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Tuesday, March 31, 2009

Red-Shouldered Hawk Territory--II

What a difference a week makes.
Yesterday, March 30th, I visited my favorite Knoxville hawks again. In southeast Tennessee redbud are peppering the hillsides with magenta pink. Dogwood are opening, bluebirds singing and in red-shouldered hawk territory, yellow jasmine and trillium are in bloom.
But what caught my attention on this visit even more, the new greenery that now conspicuously decorates the hawk's nest. In the image below, the female is incubating on the nest. All around her you can see sprigs of green pine needles. Notice, also, the downy white feathers scattered about.Females are known to pluck feathers from the 'sweet spot', the place on their breast that makes contact with the eggs during incubation. This allows for more warmth to the eggs, as well as providing a downy material to tuck into the nest for softness.

I have marveled on more than one occasion at the synchronous cooperation between these two hawks, the innate knowledge that moves them to cooperate, to hold tight to the nest, to share their food. Just what prompts raptors to add fresh greens to the nest while incubating is uncertain. Biologists speculate that the aroma may deter insects. Others have referred to this as an announcement to other raptors that this nest is occupied.
Above you see the female carrying prey, a squirrel that the male has brought her. At the moment she comes to his perch for the food, the male zooms back to the nest to take over incubation. More details on how this cooperation works, coming up.
Bottom photo, trillium; top photo, jasmine; second image, eastern bluebird male on dogwood.

This post is part of a series on a nesting pair of red-shouldered hawks. To see the entire series, click here.

Friday, March 27, 2009

Red-shouldered Hawk Territory

My most recent visit with the hawk pair was March 23rd and spanned nearly four hours. I could see that a hawk was incubating on the nest, but I couldn't see which hawk it was from where I normally watch.
So I walked across the leaves to the top of the neighboring driveway to get a better look and confirmed it was the female. In my previous position I could see her turning her head, watching movement in the yard. But when I stood in this spot, she stared at me intently.
Afraid she might leave the nest, I snapped a few images and retreated. When I returned to my previous location, she resumed looking around.

While I sit with the hawks I sketch and watch the other wildlife in the yard.
Squirrels and other birds are busy all around me. I wondered if one of the squirrels was any the wiser for his experience. He seemed to be missing some of his tail. On the other hand, I've now seen the speed of a strike and I'm sure no matter how alert the prey, the outcome lies in the skill of the hawk.
This stunning female cardinal landed on the dogwood in front of me while her mate or suitor sat on the roof over my head calling with steady 'beeps'. She hopped and turned and flared her crest into spikes.
And just as I was thinking, I'm not going to see the male hawk today, I looked beyond the cardinal and there he was, perched high in a tree to my back while I was sketching.
Next: Domestic duties, hawk style.
This post is part of a series on a nesting pair of red-shouldered hawks. To see the entire series click here.
Linked to Bird Photography Weekly #31 at Birdfreak.com to promote conservation of our world's birds.

Wednesday, March 25, 2009

Red-Shouldered Hawks--Part V

After the pair rested for a moment, the male dropped off the perch.
My eyes left the lens for an instant to see where he was headed and to my surprise he landed on a limb even closer to me. I have seen him do this several times now, see movement, land on a perch closer, then strike. He paused on this limb long enough for me to snap a few shots before flipping around and landing on the ground even closer.
Once on the ground he immediately began to hop among the leaves, pausing only once to listen to the camera click.
Within seconds his attention returned to movement and I had the joy of watching him hop, spin, and flip leaves with his talons to uncover what was stirring beneath. Below you can see a little bit of the action. I've included the blurred shot to give you an idea of how he used his wings for balance.
In the end, he abandoned the hunt and left to find a meal elsewhere while the female stayed close by. The activities here and in the previous four entries ocurred on March 7th. The pair is now incubating. The eggs generally hatch in 33 days, giving us an estimated hatch date of April 15th.

