Yes, birds are looking for insects, webworms and caterpillars in the soil.
They poke, pick up a little bit of turf and toss it aside.
Crows, Starlings and even Turkeys in some regions will do this.
Do some poking around yourself, if you are seeing webworms you will want to treat them.
You can take 1 gallon of water and mix 1/2 cup of dishwashing soap.
Take a 1 foot square area and pour on the mixture, wait 5 to 10 minutes. If you are seeing 5-10 webworms in this area, you should treat the lawn.