The total population is estimated to number c.530,000-830,000 individuals (Delany and Scott 2006), probably including c.350,000-560,000 mature individuals, on the basis that they probably account for around 2/3 of the population.

Population Trend


NatureServe Conservation Status

Rounded Global Status Rank: G5 - Secure

Reasons: Large global population with very large and widely dispersed continental subpopulations, fairly low degree of threat, particularly on breeding grounds.

National NatureServe Conservation Status


Rounded National Status Rank: N5B,N4N : N5B: Secure - Breeding, N4N: Apparently Secure - Nonbreeding

United States

Rounded National Status Rank: N5B,N5N : N5B: Secure - Breeding, N5N: Secure - Nonbreeding

IUCN Red List Assessment

Red List Category
Near Threatened

Red List Criteria



Year Assessed



BirdLife International


Butchart, S.


Bowman, T., Moores, N. & Pihl, S.


In northern Quebec, egg laying began in the first week of June; hatching occurred in the second and third weeks of July (Savard and Lamothe, 1991, Can. Field-Nat. 105:488-496). Clutch size is 5-8 (often 8). Incubation lasts 27-28 days (Terres 1980). Young are tended by female, independent in 6-7 weeks (Harrison 1978).

Global Abundance

>1,000,000 individuals

Comments: No precise estimates available, but minimum numbers are at least 500,000 individuals in western Europe in winter (early 1970's) and 500,000 individuals in North America, with additional large numbers in eastern Asia (Madge and Burn 1988).

Number of Occurrences

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: Except in inland habitats, mollusks comprise a majority of the diet; the blue mussel (MYTILUS EDULIS) often is a major food (Bellrose 1976). Also eats crustaceans, some fishes and plant foods, the latter being most important in inland habitats. Usually feeds in protected areas where water is no more than 25 ft deep.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Depth range based on 1 specimen in 1 taxon.

Environmental ranges
  Depth range (m): 0 - 0
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.


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