MORE FROM JOHN BLAKEMAN ON SEXING RED-TAILS

Divine Fledglings 28 Jun 2006


More from John Blakeman, prairie expert, falconer, and frequent contributer of Red-tail information to New York City's urban hawkwatchers.


(The paper mentioned below is Sex determination of Red-tailed Hawks (Buteo jamaicensis calurus) using DNA analysis and morphometrics, J Field Ornithology, Vol 77, Issue 1, pp. 74-79. And as most of you know Bruce Yolton is one of our local hawkwatchers. D.B.)


Donna,

I believe I sent you an email in reference to a photo of the two Divine eyasses next to each other. I noted that the larger one on the left was decidedly a female, the other a male. No doubt in my mind.

Bruce Yolton has just posted a note that sexing red-tails is very hard, and he doesn't recommend it. He references a new article on the subject.

I've read the article, and in fact, it shows that in-hand measurement data of red-tails can accurately reveal the sex (as confirmed by PCR DNA analysis) at 97 and 98% accuracy rates. I don't know the basis of Bruce's caution.

In fact, for those of us who have trapped, handled, and trained literally hundreds of red-tails, sexing is seldom questionable. Males have a male "look," and females a female visage.

All of us falconers have trapped "in betweeners," birds that tend to look one way or the other, but aren't absolutely definitive. If you trap a 1500 gram red-tail, she's a female. A 1100 gram bird is always a male (unless the bird is emaciated from disease, but these birds are then re-fed and they gain back their lost weight). But a 1200 gram bird might be a tiny female, or a giant male. That's where those of us familiar with the species just look at the head to see if it looks like a female or male. Males tend to have narrower heads and smaller bills (minutely).

When there is a decided size difference as in the photo, there is no doubt about the birds' sexes. The size difference was big enough that anyone, even the inexperienced, could have noted it. Males tend to be narrower across the shoulders, as in the photo your description of the female being "chunkier" is perfect. They are just that.

For the experienced, sexing red-tails is not mysterious or erroneous. We are correct at least 97% of the time.

--John Blakeman

The Whole Family at the Cathedral, 27 Jun 2006

Youngest preening.
But just where is what body part?
Orangey chest where one might expect her back to be, as her head it pointing in this direction. Where are her wings and what about that leg? Well...? Hmmm.

Who needs a roller coaster? Attempting to perch in the wind.


Eldest's back. Note the identifying pattern of light and dark.


Eldest


Photograph by Samantha Browne-Walters
8:04pm The reason we were having such trouble finding her.


Youngest Photograph by Eleanor Tauber

( The Blog is being contrary about posting photos, therefore I was only able to get Eleanor's to go up. Will post more when the blog is amenable.)

CATHEDRAL RED-TAILS 27 Jun 2006

Temperature 74 F.
Cloudy
Wind SSE to 17MPH
Gusts to 25MPH
Humidity 94%

Tonight's Intrepid Fledge Followers, willing to put up with poor visibility, wind, and far too much foliage: Samantha Browne-Walters, Robert Schumunk, Jean Dane, Eleanor Tauber, Liz, and I.

6:08 Sam and I arrive on Morningside Dr.
6:27pm We discover Youngest in Locust Tree in Park, E of lower path, 35 ft. north of bottom door to Overlook mobbed by Robins. (Many thanks to them.) Liz and Eleanor arrive, Liz has seen Youngest also.
6:40pm Youngest to new branch...somewhere in same tree.
6:43pm Mom flies past Youngest's tree, east to west. Youngest begs in a serious and double pitched cry then suddenly stops.
6:45pm Sam on the lower path glimpses RT from Youngest tree heading for the Cathedral. We later surmise it is Youngest and attempt to find her feeding at the Cathedral. But fail.
7:12pm We catch sight of immature RT over park, circling, then to Locust south end of park.
7:13pm Robert reports Fledge being mobbed by Robins in Locust Tree, within S Park near border midway between Morningside and Manhattan Ave.
7:15pm Jean identifies a fledgling in Locust Tree, second S from bench area in overlook nearest mid-entrance...Youngest.
7:33pm M0m to Locust in Park opposite Cathedral School, then out.
7:43pm Eldest flies to Locust tree at the edge of the park, midway between Morningside and Manhattan Ave. Robins mob. (Same tree, fledge was spotted in earlier in the evening by Robert Schmunk.)
8:05pm Two RTs spotted flying high over Cathedral.
8:07pm Jean spots Dad sitting on decoration belonging to St. James the Greater on Cathedral.
8:09pm Dad off St. James, circles above park, looks to go into Eldest's tree, but not sighted there again.
8:16pm Dad circles over park and church.
8:18pm Eldest hops to new branch, same tree. Robins are really heating up vocally.
8:22pm Fledge moves again, new branch, same tree. Tree is blowing so much, her branch swaying and bobbing, it is as if she is on a roller coaster.
8:28pm Mom flies into tree inside Cathedral grounds just north of first light pole from Morningside and 110th.
8:32pm Dad? from Cathedral, circles over Morningside Dr., then curves over corner of 110th and Morningside. Disappears behind middle "Cheese Wedge" building on the SE corner.
9:10pm Gab is illuminated tonight as well. This time he/she looks silver. Floodlit?
9:15pm After getting some take-out Banana Pudding from Miss Maimie's Spoonbread Too, which we highly recommend by the way, we exit.

