I have had similar problems with identifying hawks, so I did some reading on this subject. It gets complicated. Hawks are considered by some to be sub-divided into races, which means that there are visible differences between individuals that belong to the same species, and can therefore reproduce. You are correct, juveniles and adults have different plumage.

Most hawks do not molt until the summer and fall. So last years' baby will be brown and mottled till it molts in adult feathers.

Here's the hawk in our much-hated Norway maple:

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My guess would be an young Coopers Hawk. Thats a nice "birds eye" view you have. Although few other birds would get that view without becoming his lunch.

Beautiful bird It looks like a red tail to me but if it's smaller maybe a cooper? Why don't you post the picture at the raptor forum someone will id it there. Sarah

Here is a link that might be useful: raptor forum

If it is slightly smaller than a redtail could it be a red-shouldered or broad winged hawk? The red shouldereds are fairly close size-wise to a redtail. I am only guessing here, but from the pics the tail looks like it might be a bit too short to be a cooper's. Also, I don't know about juvies but adult redtails don't have the barring on the tail so perhaps that helps narrow the options a bit. Have you heard any vocalizations?
We have red shouldered hawks like crazy here in the lowlands and this time of year they are really talkative.

Well, went back and had a second look at the photos and now I'm not really sure at all that it isn't a Cooper's. Hmmm. Now I'm really curious. Can you get any other pics at different angles?
Here's another question: what have you seen it doing?

Elaine: Definitely post those over at the raptor or bird forum. There are a few people over there that are very good at id-ing raptors. I think Elly is good at it too though. Maybe she'll come back here.

This is tough because we are looking up at it. But I don't think it's a Coop because the wing tips reach the tail, and in Coops the tail is way longer than the wing tips.

How big was it, compared to a crow?

If that is a picture of the hawk, then it is without a doubt, 100% a coopers hawk, the barring on the chest is far too light to be a sharpie, and the head appears large.
Nathan

The wings of an accipiter should be shorter on the back instead of lining up with the wings.

Here is a picture of a Cooper's hawk in hand to show you what I mean:

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See how the wings would just go not eve halfway down the tail if this bird had her wings folded? The bird in Elaine's picture has longer wings and a shorter tail.

I think it is difficult to judge head shape here; maybe I'm misinterpreting the picture. But Cooper's hawks' wings just aren't that long.

Nathan, you're slipping. Look at that tail. This looks very much like the imm. Red-shouldered Hawks we've been playing the ID game with lately.

-O-

Here's the continued thread on the raptor forum.

-O-

Here is a link that might be useful: raptor forum thread

Looking forward to that raptor page help you might get Elaine... Because I wouldn't be surprised this would be - yet again a new species thrown in here for good measure! - an immature, light phase, SWAINSON's hawk! Way back out East from its normal range! But there >hasThe one detail that leads me to this species, relying solely on the Peterson guide, is the absence of dark band on the TIP of the tail, which your excellent photos seem to reveal. In the book I see no other non-accipiter hawk (wings do seem too long for an accipiter) with barred chest and banded tail that shows this characteristic. MAXIMUM dimensions are also quite smaller than a Red-tail's.
This would be a great bird finding for you to report to the specialists!

It is, I think, an immature Broad-winged hawk.

Again, have you heard any vocalizations or noticed any specific behavior that might help add to the description?

Almost has to be broad-winged or red-shouldered. As Elly points out, the wings are too long for an accipiter; otherwise I would call it a sharp-shin. According to Kaufmann, the last band on the tail should be thicker if BWHA, and I don't see that on this bird. Also, how many broad-wings are in NJ in the winter? (That's an honest question.) Swainson's would be fun, but it should have that ruddy turnstone-like collar, shouldn't it? Overall I favor red-shouldered.

This has been fascinating. Here's the tally, from this thread and the one on the raptor forum:

Red-shouldered: 4 votes
Cooper's: 3
Broad wing: 2
Swainson: 1

Sure wish we could ask the hawk!

Pictures can be deceiving. Was this bird crow-size or larger than?

Whatever he is, he's hanging around. As a result, we are seeing much less rabbit damage to our shrubs this winter than in past years. Go hawk!

I'm fairly certain we saw a red-shouldered in Bucks County, PA this weekend, so maybe there are some either back early or hanging around (looks like southern PA and NJ are right on the northern border of their winter range). Couldn't get a definite ID, but I'm pretty sure.

I believe Broad-wings and Red-shouldereds move north in February. They may begin moving in January. By March, many are already re-establishing pair bonds and reinforcing territory.