OP, have a read of this:
"Here is the guidance from our accrediting body The Arboricultural Association which you can also find on their website.
‘The ‘Bird Nesting Season’ is officially from February until August and it is recommended that vegetation works (tree or hedge cutting) or site clearance should be done outside of the nesting season. However, in reality the nesting period may start before this and extend beyond it, in some cases. The busiest time for nesting birds is from 1st March until 31st July and of course varies according to species, etc.
As contractors we must aim to avoid impact to nesting birds and infringement of the Wildlife and Countryside Act 1981 and breaching the European Habitats Directive 1992/Nesting Birds Directive.
When tree or vegetation clearance work has to be undertaken during the nesting season, a pre-works survey needs to be carried out by a suitably competent person. As a general rule, it should be assumed that birds will be nesting in trees, and as contractors it is down to us to assess, record and confirm that any works carried out in the management of trees and other vegetation has not disturbed actively nesting birds.
Ground vegetation, and therefore ground nesting birds, can often be overlooked by tree workers so additional care and controls should be taken when access and egress to the work site may also cause disturbance or damage to a nesting site. This is also true for retained trees on site as the removal of adjacent trees or remedial works on a tree may lead to the established nest being abandoned, exposed to the elements or predation."
www.teigntrees.co.uk/blog/2019/tree-work-during-nesting-season-the-facts
Even if a tree doesn't have a nest in it, it can still provide shade, shelter and a food source for garden birds. Chopping down a tree at this time of year is an awful thing to do. I think I might have been tempted to report a neighbour who'd done this, and I'm usually the last to grass.