Britain’s swifts, whose populations have fallen by 68% between 1995 and 2003, are at the centre of a growing debate over how new developments can serve both people and wildlife. In a new paper published in npj Urban Sustainability, the authors studied the debate regarding mandating swift bricks in all new residential buildings through the lens of multispecies justice.
This research was carried out by Jakub Kronenberg, who was a visiting academic at the Conservation Research Institute (CRI), University of Cambridge, during this research, and has now returned to the University of Lodz; Erik Andersson (Stockholm University), who was a short-term visitor to the CRI in early 2025; and Chris Sandbrook (CRI). Read the summary of the paper's findings below:
Conservationists argue that installing “swift bricks”—hollow bricks with small entry holes—could provide safe nesting sites for these red-listed birds. Cheap, permanent, and maintenance-free, the measure is often described as “a no-brainer.” The campaign for mandating swift bricks in all new residential developments gained momentum after activist Hannah Bourne-Taylor, the activist-conservationist, launched her “Feather Speech” in 2022, symbolically giving swifts a voice. Her petition gathered almost 110,000 signatures, obliging Parliament to debate whether bricks should be mandatory in all new housing.
In Parliament, there was rare cross-party support for the idea. Green MP Caroline Lucas framed mandating swift bricks as “a symbol of our recognition of deeper interconnectedness,” while Conservative MP Robert Courts argued that humans owed action to swifts that had adapted to live alongside us. Some MPs even urged expanding requirements to other types of buildings and extensions of existing residential buildings.
However, the government resisted calls for legislation, insisting local authorities and developers should decide “proportionate” action on a case-by-case basis. Ministers placed swift bricks within existing frameworks like the National Planning Policy Framework and biodiversity net gain provisions—measures critics argue are too generic to safeguard specific species.
At stake is more than one bird species. The debate exposes tension between technocratic approaches to biodiversity and calls for multispecies justice, which demands recognition of nonhuman interests and agency in planning. Hannah Bourne-Taylor recognised the swifts’ agency and representation. Reflecting the broader societal perspective, the parliamentary debate showed many expressions of admiration for the wonder of nature that the swifts epitomise, but not so much in terms of justice and recognising their rights and agency. Although the debate was initiated by an activist-conservationist who claimed to give voice to swifts, when confronted with formal politics, the questions of representation and agency of swifts receded to the background. The political debate over mandating swift bricks, and thus normalising human–nonhuman cohabitation, at least with regard to certain nonhuman actors, has been dominated by human perspectives on sharing space.
While politicians welcomed the idea of humans living with swifts, some were sceptical of normalising it through legislation that might then be translated into an obligation to recognise and meet nonhuman needs. Broader exposure to arguments regarding nature’s representation and agency, particularly those rooted in non-Western and non-anthropocentric worldviews and value systems, might increase the opportunities to include them in political debates. Similarly, broadening the debate on nature-based solutions and biodiversity net gain to cover non-biological components and nonhuman interests would help to make human-built infrastructure less detrimental to nonhuman beings.
For now, swift bricks remain optional—an emblem of the gap between public appetite for visible biodiversity action and the government’s reluctance to legislate for nature in the built environment.
Read the paper here:
Kronenberg, J., Andersson, E., Sandbrook, C. (2025). If a swift could fight for their existence with words: Nonhuman interests and politics. npj Urban Sustainability, 5(1), 70.
Photo: Apus apus swift falciot
(Photo courtesy of Pixabay and was published prior to July 2017 under the Creative Commons CC0 1.0 Universal Public Domain Dedication license)