Last week was an extremely exciting one for me and a week that has been written in my calendar since I first started my job last November! Last week I was Gull Ringing Week in Guernsey! Ringing is a term used by people who catch birds and put a metal ring on their leg. The ring is extremely lightweight and is no different to you or I carrying a wallet in our pockets so it doesn’t affect the bird in any way and the health of the birds we capture is always our highest concern! Here in the Channel Islands we have our own ringing scheme which is slightly different than the one most people are used to in England which is run by the BTO (British Trust for Ornithology) but it does exactly the same job. The main reason we ring birds is for scientific purposes. Each ring has a unique number written on it so that if we re-capture the bird then we can find out where it was last caught and where it came from!
We gather as much data on individual species as possible so that we can learn more about where they go in the winter, if birds are changing where they feed and how well fed they are. The most common measurements we collect are the birds weight, sex (male or female – some are easier than others!), the length of their wing, the length of their head and bill (this can sometimes help tell us whether they are male or female) and the last and maybe the most important is the state of their feathers. All birds undergo something that is called a moult – similar to when your cat or dog loses fur in the summer, except birds are slightly different. In the summer they are busy feeding their chicks so their biggest job is to make sure they gather enough food to grow a healthy chick that can leave the nest. This means that at the end of a very busy breeding season most birds feathers are extremely tatty and they wouldn’t get them very far when they leave their summer breeding grounds for their winter migration. Therefore at the end of summer most birds go through a moult and drop their old feathers and grow shiny new ones! When they are doing this it can be much easier to tell the difference between an adult and a chick and from this we can try and tell how old the bird is! Birds that only live between 6-10 years such as blue tits and robins can be much easier to age than most gulls that can live over 25 years!
Whilst in Guernsey we concentrated on catching three different species of Gull. These were Herring Gulls, Lesser Black-backed Gulls and Greater Black-backed Gulls.
At the end of the week we worked out that we had caught over 1,500 birds and I had ringed 90 of them! We caught all of the birds at the rubbish tip in Guernsey. Why do you think human rubbish attracts Gulls? What do you think we can do to try and make them eat more food from the sea? Why do you think ringing birds is important for science?