Packham 'outraged' by Cambridge University bird netting Published duration 28 February

image caption Nets have been put on about 20 trees at a Cambridge University campus

Naturalist Chris Packham has slammed the University of Cambridge for putting "absolutely outrageous" anti-bird nets over a row of trees.

Protective netting appeared on more than 20 trees at the Whittle Laboratory on JJ Thomson Avenue in the city.

A university spokesman previously said they were added "to discourage birds from nesting" during building work.

It has since "unreservedly" apologised and said it would remove the netting that had "upset people".

Before the university's announcement, Packham has responded to pictures of the nets on Twitter, writing: "Seriously? I thought we'd been through this last year!"

"This is absolutely outrageous".

'Nets mean trouble'

The use of netting on trees, bushes and hedgerows to prevent nesting birds is not illegal - but has long come under fire from conservation groups.

Packham told the BBC: "At a time when many of our bird populations are in free fall and the majority of people are trying to conserve them, these nets are totemic symbols of the destruction or disturbance of their habitat."

If not fitted properly, he said they were "shown to be lethal".

"From my point of view... nets mean trouble, so if you put them up you can expect it to follow."

image copyright PA Media image caption Naturalist Chris Packham lashed out at the university when he saw photos of the netting

The university had previously said the affected trees "will be checked for wildlife three times a day" and a spokesman did not confirm whether the trees would be cut down.

On Thursday night climate activists from Extinction Rebellion cut down and removed a number of the nets.

image caption The university said the nets were to discourage birds nesting during building work

Martin Fowlie, of the RSPB, which is calling for new safeguards , said the decision to cover the branches is "morally dubious".

"In the middle of a climate and wildlife emergency, we cannot continue to squeeze nature into small spaces," he said.

"Depending on the size of the mesh, it is difficult to exclude birds, they'll get through the gaps looking for food."

Members of Extinction Rebellion reacted to the bird nets by describing the university as "an enemy of nature" and removing some of the netting overnight.

image copyright XR Cambridge image caption On Thursday night members of Extinction Rebellion cut some of the netting from trees

"We've freed some of the @Cambridge_Uni trees from their nets," the group tweeted.