Tuesday, August 25, 2009

A Busy Week with the Haggards

The haggards are in the midst of their summer molt, and have clearly moved to the Art Museum area. The proximity to the river shallows may have helped them cool off in the recent heatwave. One eyass still seems to be hanging out around the parent birds. It has been a couple of weeks now since we've seen more than one eyass, but it's hard to know if it's the same one we're seeing, or different ones, just one at a time.

Carolyn has been posting her sightings on the Facebook page with some great pictures, and has also emailed me, so I thought I'd compile all this material and put it here in one posting in chronological order:

Carolyn's posts:

Friday, August 21

Was near the museum between 6:30 and 8:00 am. No eyasses, but I found my haggard again this morning, sitting on that same light pole at the foot of Spring Garden St. on the ramp to the Parkway.

Then what should appear but another hawk, incoming from Eakins Oval! TWO haggards on the same street lamp! I thought I'd died and gone to heaven. I think the one on the left (in the face-on views) is dad.

He took off after a while and flew to the other side of the Parkway and landed on a pole. Eventually he took off towards the river.

Saturday, August 22

Heavy rain, and the hawks did get wet today; so did I, as I spent two hours in rainy Hawk Heaven. This morning's sightings (all in the same area near the 24th Street ramp from the Ben Franklin Parkway to Vine St. Expressway), were even better than yesterday's.

I saw mom, dad and one eyass. The eyass sat with each parent, did a bit of hunting (though didn't catch anything), squawked a bit when close to mom and dad, but was silent otherwise. The small birds never stopped tormenting the eyass. They buzzed her in five different locations, but ignored the parents.

Mom and dad sat together for a while - I think trying to figure out what to do to get their "kid" to be more self reliant!

Took some cool pictures of all the birds, even though it was gray and rainy.

Several pictures really show the difference in size between the haggards, and the eyass seems bigger than mom.

The eyass did not squawk incessantly, only when it was really near the parents, and less stridently than it used to. Based on size, I think this eyass is one of the girls (Miss Piggy?)

It's hard to tell whether the parents are hanging near this area because the eyass is still around, or whether the eyass is staying here because it is the parents' favorite place.

Here is the eyass chasing the parents. It is not very clear, but one haggard is in the left lower corner, and the other is behind the light pole. That's Junior flying in to land.

Sunday, August 23
I found mom at 6:45, hanging out on one of her favorite poles on 24th Street on the ramp to the Vine St. Expressway. I heard what I thought was a faint eyass call and discovered that our favorite sib had flown to a pole behind me while I was busy watching mom.

The eyass chased the haggard from pole to pole for a half hour before disappearing into the Parktowne Place courtyard (nearby apartment building). Mom returned to her preening.

I noticed that there is a perfect view of the nest from this area - it's just three blocks away.

Tuesday, August 25

No hawks on Monday, but today I spent two hours photographing Mom on lots of poles near the art museum this morning.

I was sitting on the rocks near where we say the eyasses and the groundhog when she flew from her pole RIGHT AT ME! She zoomed past my shoulder and trapped something against a stone retaining wall....not four feet from me!

Here she is "mantling" to protect her prey from prying eyes (mine).

Saturday, August 22, 2009

Hawks and summer heat

Here in Philadelphia we have been enduring an August heatwave with several days straight of 90 degree plus temperatures and drenching hunidity. It's been much harder to find the hawks, especially the eyasses.

Several of this blog's readers have asked me whether the heat affects the hawls and how they deal with it. Great questions -- and I asked John Blakeman to weigh in with his bottomless expertise:

"The 90-degree heat is a mere inconvenience to the birds. They don't like it any more than we do. To keep cool they either soar off high in the sky (haggards, mostly), or they sit around quietly and do some panting, evaporating a bit of moisture off their lung and air tube surfaces to cool down.

