2/28/09 Nest Monitoring

As we headed down the trail from the parking area toward the prairie falcon nest area around 10 am , we could see a large falcon on top of the rock outcropping where last year’s eyrie was.  She flew and by the time we walked out there, we saw nothing.  So we set up our scopes and scanned the outcroppings and trees, and waited.

At 11:11 we saw the male in a hole on the left slope of the backside of the eyrie.  We hadn’t seen him fly in.  He had a very full crop so we thought maybe he’d been deeper in the hole eating.

We heard wailing at 11:24.  The male dropped down into the hole out of sight.  A minute late, wailing, he came out, flew straight down.

The falcon appeared from below him and flew to the top of a rock to the right of the eyrie.  He followed, landed on her and they copulated.  She stayed on the rock and he flew somewhere behind it, out of sight.  We could hear both of them wailing periodically.

We left at noon and headed out to the peregrine eyrie.

We were walking down the trail and saw a peregrine flying from the ridge on the opposite side of the canyon toward the Climbing Rock area.  We lost sight of it as it flew low over the trees.

We set up in the meadow below the nest cave and scanned everything, seeing and hearing nothing.

At 3:45 we heard wailing from behind us at the top of the ridge in the trees.  At 3:55, again we heard wailing and from behind us the falcon came flying in.  From the north we saw the tiercel also flying in.  He landed in the nest cave and she landed on top of the nest rock.

At 4:14, he flew out of the cave, circled and landed on the falcon, copulating, with a lot of e-chupping from both.  He flew back to the nest cave.  They continued  to wail and e-chup.  At 4:20, the falcon flew from the rock top to the area behind Castle Rock.  A minute later, she had circled around and was flying in from the south.  She landed out of our sight but we could hear her.

Tiercel approaches falcon

Tiercel approaches falcon


As we walked out, we heard a great horned owl calling from the trees on the ridge opposite the nest cave.  Hope it has plenty to eat and leaves the eyases alone.

There is some new graffiti on the rocks in the area of Climbing Rock, but not in the area of the nest cave.  Inside one of the caves in Pyramid Rock, there is some new graffiti, carved into the rock.

It looks like both pairs are well on their way to a nesting season.


2/10/09 Nest Site

I went out to the peregrine nest site today. Claire was here from the UK  so I took her out to see the canyon.

We got there around 9:30.  It was cold when we got there but we warmed up walking in.   The canyon was in sun and it was comfortable enough that I took off my coat to sit on.  (I didn’t have Cheryl along so didn’t have her curtains to sit on–I’m just not as organized as Cheryl).

Ms X was in the smaller hole above and to the right of the largest cave.  At 9:50, the tiercel flew in with some food for her.  They both flew off and sailed around for a short time.  She seems to have her own favorite perches, different from the past falcon’s old favorites and different from the tiercel’s.  She went to the front face of Pyramid Rock, flew to an area to the left of the cliff face.  We saw a turkey vulture jump as she sailed by wailing.

For a long time I could hear her but couldn’t see her.  Then she flew past the TV again, back again, and I found her in a small hole in a rock to the left of the outcrop where the horizontal crack is.  She flew up to the left edge of that rock, took the bird that the tiercel had brought for her and plucked and ate it.

The tiercel was sitting in the spot the falcon had been in when we first got there.

Ms X finished eating and flew to the nest cave.  From there, she flew out of sight between Pyramid and the nest cave.  We could hear her.  They both flew around, landing in the nest cave, then out again and off to the area behind the ridge.

Claire and I went for a walk down the trail.  We saw them flying around once while we were walking.  We turned back, passing the nest area, not seeing the peregrines.  We said goodbye to them and left.

We saw three redtails in the area between the swimming pool and the parking lot, an acorn woodpecker near the rest room.  The usual turkey vultures were around.  No coyotes today.

We took the North Road into the Park and stopped many times to look at the 30 or so redtails.  We saw a beautiful chocolate colored dark morph.  There was a pair doing some talon-linked sky dancing.

We left the park on the South Road.  As we were making our way down to the freeway, a red shoulder flew out of the trees and landed on a traffic sign just at the edge of the road in front of us.  I pulled as far off the road as I could, put on my flashers and we sat and watched the redshoulder.  Beautiful bird and only about 15 feet in front of the car.

Redshouldered Hawk

Redshouldered Hawk

We got home after 3 pm.

