Mergus serrator

Status:  Uncommon regular spring migrant east and central, rare west. Uncommon regular fall migrant statewide. Rare casual summer visitor central. Rare regular winter visitor Keith Co, rare casual elsewhere.

Documentation: Specimen: HMM 2492, Apr 1900 Funk WPA, Phelps Co.

Taxonomy:  No subspecies currently recognized (Gill and Donsker 2017).

Spring:  Jan 28, 29, 30 <<<>>> May 7, 8, 9

Early dates above are away from Keith Co and of non-wintering birds. Later reports away from Keith Co are 10-13 May 2017 Lancaster Co, 13 May 2021 Gavin’s Point Dam, Cedar Co, 16-17 May 2016 Lancaster Co, 19 May 2016 Lancaster Co, 20 May 2011 Hall Co, 22 May 2016 Lancaster Co, 24 May 2014 Dawes Co, and 26 May 2020 Buffalo Co.

It is a later migrant than the Common Merganser, typically arriving in mid-to late Mar. About one-third of spring records are for the last week of Mar, but the species may be seen regularly into mid-Apr. Most reports are from the east, although it occurs with some regularity at Lake Ogallala and Lake Minatare, Scotts Bluff Co. It is rare in the Rainwater Basin; the first spring record there was of two in Clay Co 7 May 2011.

  • High counts:  300 at Lake Yankton, Cedar Co 29 Mar 2008, “hundreds” there 27 Mar 2011, 133 at Pawnee Lake, Lancaster Co 24 Mar 2019, and 103 at Lake Ogallala on 18 Apr 1998.

SummerThere are two records: a female summered at Lake Ogallala in 2001, another female was there 7 and 22 Aug 2000, and one was at Harlan Co Reservoir, Harlan Co 20 Jun 2004. Three, including a “non-breeding” male, were about 10 miles west of Norden Bridge on the Niobrara River 3 Jul 2013; these may have been molt migrants (see Fall).

Fall:  Oct 26, 26, 27 <<<>>> Dec 14, 14, 14

The fall migration is more leisurely than in spring, without large concentrations or a significant peak. This species is less cold-tolerant than the other merganser species, and generally leaves before Dec. There are far fewer fall reports than spring reports, but a greater proportion are from the west. A few records from North Platte NWR, Scotts Bluff Co suggest early Oct arrivals there might be molt migrants along with the larger numbers of Common Mergansers; seven were at Lake Alice 10 Oct 2020 and one at Lake Minatare 19 Oct 2020. These early dates may also be of molt migrants in Scotts Bluff Co: 22 Sep 1978, 23 Sep 1981, 3 Oct 1984, and 11 Oct 1977.

There are earlier reports away from Lake Ogallala of two on 16 Sep 2017 at Sutherland Reservoir, Lincoln Co, 12 on 20 Sep 2012 in Cherry Co, 12 Oct 2003 Lancaster Co, and 23 Oct 2010 Lancaster Co, and later reports of four on 17 Dec 2017 Lancaster Co, two in Lincoln Co 18 Dec 2017, six on 21 Dec 2015 Sarpy Co, 29 Dec 2015 Branched Oak Lake, Lancaster Co.

  • High counts:  58 in Lancaster Co 8 Nov 2009, 47 at Summit Reservoir SRA, Burt Co 9 Nov 1997, 47 at Pawnee Lake, Lancaster Co 12 Nov 2019, and 40-50 at Branched Oak Lake 20 Nov 2015.

A total of 137 was reported in fall 1996, most at eastern reservoirs (Grzybowski 1997).

Winter:  There are several reports of overwintering, mostly of small numbers mixed with large wintering flocks of Common Mergansers. Most such records are on major Platte River Valley reservoirs, Harlan Co Reservoir, and below Gavin’s Point Dam, Cedar Co. At Lake McConaughy, 27 wintered 1999-2000, 14+ were there 23 Jan 2004, up to five 30 Dec 2017-20 Jan 2018, up to four 1-19 Jan 2020, and 38 were on the CBC there 2 Jan 2021. At least two wintered at Harlan Co Reservoir 1999-2000, two were there 1 Jan 2001, and one from 15-20 Jan 2002. This species wintered at the spillway of Gavin’s Point Dam, Cedar Co 1982-83 (South Dakota Ornithologists’ Union 1991), 1-3 wintered there 2002-2003, 3-9 were there 20-28 Jan 2007, and two were there 29 Jan 2017. A single male wintered at Carter Lake, Omaha 2015-16 and two were at Sutherland Reservoir 9-20 Jan 2018.

Elsewhere there are these midwinter reports in the period 15 Dec-27 Jan, none north of the Platte and North Platte river valleys: 26 Dec 2020 Enders Reservoir, Chase Co, 1 Jan-4 Feb 1965 Douglas-Sarpy Cos, three on 1-3 Jan 2010 Sutherland Reservoir, 5 Jan 2020 Dawson Co, 7 Jan 2001 Johnson Lake SRA, Dawson and Gosper Cos, 8-29 Jan 2014 Lincoln Co, 8 Jan-4 Feb 2016 Carter Lake, Douglas Co, 9-20 Jan 2018 Sutherland Reservoir, 10 Jan 2012 two Lancaster Co, 10 and 24 Jan 2015 Sutherland Reservoir, 11 Jan 2000 Otoe Co (Falk 2002); 13 Jan 1995 Sutherland Reservoir, 13 Jan 2000 Branched Oak Lake, 23 Jan 2021 (2) Lincoln Co,  and 26 Jan 2008 Buffalo Co.


HMM: Hastings Municipal Museum
NWR: National Wildlife Refuge
SRA: State Recreation Area


Photograph (top) of a Red-breasted Merganser at Base Lake, Sarpy Co, on 5 Apr 2014 by Phil Swanson.

Literature Cited

Brown, C.R., and M.B. Brown. 2001. Birds of the Cedar Point Biological Station. Occasional Papers of the Cedar Point Biological Station, No. 1.

Falk, L. 2002. Birds in Otoe County.  Published by the author, Nebraska City, Nebraska, USA.

Gill, F., and D. Donsker (Eds). 2017. IOC World Bird List (v 7.3), accessed 30 January 2018.

Grzybowski, J.A. 1997. Southern Great Plains Region. Field Notes 51: 78-82.

South Dakota Ornithologists’ Union. 1991. The birds of South Dakota. Northern State University Press, Aberdeen, South Dakota, USA.

Recommended Citation

Silcock, W.R., and J.G. Jorgensen.  2021.  Red-breasted Merganser (Mergus serrator). In Birds of Nebraska — Online.

Birds of Nebraska – Online

Updated 28 May 2021