But they don't have much water to allow significant evaporative cooling, so they do something that most mammals can't do. They just turn down their body thermostat and burn less food energy. Body temperatures of red-tails (and other similar hawks) can be rather variable---not as much as poikilothermous animals ("cold-blooded," such as reptiles). But red-tail body temps only hover around 103 F or so. At night, during sleep, it can dip into the mid 90s, from some experimentation I helped with in undergraduate school.

However, I don't know how hot the body temperature can get when a red-tail does a full-out pursuit of a rabbit or other prey animal on a hot day. Actually, I don't see red-tails doing much of that on hot days. They aren't dumb.

On the other hand, the birds are not intimidated by normal winter temperatures. They are so well insultated, and have the resources to generate massive amounts of body heat if required, that the winter is a welcome time. Unless the temperatures drop below zero F or more, red-tails seem to thrive in cold weather.

I see this when hunting my red-tails. In warm September, the birds are rather lackluster in pursuing fleeing rabbits. But with a bit of autumnal chill in October, their hunting attitudes change altogether. Cool and cold are preferred over warm and hot.

But the birds live from the low Arctic down through much of desert Mexico. They can handle it all."

--John Blakeman

Thursday, August 20, 2009

Thursday is bath day!

Yesterday was a bittersweet morning of hawk watching as once again, there were no eyasses to be seen. I last saw an eyass - think it was Portico - last Friday up at the Art Museum (see the previous blog post for pics), and Carolyn saw a single one last Tuesday. They have clearly separated from the parents, and are making their way as independent birds.

Another possible reason for their scarcity is the incredibly hot weather we currently have in Philadelphia. Today is the fifth day of the heatwave with temperatures well into the 90's. Maybe the eyasses are shading up out of the sun and heat.

However, just as I thought it was going to be a hawkless morning, I spied a haggard up on the ledge of the Franklin Institute, quite close to the nest. But this did not look like the sleek, well-feathered birds we're used to seeing! Its head and neck were soaked, and its feathers were a real mess. Molting is definitely underway.

Based on the dark face coloring, we think this was the tiercel (Dad).

As the hawk started to preen, we could see that he was wet all over, and probably had recently had a bath - maybe in the fountains at nearby Logan Square.

Up on the ledge, he was catching the breezes and sun to get dried out.

He kept his eyes on Kay as if to say, "Can't you leave me in peace just this one time?"

Saturday, August 15, 2009

Eyass at the Art Museum

One of the eyasses seems to have made the Philadelphia Museum of Art and its surroundings its personal stomping grounds. Yesterday, Kay, Carolyn and I found it perched on a railing right next to the Rocky steps at the front of the Museum. It had flown in from the nearby trees, and swooped down to a grassy area then onto the railing.

It was definitely hunting, and made a grab for some unlucky creature, but it turned out to be a very lucky - or perhaps just extremely agile - creature, as all our eyass caught was a beakful of grass!

It then sat there calmly watching all the Friday morning rush hour activity around the Museum that included the finish line of a 5K race nearby. It takes a lot now to startle these hawks.

Kay was able to move really close in, and as the eyass observed her with great curiosity, one got the feeling that they almost recognize us as the folks that hike around with them in their early morning jaunts!

This eyass then flew up to the Art Museum roof and appeared to pounce on something - probably a sparrow. We watched it start to eat behind one of the gargoyle-like structures, and once again it peeked down at us as if to say, "Are youse guys STILL there?" (It's a Philly hawk!)

On the river side of the Museum, a skateboard park is being constructed as part of the Schuylkill Banks development. The construction crew (Dave and Glenn) report sightings of the hawks most every day hunting in that area. The female haggard, in particular, has claimed this area and earlier this week, Carolyn spied her in a tree overhanging the river. The shadows make her neck look vulture-skinny!

