Nesting birds really don’t want us around. They go about their business gathering nesting supplies without our assistance but we can help them anyway.
When I had my two large northern breed dogs, a Samoyed and an Akita, I would save all their fluffy white hair for the birds each spring. I would just drop it on the lawn and birds would shower the garden carrying off as much as they could and still fly. They took it as fast as I put it out there. It was like lining a palace it was so soft. I have a pet cockatoo also that molts in spring, so I gather his down feathers when I clean his cage. The outdoor birds like that too.
Another thing to consider is holding off trimming the hedges. A few birds use them for nesting. Now I have a robin family in my Arborvitae.
Helping birds replace calcium used in making eggs, I put out crumbled egg shells for them. Squirrels also need calcium and will benefit.
Keep fields and meadows long and grassy all summer long. Field sparrows, prairie warblers, meadowlark, bobolinks, and other birds will be able to nest in peace. I was just at such a place today. I saw so many bobolink and bluebird pairs. Such a relaxing day.