Saturday, March 15, 2008

Should We "Interfere"? Helping in the Urban Jungle.


Eldest (St. John's nest, 2006) on the short roof of the chapel at the rear of the Cathedral. These roofs have accessibility to trees.

In response to yesterday's post concerning the possibility of helping fledged eyasses, who cannot gain altitude for flight the first few days, or help themselves up out of harms way, blog reader Roe who is a falconer, sent a comment concerning grounded eyasses. ---


If the hawk is going to live in the city he'll have to learn about it. I wouldn't interfere at all. Though it would be hard on me if he were killed, I am a falconer and have one of these birds myself. He's got to learn about fences and cars and people the hard way because that's nature’s way.

Roe


Cathedral eyass eating food dropped off by her parents on the landing of scaffolding. These positions helped keep the eyasses out of the parking lot with its cars just below the nest.

Roe,

Without a doubt there is some relevance to that point of view and you're right the youngster will have to learn about all the challenges that cities are crammed with. In fact not interfering in nature's way is a view commonly held by many. I've noticed many who do hold the view live in the country where wildlife is often living in natural environments for which their species has evolved. Where my country uncle for instance puts it rather over bluntly, "Some animals are just too dumb to live." And there could be something to that, though perhaps put a little less bluntly.

In fact most of us would probably find that bluntness more than a little over the top, but it did get me to thinking about whether or not there was some truth to it. If an animal can't figure out a fence, or cars, or whatever urban trials might come it's way, during the first 2 or 3 days off the nest, is that a lack of cognition, is the bird just a little dummy, or is there some bad timing, or we could say, bad luck, involved if she finds herself flightless and grounded and runs in front of a car.


This eyass has managed to get up the scaffolding and side of the Cathedral to perch on the long balustrade of a wide balcony on the church.

Back when I was training in field biology, I went to a conference at the Field Museum in Chicago at which a number of scientific papers was being read. Now, we've been taught in regards to evolution, that the most fit for survival members of a species are the ones who survive to reproduce. (Technically it should be ...the ones who tend to survive to reproduce.)

At any rate, at that conference a scientist presented a paper which suggested that things weren't really quite that simple because there were any number of anomalies which could cause a group of animals to survive who might not technically be the fittest. For instance, say a virus is devastating a species of marine life. This virus is carried by certain ocean currents of a certain temperature. If a group of these marine animals happen to be in a bay in which the infected currents do not reach, then they have had the luck to survive and reproduce.


Eyass trundles over into the shade and watches the sparrows and people below from the safety of a landing in the scaffolding.

Red-tailed Eyasses have evolved to survive in certain environments, and fledging off buildings into areas without branching opportunities or anything that will allow any of them to get any elevation and out of danger, wasn't in the usual evolutionary game plan.


Mom circles with food. If the eyass is high enough, in a position the parent finds safe for her, the parent will deposit the food nearby. If it doesn't look safe to mom she will tempt the eyass from a higher position hoping to tempt the eyass into trying to find a way to get up to the food and therefore a safer position.

True, true, Red-tailed hawks are adaptable generalists and the bonded adults have adapted to living, breeding, and finding nesting sites in urban areas. These sites are hard to come by and don't often match all the possible criteria for the perfect dream nest site. And it looks to me, from looking at the various very urban sites, that just exactly where the eyasses may land on their maiden flight, and whether they'll have branching opportunities to get some height when they are grounded is way down the list of adult hawk criteria. Behind such factors as will the spot hold up a nest? Will the young and sitting bird be reasonably safe from people and predators? Does the spot have some privacy? Are there adjacent hunting grounds? The list goes on and on.


Having found a parentally placed snack this eyass now perches on a scaffold bar and looks down. He is considering killing a rock, which he will soon pounce on. The rock is some feet down on a "step" of the Cathedral wall. This impulse will cause him to go low again and he will have to be tempted to branch back up again by food.

Because eyasses come off nests without the ability to gain elevation and there are often no branching opportunities in most urban settings, yes I think we should help them to help themselves by possibly increasing branching opportunities and looking out for them the first few days. In more natural settings eyasses seldom have the bad luck to have a street with cars as their most likely first landing area.

