Best time to have trees topped?

[SofaToad]

We have some very tall trees at the end of the garden, if they come down in a storm they would certainly hit the house.

We also have birds nesting in them, including parakeets and a pair of wood pigeons which I enjoy watching, blackbirds, and various others.

I don't want to remove their home, so will be looking for a bird friendly tree surgeon, what is the best time to get them done to be bird friendly?

I think the best time is February/March, before the sap starts to rise and the birds start thinking about nest sites.

When they have no leaves. The birds will come back if you maintain a good shape and this is better done in the winter without leaves.

Thank you, I am worried about them losing their nests, not familiar with nesting habits. One of them is a Leylandii which is the popular one and obviously can't see what is in it, the other one does lose it's leaves but I don't know what it is.

So November until about February is good?