At about 15.20 hrs on 18th June 2015, I noted some unusual vocalisations from the Eurasian Jays Garrulus glandarius that were provisioning a nest near to my garden in north Cambridgeshire. As well as the more familiar screeching, I heard what sounded like the soft hooting of a Tawny Owl Strix aluco. Knowing that Jays are proficient mimics, including in certain threat situations, I tried to establish whether the Jay or indeed a Tawny Owl was making these sounds, and for what reason. A second Jay arrived on the scene, and seconds later a Carrion Crow Corvus corone flew out of the tall Norway Spruce Picea abies in which all three birds were perched. The Jays pursued the crow, and the ‘owl’ calls continued, among other calls, from one or both of the Jays, which had landed in clear sight in a dead Elm Ulmus procera, until my further approach put the crow to flight. The crow may not have been unsettled by the call, given that the producer(s) were in full view, and I saw no evidence that it was having a deterrent effect. It may be significant that a range of calls were being uttered by the Jays, or perhaps ‘tried out’ as a response to a stressful situation.
Almost a year later, at about 13.00 hrs on 12th June 2016, my attention was again drawn to a convincing and drawn-out hoot resembling a Tawny Owl . Further investigation revealed two Jays in an agitated state, while a nearby Magpie Pica pica was also making alarm calls. A minute or so later a hitherto unseen (by me) Carrion Crow took flight, with the Jays following closely.
Conor Jameson; e-mail firstname.lastname@example.org