Well, someone might say, their parents placed the nest there. It's their look out. Yes, their parents did. Their parents didn't have a whole lot of nesting site options and as I inferred, I'm not sure the parents are wired to take fledge landing into their top criteria priorities.

Okay, perhaps then the young shouldn't survive? Evolution will eventually introduce fledge landing criteria for the adult's wired criteria lists. And maybe that's true.

But in the meantime, we'll loose more eyasses than we already do despite our best efforts. Urban Red-tails do us a lot of favors by being here. The Red-tails at St. John's in previous years have killed and eaten hundreds of rats. Much nicer and natural than rat poison.

Urban Red-tails introduce many many urban people and their children to the wonder and beauty of nature. There are some people in cities who can't believe that there are actually large birds, such as raptors who aren't owned by anyone. That they actually do take care of themselves is a new idea for some people.

When someone unfamiliar with wildlife looks though a birding scope at an urban hawk's nest, their face often transforms. For some, that look not only transforms their faces it transforms their lives. Therefore a little help on our end for a few days for the fledglings, seems a fair trade as we've created an environment in which a few necessary pieces for ready survival of young can sometimes be missing.


Eldest and Youngest, after they've increased their strength enough to gain elevation in flight, perched on the Cathedral School.

By the time the eyasses are able to gain elevation in flight, there are still myriad challenges that will test their fitness and their capacity for survival.

Those young that do not learn their lessons about cars, poisoned rats, fences, and how to hunt-- to name a few, will not survive. Or, as this isn't a natural environment where a damaged animal just "disappears", there could be the chaos that ensued last season when Charlotte and Jr.'s eyass found herself grounded. Lots of city personnel spent time on the issue. Time and money were spent by wildlife rehabilitator Bobby Horvath in tending the eyass for some weeks before permission could be gotten from the city to release the eyass. In the meantime her parents were at their wits end looking for her. And what if the eyass for want of branching opportunities, was hit by a car, not killed outright and then after pain and suffering had to be euthanized as there are no wolves or fox to quickly end the youngster's suffering?

We have skewered nature in urban areas and perhaps we owe a helping hand now and again. It won't always work, but in the meantime we can experiment with options and we will learn to give the right helping hands, come the time when perhaps there aren't so many Red-tails left on the Earth anymore as has happened in the past with our Peregrines and Bald Eagles.


Besides look at that face!
That is a face that those following the nest's story will have watched start as an egg, hatch into a white fluff ball, and eventually gain flight feathers. People will have gasped at their danger when the Falcons attack, worried they're getting enough to eat, had heart palpitations when they flap and hop on the edge of the nest, and then held their breath with a surge of adrenalin when they finally make their first flight.

For some it is not science. Particularly for those who have never been allowed contact with any animals at all. For those who have never watched another species, another nation with it's own families going about their daily business, it is a revelation. For many it does become personal and that can be a good thing for the world's future. And for themselves, they will remember the experience with joy for the rest of their lives.

Donegal Browne.

P.S. Not only do many adults follow the stories of our nesting urban Red-tails and therefore would be sad if they ended up hit by a car, but there are any number of small children who follow the birds adventures daily. The empathy for wildlife learned at this age will last a lifetime. These children will be the hope for a future with an environmental conscience They will learn soon enough that some young animals will not make it to adulthood. Best first to hope they have the joy to see some that do live, thrive, and fly free, so they will continue to watch, not turn away in tears and not look back.

How Can We Help a Grounded Eyass Help Herself?


This is Youngest from the St. John the Divine Cathedral Church nest in 2006. Youngest is stuck. I showed up one afternoon and there he was wandering around the sidewalk. Just as I saw him down the sidewalk, a pedestrian ahead of me almost spooked him into the street. So I got in the street hoping to keep him on the sidewalk. Notice his annoyed look. About then the parking lot attendant called to me that he'd been on the ground wandering around the parking lot and now outside the chain link fence most of the day. He considers attempting to get to the roof of the parked car. Something we've seen eyasses do in an attempt to get into a tree. It doesn't usually work and puts them into more trouble on the slippery car roof where they slide into the road.


