'Glaucous-like Gull' - northern New Jersey, 30 December 2005

Introduction: Towards the end of an enjoyable but somewhat windy inshore pelagic off northern New Jersey (30 Dec 2005, Belmar CBC run by Paul Guris and See Life Paulagics), we encountered an interesting large gull about half a mile off the beach near Sea Girt, New Jersey. Initially called out as a Glaucous Gull due to its massive size, generally whitish plumage, relatively short wings and obviously bicolored bill, we quickly realized some aspects of the plumage were not typical for Glaucous. Possibilities we immediately considered include a Glaucous x Great Black-backed Gull hybrid, Glaucous x Herring Gull hybrid (so-called Nelson's Gull) or an aberrant Glaucous Gull. It should be stressed that the bird was very white and the warm tones of the setting sun give the bird more color in the photographs than it might show in neutral light. Thoughts on the identification are welcome. Based of conventional wisdom, it seems that a Glaucous x American Herring Gull combination offers the best fit but we are open to other competing opinions.

Analysis: The bird can be tentatively aged as a 2nd winter based on the abraded patterning on the upperparts, pale iris and relatively fresh state of the primaries and rectrices. Also, there is perhaps a hint of a pale tip to the bill (see Fig.2). When evaluating the structure it is worth noting that the just prior to these shots the gull had wolfed down a huge partly-frozen fish head which no doubt accentuates the bull-necked appearance. The bird was very large, similar in size to the many Great Black-backed Gulls present in the same flock. The primaries only extended slightly beyond the tail tip giving a stubby appearance to this otherwise long-bodied bird. This was very evident in flight and the bird could easily be picked out on silhouette alone against the sun glare.

Figure 1. Circling over the chum-induced frenzy at the stern of the 'Suzi Girl', this large gull was uninformly identified as a Glaucous Gull by virtue of the sharply defined bicolored bill, whitish wings and heavy body and head. Only when it settled on the water in better light did we realize the ID might not be so straightforward. Photo Copyright © Mitchell Hait 2005.

Figure 2. The iris appeared pale yellow with hints of a reddish or perhaps plum eye ring. The bill was strongly bicolored with a pinkish base and dark brown tip. Photo Copyright © Angus Wilson 2005.

Figure 3. Another view in slightly better lighting. Notice how the bulk of the plumage appears white rather than cream colored. The primaries are the darkest feathers, the tips showing solid brown centers with crisp pale edging. The tail is also brown fading to white at the tip. The undertail coverts are strongly barred. Photo Copyright © Angus Wilson 2005.

Figure 4. One of the few flight shots I managed to get that wasn't directly into the sun! The brownish tail band is very obvious here and appears to be way too dark for a Glaucous Gull. Photo Copyright © Angus Wilson 2005.

Figure 5. Close-up and personal shot showing the strong barring on the undertail coverts. Photo Copyright © Angus Wilson 2005.

Figure 6. Wings raised as it settles on the water. Unfortunately, the white body feathers are a little overexposed in the harsh late-afternoon sun. Photo Copyright © Angus Wilson 2005.

Closing Thoughts: Based on the available literature, this bird seems a better fit for a Glaucous x American Herring Gull combination rather than Glaucous x Great Black-backed. An important caveat is that plumage of hybrid gulls (especially the larger species) are not well-known and the literature is rife with assumptions. In other words, identifications are often reasoned guesses and not based on birds of known parentage. Making matters more difficult still, hybrids tend to be less numerous and show more individual variability than the parental species and making it especially difficult to establish firm identification criteria.

Presumed Glaucous x American Herring Gull Hybrid (Nelson's Gull)
Presumed 2nd-winter Nelson's Gull, Seneca Falls, NY, USA 09 Dec. 2000
Presumed 1st-winter Nelson's Gull, Plymouth Harbor, MA, USA 26 Jan. 2002
Presumed 1st winter Nelson's Gull, California? Date? 1998
Presumed 1st winter Nelson's Gull, Manasquan Inlet, NJ, USA 21 Feb. 2004 (could this even be the same bird? We were in sight of the Manasquan Inlet)

Presumed Glaucous x Great Black-backed Gull Hybrid
Presumed 1st-winter, St. Johns, NF, Canada 24 Jan. 2004

See Life Paulagics specializes in pelagic trips off the mid-Atlantic states, principally New Jersey, Delaware, Maryland and New York. By actively chumming throughout the trip, we usually manage to keep a large flock of hungry gulls behind the boat and this often attracts white-winged gulls.


Figure 7& 8. Adult and first-winter Kumlein's Gulls off Belmar, New Jersey. Photo Copyright © Angus Wilson 2004.

Acknowledgements: Many thanks to Sandra Keller for relaying Mitchell's insightful photograph.

Photograph in Figure 1 copyright of Mitchell Hait © 2005 All rights reserved.
All other text and photographs copyright of Angus Wilson/Ocean Wanderers © 2005 All rights reserved.
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