Bird Spikes on Trees in Bristol: The 2017 Clifton Row

Bare winter branches lined with white anti-bird spikes above the Bartlett Court car park in Clifton, Bristol, December 2017.

In December 2017 a photograph of two trees in Clifton, Bristol, with rows of metal anti-bird spikes strapped along their lower branches, set off a national argument in the UK. Critics called it a war on wildlife waged to keep pigeon droppings off expensive cars. The company that manages the flats beneath the trees said it was a health measure that had been in place, quietly, for three years.

Both sides had a point, and the row became a small but telling case study in how cities share space between people and the animals that live among them.

Where and when it happened

The trees stand at the corners of Pembroke Road and Clifton Down, in one of Bristol's most affluent suburbs, above a private car park belonging to Bartlett Court, a block of 49 flats. On Monday 18 December 2017 Jennifer Garrett, a local nature lover, posted a picture of the spiked branches on Twitter, crediting the photo to Anna Francis. Within a day it had been shared well over a thousand times, and the story was picked up by Bristol24/7, the BBC, The Guardian and news sites around the world. It was also debated on BBC Two's Jeremy Vine show.

The spikes themselves were not new. They had been installed in 2014 by Hillcrest Estate Management, the company employed by the Bartlett Court Residents' Association to look after the building.

The post that took the story national: Jennifer Garrett's tweet of 18 December 2017 showing spikes fixed along the branches over the Bartlett Court car park, with the photo credited to Anna Francis.

Why the spikes were installed

Hillcrest set out its reasons in a statement to Bristol24/7 three days after the photo went viral. Pigeons roosting in the overhanging branches left droppings on the cars below and on the footpath to the building. Residents trod the mess indoors and onto carpets, which the company described as "a health hazard for residents and their children". Leaseholders had asked it to act, and bird droppings left on car paint can damage it permanently.

The company said it had tried gentler options first: fake birds of prey, CDs hung in the branches, night-time noise deterrents and cutting back branches where the council allowed it. None made much difference. A car port was ruled out because the flats are in a conservation area, and car covers were dismissed as impractical. After advice from a tree surgeon and a pest-control firm, it chose spikes as the most humane option.

Some of the early reporting was also wrong. The spikes were not nailed into the trees, as several posts claimed; they were fixed with cable ties so they could be removed without harming the bark. And they covered about 20 per cent of the lower branches, the ones birds favoured for roosting over the car park, not the whole of each tree.

Why people were angry

For many who saw the picture, the image was simply jarring: a living tree armoured against the creatures that would normally use it. Local Green Party councillor Paula O'Rourke acknowledged that the landowner might be within their rights, since the trees appeared to be on private land, but said the spikes looked awful and that it was a shame to see trees made uninhabitable to birds, apparently for the sake of parking. She said she would raise the matter at the council.

The Royal Society for the Protection of Birds (RSPB) generally regards spikes as a humane, non-lethal way of keeping birds off buildings. Its spokesperson Jeff Knott nonetheless criticised this use, pointing to the State of Nature report's finding that more than half of UK wildlife species had declined over the previous 40 years. "Instead of looking at ways we can force nature into an ever smaller space," he said, people should look at how to live alongside wildlife in towns and cities.

Class played a part too. Coverage often stressed the wealth of the neighbourhood and the price of the cars, which helped turn a dispute over pigeons into a story about privilege.

Could the council step in?

Bristol City Council said the trees were on private land and that it could not intervene. Reports at the time described this as the trees not being covered by a tree protection order, while Hillcrest said the estate's large trees did have Tree Preservation Orders. The two statements are not necessarily in conflict: a TPO protects a tree from being cut down or damaged, and spikes held on with cable ties do not obviously damage it. As Bristol24/7 noted, there seems to be little regulation of spikes on private trees.

Wild birds' nests are protected by law in the UK while in use, which is one reason spikes and netting are normally fitted outside the nesting season. Roosting pigeons in a car park tree do not enjoy the same protection.

The wildlife next door

Part of the irony was the location. The flats sit just above the Downs, a large public park, and a short walk from the Avon Gorge, a Site of Special Scientific Interest famous for rare plants such as the Bristol whitebeam, which grows nowhere else. The gorge's cliffs are also a nesting site for peregrine falcons. Peregrines vanished from the gorge after the 1930s, when the species became rare in Britain, and returned in 1990; they have bred there in most years since. Their favourite prey includes pigeons, so the neighbourhood already has its own natural pest control, if not one that guarantees a clean windscreen.

Pigeons themselves are descendants of rock doves that nested on sea cliffs, which is why tall buildings and dense trees suit them so well. They thrive in cities largely because people drop food.

Spikes, shared space and better alternatives

The Bristol trees became a talking point in debates about "hostile architecture", the design of public space to keep away unwanted users, from spiked ledges for pigeons to benches built so no one can lie on them. Writing in Atlas Obscura days after the photo spread, Cara Giaimo noted that designers see a common principle behind both.

For anyone facing a similar problem, a few practical lessons stand out:

• Remove the attraction. Pigeons gather where food is easy. Clearing litter, securing bins and asking neighbours not to feed them reduces numbers more than any deterrent.
• Change the layout. Where possible, park away from roosting branches, or cover just the few spaces directly beneath them.
• Use the lightest effective measure. If deterrents are needed, target the specific perches birds use, avoid the nesting season, and choose fittings that can be removed without harming the tree.
• Talk first. Much of the anger in Clifton came from a photograph without explanation. Telling neighbours what is being done and why can defuse a row before it starts.

Readers interested in how nature reclaims built places may also like our gallery on nature reclaiming built spaces in photographs.

Sources: Bristol24/7, 19 December 2017; Bristol24/7, 21 December 2017: Why we installed anti-bird spikes on Clifton trees; ScienceAlert, December 2017; Atlas Obscura, 22 December 2017; Wikipedia: Avon Gorge. Photo: Anna Francis, via Jennifer Garrett on Twitter. Story first shared via Mystical Raven.