A very dangerous place for an eyass to be on a busy corner with oblivious drivers of cars roaring by. As you can see he wants to get over the fence to the nest area. That's security. He also, while I watched, checked out the lamp post, the trees, anything with height where he might branch into a tree. There is nothing for him to use. This may well happen again this year. How could we help?

A blog reader from Illinois who, when I asked for brainstorming on the topic, began researching the question and found this:


MIT in Boston had a RTH nest site last year in a large pine, and after spotting it, set up a cam focused on the nest. I was reading the site this afternoon, and they have some nest video as well, of the young eyasses and their progress and growth and nest bouncing.

When the first eyass fledged it batted and buffeted down to the student center across the street, and there, guarded by passersby, it branched for most of a day among the bicycles parked there, from handlebars to handlebars and eventually, back up into the nesting tree. So it would not have to be very big, to support branching, apparently, at least not for that fledgling. Just several sets of bicycle handlebars welded together.

More brainstorming needed. (grin)


(I like the idea of handle bar art for branching though with all the bike thieves it might well disappear before the birds could use it. But it does show that just about anything would work if it gave some height near a tree. D.B.)


Youngest panics as another pedestrian begins coming toward him and he heads for the other street of the intersection. Morningside which is rank with speeding traffic. That's when I begin to call for the help of passers-by. Not the best solution but the only one I had at the time. We managed to stop traffic and he made it across the street without being squashed only to find-- yes you guessed it, another obstacle. The park fence.

He jumped 9 times, while we held our breathe and asked pedestrians to make a detour to the other side of the street, before making it to the top of the stone base of the fence.

The gate to the park is not at all far on his left, but they seem to have pinpoint focus and don't notice the big picture. He's looking for trees. He sees trees. He goes for trees. The view through the gate is quite an expanse of path at least from his level.

He finally makes it and has to totally scrunch himself to get through the bars.
(What is temporary, wouldn't get stolen, vandalized, or otherwise disabled that could be used on or near a tree to get them off the ground? D.B.)

Once through the gap he makes a leap for the top of the bush. No good. He falls back down.

Then tired, possibly hungry, and probably more than a little dehydrated he sits while the Catbirds scream behind his head to rest and think about the situation.

Most of the pedestrians that walked by, didn't notice him stashed on the other side of the fence. But for those who did, there were cell phone photos a foot from his head and the child who reached out a hand to touch him. Thankfully two other Hawkwatchers arrived to monitor the situation as I had to leave. But it just goes to show, not only is the eyass safer off the ground but so is your average pedestrian.
Eventually Youngest made it to a small tree and by the next day was way up in the large trees with his sister, gobbling drop off meals brought by this parents.
SUGGESTIONS?
Donegal Browne
P.S. There is a much more detailed account and quite a number of other photos of Youngest's predicament which can be found at --http://palemaleirregulars.blogspot.com/2006_06_18_archive.html
Just scroll down the page that comes up.

Wednesday, March 12, 2008

The Riverside Nest and The Robot Nabbing Hawk


1:05PM Riverside Park: The nest is bigger than the last photo I've seen of it. That's comforting. More and bigger can't help but increase their chances of success.


1:06PM View of the nest from the north. This is my first visit so I don't know if the hawk on the nest is the formel or the tiercel.
1 07 31PM The bird is more hidden from this angle. This is the view from the nearest park bench.

