A decade-long biodiversity initiative by the Duchy of Cornwall is proving a major success, with nearly half of its built-in nest boxes now showing signs of use.
Working in partnership with the RSPB, the Duchy has installed 1,289 integrated nest boxes across its developments, including Nansledan and Poundbury, to encourage wild birds to nest in buildings. The latest survey revealed that 49% of these boxes were occupied in 2024—a steady increase from previous years.
House Sparrows, Starlings, and House Martins—species in long-term decline across the UK—are among the birds benefiting from these specially designed homes. In Nansledan alone, 620 nest boxes have been installed, with half showing signs of use.
This initiative is part of the Duchy’s wider commitment to biodiversity, which includes hedgehog highways, bee bricks, and habitat corridors. At Nansledan, biodiversity is expected to increase by 24% upon completion.
The Duchy has committed to installing an average of one nest box per home built, including at its proposed new 2,500-home development at South East Faversham in Kent. The new neighbourhood aims to achieve a 20% biodiversity net gain through woodlands, ponds, orchards, and wildflower meadows. Hedgerows and tree lines will enhance habitat connectivity for birds, bats, and Hazel Dormice.
Ben Murphy, Estate Director at the Duchy of Cornwall said:
“When we started this initiative with the RSPB over 10 years ago, our aim was to help address the decline in wild bird populations as part of our plans for boosting biodiversity by pioneering the use of built-in nest boxes in new developments.
“With thanks to the RSPB for their guidance in the design and installation of these boxes we’re delighted to see year-on-year increases in the rate of occupancy, and the extent to which the wider housebuilding industry is taking on board the importance of supporting wildlife in this way.”
The Duchy’s nest box initiative is being supported by biodiversity expert Dr Thais Martins. Since 2019 she has worked every year with residents of the Duchy developments to conduct The Big Duchy Bird Box Survey of nest boxes to find out how many are being used, and by which species of birds.