06-03-08 Fledging!

I went to the nest site the back way.

When I got there, the adult female was on top of the nest cave. One fledgling was on the top of Pyramid Rock. I’d been hearing baby wailing for the last 1/4 mile of my walk there, so found it easily. The other was nowhere to be seen or heard.

The adult male brought food to the one, put both feet down on the rock top, dropped food and immediately stepped off. The food fell and the baby wailed…. for five minutes.

The falcon left the nest rock and headed out into the canyon and came back a minute later and gave the fledgling a bird. He plucked it and ate it. And after he finished, the other fledgling landed on the side of Pyramid and after a rest, scrambled to the top and ate.

They sat together, one lay down, they ‘beaked’ each other, one poked and plucked at the others feathers. Then after an hour, the same fledgling who flew earlier stepped off the side and flew to a rock directly in front of the nest cave.

Another bird was delivered to Pyramid, and the fledgling flew back to share again. The same fledgling later flew to the same rock in front of the nest cave, and back again.

He later flew to the top of the nest cave rock, where he was when I left.

So, one flying well. One seems to have just fledged and is sitting and waiting for awhile to try again. I’m guessing one fledged 6/2/08 and one this morning 6/3/08.  Two males.

Both adults are around.

Today is day 39-40 since hatch.

The Falon eating

Site Monitoring 5-28-08

I went up the back side of the cliff nest scrape with my bird blind.
Both falcon and tiercel were out when I got there so I waited on the
ridge trail until they left (took some photos while I waited), then
when they went off somewhere, I moved into place where I could see the
entrance to the scrape.  The eyases came out.  They are getting very
brown.   One eyas started screaming for food and the falcon brought
something.  She barely got to the porch when one came out and
grabbed it and ran.  The falcon flew.  I hope the one shared it with
the other, but possibly the other had already eaten.  We’ve seen that several times that they alternate eating.

Then the falcon went to Sentinel and sat.  I could hear the tiercel
cakking somewhere near the nest scrape when I left.

Site Monitoring 5/24/08

Last week we had a temperature of 98 with hot sun, hot breezes, thin
shade. Today it was 45-50, cold wind, overcast skies, sprinkles.
Hard to believe it was the same place a week later.

Cheryl and I arrived on the hilltop at 9:21, having hiked in to the hilltop opposite the cliff site.

One eyas was standing on some prey, eating. Both falcon and tiercel
were on Sentinel Rock.

A few minutes later, the second eyas moved from the left rear of the
cave to the right side. The tiercel flew off.

At 9:30 the falcon flew into the scrape and ate the bird the eyas had
been eating. We heard wailing. At 9:43, she flew to Sentinel and at
10:03 she flew north wailing.

Both eyases are up briefly, then they lie down side by side. We are
thinking one male and one female. But at 1/3 mile away, we are still
not certain.

10:20 we hear cakking in front of the nest rock and one peregrine
flies past. We see the falcon on Bindi Rock.

She is looking around. We see a man in a blue jacket, red packpack ,
grey hair, and binoculars on the trail directly behind Bindi Rock. He
and Cheryl look through their binos at each other. He moves north,
stopping periodically to look down through his binoculars. On
Thursday someone posted to a birding listserve seeing two downy
peregrine chicks at this sits and described perfectly how to find
them, despite the policy of Birding Ethics (from
the American Birding Association) against the revealing of nests of
rare birds. Based on the way he is looking for something specific, we
think this is the person who posted this site or someone who read
about it and is looking for the scrape. It is not a random birder.

At 10:27, the falcon flies to Sentinel and two minutes later the same
man is now moving back along the trail to the south, again stopping
periodically to scan with his binoculars. We don’t think he’s found
the peregrines because he doesn’t stop and look for long. This even
though the falcon is sitting on a rock about 200 feet in front of him.
He continues to move south down the trail and out of sight.

At 11:02 we hear cakking. The falcon is alert and both eyases are
up, preening.

At 11:32 we find the tiercel on South Rock. Ten minutes later he
flies toward the nest scrape and stoops above the climbing rock. The falcon
remains on Sentinel.

At 12:28 the falcon flies to South Rock and sits just above where the
tiercel had been sitting earlier.
12:31 one eyas is on the porch flapping. At 12:46 the second eyas
joins the first. Both are flapping their wings. One eyas stands on
the edge and looks down.