Yes indeed, the nest does over hang the entrance ramp. What criteria made them choose this particular spot? I admit that this is pretty much a rhetorical question, but I can't help trying to figure out why this spot might be "better" in Red-tail eyes than any of the other possibilities in this territory.
This tree is isolated enough so that the parents can come out of it easily from all angles. It has some height above the surrounding area for an elevated view.
The branch that holds the nest seems to be flatter as opposed to tipping up. Was it originally flatter than it's neighbors? Or is the flatness a product of the weight of the nest?
1:08PM The hawk begins to re-situate twigs.
1:11PM She places a twig to the rear.
1:13PM The hawk stands and looks at something in the distance. A few moments later I see another Red-tail beyond the nest flying in the opposite direction.
1:14:14PM Twig in beak. Focus.
1:14:59PM Then the hawk is off the nest and perches in a nearby tree. What is she looking at?
1:17PM She's switched trees again and her beak goes down and small fragments blow away. Feathers? Stashed food? Or bark? Clipping twigs?
1:18:37PM No twig in her beak so perhaps stashed food. Though if it was food, it either wasn't much of a snack or it's hanging from a talon on the far side of the branch.
1:19PM One thing I did notice about the area inside the park, is even in early afternoon, the place is chock full of dogs. Red-tails are not fond of dogs. They seem to get used to people to some extent but are always wary of dogs. I suspect there is wiring involved. See the fence beyond the dog walker? The nest tree is on the far side of that fence. And on the far side of the fence there are no dogs. No dogs could possibly be a criteria for the choice of that tree.
1:22PM The pigeons are lining up on the roofs across the street. The Red-tail larder is looking quite full.
I'm betting that someone comes daily at a specific time and feeds these pigeons. Making the area not far from the nest a prime hunting ground. Handy food. Another possible plus for this nest site.
1:24PM Look between the two largest tree trunks and there is the view of the nest from the sidewalk outside the park.
By the time I cross the street to leave, have gone a block, and look back. There is a pigeon feeder going about her charitable task to the pigeons glee.
Photograph Courtesy of Mary McGorry and NPR.
Yes, this young Red-tail has grabbed a child's Christmas toy. Experts then come into play. Check it out.
Dragonfly Robot nabbing Red-tail link sent in by Anne of Charlotte NC.- http://www.npr.org/templates/story/story.php?storyId=88074725
Donegal Browne

PRESS RELEASE: NYC Audubon Breaks the News on the Pale Male Nest Fix


Photograph: Donegal Browne
Pale Male checks out the adjusted nest during a few minute break in the work,
January 29, 2008


Photograph: Dongegal Browne
The work then continued with more spikes being clipped from the carriage.


Today's Press Release from NYC Audubon and City of New York Parks and Recreation--sent in by Board Member Sandy Fiebelkorn, who was the liason with 927 Fifth Avenue--

Parks, NYC Audubon, and Leading Hawk Experts Restore
Red-Tail Hawks Pale Male and Lola’s Fifth Avenue Coop

The Parks Department, NYC Audubon and red-tailed hawk experts today announced the restoration of the nest of the legendary red-tail hawks Pale Male and Lola on the 12th floor cornice of 927 Fifth Avenue. Concerned that this historically reproductive avian pair has failed to hatch chicks since re-establishing their nest on the Fifth Avenue building in the spring of 2005, Parks and New York City Audubon recently spearheaded a restoration of the duo’s nest and positive signs of copulation have since been observed.

“Over the years, the story of Pale Male and Lola has enthralled New Yorkers and nature lovers all over the world; we are thrilled to be able help make the Fifth Avenue nest a friendlier environment.” said NYC Parks & Recreation Commissioner Adrian Benepe. “Red-tail hawks are native to New York City and this spring we are hopeful that new chicks are born to continue the cycle of life.”

With the permission of the appropriate City agencies and the building’s co-op board, scaffold workers, under the direction of New York City Audubon, successfully removed stainless steel pigeon spikes protruding from the nest cradle that extended above the nest material and posed a potential threat to embryo development during the 5-6 week egg incubation period.

The spikes were discovered through NYC Audubon-commissioned photographs of the interior of the nest, taken from the building’s roof by wildlife photographers Donegal Browne and Jeff Kollbrunner. The spikes appeared to impede the bird’s ability to roll their eggs to evenly distribute embryonic fluids and tissues. The spikes also appeared to interfere with the hen’s ability to make proper contact with the eggs to her brood patch and keep the eggs consistently warm.

A study of three retrieved eggs laid in Spring 2007 by Dr. Ward Stone, Head of the NYS Wildlife Pathology Unit, revealed that toxicity was not a preventative factor in reproduction success.

The photographs led the panel of red-tailed hawk experts assembled by NYC Audubon to recommend the removal of the pigeon spikes. Panel members were Ron Austing, Dr. Keith Bildstein, John Blakeman and Dr. Heinz Meng. The repair of the nest’s cradle could be critical to the birds’ ability to produce chicks this spring and in the years to come.

