- [Narrator] For several years, Air Force veteran Len Hershey has observed a pair of red-tailed hawks perching in his eucalyptus trees.

But on Independence Day, Len found the male bird on the ground injured.

- My first instinct was, gosh, I hope I can get ahold of someone because we do have foxes and other animals out here, and if that bird can't fly, it could be in danger.

So at 1:30 on the 4th of July, I called the Bird Rescue Center, and lo and behold, a woman answered the phone, and about a half an hour later, Brad Marsh came out and rescued the bird.

- Its mate was in a tree above me the whole time that we were getting the bird.

This pair's been there for at least six or seven years in the same tree, and they did not have a nest this year, but he's a pretty old guy, 15, so he probably wanted to take a break.

But he's a beautiful bird and we wanna get him back out there.

- [Narrator] Just weeks after being diagnosed with spinal shock trauma, probably caused by impact from a car, the red-tailed hawk is starting to fly again.

Creancing, a technique borrowed from falconry traditions, is part of the Bird Rescue Center's raptor rehabilitation program.

The red-tailed hawk is tethered to a creance line for short test flights.

Specialists carefully observe each flight in order to assess the bird's recovery.

For four decades, the Bird Rescue Center of Sonoma County has specialized in the rescue, treatment, and release of injured, orphaned, and ill wild birds.

- This is where all new patients come when they are first admitted to the Bird Rescue Center, and this is also where we do all of our weekly raptor rechecks.

We do raptor rechecks on average about three times a week.

- [Narrator] This young red-shouldered hawk was also hit by a car.

- To be able to see under their feathers since their feathers are waterproof, we'll use rubbing alcohol.

And it just helps actually dampen the feathers so that we can see down to the skin line.

And luckily it's nice and hot today, so when it evaporates, he shouldn't be too upset.

Looking down his chest though, you can see there's clearly some trauma.

This is normal tissue color up here, and just like in humans, this heavy dark, this heavy bruising on this little guy.

And the reason I'm blowing on his feathers is raptors and songbirds, their feathers grow on feather tracks.

They're not fully feathered like you would think of a dog having fully fur, I guess.

So you can actually blow the feathers apart on their naked areas and that way, we're able to see their body without alcoholing them.

Feeling both legs again to feel for fractures as well as range of motion.

Make sure all the joints are in order.

You can also palpate swelling.

Now I see he's got a little bit of road rash on his feet, but otherwise he's got beautiful little red-shoulder feet.

So his wings are both in pretty good working order.

Both feel good, has a good range of motion out and over his back.

- [Narrator] This fledgling western screech owl fell from his nest cavity and was injured by a cat.

The hospital treats some 3,000 birds a year which are rescued from all over Northern California.

- So with all birds, they should be able to hyper-extend at their wrists, so this would be a full extension.

A healthy wing should be able to do this.

Whoop, I can also go up over their back like that.

(owl screams) This is a young acorn woodpecker.

He just came in from Willits, California, so he just had a long drive down here.

So we don't want him to get too stressed out, but we're gonna give just a quick intake exam and just see how things are doing, and then we'll give him a break and probably give him a slightly more thorough exam in a half hour or so.

- [Narrator] This baby house finch was brought to the Bird Rescue Center after falling from its nest.

Once fed, the bird will be returned to its incubator.

(bird softly chirping) The Bird Rescue Center is currently fundraising to build a new facility to better accommodate the diverse array of birds it cares for and treats.

(triumphant music) To speed the recovery and release process, Brad performs a procedure called imping.

- [Brad] This is not at all a new procedure.

It goes back to falconry traditions that go back thousands of years.

- [Narrator] Quick drying epoxy is applied to a bamboo dowel that is attached to the end of the donor feather, which is then attached to the bird.

- [Brad] We have now used this falconry tradition in rehab and taken it, in some ways, a step further because it's almost like we've rebuilt a half a bird at times, it seems like it, with as many feathers as we put into a bird.

It serves us well, getting the birds out, and the birds very well, getting them out of here much quicker and not having the stress of being in captivity.

- [Narrator] Damaged or missing feathers are replaced with donor feathers that will help this young osprey fly.

- Yeah, you need it to be lined up when the tail is fanned out as well as when the tail is relaxed, and the fanning is usually the more difficult part, 'cause generally when you're imping, you're kind of doing in this realm, but when they're taking flight, you need to be able to open that tail up and have it be solid on all planes.

Which I think you nailed it, so.

- [Narrator] These transplanted feathers will fall out when the bird molts and new feathers grow in.

(triumphant music) A month after its July 4th injury, the red-tailed hawk has completed rehab and is ready for release and reunion with his mate.

- This is what we're here for, this is what we do, is to get these birds back into the wild.

So these are the days that I love.

These are the reasons I get up and go to work every day.

This is where he was found, this is where we know his mate is, so this is a territory he should be very familiar with.

But we'll make sure to give him the time to readjust before we just take the hood off and let him go.