At 12:54 the falcon flapped and jumped and disappeared behind South
Rock. A minute later she is on Sentinel wailing. The eyases are now
in the rear of the cave also wailing.

12:56 Both eyases are again on the porch wailing. A swift flies into
its nest in the ceiling of the cave and one eyas watches it come and
go. As it’s watching, it trips on the edge of the porch. It recovers
its balance.

1:07 one eyas is wailing and walks to the far right edge of the porch,
still wailing.

1:13 the falcon flies, e-chups and the tiercel flies in from the north
and there is a side-by-side food exchange. The falcon goes into the
scrape and the eyases run to the food. She feeds them.

At 1:19 she leaves and returns to Sentinel. The eyases are on the
porch and seem to be watching her. They do some head bobbing. One
is particularly good at preening its tail feathers, pulling and
separating feathers.

1:45 both eyases are wailing, sitting together on the porch. We get a
good look at them. One is larger and lighter in color. The smaller
one is darker on the breast. Both have some brown on the sides of
their breast. We’ve decided it’s one male and one female.

We get distracted for awhile. Cheryl starts to lean back on her
backpack and sees a pair of brown ears coming up the hill below us.
She first thinks mountain lion and then realizes it’s a young coyote.
He sees us and stops. He sits and watches us and we watch him. He
sticks his muzzle in the air and sniffs, then turns and sniffs again,
turns to the other side and sniffs. He opens his mouth and tastes the
air, then sniffs again. He starts barking at us. I pulled out my
phone and started to record him and his barking. This goes on for
several minutes and we get up to discourage him. He turns around and
starts to the right and downhill. Just as he disappears, we hear him
bark again. We walk down hill toward him and he moves to the right
away from us. He’s going to be trouble some day. If we see him
again, we will be more aggressive to scare him

2:28 the falcon flies to South Rock, this time sitting on top.

At 2:30 two men are climbing up and going behind the nest cave. The
falcon leaves South Rock at 2:42 and stoops behind the nest rock.

At 2:50 both eyases are up and on the porch. We see 4 people heading
for the rock and at 3:04 the tiercel is stooping and cakking. He
attacks again at 3:13 and stoops twice. And again two minutes later.
At 3:17 a girl is climbing through the hole in the rock to the left of
the nest cave. We hear e-chups and wailing.

Two of the people have left and are on another rock to the north. We
hear the others talking somewhere above the climbing rock.

At 3:38 the falcon stoops on a turkey vulture and soars above the nest
cave cakking.

We pack up and leave.

As we are approaching Coyote Alley, we see a very large dark bird take
off from the ground about 100 feet in front of us, along the trail.
It’s a golden eagle. If we’d been a little more alert we might have
been able to see it and stop and get a better look to see if it was
eating. It flies and we follow it with our binoculars. In the air
nearby is a pair of adult redtails, talons down. We watch for a
talon-linked skydance but they move behind some trees on the ridge.
We continue on down the hill and out.

The eyases are 29-30 days old.

05-17-08 Site Monitoring

Cheryl and I planned for an earlier start and earlier end to the day so we wouldn’t be out in the heat in the middle of the day, since expected temperatures were high.

We went in via the route to the hill on the side of the canyon opposite the cliff site.  The eyases were being fed.  They have black around their wing feathers and black around the eyes.  They seem to be about the same size.  Just smaller than the female currently.  My guess is they are both females but they still have some growing to do and this was the only time this day that we saw them together with an adult to compare sizes.

8:59 we hear cakking and the female leaves.  We hear lots of cakking—5 minutes of it, all coming from the area of the nest cave.  We can’t see either adult or any other bird or any other kind of intruder, but we believe the noise and are certain something is around.

The eyases continue to pull at something on the ground in front of them.  They then move out of our sight to the rear of the cave.

At 9:21 the falcon is on Sentinel Rock and a few minutes later she is flying overhead after some TV’s.

At 9:40 she is on a rock on top of the nest cave.  At 9:55 she moves back to Sentinel.

10:18 she flies from Sentinel across the rock face of the nest area, then flies up and to the south.  Five minutes later we again hear cakking in the area of the cave but we again don’t see anything.

10:27  Both peregrines fly fron the east over the ridge behind the cave and both go into the cave.  The female stays and the male leaves.  We hear wailing and e-chups and the eyases are bing fed.  The male heads south and we lose sight of him as he goes past Little Half Dome.

