Chapel's swifts, part 2 - What's been going on with the Chapel Milton Viaducts?

Read Chapel's swifts part 1: Why they matter

Many people have asked for some background and updates on what has been going on with the swift nests at Chapel Milton. What follows is necessarily long and detailed - because the history of engagement and decision‑making matters.

We love the Chapel Milton Viaducts and are fully behind efforts to protect them, but we want wildlife to be protected too. As explained in our press release and this Guardian article, we are concerned that swift nest site entry points on one of the pillars of the Chapel Milton Viaducts have been filled in as part of their renovation works.

Photo © SMJ (cc-by-sa/2.0) geograph.org.uk/p/2071664
Chapel Milton railway viaducts, taken 18/09/2010

 

Members of the biodiversity group spent a great deal of time last year gathering details of where swift nest sites are - we documented nine nests in the structure. We informed Network Rail, on numerous occasions, of exactly where the sites are. And yet we now see that three of the nest site entry points appear to have been blocked.  

The immediate and long term consequences of blocked nest entry points

When swifts return to a blocked nest they try repeatedly to access their entry point, which can have fatal consequences. This is deeply upsetting. But even if they live, when a nest site is lost, they are unlikely to continue breeding. Swifts are a long-lived bird that breeds again and again - often for over a decade - with an average success rate of 1.5 to 2 young per year. Those offspring that survive to breeding age go on to have chicks of their own, and so on. 

So when a swift nest is blocked, it doesn’t just stop one summer’s breeding. It removes a lineage that would have returned year after year, turning what might seem like a small action by Network Rail into a long‑term population loss. Swifts are rapidly declining in the UK and are on the Red List of Birds of Conservation Concern. According to the 2025 British Trust for Ornithology Breeding Bird Survey, swifts have declined by 70% in the UK since 1995.

 

What happened in 2025 - Documenting swifts and our FOI request

Our advocacy for the swifts of Chapel Milton didn't just start this month - this has been a long running issue, where we have been cautious about too much publicity because of an ongoing police investigation. Here's what we can tell you.

Led by local swift champion Deborah Pitman and with other members of the Chapel Biodiversity Group, local people started monitoring swift populations at the Viaducts in 2025, videoing and documenting their comings and goings, identifying their nest sites, and passing this information to Network Rail.

Network Rail put out a letter (shared by Chapel Parish Council on their behalf) to the local community in May 2025 (pdf) which included the following statements:

"Our ecologists will be carrying out biodiversity and ecology studies."

and "...we are committing to a biodiversity net gain of 10%. This means whatever is removed during the course of the work will be replaced with an additional 10%."

We submitted an FOI Request on 1 October 2025 to find out more about the surveys, how the 'net gain' of 10% would work, and whether local groups would be involved in the plans for biodiversity restitution and net gain. 

You can read the Network Rail response here (our request is reproduced at the end of the document). Briefly, this response made clear that Network Rail did carry out ecological surveys, but stated that they could not share the survey reports themselves, what they found, or exactly when the surveys took place because of an ongoing police investigation. 

The response also explained that Network Rail stepped back from its earlier commitment to deliver a 10% biodiversity net gain, saying that works were now classed as permitted development and therefore did not require it. They also stated that the project did not include mitigation funding or formal arrangements for community involvement.

What's happened so far in April 2026

We've been campaigning vigorously since we found out about the blocked entry points, urging Network Rail to unblock them as soon as possible. Swifts will be arriving in Derbyshire very soon. We're so grateful for the levels of support we've received, from fellow wildlife-lovers and birders to local and Network conservation and biodiversity groups.

Here's where we are, as of 13 April:

• Hannah Bourne-Taylor has been a fantastic source of support, and thanks to her advocacy on behalf of Chapel's swifts, we've had national engagement and support including from Deborah Meaden, Carl Bovis, and Baroness Jenny Jones.

• We generated widespread national attention across social media (Twitter/X and Facebook).

• The Guardian's Patrick Barkham reported our concerns in an article that was the 'most read' in the 'Environment' category on The Guardian website on the day it was published.

• We've lost track of the number of people who have told us that they have written to Network Rail's CEO Jeremy Westlake (email: jeremy.westlake@networkrail.co.uk).

• Jenny Jones has raised the situation with ministers and has been told by the Rail Minister Peter Hendy that he will speak to Network Rail. 

 

Photo: Deborah Pitman

 

 What has Network Rail said in response?

Network Rail started replying to the emails they received from 9 April onwards, with a long reply from Jake Kelly, "Regional director for North West and Central". This includes details of "endoscopic rope‑access surveys" that were used to determine whether crevices / nests were occupied.

The email states that 

"...certain structural cracks and crevices within the masonry had to be filled on safety grounds as part of the approved remedial design" 

and 

"Endoscopic surveys ... examined the specific crevices in question and found no evidence of active nesting"

They further said that they "recognise the strength of feeling in the local community" about this matter and made a statement of intent to install nest boxes to replace the blocked holes, subject to Historic England advice (the Viaducts are Grade II listed). 

Confusingly, there seem to be two versions of this reply. Some correspondents have a reply that states surveys were carried out in June and July, and others have a reply that states surveys were carried out in September 2025. The replies are otherwise identical in wording. Network Rail has been asked for clarification. 

Extract from Network Rail reply 9 April

Extract from Network Rail reply 10 April (FYI, September is not the height of nesting season!)

We appreciate the detailed reply and the constructive tone, but there are a number of elements we would challenge (much of which we'll have to leave for a future post). Most importantly right now, the fact that swifts return to precisely the same site each year means that blocking access between seasons has real consequences even if nests are not occupied at the moment of work.

What next?

As of 13 April, Network Rail has not committed to reopening the entry holes, and getting permission to install nest boxes is unlikely to be a quick process. Swifts will be here very soon.  

We are not stopping - we will continue to do everything we can to help these precious summer residents, and we really appreciate everything everyone has been doing to support us by continuing to email Network Rail's CEO Jeremy Westlake (jeremy.westlake@networkrail.co.uk), to publicise the campaign and to press Network Rail to unblock the nests as a matter of urgency.

We'll keep updating on this website when we get a moment. You can also see videos and images from our campaigning on our new Instagram page.