Status: No accepted records.
Taxonomy: No subspecies are recognized.
Comments: There is a report of a basic adult at Harlan Co Reservoir, Harlan Co 22 Jan 2000 (eBird.org checklist, Jorgensen 2002). Photographs were obtained, and all features visible in the photographs and noted in the observer’s description indicated this species. However, a key field mark, the under-primary pattern, was not observed as the bird was lost when the flock flushed and the bird could not be relocated despite extensive searching. The report was judged “Not Accepted” by the NOURC (Jorgensen 2002).
A report was received of one at Offutt Base Lake, Sarpy Co, 21 Dec 2006 during the period when an undisputed adult was at nearby Lake Manawa in Iowa. No details were provided, however, for this likely correct report; the NOURC rejected the report based on a lack of submitted details (Brogie 2008).
There are six records from surrounding states, all but one in the period 2 Dec-29 Jan; the exception is one that remained in Colorado 7 Mar-6 Apr 2000 (CBRC 2017), raising the possibility that it and the putative Nebraska bird 22 Jan 2000 (see above) might have been the same individual.
CBRC: Colorado Bird Records Committee
NOURC: Nebraska Ornithologists’ Union Records Committee
Photograph of a possible Slaty-backed Gull (center) with Ring-billed and Herring gulls at Harlan Co Reservoir, Harlan Co 22 Jan 2000 by Joel G. Jorgensen.
Brogie, M.A. 2008. 2007 (19th) Report of the NOU Records Committee. NBR 76: 111-119.
CBRC [Colorado Bird Records Committee]. 2017. Slaty-backed Gull. Colorado Bird Records Committee database, accessed 20 December 2017.
Jorgensen, J.G. 2002. 2002 (sic; =2000) (12th) Report of the NOU Records Committee. NBR 70: 84-90.
Silcock, W.R., and J.G. Jorgensen. 2017. Slaty-backed Gull (Larus schistisagus), Version 1.0. In Birds of Nebraska — Online. www.BirdsofNebraska.org