Carolyn sent me the following comments on her hawk watch: "I saw an eyass fly from the Museum roof to the construction area and was trying to track it when Dave and Glenn pointed out the other hawks sitting quite visibly on low tree branches right above the river banks. They told me they often see three hawks there, catching snakes, mice, etc. I saw an eyass make a pass at a jumping fish while flying from a tree on the other side of the river. I saw Mom dive from her branch onto something in the brush below and eat it very quickly. She spent a couple of hours perching on a variety of poles and trees, watching intently. This seems like a REALLY good place to hunt, what with the digging, steep brush covered riverbanks, and clear sightlines."

This morning (Saturday) Carolyn noted that the eyass was very visible around the Museum. She also saw a haggard earlier but it was chased away by the eyass. There was minimal squawking, only when the parent was around.

Sunday, August 9, 2009

Busy weekend for hawk watchers!

Friday, August 7 gave us a spectacular morning of hawk watching down by the Franklin Institute and along the Parkway. It was a relatively cool, sunny morning with low humidity and a light breeze. We've begun to notice that the hawks share our weather preferences, and are more active when it is more pleasant -- at least in the early morning.

I was down there with Kay and Carolyn at 6 AM and we were joined by Barbara Reisenwitz and her eleven year old daughter Annie. At first, we could see no hawks, but Annie's sharp eyes spotted a hawk on the nest - right at the back. We crossed the Parkway and were back on the familiar territory of Winter Street, looking up at the nest.

The hawk turned out to be the male haggard - Dad - and we watched him make at least five trips back and forth from the nest to nearby trees, each time bringing back a leafy twig or small branch which he then added to the nest.

Then we heard squawking, looked around and found The Squawker up on the Library ledge. We have nicknamed this eyass because she is one who makes the most noise still. The other two tend to hunt purposefully, silently and effectively, while this one still calls out to the haggards for a food delivery.
Last Sunday atop the crucifix on the Cathedral Basilica we saw The Squawker. She was quite pathetic up there on the highest point of the non-skyscraper buildings, and because it was so early (6:30 am) on Sunday the city was almost silent as her calls echoed eerily over quite a distance, and though I could barely see her, I could hear her clearly. No-one brought her any food, and she eventually flew away. She's the one that worries us a bit as the other two are becoming excellent hunters and seem very self-sufficient now.

John Blakeman shares this concern: "The vocalizing bird on the church is just typical of August. And yes, you should be concerned. The bird's got August to learn to hunt, or she's history. We see this out here in rural areas, too. Often, these are birds who had overly attentive parents in June and July, and they've merely gotten addicted to Mom and Pop providing food when they wail. The parents have now cut off the free food, but the little tyke still thinks that if she wails louder and longer, something will turn up. It won't. She will quickly get serious about capturing food, or starve."

After The Squawker left the ledge, we were suddenly inundated with eyasses flying back and forth across the Parkway trying to make landings on the nest. The haggard did not want to share and took off as soon as the eyass landed. Notice the red tail feathers with no bands.

It has been a challenge sometimes to sort out eyasses from haggards, and the tiercel (Dad) from the formel (Mom).This one had us stumped as there were no bands on the tail, but no real red feathers either. John Blakeman sent some helpful commentary about this picture: "The bird on the light pole is a haggard. Look at the eyes. Hags all have brown eyes, immatures (eyasses) have yellow eyes. This bird also has some pretty ragged and
varying feathers on the back. This bird is molting, which this year's eyasses don't do. The tail lacks horizontal
bands, which all immatures have. It's a bit dark, either from being wet or dirty, probably wet. The very dark ends of these tail feathers is very non-typical. But this is an adult. The bill (beak) looks a bit small, so I'm guessing (guessing!) that this is a tiercel."

Here's a recent picture of an eyass visiting the nest, and you can clearly see the yellow eyes.

And here you can see the horizontal bands across the tail.

The highlight of the morning was seeing one of the eyasses with a freshly caught squirrel up on the Library ledge on the corner of 20th Street. A moment after Kay took this picture, the eyass yanked the tail up and out of sight as if it were afraid we would come after it!