10:30 cakking to the south and the falcon leaves the cave

At 10:49 she returns with food carried in her beak and hops to the back of the cave and again feeds the eyases.

She doesn’t feed them for very long and at 10:52 she take s the bird and leaves.

She is flying with the bird aroudn the canyon and is joined by the male.  They fly togethers, she carrying prey in her talons.  They spend several minutes flying around each other and we wath the aerial ballet.

At 10:56 she again heads back to the scrape and continues to feed the eyases.

And we were expecting with the heat that they would be mostly sitting!

11:08 she leaves.   One eyas toddles from the back of the cave to the old egg scrape area and lays down

11:46 a peregrine is flying over the climbing rock area riding the thermals.  At 11:48 the male flies in from the SE carrying food.  They sail together with wails and e-chups and we watch a food exchange.

The falcon flies around with the food and at 11:53 she again goes into the scrape and feeds the eyas in the back.  One is still asleep i the egg area in the center and isn’t fed.

Who is watching whom?

At 11:56 she leaves.  We hear a lot of wailing and e-chups to the north.  The raves are ‘gronking’ also.

12:02  She is still wailing.  The eyas is waling around in the srape.

12:56 again wailing from the same area in the north.

12:02 the eyas int he front of the scrape is again up.

1:43 the falcon flies from north to south.  The yeas int he front is up and toddling and stretching its’ wings.  It goes to the back of the scrape where the other eyas is.

We pack up at 2:05 and toddle down the hill to the car.  When we get through the Caldecott Tunnel and see Oakland, we see fog coming in through the Golden Gate and we both cheer.  I checked the temperature in the area and find it is 98 degrees.

05-10-08 Site Monitoring

The falcon was sitting in her usual spot on Sentinel Rock when we got
to the top of the hill opposite the nest cave at 9:20.

We could see one eyas in the scrape.

After the falcon did a touch and go landing on the porch, both eyases
were up and stretching.

At 10:52 the falcon is joined by the male who flies by her around
Sentinel several times.

We see our first feeding of the day at 10:55, ending at 11:04

Throughout the morning, the falcon is mostly sitting on Sentinel and
the tiercel does an occasional fly by. Cheryl sees an in-air food
delivery, falcon talons-up under the male at 12:24 and we watch

another feeding.

At 2:18, the tiercel delivers some food to a crack to the right of the
large central cave. The falcon flies down to the area but doesn’t go
into the crack. A RTHA is chased away by the falcon.

At 2:54 4 climbers go from the northern area to behind the nest
rock. We’ve never seen this particular approach to the area. They
don’t go to the top, but to an area just to the left of the cave. At
3:05 one young man appears to the left of the cave, less than 20 feet
from the opening

The tiercel has been sitting on a rock above and to the south of
Sentinel (we’ve named it Bindi Rock for the round rock inclusion
centered in what looks like the forehead of a face)

At 3:10 the tiercel dive bombs the climber who yells and disappears
behind the rock. The tiercel dive bombs 4 times and we hear shouting
each time. The climbers quickly climb down. Several times we hear
things like “he dove on me” Yes, he did.

At 3:18, the falcon is back on Sentinel and the tiercel is on Bindi.

Usually after someone is climbing in the area it takes the pair about
1/2 hour to return to the nest scrape, but this seems to have been a
bigger intrusion and we decide to wait until they have gotten
comfortable and the eyases have been fed.

At 3:48 the falcon flies and hits an RTHA north of the rock outcrop. She
returns at 3:50 and lands on the top of the nest cave rock.

At 3:58 she returns to Sentinel and the tiercel is still on Bindi.

4:07 the tiercel flies into the scrape and goes to the eyases.

4:10 the falcon flies to a hole in the side of the rock adjacent to
the trail to the top of the climbing rock. She disappears completely inside
and then sits for a little while with her head sticking out. She
flies around in front of the rock face and then disappears.

4:14 the tiercel sits on the porch and the eyases are standing in the scrape.

4:30 the falcon returns to Sentinel with prey. She lands on the far
south edge of Sentinel and drags a HUGE pigeon (missing it’s head, but
not plucked) to the top of Sentinel. She is having trouble. We tell
her to eat some before she tries to carry it up to the scrape (until
we think with our little bird brains that the weight will be
transferred from the pigeon to the falcon and won’t make the job any

She rests until 4:51 when she struggles with it to the cave and feed the eyases.

We leave.