I saw something similar yesterday afternoon as a charger in San Diego. There was a large group of about 20 birds with $5 bounties that all said 0% battery in my app. I thought they were likely not there because of the density, but tried anyway. When I arrived I saw about 10 birds in a row on either side of the street and they were placed perfectly very similar to that pic. I walked over and attempted to scan one and it let me capture it. I continued down the line and was able to capture 14 birds in one go. I would’ve gotten more but my that’s the max for my car. Also, none of the batteries were dead, they were all around 70-80%. And the birds all looked almost brand new. Still had the plastic covers on the screen display and they were very clean.
Still not sure what happened, but I cleaned up. Took me 30 minutes to drive there ,capture them, and take them back home to charge. I finally got to sleep the night without waking up to plug in birds.