Look up on a summer evening in London and you may catch sight of one of the city’s most extraordinary residents.
Swifts are among the most remarkable birds found in the capital. They spend almost their entire lives in flight, eating, sleeping and even mating in the air. Each year they travel thousands of miles between Britain and southern Africa, returning to the same nesting sites across London to raise their young.
Yet despite their astonishing abilities, swifts are disappearing from our city.
Over the past two decades, the UK population has fallen dramatically. One of the main reasons is surprisingly simple: they are running out of places to live.
Long before cities spread across Europe, swifts nested in holes within ancient trees. As forests disappeared, they adapted. Instead of tree cavities, they began nesting in the gaps, eaves and ventilation spaces of buildings.
For generations, London’s homes provided thousands of suitable nesting places. Victorian terraces, Edwardian houses and older public buildings offered countless small openings that swifts could use during the breeding season.
Today, however, many of those spaces are disappearing.
As buildings are renovated, insulated and sealed to improve energy efficiency, traditional nesting sites are often lost. New developments frequently offer few opportunities for wildlife to coexist alongside people. The result is that many swifts return from their annual migration only to find that the places they have relied upon for generations no longer exist.
Edward Mayer, founder of Swift Conservation, explains that swifts were effectively forced to move into buildings after the widespread loss of Europe’s ancient forests. Having adapted to live alongside us, they are now facing a new challenge as modern construction methods unintentionally remove the spaces they depend upon.
At The London Society, we often discuss how the built environment affects health, wellbeing, opportunity and community. Swifts are a reminder that the impact of our buildings extends beyond people.
The choices we make when designing, retrofitting and maintaining buildings can influence biodiversity across the city. Small details, often invisible to most of us, can determine whether wildlife is able to thrive alongside London’s growing population.
As London seeks to deliver new homes, improve energy performance and adapt to climate change, there is an opportunity to think more broadly about what good development looks like. Can we create buildings that are warmer, healthier and more efficient while also making space for nature?
These are not competing priorities. In many cases, the solutions are remarkably simple.
The encouraging news is that helping swifts does not require major interventions.
Specially designed swift bricks can be incorporated into new buildings at relatively little cost. Nest boxes can be added to existing properties. These simple measures can provide secure nesting places for birds that may return to the same location year after year.
For a species that spends most of its life crossing continents and oceans, the difference between survival and decline can come down to a single space beneath a roofline.
Swifts are also extraordinary insect hunters. When feeding their young they can catch thousands of flying insects every day, making them an important part of London’s urban ecosystem. Their presence is often a sign of a healthy and biodiverse environment.
This is not simply a conservation issue. It is a city-making issue.
London is preparing for significant growth over the coming decades. New homes need to be built, existing buildings need to be retrofitted, and neighbourhoods need to become more resilient to climate change. As we make those changes, we have an opportunity to think about how nature fits into the future of the city.
There are already encouraging examples across London. Swift bricks have been incorporated into major developments including the Olympic Village and New Scotland Yard, as well as other high-profile sites such as the restored Ragged School in East London, and Terry Farrell’s Swiss Cottage Leisure Centre, and nest boxes have been installed in schools in Hackney, to name just a few. This demonstrates that biodiversity can be designed into new buildings without compromising their function or appearance.
Swift Conservation has also worked with developers, contractors, architects, local authorities and community groups across the capital to help retain and create nesting opportunities during refurbishment and redevelopment projects. Their work shows that supporting wildlife does not require grand gestures. It requires awareness and a willingness to consider nature as part of the design process.
Policy is beginning to move in the same direction. The London Plan encourages measures that support urban biodiversity, while a growing number of boroughs are exploring how swift bricks and other wildlife-friendly features can become a normal part of development. These interventions are inexpensive, proven and entirely compatible with the delivery of much-needed new homes.
The story of the swift reminds us that good development is often about the details. A small opening in a wall can provide a home for a bird that has travelled thousands of miles to return to London. It is a simple example of how thoughtful design can help create a city where people and nature flourish together.
As we think about the future of London’s built environment, perhaps we should ask a simple question: what kind of city do we want to create, and who is it for?
To learn more about swifts, nesting opportunities and practical ways to support them in London, visit Swift Conservation at www.swift-conservation.org.
Swift Conservation provides advice for homeowners, community groups, developers and local authorities, as well as talks and educational resources about one of Britain’s most fascinating birds.
You can also contact the organisation directly at mail@swift-conservation.org.
Brian May’s Message for World Swift Day, is also well worth watching: https://www.worldswiftday.org/world-swift-day/
The future of London’s skyline will be shaped by countless decisions about buildings, infrastructure and growth. With a little thought, it can remain a place where the city’s fastest residents continue to call home.
