Just a word of warning to you all:
Last week, we were experiencing predation problems with our small mixed flock of broilers and Silkie chicks. Broilers were 7 weeks old, Silkies about 3 months. They were free-range only during the day and put up at dusk.
I found a dead Silkie and then a dead broiler the next day. Then, last week, we lost SEVEN babies in a single day while we were at work. Heads were missing and it appeared that hearts were torn out and livers lacerated fron a wound created under the wing area. My first thought was raccoons, because we have experienced such loss before in a similar manner, although the coons tend to take the crop, whereas here the crop was still intact. When I discovered 6 dead chicks, we were actually on our way to the store in town. I picked up the bodies and then we left. We came home about 45 minutes later, and yet another chick was freshly killed. So here was some predator attacking during the day (this was about 6:30-7pm)
So, I set up a game cam, baiting it with some eggs and the chick's bodies. According to the cam, within minutes the bait area was covered in crows, so although crows were not an initial suspect, I investigated. I did a search online (a few forums do state that 'crows will NOT eat heads of chicks, etc.) and found a farm blog stating that yes, they certainly will and do eat chicks: heads and hearts. My husband had said that he had seen a large group (murder) of crows flying around and lurking around the orchard in the past week. It was all the evidence that I needed.
Obviously, I immediately moved them to a covered pen. No problems since (of course). I did move another group of silkie chicks to the orchard, though they are in a chicken tractor. I have noticed that all day today, the crows are close by and calling to each other.
Now, I do like the crows. They DO keep away hawks and when they 'caw', the adult chickens go scattering for shelter. I even throw old eggs out just for the crows. Still, be aware that if your group of crows ever figure out how to kill baby chicks that they will take advantage of that food source. Also, I have another older group of Silkie/SGs, with some 4 and 5 month olds alongside the adults (I have 2 roos protecting that pen). No problems YET there.