Trees have had spikes fitted to stop birds pooing on cars in Oxford.
Campaigners have reacted with fury at the move - which first happened a year ago but they are yet to be removed.
Activist Hugh Warwick told the BBC : "Well the initial reaction was 'Oh for goodness sake, this is ridiculous."
He said the spikes were "preventing birds from using their very natural habitat".
Hugh shared a picture of the spiked tree on Facebook in the hope of raising awareness about the issue.
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He wrote: "How much do we hate wildlife that we want to keep it from interfering with our lives so very much?
"We need connection to nature to stay well - physiologically and psychologically - but we actively try and separate ourselves from nature.
"But above that, we need, like all toddlers are taught, to learn to share."
Several enraged social media users have spoken out about their anger.
Claire Kemmitt wrote: "I would publicly name and shame them".
Mark Robinson added: "How ridiculous, and actually quite sad!"
And Charles Howie said simply: "Absolutely ghastly."
The tree owner has not publicly commented.
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The campaigner who spotted the fittings conceded that they can sometimes be useful in the right context.
Hugh said: "Spikes are a really valuable tool.
"If you look around Oxford there are many colleges, many buildings which use spikes to prevent the birds landing there, roosting there and their droppings corroding the buildings.
"But the presence of spikes on a tree is something which I feel is moving into a different league.
"It's preventing birds from using their very natural habitat."
