What now?
If the sparrows roost in the coop, a nighttime attack with flashlight and BB gun would be effective.
OMG! Did you ever trigger an old memory. When I was about 6 years old (1944), I used to spend a lot of time at my Grand Father's farm. There were two of my older uncles still at home, and they used to take me out to the chicken house...get this...at night, with a flashlight and a BB gun. The sparrow population in the chicken house was pretty much kept under control.