It's great to see the return of these elegant birds just off our beaches. They are the sleek white sea birds gliding above the waves and dramatically changing direction to dive head first into the water to catch their prey. The Tern are the smaller, sharp winged birds that have a fantastic 'lollopping' wing beat and the Gannet are the larger birds with long, thin wings that are very black wing at the tips, and they have a glorious long yellow neck and head; unmistakable when the sun catches them as they glide in the distance.
Both birds tuck their wings into their bodies to form an arrow shape just as they dive deep under the water in search of their food. At this time of year there are lots of juveniles learning the ropes. A few days ago I watched a Common Tern catch a fish and lead its young to a sand bar to feed it; unfortunately my camera is being repaired so I missed a great opportunity to catch it on film. But as Kate always says, it's in the memory where it really matters!
The presence of the Terns was brought to my attention by a friend who is lucky enough to take regular trips along our coast line to the Old Bar. He asked about the easiest way to distinguish between Common and Sandwich Terns. I really struggle with this when out on the shore front; size, colour of bill and markings on the head are the things to look for, but with the birds invariably in the air and darting around so quickly, it is hard to identify the key distinguishing features. It is also very difficult with so many indistinguishable young around! If you happen to be near the roost or the nesting areas (beware, they are very protective of their young!) to see them at rest, look out for the colour of bill: red bill with black tip on Common and black bill with yellow tip on Sandwich. As for size: very hard to compare unless two species are side by side.
I have a couple of pictures (not taken by me) below to help (Common in first picture and Sandwich in the second one):
I never commit to the correct identity of a bird unless absolutely sure; so when asked to help identify a bird diving off the beach, I always play safe and say Terns! The Gannets are much easier as there is just the one type and they can be identified simply by their flight pattern and size, and the shining white and black bodies.
When you stop to look at these birds, watch how some of them hang around observing their mates doing the hard work and then attack them, forcing them to drop their catch so that they can collect the prize! Last year I was sitting on the pier and was lucky enough to catch sight of a Skua bully its way into a group of terns and grab their catch.
So keep your eyes open and happy birding!