An uncommon tern of events (Common Terns Sterna hirundo in Evesham)

Mark Turner

13.30 hrs on Friday 30^th July 2010 was one of those all too rare occasions when you make a new discovery right on your doorstep. Taking a short path behind the converted mill in Common Road, Evesham and along the tow-path towards the weir (SP043439) past the Lockkeeper’s house, I was immediately aware of familiar calls normally associated with different locations entirely. A new floating safety boom now straddles the top of the weir and atop the large green drums I discovered two noisy juvenile Common Terns Sterna hirundo and one adult. The two youngsters were subtly different to look at, both with the usual gingery tones to the plumage and a sooty head with pale forehead, but one had a more pronounced dark carpal bar. This one also proved to be the most vocal and active; keeping the parent constantly alert. In fact whilst watching the parent I noticed it glancing skyward followed by a brief burst of alarm notes; sure enough a female Sparrowhawk Accipiter nisus was gliding high above following the course of the river.

With the tow path so close to the action I had some wonderful views of the terns flying by me including a plunge dive by one of the juveniles and a fish lunch being offered by the parent again atop the green drums. The adult incidentally was wearing a BTO-type band on its right leg.

I returned the following day at around the same time with my wife and her camera. It was fortunate timing as after half an hour of loafing and preening the three terns became restless and vocal and then the adult led the way up river. We followed their route on passed Evesham Marina for a short distance, but there was no sign of them at all.

However, that was not the end of the story. Again I paid a return visit on Monday 2^nd August at midday only to find not just the family threesome but three adults and the two juveniles. Two adults were already fishing when I arrived and the sudden excitement of a juvenile alerted me to the arrival of a third adult. This bird like the original parent sported a BTO-type band on its right leg suggesting to me all the terns had perhaps come from the same breeding site. I made a second call to Birdline West Midlands and another to fellow local birder Peter F Stewart.

An afternoon visit to the lock and weir off Common Road on 7^th August revealed an adult Common Tern still present and giving great views. The bird perched openly on the handrail of a raised walkway at the approach to the lock gates.

Before we left my wife and I were treated to some classic seabird behaviour when an adult Lesser Black-backed Gull gave chase trying to force the tern to drop a good size fish that it was carrying. The determined gull was however unsuccessful, the tern flew up and down the river, made tight turns round tall trees even passing us overhead during the pursuit. The gull gave up and the tern came back to the floating barrier to rest and digest.