After the discovery of a small sand martin colony set amongst sand dunes on Nairn Dunbar Golf Links in 2017 we have been studying the sand martin colony ever since with the help of Darrell Stevens, conservation officer from RSPB Scotland and Benjamin Jones who is training for his BTO bird ringing licence. The colony was very active and sand martins have been buzzing in and out of the holes throughout the early summer months, busily excavating tunnels and nests ready for the oncoming breeding season .Sand martins feed on small aerial insects throughout the year and come to the UK in the summer where they search out sandy banks and cliffs for nesting. They excavate a nest chamber into a vertical sandy face, which is about a meter deep, and lay 4-5 eggs in a small chamber where they incubate them for 14-15 days. Once hatched the chicks grow rapidly and fledge after 19-21 days.
The 2018 was the second year of the sand martin (Riparia riparia) study which was carried out in June. Over 50 birds were ringed in 2017. The number ringed in 2018 was only just over 20 and surprisingly we were unable to capture any of previous years ringed birds to retrieve any data. The colony size was reduced this year likely a result of spring storms further south. Sand martins were not the only birds affected by this, many of our summer migrant birds tuned up later than usual, some maybe deciding to nest further south instead of making the journey up to the Highlands.
The sand martins that nest here travel to us all the way from sub Saharan Africa over 4000 miles away. They can undertake this journey when they are only a few weeks old and navigate the entire way on their own, quite an amazing feat of endurance and stamina. This area is an important area for wintering European migrant song birds who also make the long journey to escape the European winter and maximise the hot sun and abundance of insect life. The Sandmartins have long wings and a small body (brilliant for gliding and travelling long distances) also have really short legs with claws on the end to excavate their tunnel nests in the sand.
The aims of the sand martin project are to learn more about the Nairn Dunbar colony such as how long do the birds live and what the chick survival rate is. Ringing birds involves trapping them in a mist net so they can be aged, sexed, weighed and measured then ringed with an official British Trust of Ornithology (BTO) ring on one leg before being released unharmed. The hope with regular study’s we will be able to retrap the ringed birds so we can check their progress. These rings have a unique individual number on them which is specific to each bird. This number enables us, in conjunction with the BTO database, to keep a track on the bird’s movements. If the bird is re-caught or found then we are informed and we can find out how far the bird has travelled. As well as ringing each bird, various other measurements are taken which include age, sex, wing length and readings, which allow us to calculate how much fat and muscle they have. All this information is then stored on the BTO database. To carry out a project like this you need to have a bird ringing licence which is issued by the BTO, it takes a long period of training to get this licence.
This data can be very useful in conservation of the species helping to better understand their lifecycle and movements. Over the next few years we hope to learn more about the Nairn Dunbar sand martin colony and how they are coping in our changing world. We look forward to continuing the project in 2019, working closely with the RSPB and BTO to keep track on the colonies movements.