Swallows – Liverpool Nature Nerds

Barn swallow (Hirundo rustica) summer 2004, Denmark. 360 on History
Barn swallow (Hirundo rustica) summer 2004, Denmark. Credit: i, Malene (Wikimedia Commons)
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Hello Liverpool Nature Nerds,

Summer is almost upon us and it time for more migratory birds to arrive in the UK from Africa. We’ve had a few already but I for one can’t wait for the swifts, swallows and martins.

These three amazing birds are often confused with each other (I know I always have a problem with their identification, so I want to talk about their differences, distribution in the UK, habits and characteristics. This one is about swallows.

Swallows (Barn swallows or Hirundo rustica, order Passeriformes)

Hirundo rustica barn swallow illustration from Biodiversity Heritage Library, Smithsonian Public Domain

Hirundo rustica barn swallow  (left) illustration from Biodiversity Heritage Library, Smithsonian Public Domain

Barn swallows are the most widespread species of swallows in the world, found in Europe, Asia, Africa and the Americas. These small birds have dark, glossy-blue backs, red throats, pale underparts. brown legs, and long tail streamers. Like the swifts, swallows are also superb fliers and the UK migrants spend their winters in South Africa, from where they fly thousands of miles to nest here in summer (March to October) – crossing the Sahara desert as they do so. They put on weight and accumulate some fat reserves but this long journey is still hazardous and exhausting for them. According to the RSPB, during migrations they cover 200 miles (322 km) a day, mainly during daylight, at speeds of 17-22 miles per hour (27 – 35 kmph), with the maximum flight speed at 35 mph (56 kmph). They arrive in the UK in March/April and return to Africa in in September/October. While wintering in Africa, they feed in small flocks but these flocks also join together to form roosting flocks of thousands of birds.

Barn Swallow Hirundo rustica. Credit: Tom Blackwell CC BY Wikimedia Commons

Some facts about swallows from the RSPB

  • They eat a variety of small invertebrates which are caught while flying
  • UK breeding poluation:860,000 territories
  • Length: 17-19cm, Wingspan: 32-35com, Weight: 16-25g, Beak: black, short and thin
  • Natural habitats: Farmland, grassland, upland, urban and suburban, and wetlands
  • UK Conservation Status: Green

They are generally found in areas with a steady population of small insects, particularly open pastures with access to water. They also like quiet farm buildings and large reedbeds. Swallows like to nest in outbuildings that provide dark ledges, nooks and crannies (with little light) and they can enter their nest sites through very small holes. They need rain not only to obtain wet mud for their nests but also for the insects they prefer to eat. However, too much rain can affect insect populations.

Barn swallow chicks

Barn swallow chicks. Credit: Mario Modesto Mata Wikimedia Commons

Barn swallow chicks in nest.

Barn swallow chicks in nest. Credit: Alvesgaspar Wikimedia Commons










Because they are such good fliers, they do not have many predatores, although hobbies or sparrowhawks may sometimes catch a weak swallow. One of their interesting characteristics is mobbing behaviour and they can be seen to mob birds of prey, crows, magpies and even people.

Swallow populations are greatly impacted by weather. Climate change in Africa and Europe has led to a decline in flying insects, thus impacting swallow populations (and their ability to breed). Furthermore, changing farming practices in Europe have reduced the number of nest sites, as well as insect accessibility.

Barn swallows nesting. Credit: Alex Malone CC0 via Wikimedia Commons

Happy swallow spotting!


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I am a Chartered Environmentalist from the Royal Society for the Environment, UK and co-owner of DoLocal Digital Marketing Agency Ltd, with a Master of Environmental Management from Yale University, an MBA in Finance, and a Bachelor of Science in Physics and Mathematics. I am passionate about science, history and environment and love to create content on these topics.