Every summer, I love to watch the swallows that visit the open barns at the equestrian unit where I make up your bird food. I feel so excited when they arrive, I love watching them build their nests and feed their young, swooping over the wildflower meadow to eat the insects there, and I always feel sad when the time comes for them to head away in winter. Every time I see a swallow resting on a power line from late August onwards, I wonder if it will be the last time I see them for the year.
Each year, millions of birds like the swallows I love to watch embark on an incredible journey, flying thousands of miles between their breeding and wintering grounds. The UK plays a crucial role, serving as a stopover or destination for many migratory species. September is a particularly exciting month for bird enthusiasts, as it marks a peak period for migratory birds. Bird migration is driven by the need to find food, favourable climates, and safe breeding sites. Some birds migrate short distances, while others undertake epic journeys spanning continents. These journeys are not random; they follow well-established routes known as flyways.
NATURE OR NURTURE?
Migration patterns are complex and have evolved over thousands of years - they form part of the birds’ genetic make up, which is why birds are able to locate their seasonal homes in their first year of migration despite having never been there before. Birds possess an innate sense, which allows them to detect the Earth’s electromagnetic fields. This ability helps them navigate vast distances with precision, even in cloudy weather. Interestingly, young birds usually embark on their first migration when they are just a few months old, relying heavily on instinct to find their way. They also learn from older, experienced birds who guide them along established routes, using the sun, stars, and even landmarks to stay on course. Most birds migrate in flocks, which re- duces energy use for bigger birds, and a lot of birds time their migration accord- ing to the weather and hours of sunlight (although Eleanora’s falcons time their migration according to the southbound passage of passerines which they use to feed their own young). The instinct to migrate is hardwired and caged birds go through a restless period in spring and autumn, repeatedly flying towards one side of the cage in a behaviour termed migratory restlessness. Male and female birds can migrate at different times of the year, and some birds only migrate during their first year. Nocturnal birds use short nocturnal flight calls to avoid collisions during their night time flights and geese migrate in a V-shaped forma- tion, taking turns to lead and dropping back when they become tired. Migration is a dangerous business. Birds often travel at night to avoid predators and take advantage of cooler temperatures, which helps conserve energy. They make regular stops at known safe locations to rest and refuel. These stopover sites are crucial for their survival, providing essential food and shelter. The swallows I love to watch travel all the way from South Africa to breed in the UK. These agile fliers cover around 200 miles a day, often following the same routes year after year. Swifts are another long-distance migrant, spending most of their lives on the wing and flying up to 6,000 miles between their African wintering grounds and UK nesting sites.
MIGRATION IN THE UK
The UK is crisscrossed by major migration routes, such as the East Atlantic Flyway, which extends from the Arctic to Africa. Key stopover sites along these routes provide essential rest and refuelling spots for migrating birds. RSPB reserves like Minsmere and Bempton Cliffs are popular locations for observing this phenomenon. Estuaries, such as The Wash and Morecambe Bay, offer rich feeding grounds for waders and waterfowl.
WHEN IT GOES WRONG
Birds can get lost and end up in unexpected places, often prompting twitchers to travel miles to see an unusual visitor. Some birds overshoot their planned destination and end up further north or south than intended, while others are blown off course by storms. Birds are a great benchmark for environmental health and the effects of climate change, and the conservation of migrating birds requires international cooperation because they cross so many borders. Pollution, hunting along migratory lines, wind farms, offshore oil rigs, storms and habitat destruction can all affect migrating birds and impact bird populations worldwide. WORLD
If you want to watch birds as they come in and out of the UK, you can head to Spurn Point in East Yorkshire, Dungeness in Kent, Portland Bill in Dorset, Blakeney Point in Norfolk or Rutland Water in the East Midlands. I’ll be sad to say goodbye to our swallows this month, and have nothing but admiration for the amazing journey they’re about to begin.
