Every year, millions of Barn Swallows (Hirundo rustica) make a remarkable journey from their breeding grounds in Europe to the warm, sun-riched plains of South Africa. This long migration is not just a testament to the species’ endurance, but also to their navigational skill and the intricate biological processes that guide them through thousands of miles/kilometres of changing landscapes. Yet, it’s not just their incredible travels that make the Barn Swallow so fascinating—it’s also the challenges they face during this journey.

Throughout their breeding season (spring and summer), Barn Swallows are found across Europe, often nesting in barns, sheds, and other structures built by humans. These swallows are highly social, often forming large colonies, and their nests are carefully crafted out of mud and grass.

The chicks of a Barn Swallow awaiting food in their mud nest in Europe. Adobe Stock Image

The Migratory Route: Europe to South Africa

As autumn approaches (August), the Barn Swallow’s biological clock triggers the start of a journey that spans thousands of miles. These birds migrate from their European breeding grounds to the South African Lowveld, where they will spend the southern hemisphere’s summer months before returning to Europe.

The exact route can vary, but it generally follows a southward trajectory from Europe, across the Mediterranean, through the Sahara Desert, and down to the subtropical and tropical zones of southern Africa. This annual journey is one of the longest migrations for a small bird, typically spanning around 10,000 kilometres (6,200 miles).

This barn swallow, although seemly injured at first, allowed us to get very close as we stayed put in the sand. After their long journey south this swallow rested on the ground for a while before taking off once more

Timing the Migration

The timing of their migration is closely linked to the changing seasons. Barn Swallows begin their migration in late August to early September, gradually moving southward in stages. They usually arrive in South Africa between October and December, where they spend the summer months feeding, nesting, and raising their young in warmer climates. Upon arrival, the juvenile barn swallow is distinguishable from the adults as they have not got their rust plumage quite yet.

As the southern hemisphere summer wanes, the swallows begin their return migration to Europe, typically starting in late March or April. The return flight is just as gruelling, as they must navigate back across the vast expanse of the Sahara Desert and the Mediterranean before reaching their northern homes in late spring. This timing ensures that they breed during the peak of summer in Europe when food sources are abundant.

Migratory Anxiety: The Mental Toll of Long Journeys

While we often think of migration as a purely physical journey, recent research has shown that there’s a psychological toll on migratory birds too—what some scientists refer to as “migratory anxiety.” Migrating birds, including Barn Swallows, are believed to experience stress during their long and exhausting travels.

Migratory anxiety stems from the complexity of the journey, the physical demands of long-distance flying, and the uncertainties they face along the way. Barn Swallows often fly in tight flocks, and though this provides a sense of safety, it also means the birds are highly attuned to changes in the group’s movements, which can cause heightened stress. Additionally, the unpredictability of weather conditions, scarcity of food sources along the migration path, and the challenge of navigating across vast, unfamiliar landscapes contribute to this anxiety.

This stress is most prominent in the first few days and weeks of migration, as birds must adjust to the rhythm of long, sustained flights. They experience physiological changes in response to stress, such as increased levels of stress hormones like corticosterone. This can affect their overall health and energy reserves, which makes finding reliable rest stops and food sources even more crucial for their survival. Zugunruhe is the German word for migratory restlessness.

We have been seeing large congregations of swallows like the one here fairly regularly over the last couple of weeks. It’s nothing unusual as these migratory birds will often flock together in larger groups than usual in anticipation of their long journey back to their winter grounds further north.

Fascinating Facts About Barn Swallows and Their Migration

1. Superior Navigation Skills: Barn Swallows use a combination of environmental cues, such as the position of the sun, the stars, and Earth’s magnetic field, to navigate their long migration routes. These birds can also learn from previous migrations, which helps them fine-tune their routes year after year.
2. Stopover Sites: On their journey, Barn Swallows rely on “stopover sites,” where they rest and refuel before continuing their migration. These sites are crucial for their survival, as they provide shelter and abundant insect populations. Some swallows even return to the same stopover locations year after year.
3. Night Flight: While many migratory birds rest at night, Barn Swallows are known to fly at night during certain parts of their migration. This helps them avoid daytime predators and makes use of cooler temperatures, allowing them to conserve energy. However, they still rely on daylight to orient themselves during key stages of the journey.
4. Multiple Generations in South Africa: While some Barn Swallows migrate alone, others may travel in family groups or as part of larger, multi-generational flocks. These family units can stay together and help protect each other during the migration.
5. Incredible Endurance: During their migration, Barn Swallows can fly up to 200 kilometres (125 miles) per day, covering vast distances over the course of weeks and months. Despite their small size, they are incredibly resilient and can fly non-stop for hours, making pit stops only when necessary.
6. Vocalization Changes: Research has shown that Barn Swallows alter their vocalizations during migration. Their calls tend to become more frequent and higher-pitched, likely as a result of the stress and social dynamics of long-distance travel.

Two Barn Swallows perch in the morning sunlight. These small birds are often found in big flocks sitting on the branches of a tree. They are Palearctic Migrants and will remain in the Southern hemisphere until March/April when they return North to breed.

The Return: Repeating the Cycle

As they complete their migration back to Europe, the Barn Swallows are greeted by warmer temperatures and the explosion of insect life that accompanies the northern spring and summer. This is the start of the breeding season once again. It’s a cycle that will repeat year after year, a true testament to the resilience and adaptability of these beautiful birds.

By the time they return to Europe, they’ve covered vast distances and overcome numerous challenges, both physical and psychological. They nest, raise their young, and prepare for yet another migration when the time comes.

The Barn Swallow’s journey from Europe to the South African Lowveld is one of nature’s most awe-inspiring migrations. Their extraordinary ability to navigate vast distances, their reliance on the social structure during travel, and the psychological toll of their long journey all contribute to the fascinating complexity of their migratory behaviour. As these birds continue to face challenges—from shifting weather patterns to the stress of the journey itself—understanding their migratory anxiety and the intricacies of their travel can help us better appreciate the resilience of one of the world’s most iconic migratory birds.

As we watch the Barn Swallows swoop gracefully across the skies and landscapes of Londolozi, we’re reminded of the incredible lengths they go to to thrive, year after year, against all odds.

With the summer rains the alates emerge from termite mounds. These two Tawny Eagles and Barn Swallows capitalised on this emergence