This is the seventh post in a series on this pair of red-shouldered hawks. To see the entire series click here. More photos, sketches and stories about my visits with this family coming up.

Sunday, March 22, 2009

Red-Shouldered Hawks--Part IV

“…those of us who have worked with these nonsocial, solitary predators always marvel at their socializing behaviors when pair bonding. All of what you described, the vocalizing, sitting close together, and especially food sharing, are so counter to normal, day to day red-tail behavior….” John A Blakeman, red-tailed hawk expert, on the distinction between mating and copulation.These words struck me as so important. Hawk pair bonding represents a dramatic change in the basic behavior of a bird that is, by nature, a solitary predator. This behavioral shift is the principle glue that enables nest building, copulation and partnered responsibility during incubation and the raising of young.

Blakeman comments further: “It’s important that observers not arbitrarily or casually ascribe human or mammalian explanations for any red-tail behaviors….It’s love all right, but very different from that of social predators…or the ultimate primate, humans. People need to understand that red-tailed hawks are altogether unique unto themselves. They are not a mirror or model of any other species. Their nobility is their own.”

And so it is with this pair of red-shouldered hawks. They behave like hawks in general and specifically, like their own species. And they have behaviors that are uniquely their own. They live in a suburban territory to which they have been loyal for fifteen years. They hunt and nest in both the front and back yards of people like you and me. People are part of their every day experience and I am fascinated with how they have adapted, how their human neighbors have adapted to them.

I was doubly fascinated on this day, when they ignored me, acting as though I were a natural part of their environment, no more threatening than a tree or a column of bricks.
And now, you may cover your eyes if you wish. I have given fair introduction to the activity you are about to witness through images. Copulation is the natural event that precedes fertile egg-laying. If I could show you egg-laying, I would, as well.

The female sat quietly on her perch after finishing her meal. But as time passed, she began to repeatedly look in the direction of the male and struck the posture you see above, with her head leaning back, her chest raised. When the moment arrived, signaled through communications too subtle for this observer, the male joined her, landing on her back.
While they rested, I remembered to breathe and continued to click the shutter. Can there be any more surprises? Well...yes.

Next: The male leaves the perch.

This is the sixth post in a series on this pair of red-shouldered hawks. To see the entire series click here. The first post will appear at the bottom.

Linked to Bird Photography Weekly #30 at Birdfreak.com to promote the conservation of our world's birds.

Saturday, March 21, 2009

Bird Salmonella in Southeast not Attributable to Peanuts

I was surprised to the point of a smile and head shake yesterday when I opened my door and two pine siskins, a house finch and a nuthatch were looking at me. My feeders are still down but my diners haven't given up. They keep checking to see what I'm offering.
And because disease in your own backyard feels personal, I was interested in this report from the Center for Infectious Disease Research (CIDRAP) released on March 18th.

The report states that the current outbreak of salmonella in the southeast has not been attributed to tainted peanuts or the salmonella that has infected humans related to peanut products. The strain that has been isolated in the bird population here is a different strain of the disease. Additionally, even though the irruptive pine siskin population has been the most affected, the disease was found in other species prior to wintering finch arrival. The report also states that outbreaks of disease occur periodically and though the reasons aren't clearly understood, it happens. This, of course, doesn't answer all our questions or dissolve the discomfort of finding diseased birds at your feeders, but at least it is more information. What feels very personal in the beginning gradually becomes another phenomenona of nature that disserves observation and research.

In the meantime, follow safe feeding procedures. Spring has arrived. Time passes and so also will disease.

Thursday, March 19, 2009

Red-Shouldered Hawks-A Day to Remember,Part III

With everything quiet around the vicinity of the nest, I took the opportunity to both photograph and sketch the nest location, curious mostly about how it was positioned and what seemed noteworthy about the selection of the nest site.