JUST THREE AGAIN, plus Peacocks 26 JUN 2006

Photograph by Samantha Browne-Walters
Blue Peacock tail...belongs at 7:01pm but somehow didn't get placed there. When you get to 7:01, just be so kind to look back up here.

We're actually going to start at....
5:35pm Sam and I walk out our lobby door to 9th Ave. A few large plops of rain fall on us. We don't mention them. Lack of attention may depress them so much they will go away.

6:19pm The Cathedral. We've searched the usual spots and so far have come up with nothing. Suddenly a mature Red-tail is circling above 109th street. Then she tucks her wings and zooms toward the west. We decide to search the Cathedral Grounds themselves.



6:38pm Sometime between when we left Morningside Dr. and got round through the front gate, Dad landed on Gabriel.

6:39pm We set the scope up and show a few passers-by. Before too long Bruce Yolton comes round a corner, sees Dad, and tells us that Mom is perched on a water tower east of us. We pick up the gear again and go to check it out.


6:48pm I look back, Stealth Dad is still there.
6:49pm Mom is still perched on the watertower and a smaller bird is perched on a vertical pipe not far from her. The little bird is not happy about Mom.

6:50pm The smaller bird takes a dive at Mom and she's up before we can get the scope on them. She circles counter clockwise over the grounds and then heads south, then circles back east, and disappears behind a building on the other side of 110th.

7:01pm Now we're back on the west side of the grounds and Sam is thinking Peacocks not hawks. We pass what she now calls the Peacock Hut and she scrambles over to it. The grating is closed down over the entrance. They must be in for the night. She peers inside. Sure enough, not only in for the night, but finished knoshing their Peacock Chow, and getting ready for bed. A long blue tail hangs down from a sort of Peacock bunk bed. (Look back up to the top, NOW.)

Is the other blue Peacock up his tree? We've heard he prefers to roost on a branch in the big tree across from the red brick Federal style building not far from the Hut. Or perhaps he has decided to hang out in the hut for the night but has his tail tucked up tidily out of sight. Nobody is talking so we'll never know if he's missing.

Speaking of the missing, where is Whitey?


Photograph by Samantha Browne-Walters
There's Whitey. Up on a private perch.

Then it's back to straining our necks and ears but further searching of the grounds for the Fledglings turns out to be fruitless. We circle around and head for 110th where Mom disappeared behind the brown building.

7:11pm After coming down 110th with no success, we see Robert Schmunk pointing out a hawk in a Locust tree near the corner of the park. Sam and I get the scope up. It's Eldest. And she has already learned the Red-tail trick of perching with a branch above her head that protects from overhead attack. The Robins are aware of her and are verbalizing their annoyance.


7:22pm Look at the back pattern, still a V and still somewhat squarish. Keep up with it, as it is a bit reshuffled with her position.


7:40pm It has become quite dar. Clouds scudding across the sky and I keep loosing sight of Eldest in the tree. Even though she isn't changing perches and I'm not changing where I am standing. All of a sudden I notice how well the juvenile feathers of a Red-tailed Hawk work when it comes to blending her into a tree. Notice how the belly spots can appear to be leaves, the pale underbelly sky, and the varigated brown face, bark. As to the bulging orangey crop, that's another discussion all together.

7:57pm We've gone off to search for Youngest. This will be the second day that we haven't seen her if we don't see her soon. Then a mature RT flies out from the Cathedral, over the park, and circles the Great Hill. Is Youngest over there?


Photograph by Samantha Browne-Walters

8:24pm Eldest, her crop stuffed full, and the light fading, begins to look very sleepy.

Photograph by Samantha Browne-Walters
8:25pm Eyelids heavy, she nodds forward, and sways on her feet ever so slightly.

Photograph by Samantha Browne-Walters
8:26pm Then, swaying gently on her branch in the breeze, she falls asleep.

8:30pm The other hawkwatchers have gone home and Sam and I are packing up our stuff in the middle of the sidewalk. Suddenly a police car pulls up beside us, and it is an officer that has spoken to us before. We chat small and point out Eldest. He wants to know how much longer we will be coming up here. I say, for as many days as we can still find them. Then I tell him, before he asks about tonight, that we're just about to go home for the day . He nods and smiles, says see you soon, and then drives off down the sidewalk. Sam states the obvious. "Ah mom, he's driving on the sidewalk." "Yes, darling", I reply, "He is. New York City policeman have been known to do that."

8:40pm It is the oddest thing. After all, it's getting quite dark. It's cloudy and dim. Sam and I are standing on the SE corner of Morningside and 110th discussing how hungry we are, when I look up the hill toward the Cathedral. To my amazement green Gabriel is turning gold. I don't mean goldish. I mean shiny gold, sparkly gold. I mean radiant, light flinging gold. I can't figure out where light would be coming from to reflect off him. In fact it looks like he's radiating the light himself. Really quite startling actually, when one considers how his solidness wouldn't allow that , and how well patinaed green he is.

Wait a minute. It's pretty much sunset right now. Is it possible that Gab is positioned just so, in order to reflect the last rays of the sun on certain days? It couldn't be everyday could it? Seems unlikely due to the changing angles...but then what do I know.

Guess I better find out.