From the 11th to the 22nd of July this year, I will be walking the North West Way. The route is 191 miles in distance, starting in Preston: it follows parts of the Ribble Way, the Penine Way, through the rugged dales of Yorkshire via the thundering waterfalls of Teesdale and High Cup Nick and follows a section of Hadrain’s Wall before finishing in Carlisle.

It's going to be 11 days of back to back walking and although 191 miles may seem a lot, it isn’t a smidge on the distance Swifts travel in their lifetime. Common Swifts, which migrate to and from Africa each year, may fly 300,000 miles non-stop between fledging late one summer and their first landing at a potential nest site two summers later. They are iconic and incredible birds which are a sign of summer for many, arriving in May and spending just 3 months in the UK. The sight of their dark, sooty brown streamline, forked tail silhouette and shrieking overhead is a memorising sight and a real spectacle!

Unfortunately, their breeding numbers plummeted by 47 per cent between 1995-2014. The causes of this decline are unknown and, although loss of nest sites through modernisation of buildings is implicated, it is very likely that this is only part of the story. 

During the breeding season, Swifts depend on large bursts of insects to collect enough food for themselves and their young. It’s likely that the decline in the abundance of invertebrates that has occurred in Britain due to climate change has reduced the amount of food available for breeding Swifts. However, little is known about their foraging behaviour during breeding due to the difficulty of following them over relatively large distances that they are thought to travel to feed.

Swifts are only present in the UK for 3 months a year, therefore it is possible that they are being affected by processes occurring elsewhere in the world, in the areas that they use outside of the breeding season. To find out more about this, the BTO plans to track Swifts on their migration. Both the swift and the cuckoo are unusual in that they are declining in Britain and failing to advance their arrival date in Spring.

By deploying miniature GPS tags on swifts at breeding colonies in England, the BTO will be able to track swifts both on their foraging flights during the breeding season and over their annual migrations. As each tag will be able to record around 300 locations per deployment, this will allow the BTO to quantify the amount of time spent over different habitats and the distances travelled from the colony through short-term deployments during the breeding season. Through longer-term deployments with different tag programmes, it will allow scientists to look in much finer detail at the use of the stopover points in West Africa on spring migration.

The money you donate will help develop these tags to ensure that they are safe enough to be deployed on Swifts during the summer and winter
so that scientists at the BTO can gather and store data on long term deployment to help them learn more about the challenges they face on migration.