The nest is located in the main fork of a large tree, but the hawks also made use of a neighboring tree limb that formed the third brace in the platform. And though the nest is primarily constructed of sticks, the dry leaves hanging from the nest make me think they also incorporated a squirrel's nest. What self-preserving squirrel is going to argue?I had just opened up my watercolor sketch kit and begun to paint when a hawk called and flew past me. Now, when I say flew past me, I'm not describing a great distance. He flew past me within 10-12 feet. I now realize, in hindsight, that where I normally sit provides a front row seat to the pair's activities, a location right beside their flight path and several favorite perches. How lucky can one person get?

I didn't see where the hawk landed and because I was still feeling some concern about disrupting nesting activity, I continued with my sketch rather than look for what turned out to be the female. In the second photo above you see what I managed to accomplished before my attention was soundly grabbed by more hawk activity.

This time the male began calling from across the culvert. I reached for my camera, but by the time I lifted it, I was watching the hawk fly past with prey in his talons. I was astounded again by the speed and efficiency of these hawks. Repeatedly, realizations of what I have just witnessed trail the hawks' swiftness by many seconds.

To my surprise the male landed on a branch in front of me and looked toward the female. Heart-pounding surprise #2. While I was trying to get my lens oriented to his new position, the female flew to his perch and hopped over him to grasp the prey. He flew to a different perch.

I watched the female eat her food offering. This was clearly a prey exchange, one of the behavioral rituals that bonds a mated pair of hawks during the breeding season. When the female finished eating, she picked up the inedible remains and dropped them over the side of the limb.Above, she checks her perch for any other remains and cleans her bill, below.
Next: The male returns.

This is the fifth post in a series on this pair of red-shouldered hawks. To see the whole series click here. The first post will appear at the bottom.

Monday, March 16, 2009

Red-Shouldered Hawks--A Day to Remember,Part II

A hawk calling.
As I was approaching my 'observation station’, a sheltered elevated patio on a wooded suburban property, I heard one of the hawks calling. This is always happy news for me. It tells me the hawks are nearby and eventually they may orient me to their location.This pair of hawks has nested in the area for years and is accustomed to people coming and going. Another human presence is nothing new or alarming. However, I am very aware that I am a visitor in their territory and that they see me far sooner and with more scrutiny than I can ever see them. My desire is to observe their natural behavior as much as time and timing will allow. And so, I am careful to not disturb, to be as still, quiet, slow moving and deliberate as possible, and to keep a respectful distance when I do know their location.
The hawk continued to call so I searched through the tangle of limbs along the border of the property and into the next yard and movement caught my eye.
The back lighting produced a silhouette image, but I snapped photos anyway, knowing I might learn more through the images. As I looked through the lens, I could see sticks, lots of sticks and realized I was looking at the nest. (Surprise # 1.)
The nest is relatively small and certainly inconspicuous. In the above photo, you can see the hawk placing lichen, moss, leaves, some kind of leafy matter in the nest. I suspect this is for the soft lining, though its impossible to know. Though the photo is poor, it at least confirms that this isn't a 'maybe' alternative nest, but their choice for the season.

After several minutes the hawk called again, this time a long series of rapid bark-like notes, ‘kar-kar-kar’. This was repeated several times and then the hawk flew. After I was sure the hawk was gone, I took the opportunity to walk around to the other side of the nest to see how it was positioned in the tree and to get a better look without the glare. Notice, below, how difficult the nest is to see, even when you know where to look. Follow the two large limbs (at the top) down to the formation of the main trunk. The cluster of rust leaves hang underneath the nest. This is what you see if you look for the nest. It is positioned in a spot where more than one tree comes together to form the support platform. And from any view from the ground, very little of the nest is visible. Soon leaves will be popping and I suspect it won't be visible at all.

The first and last photos are images of the male. Next: When both hawks return.

This is the fourth post in a series on a pair of Red-shouldered hawks. To see the entire series, click here. The first post will appear last.