"I'm so pleased to learn that this crucial project went forward and came to some useful completion -- just in time, too,” said John Blakeman, one of the panel experts and the author of NYC Audubon’s report. “I commend everyone who brought all of this together, especially the people at NYC Audubon. It's one thing to educate the public on natural resources and conservation problems, which Audubon intelligently does. But it's another matter to step forward, commit institution resources, and actually get things done.”

Pale Male and Lola are now exhibiting promising reproductive success this spring. Over the last week, Pale Male has been seen delivering pine sprigs to the nest, a hopeful sign. In addition, over the past few nights, Pale Male and Lola have both been seen alternating sitting for hours at a time on the nest, leading experts to believe that perhaps one egg has already been laid.

Prior to Spring 2005, Pale Male and his mate produced chicks each year from 1995 through 2004 – a total of 26 hatchlings, of which 19 survived to fledge – making Pale Male one of the most successful red-tailed hawks ever documented.

“NYC Audubon has taken a brave and difficult step. No matter what the outcome -- and you never know in the unpredictable world of nature --we Pale Male and Lola fans will be forever grateful to them,” said Marie Winn, author of Red-tails in Love: Pale Male's Story.

There is no guarantee that this improvement of the birds’ habitat will mean chicks in mid-April, as the recent lack of reproductive success may have other causes, but we have cleared the way.


30


Hope!
Donegal Browne

Tuesday, March 11, 2008

Pale Male, Lola, and the Fifth Avenue Nest


11:05:00AM Word from the Bench is that there is a hawk on the nest but opinions differ as to exactly which one it is. And the nest sitter isn't showing so much as an eye through the twigs so the discussion continues on the Bench as to just who is up there. And then they wait, and wait some more.


11:33:54AM Then a Red-tail appears to the north. Five minutes of very large circles over the area to the north. Then behind Shipshape back out again, then north on Madison, curves around and onto Stovepipe railing.

11:38:14AM It's Pale Male. Lola's on the nest.
12:01:38PM He's up and heads high.
12:02:07PM And higher, circling. Disappears to the east.
12:11:19PM Pale reappears from behind Woody and heads north. He's got something in his beak. Twigs? Dried grass? Has he been gleaning from the potted plants up on the Woody terrace again? More circles.
12:11:31PM Whatever he's got, he seems quite proud of it. Is he attempting to get Lola's attention or just feeling very pleased with himself in the sunshine?
12:11:40PM He circles back, passes Balance Beam, Shipshape, and Woody.
12:11:46PM Heading towards the nest from the north.
12:11:48PM Swerves out and around. He's high enough to make a landing but doesn't. Circles in
the south. Disappears in trees. Then back up north treeline, turn at Balance Beam and back toward nest. Lola is standing on right side of nest.

12:15:33PM Pale Male lands on left side as usual. What has he done with his cellulose present?

Pale Male stands left surveying area. Lola stands right, same.




12:15:51PM Pale Male stares at Lola. Lola looks around. No break? Pale Male off nest.

12:15:58PM Lola looks fixedly into the nest bowl.
12:16:15PM Lola leans into the bowl and does something. Incorporating Pale Male's offering? Rolling eggs?
12:16:59 PM Lola settles back into the nest.
Donegal Browne

Blakeman on Brown-tails and Sex Hormones


The stick killing Brown-tail flies perpendicularly.

After reading yesterday's post about the stick killing yearling Red-tail, John Blakeman sent in his thoughts.--


Donna,

Actually, I think the immature's attacking of a stick is a combination of -- a season's confusion of -- normal hunting behaviors and the effects of lengthening days on breeding behaviors. As with Pale Male in his first breeding attempt, first year birds are affected by spring sex hormones. So, with this bird, it's impelled to do something with a stick. Hormone-induced instinct prompts this, but there is no mate, no nest territory, or other more mature factors to shape this behavior into real nest building.

This bird is an immature, acting immaturely, much like a child playing house or building a shack out behind the barn. It's preparation for the more serious and adult breeding behaviors in years to come.

