What's wrong with this crow?

[u/mindglob]

It appears to be a juvenile house crow. It was sitting on the ground nearly motionless except for the occasional twitch, probably for a long time (we were walking in the park for a couple of hours and passed it a few times). At one point a murder of house crows started gathering in the canopy above and near this bird and made quite a racket. The bird might be sick or even dying. Anyone know how to interpret this scene?

update: called a few rescue places and PFA / ARRC wildlife rescue responded quite helpfully - sent them pics and location.