Later on, this eyass left the half-eaten squirrel on the ledge, and The Squawker moved in to clean up, so she did get some food, but not through her own hunting efforts.

On Saturday, August 8, Carolyn sent me the following report: "Today's action was terrific - similar in time and behavior to yesterday with the same players. I followed the squawks of one eyass from Art Museum to the roof of Parkway House [apartment building alongside the Parkway].

When I drove over to investigate, I entered the driveway into the recreation area that borders the ramp to the Vine Street Expressway. I found the bird with missing tail feather that we're pretty sure is Dad, big as life perched on a dead tree.

As I was taking pictures another eyass flew in (squawking) to challenge him for possession of the tree. Dad flew off. I could see the red tail feathers quite clearly.

Dad and at least one eyass showed up around the nest later on,
behaving much as they did yesterday (Friday). I did not see
both birds when I first looked at this picture. You can see the
reflection of the bottom bird in the window - two birds,
two shadows, one reflection - cool!

Wednesday, August 5, 2009

Feathers and another casting!

Over the past few weeks of watching the hawks in the Franklin Institute/Parkway/Art Museum area, I have picked up various feathers that I figured might be hawk heathers dropped either from preening or in flight. I took pictures of the feathers and sent the images to John Blakeman. It turned out that three of these feathers were indeed from red-tailed hawks. The others turned out to be turkey feathers (I wonder where they hang out downtown?!)

John sent back some fascinating commentary on the feathers that included the disquieting information that I had been breaking state and federal laws when I picked up these feathers:

"No one is permitted to so much as pick up one of these discarded or molted red-tail feathers and take them home, for any purpose. The Migratory Bird Treaty Act, passed a century ago to stop the feather trade supplying decoration for women's hats, expressly prohibits the possession of any part of a protected species, which the red-tailed hawk now is.

Turkeys, a game bird, are not so protected, so you can possess those feathers. But if you inadvertently took home feathers 1, 3, or 6, discard them immediately. No can have! It's a state and federal law.

As a falconer, I'm allowed to possess the feathers that my falconry red-tail molts, but they can only be used to "imp" (replace) broken flight feathers. I'm not allowed to display these or use them for any other purpose."

-- John Blakeman

Since learning this dire information, any further feathers we found stayed right there and were photographed
in situ! John later relieved my guilt somewhat about the feathers I had taken home to photograph:

"You aren't the only person unaware of the protected status of most bird feathers. You might want to post the photos and my note on the matter. The Feds would take no offense. Taking photographs of the feathers is not illegal. Putting them in your pocket and taking them home would be. Actually, the wildlife authorities would welcome this public education effort helping to spread the word on the matter.

Here is John's run down on the feathers:

1A – A molted breast feather from a haggard. It's not from an eyass

3A – This is a left-wing secondary from a haggard. It grew just inside of the “elbow.” It was dropped during the molt, which is now continuing.

6A – This is REALLY interesting. This is an outer left tail feather of a red-tail hatched in the spring of 2008. It’s worn and was dropped now in the bird’s first molt, now being replaced with a red feather. This is not from this year’s eyasses, by any means. A wandering one-year old vagrant drifted in and deposited this feather.
This could mean that an immature red-tail may be flying around with all the resident family. Watchers will need to look for missing tail or wing feathers to identify this as a bird from last year. By now, a few new red tail feathers should be apparent in this bird (if it's still hanging around).

This one is a bit tougher to parse out. It's a red-tail feather, for sure. But I can't tell if it's from an adult (most likely), or did it drop off the one-year old interloper? Some of these brown feathers are almost identical in eyasses and haggards. Most likely, it's from one of the resident haggards. It's certainly not from any of the eyasses, as they aren't molting in their first summer. They will be doing that next summer. The feather looks to be a larger covert, a covering feather, from the top of the wing, probably over the first or inner wing segment.

