I was asked recently what signs there were at Forvie showing that it was the end of summer. The beginning of autumn can be easier to mark, with geese, winter thrushes and berries all appearing then, but one sign for me that signals summer coming to the end is the arrival of the sand sprites, the forever runners, the sanderlings.
These are waders, small birds that if you walk along the beach you will see constantly running along the very edge of the water, working the space that is the pause between waves.
It is at this time of year that sanderlings are appearing on the beach at Forvie, to feed-up and grow some new feathers in a pause in their southwards migration. Their summer has finished and they bring with them the end of summer for us.
Summer for a sanderling is nothing but a mad rush. They breed about as far north as you can go, right on the northern limits of land, Spitzbergen, Greenland, Arctic Canada and Russia. Summer is short in the Arctic but with 24 hours sunlight and millions of biting and buzzing insects it is possible for sanderlings to go through a high speed breeding season.
Adult sanderlings arrive in their breeding grounds in late May, early June but in only 6 weeks they will have laid eggs, incubated them and the chicks grown to full-size. To increase productivity the females will lay 2 clutches of 4 eggs, she will hatch one, the male will hatch the other. This is pretty hard work for the female, the weight of 8 eggs is the equivalent of 3/4’s of her body weight that that takes so doing! By August the adults have had enough and start to head south, the youngsters following soon after. Their autumn journey will take them all the way down the west African coast – 5000km long. So a stop on a beach at Forvie is a welcome refuelling opportunity and with good feeding they can put on 4g a day. Not bad for a bird that usually only weighs up to 80gs. They are brilliantly adapted to feed fast, they have big eyes for spotting prey, they have lost their back toe to be able to run faster and feed continuously, only stopping for a couple of hours over high tide. They are the hardest working wader in town.
So their arrival here heading south after an Arctic breeding attempt, whether successful or not, heralds a shortening of day length, a browning of the green and a slight edge in the morning air, that means summer is nearly done and autumn on the way.
David Pickett | Forvie NNR Nature Reserve Manager