The Barre de Portneuf is a sandbar extending southward, from the mouth of the Portneuf River, into the lower St. Lawrence River, Quebec. The sandbar originates from the southern side of the mouth of the Portneuf River. It extends southward and upstream into the St. Lawrence River, for a distance of 4.5 kilometres and a maximum width of 250 metres. A bay is created between the mainland and the sandbar which is inundated at high tide, and is mixture of one-third Spartina salt marsh and two-thirds mudflats at low tide. The middle portion of the sandbar is colonized by xeric plant species associated with sandy areas (mostly sea lyme-grass) while small stands of conifers and alders are established on higher parts.
This area is probably one of the most important fall migratory stopovers for shorebirds in the St. Lawrence River estuary. The sandbar is, accordingly, one of the favorite spots for birdwatchers interested in shorebirds in Quebec. Least Sandpipers peak during August, with up to 750 birds being seen daily.
Over 25 shorebird species have been seen at Barre de Portneuf. The highest one-day total of all shorebirds was 8,832 on August 21, 1995. If ‘bird days’ are considered – an estimate of the season total, that assumes daily turnover – then 182,501 shorebird bird days were calculated for the 1995 season.
The highest one-day total of any one species was 7,000 Semipalmated Sandpipers on August 22 and 23, 1994 (116,925 bird days, 1995). White-rumped Sandpipers also feed at the site in large numbers, with up to 1,000 birds present daily (> 500 regularly) during their long peak period, which lasts from early August to mid-September. Black-bellied Plovers pass through here from early summer into October, with their peak numbers occurring in the second half of August. Up to 650 birds have been recorded, and between 500 and 600 per day seen regularly. Additional common migrants are Semipalmated Plover, Ruddy Turnstone, Red Knot, Greater and Lesser Yellowlegs, and Sanderling. Uncommon migrants include American Golden-Plover, Pectoral, Baird’s and Least Sandpipers, Whimbrel, Hudsonian Godwit, Short-billed Dowitcher and Dunlin. Shorebirds that occur here rarely include Marbled Godwit, Western Sandpiper and Buff-breasted Sandpiper.
Large numbers of gulls and terns congregate on the sandbar, for both breeding and roosting purposes. The Portneuf sandbar, along with another sandbar located near Pointe-Lebel, are the only two sites where Parasitic Jaegers commonly come to shore, often to feed on shorebirds.
BirdLife International (2020) Important Bird Areas factsheet: Barre de Portneuf. Downloaded from http://www.birdlife.org on 12/08/2020.