--John Blakeman

I'd wondered if the young Red-tails behavior might have been a response to a surge of Springtime hormones. He was having a strong urge that was compelling the adolescent to do something but he just couldn't figure out just yet what it might be. John came up with an excellent deduction which makes perfect sense. The use of large sticks to practice hunting behavior in the youngest Red-tails just might be becoming confused with the use of smaller sticks to build nests by mature. Both activities start with sticks after all. And as John suggests, without all the other cues, the poor guy just didn't have the whole thing nailed down yet and reverted to "baby" behavior.

I've also always thought that as all Red-tails don't do things exactly alike that their "wiring" isn't as specific as some birds. Therefore more trial and error behavior must be undertaken to solve what feels right to satisfy the urge of the moment. That way, appropriate solutions can be found for a variety of situations and environments.

One of the things that made me think about hormone surges was the top photograph. The Brown-tail took off at break neck speed and then flipped to the perpendicular and flew quite a long way, sideways. Was he having an urge towards courtship flight? Or was he just so fired up with Spring that he was doing the Red-tail equivalent of a teenaged human with a sports car?



Donegal Browne


Monday, March 10, 2008

A Brown-tail Kill and John Blakeman on Finding Replacement Mates


A yearling Red-tail in Caumett Park has a bite of newly caught prey.

Even though we later learn these two raptors are in one of the Osprey's favorite trees at Caumett Park, the Ospreys obviously aren't back for the season as yet, or this pair of relaxed Red-tails, (note the lower bird has fanned out her red tail), just might have been a dispute waiting to happen. Microbiologist Linda Schiess and I decided to go check out Caumett Park, Sunday, without any optical help in the way of magnification if you can believe it, and the place was crawling with Red-tailed Hawks, flocks of Canada Geese, Red-winged Blackbirds, Robins, lesser groups of assorted other migratory birds plus, my favorite, an escape artist Kestrel in the Gift Shop.

3:13:41PM A Red-tail, whose tail is brown therefore a yearling, is perched near the paved path. All is well for photography as long as I stay on the path. The moment I step off she's gone. But as it turns out, not gone for long, as she's got a kill in mind.

3:15:55PM We've perhaps gone a half dozen yards past the tree the brown-tail was perched in, when towards our side of the mowed grass area coming from the other side, a Red-tail swoops by and pounces on prey in the leafy verge of the tree line.

3:16PM She stands gripping for a few moments.

3:17:00PM Then, BAM, BAM, she lifts up off the ground, prey in talons, and smashes something gray onto the ground repeatedly. BAM! She then flips whatever it is up in the air and grabs it again. BAM! BAM!

3:17:21PM She hops over and looks down.
3:17:31PM The prey flips into the air again, Brown-tail turns and takes a heroic stance, looking left. Has anyone noticed?
3:17:36PM Now she looks front.
3:17:49PM Brown-tail straddles the prey, then leaps into the air and comes down, talons extended. By this time, a small group of watchers has gathered.
3:17:54PM Leaning down, see today's top blog photo, she takes a bite of her prey. Gray prey takes to the air once again albeit stiffly and someone behind me says, "It's a squirrel. I have to leave. I have to leave!" Everyone leaves but Linda and I.

3:17:59PM Brown-tail mantles and watches them go.


3:18:11PM Oops, not dead yet. Get it! Get it!


3:18:16PM Wings up, talons raking.

3:18:20PM MINE!

3:18:26PM Is anyone looking?

3:18:31PM Bang! Smack! Dead yet? One talon is extended. Stab! Stab!


3:18:43PM Get it!


3:18:55PM She pounces. Leaves swirl up.


3:19:11PM She's up on her toes, she grabs, prey flies through air again.

3:19:17PM Finally!


3:19:44PM But a little more bamming can't hurt.

3:19:49PM Take that!
I make the mistake of stepping off the path, desperate for a better look.
3:20:17PM I take another step and off she goes. She hasn't anything in her talons. Her prey has been left behind. She'll be back.
What is the prey by the way? Is it a squirrel? We scurry over to check. Where is it? Linda says dryly, "I think it's that stick."


