Can a red shouldered hawk kill a mallard duck?

[trebkiwi]

Vultures are good. They're carrion birds they clean up all the unsightly stuff on the side of the road. They will almost never kill a live animal, it's just not what they do when there's 80lbs of deer meat around the corner...

I do love some of nature's garbagemen though , these guys included. They're just very intimidating looking, especially up close. As long as they don't take my ducks for a ride, they're welcome on my roof.

 

[trebkiwi]

I'd never think that I'd have to worry about any other predators other than raccoons, however today I saw more than five hawks circling my house. Upon a quick Google search, I found out that they were red shoulders hawks. My ducks didn't seem to care but my ducklings were terrified.
We also have a barred owl or two that come around at night and sometimes I hear them in the day. I only free range my ducks when I'm out in the backyard. And sometimes if they see crows they'll crouch down real low.

Should I be concerned about either of the two birds being able to kill/hurt my ducks?

EDIT:
Today I was out with my ducks today and what do you know? This big guy lands on my neighbors roof. I saw him in the sky and was hoping he'd land somewhere so I'd get to a look at him. This time though, he didn't have his friends. The dogs were going crazy! My ducks... Not so much. I've also read that blue jays (which we have a ton of) imitate red shouldered hawk calls, which would explain why I heard multiple of them. But I'd assume there had to be at least one in the area.