I found out these grackles weren't just sitting on the trash can to get some sun and have a chat. They were waiting for the other grackles already inside the trash can to leave so they could have lunch, too.
This grackle was apparently looking for nesting material or maybe just trying to clean things up a bit (I lean toward the former) and ended up getting string wrapped around its head.
Trashy though they may be at times, even grackles enjoy some summertime watermelon. The fact it has the consistency of jelly is apparently not a deterrent.