Hilchos Shechita 13:12

If one cut part of the mother bird’s esophagus before taking her, he must send her away; if he didn’t do so, he’s not liable to the penalty of lashes.

Hilchos Shechita 13:13

If the mother bird is hovering with her wings touching the nest, one must send her away; if her wings are not touching the nest, he need not do so. If a cloth or some feathers are between her wings and the nest, one must send her away but failure to do so will not make one liable to lashes.