This is a molted tail feather - or retrice - from one of the haggards. It's from the right side, probably close to the center. It's not an outer tail feather. Those molt later, and the feather shaft is a bit offset to the side with those, with a slight bend at the proximal end of the quill. If you see the bird soaring, you will clearly see the gap in the tail where the feather used to be. Where was this? [Carolyn found this at the Art Museum]. In most cases, the feathers are dropped or shed during morning preening. In most cases,but not always, the bird spent the night above the shed feather."

Our next exciting discovery was actually seeing an eyass eject a casting (hawk version of a hairball). The hawk was perched on a lamp pole along Spring Garden Street behind the Art Museum.
The casting fell to the sidewalk beneath the lamp pole. It is about 2" long and is definitely a candidate for the Gross Hall of Fame. I scraped it carefully into a paper cup and it is now sitting in a dry spot in my basement.

If you want to learn more about castings, check out the blog entry of July 10 entitled "Look what the hawks left on the roof!" It includes another graphic image of a casting!

John Blakeman comments that the casting "must have fallen from some distance as it fell apart on impact. You are allowed to possess these." [Phew!]

"A field biologist at The Franklin Institute (or elsewhere) could put it under a dissecting microscope and discern its composition. With a hand lens or magnifying glass you can determine if it's feathers or fur. A good lab ornithologist or mammalogist can figure the consumed animals. Pigeon feathers are pretty easy to ID. Others can be difficult. Separating the fur of the various mammals should be done by someone who is experienced."

--John Blakeman

Monday, August 3, 2009

The Franklin Hawks are on the move

Apologies for the lack of blog entries this week. I got myself a bit backed up with summer activities, but the production line is rolling again!!

The Franklin Hawks are extending their territory up the Benjamin Franklin Parkway to the Philadelphia Museum of Art which is renowned for its steps up which Rocky ran in the movie of the same name.

More importantly for the hawks, the Art Museum and its surroundings provide an almost perfect habitat for perching and hunting as it is set up high above the city, and on its river side has well spaced trees, bushes and open grassy areas.
The buildings below the Museum are the Philadelphia Waterworks which have been converted to a restaurant.

Over the past ten days, we have observed all three eyasses and at least one haggard perching, flying and hunting all around this area. On the topmost parts of the Museum roof are several large gargoyle-like metal carvings, and the hawks love to perch up there.

This has to provide them with THE BEST possible view out over the city! It can be quite hard to spot them up there amongst the ornate decorations along the roof line.

Down behind the Museum is a row of trees overlooking a grassy area. We have a grandstand view of the action from the parking area at the back of the Museum and frequently find ourselves at eye level with the hawks flying by -- quite an extraordinary experience.

The hawks perch in the trees that are also at eye level. In the picture below, can you spot the haggard through the gap in the bushes? We're pretty certain this was the formel (Mom).

Watching the eyasses polish their hunting skills has provided some memorable moments. This eyass flew in and perched right opposite me.

I noticed a groundhog whiffling along in the grass below. The eyass appeared to be calculating whether it was catchable.

The groundhog was absolutely unconcerned about the possibility of being breakfast, and seemed to know that its size kept it safe.

Suddenly, a second eyass landed on a rock only a few feet away from the groundhog. This was getting a bit intense!

Now that the groundhog realized he was being double-teamed, he looked a little more concerned about his situation, and warily watched the eyass as he continued to eat grass.

This ended in a stalemate with the eyasses ignoring the groundhog, and eventually flying away to new perches.

Right next to this grassy area is Spring Garden Street, and the wall that edges the road is another favorite perching spot.

The lamp poles that line this street are also popular hawk hang-outs.

It is a worry to see our hawks so close to busy traffic, but they have safely made it to August, and each day they are becoming more self-sufficient and savvy about their environment. It's good to see them expanding their world.