As you've no doubt seen from the zoomed photos all along, "the prey" is a heavy stout stick. Zoom being an advantage we didn't have at the time with our very long range view, sans binoculars. More fools we, the jokes on us.
It really was quite the display which went on for a good five minutes. I wonder how much longer it would have gone had I not stepped off the path? It did get me to thinking. Killing rocks and sticks is something we've seen very young Red-tails do. I'd no idea that a yearling would participate in imaginary killing at this late age. Strength training? It is a far heavier object than those chosen by just fledged eyasses. Or perhaps the bird I've been calling a she, is really a he, and he's hoping to impress a possible future mate with his strength, speed, prowess, and last but not least--creativity?


Never underestimate a Red-tail.


Speaking of unusual behavior, as I've previously posted, James O'Brian, http://yojimbot.blogspot.com/, saw Isolde of the Cathedral nest, do something he'd not seen her do before. She flew up very very high and then made a beeline into other Red-tail territory. James felt she might well be off to choose a new mate at the time. I felt that might well be the case as she had been being harrassed by other raptors, and mobbed by Crows Isolde needed some help to hold the territory and Red-tails do come up with new mates very quickly. So I emailed John Blakeman with some questions about how Red-tails might acquire new mates so quickly and forwarded along James O'Brian's sighting and theory. I also asked for his thoughts concerning Rob Jett's sighting of the interaction between the resident formel in the territory he watches and the confined female. Here's what Ohio Red-tail expert, Mr. Blakeman had to say---

Donna,

Yes, perchance, I did see the photos and story on the free-flying RT harassing the enclosed bird. The crucial, revelatory behavior here was the bowing of the wild bird. Red-tails have an interesting intraspecific (same species) threat display, contrasted to threat displays against other species.

To threaten a non-Red-tail, some other bird or animal, a resident bird will flare its hackles (head feathers), open its wings, and stand very erect. This warns any nearby species that the hawk means business and is about to attack if threatened. Eyasses do this when a human approaches them on a nest.

But these flared-wing displays are never used to warn nearby or intruding Red-tails. Instead, the offended resident hawk takes a perch and leans over and assumes a very horizontal posture, with the wings sometimes slightly flared a bit out to the side, and the head just a bit lower than the horizontal back of the bird.

I once had a Red-tail that was illegally taken from a nest as an eyass. It imprinted to the teenager who tried to raise it, before wildlife officers confiscated it. Because it was so severely imprinted to humans, it was given to me to use as a hawk in my education raptor education programs.

I could never figure out if the bird thought it was a human, or if I was a hawk. At any rate, especially in winter and early spring, when breeding hormones were flowing, Goldie (she was one of the local birds at the west end of Lake Erie with a peculiarly golden plumage) would bow right to the ground when I approached her enclosure. If I walked up to her, she would grab my foot or gloved hand. She never figured out why I didn't appropriately retreat when she so clearly displayed her displeasure of my encroaching upon her territory.

My falconry Red-tails, all taken in the fall migration, never display the low, bowing intraspecific threat displays. They know they are hawks and I'm something else.

Goldie, by the way, was the female in my captive breeding program, from whom I learned first-hand how Red-tails behave on the nest and with eggs and eyasses.

Now, just how do hawk widows or widowers attract, gain, or accept new mates, and how does this happen so quickly? The details of all of this will probably be an entire chapter in my Red-tail book -- a chapter I'll have to spend a great deal of time working out. In short, no one really knows exactly how new mate selection and acceptance really works. It's almost always very quick, often within days, or even hours, of the loss of a mate. Was the new mate, a "floater," hanging around at the periphery of the territory, awaiting a mating opportunity? Do floaters, unmated young adults, spend their winters and early springs flying a circuit between the edges of multiple occupied Red-tail territories, on the continual search for new "openings?"

The observation of the new widow skying up and off into the distance, perhaps thereby announcing her availability, is very intriguing. I've never seen this, but I don't get to see nesting Red-tails as continuously has they could be studied -- of all places -- in Manhattan. This is a very reasonable possibility.

There is so much we now know about this remarkable species. But for each new behavior we discern, there are a dozen other antecedents that remain unexplained

--John A. Blakeman


Indeed.
Donegal Browne