Bonaparte's Gull

Bonaparte’s Gull

Chroicocephalus philadelphia

Bonaparte’s Gull has been a predicted bird to appear on the Severnside Patch with recent records on the Severn Estuary at Cardiff, Slimbridge and Portbury Warth and local birders have scanned through many flocks of Black-headed Gulls in the hope of identifying one.

Well on 28th July 2026 the hoped for unexpectedly happened......

At about 8.20 am I was standing by the pipes at Severn Beach. There were hundreds of Black-headed Gulls lingering on the river waiting for the tide to drop as there only a few metres of exposed mud. I happened to notice a smaller gull flying past and away from me with a Black-headed Gull and fortunately both landed on a strip of exposed mud about 70 metres from me. Through my binoculars it definitely looked “interesting” and smaller so I quickly took some pictures over the next 4 minutes when it disappeared while I was viewing the images I had taken.

I presumed it had headed up river as that was the direction the other gulls were heading. The smaller size, all black bill, black not brown head markings, black ear spot, grey nape, short pink legs all made me think it was a Bonaparte’s Gull. I would have been happier if I had seen the underside of the primary feathers. I had limited experience of this species have only seen 3 others in the UK and just one in Canada. I quickly sent some images to other birders for their opinions. Eventually all confirmed it was a Bonaparte’s Gull and aged as a first summer/ second calendar year bird due to some black feathers retained from a carpal bar.

Amazingly the same bird was relocated at New Passage in the evening. It was subsequently seen over the next few days and into August at New Passage and Pilning Wetland and last reported on August 12th.

Bonaparte’s Gull and Black-headed Gull, Severn Beach 28.7.26

Bonaparte’s Gull, Severn Beach 28.7.26

Bonaparte’s Gull, New Passage 28.7.26

Bonaparte’s Gull and juvenile Black-headed Gull, Pilning Wetland 30.7.26