At about midday on 11th March 2016, at Seaton Wetlands in Devon, a Carrion Crow Corvus corone was harrying an adult Black-headed Gull Chroicocephalus ridibundus as both flew low above the ground across a field. The crow suddenly grabbed the gull, perhaps by the feet although I cannot be certain about that, and both fell to the ground. From that point, the action was generally obscured by tufts of sedge. The crow appeared to land on top of the gull but then hopped to one side. The gull staggered a few steps and the crow grabbed it again and gave it three strong pecks to its nape. Two other crows landed close by but took no part in the attack. The gull again made a few steps and wing flaps but these may have been post-death spasms. At this point both birds were lost to sight but the crow was still with its prey.
It is well known that Carrion Crows will attack weak or injured animals on the ground, including accusations of killing new-born lambs, and will take nestling birds. They also mob larger birds in flight, but usually not with lethal intent, and chase birds to steal food. In over 50 years of birding I had not heard of crows actively predating a flying bird, and this observation was a shock to me. BB has published reports of fatal attacks in 1947 on a Magpie Pica pica, possibly a fledgeling, and in 1950 on a flying Wood Pigeon Columba palumbus. A more recent note described a Carrion Crow attacking and grounding (though not killing) a Herring Gull Larus argentatus, in Caernarfonshire in June 1993.
Allan Reese, Riverside Cottage, Forston, Dorchester DT2 7AA; e-mail email@example.com