29 April 2026

Residents across Duchy of Cornwall developments are being encouraged to take part in this year’s Big Duchy Bird Box Survey, after a landmark year for the long-running initiative which saw swifts nesting for the first time.

The annual survey, which runs from May to August, monitors the use of built-in nest boxes across Duchy developments and forms a key part of its wider commitment to support biodiversity and reconnect communities with nature.

The Duchy has worked with the RSPB for more than a decade to integrate nest boxes into new homes and buildings, helping to address the decline of cavity-nesting birds across the UK. The so-called 'swift bricks' resemble normal bricks or blocks but are hollow inside.

The initiative, which celebrated its 10th anniversary last year, is part of the Duchy's broader approach to sustainability, which includes habitat creation, green spaces, and measures to support wildlife across its estate. It aims to install an average of one nest box per new home built.

The UK Government has recently consulted on making swift bricks a requirement in new developments, and the Scottish Parliament passed just such a law in January.

The annual Big Duchy Bird Box Survey spans the Duchy’s Cornwall developments at Nansledan and Tregunnel Hill in Newquay and Trevethow Riel in Truro, and Poundbury in Dorset.

The latest survey results show a total of 1,497 nest boxes installed across Duchy developments, an increase of almost 200 on the year before, with 684 boxes (almost 46%) showing signs of use during the 2025 breeding season.

House Sparrows remained the most common species, with 159 confirmed nests, followed by House Martins (93) and Starlings (71).

Significantly, swifts were recorded nesting in Duchy-built boxes for the first time, with six nests identified across Tregunnel Hill and Poundbury. The hope now is that numbers will grow and swifts also move into the other sites.

“Seeing swifts begin to nest in the Duchy’s boxes for the first time is incredibly exciting. These birds are famously slow to adopt new nesting sites, so this was always something we expected would take time.

What this shows is that by putting the right infrastructure in place and being patient, we can create real opportunities for species that are in long-term decline. We’re hopeful this is just the beginning and that we will see many more swifts using these boxes in the years ahead.”

“The nest box initiative is an example of how we are embedding nature into the fabric of our communities from the outset. It not only supports wildlife but helps residents connect more closely with the natural environment around them. We're keen to recruit even more spotters for this year's survey and look forward to seeing the results."

This year's survey will go live on May 10, with residents once again invited to take part by recording activity in nest boxes. The survey will be available via a dedicated Facebook page.

Residents in Nansledan can also learn more about the project at a special talk by Dr Thaís Martins on May 12th at 6pm, at the Nansledan Community Centre.

Dr Martins added: “The survey is a fantastic way for residents and families to get involved in a real citizen science project. Every observation helps us build a clearer picture of how these species are responding and how we can continue to support them, so we hope as many people as possible take part this year.”