated Plovers (20+) and Willow Ptarmigan (50+) among many others. In 1997, nesting Barn Swallows were also recorded. This is of ornithological interest since it is a range extension of at least 250 km to the northeast of this species' normal breeding range.
BirdLife International (2020) Important Bird Areas factsheet: Kaskattama River Mouth. Downloaded from http://www.birdlife.org on 21/10/2020.