Tuesday, March 29, 2005



3/29/05 ---Today after the Feeder-Filling get-together at the Evodia Field, Lincoln Karim and I walked to the North Woods to try to see the Screech Owl Family. Almost everyone besides us had already seen the Fabulous Fivesome. We headed to the little wooded area a little east of the Pool and there met Jim Demos, who was also Owl prowling. He, however, had seen them before, five times, to be exact. [Jim Demos is the man who achieved birdwatching fame last December when he discovered a highly unusual owl, a Boreal, in an evergreen near Tavern On The Green.]

We split up and diligently searched for at least an hour. At the northeast corner of the Pool, just where the downhill path to the Loch and Wildflower meadow begins, we finally converged, and ran into three other birdwatchers looking for the owls. We chatted for a while about our unsuccessful search.

At this point it was 3:00 pm and I, consumed with guilt about work undone, left for my office. A few minutes after I arrived Lloyd Spitalnik called. They had found the owls. Where? In a small pine at the northeast corner of the Pool. just where the path to the Loch and Wildflower Meadow begins.


sent by Pierre Henkart, a biochemist/immunologist in Bethesda, MD:

Reading your discussion of why female red-tails are larger than males (reverse sexual dimorphism, or RS D), I got curious about this and have ferreted out some interesting material from the internet. In particular, there is a recent PhD thesis by PG McDonald describing a study of Australian brown falcons that seems potentially relevant to our red-tails. It attributes RSD in the falcons to “intrasexual selection” among the females (in which larger females compete more successfully with other females for access to males with breeding territories), as well as increased mortality of larger immature males and greater breeding success of larger females. The female competition idea seemed to be in line with Pale Male’s quick replacement of mates over the years. In any case Chapter 7 of the thesis contains the most relevant material, including a summary of the 20 hypotheses proposed in the biological literature to explain RSD. Something close to this chapter was recently published in the biological journal Behavioral Ecology, vol 16, pp48-56 (2005; alas, not freely web-accessible). The full-blown academic style with data tables, statistics, etc., may be hard to swallow for some, but I would really love to get John Blakeman’s thoughts on whether the proposed explanations for brown falcon RSD apply to red-tails. The whole thesis (200 plus pages) can be freely accessed at: [See link below]
Since none of the simpler explanations seem to work to explain RSD, it may be worth the effort to see what some of the professional bird biologists think.

Click here for text of thesis

Sunset 6:16PM,
Temp. 43F,
W. Chill 38F,
Heavy Rain,
Wind ENE Gusts to 15 to 25 MPH,

3:49PM Heavy rain, Hawk not visible in nest. Mallards
out of Boat Pond sheltering under shrubbery S of Hans
and browsing in standing water on lawn.
3:59PM Dog appears, ducks back to pond, very wet Lola
head appears above nest.
4:02PM Lola disappears into nest, rain continues.
4:25PM Mallards out of pond return to Hans area.
4:40PM Mallards chased by dog back to pond. Lola head
up, then down.
4:43PM Very wet Lola stands, much digging with feet,
she turns eggs. Preens, looks to be striping water out
of breast feathers. Pelting rain begins, she quickly
settles into nest.
4:50PM Mallards tuck bills into wings.
4:51PM Lola head up, alert, then disappears into nest.
5:09PM Male Cardinal appears for daily peanut, he then
cracks it open and feeds mate in Cornelian Cherry
directly behind bench.
5:11PM Lola still not visible.
5:12PM Central Park path lights come on.
5:15PM Exit, no hawks in sight.
Central Park puddles over 9 inches. Much soil from
denuded portions of Pilgrim Hill washed into path.
Submitted: Donna Browne



Like others, I appreciate your posting of the kestrel notes. The species was the first raptor to invade and abide in urban areas, in the 19th century with the construction of taller buildings.

I don't think we want this website to stray too far from Central Park's red-tails, a central story theme of your wonderful webpage. But because American kestrels (formerly called "sparrow hawks") can be so commonly encountered in every city of any size, their appearance here only adds to the urban hawk story. These delightful little falcons are full of spunk and inhabit cities without inhibition.
Urban hawk watchers should be aware (as many certainly are) of this engaging species. It was the first raptor I worked with, and I shall never forget its wonderful personality. These little falcons always act like they are the size of gyrfalcons, uninhibited by hardly anything they encounter in the city.

In rural areas, they share one trait with the red-tail that keeps them from being held in universal high regard -- they are merely common. Personally, I don't let commonality restrict my respect and esteem for either species. Some folks think they have to go to the Arctic to see a wild gyrfalcon, or to Africa to see a hawk-eagle of some sort to be "significant." For me, the kestrel and red-tail are quite sufficient. As visitors here can see, there is still much to be learned about these common species, and always much to be thrilled by. I'll leave the gyrs and African raptors to others. My spirits rise when I see a rural kestrel or red-tail -- and even more so at the sight of one in the city.

[And may I help everyone get the pronunciation of "gyrfalcon" right? I know, it looks like it should be "GIRE-falcon." But like so much else dealing with raptors used in early falconry, the bird's name derives from some antiquated terms from a former time in the development of English. The proper modern pronunciation is "JERR-falcon," spelling notwithstanding. And technically, a male gyrfalcon is called the jerkin, pronounced as spelled.

I hope this helps someone new to all of this. I embarrassed myself royally before some professors as a freshmen when I made some revelatory comment in class about a "gire-falcon." Oh, well.]


John A. Blakeman


Steve Watson writes that there are FIVE eggs now in the box, and incubation has begun.

Photo by Steve Watson
Pair of Kestrels nesting in a Santa Clarita nestbox near home of photographerA NEW SPECIES OF HAWK FOR BLAKEMAN TO COMMENT ON


Wondering if you could ask your friend John Blakeman if he knows of any way to identify individual kestrels. We have a pair that has moved into the nestbox we installed, and we're watching anxiously via the nestbox cam (and hundreds of people are watching on the Internet) to see how many eggs she lays (3 so far) and how many chicks hatch, etc. But we've begun wondering...how will we know if they come back next year, if this is the same pair, or a different one? I'm *terrible* at individual bird identification, even for large raptors (I'm much better at large mammalian predators, like wolves)...so do these small falcons have any unique *individual* markings that we could observe?

Here's a quick pic of our two...quite the couple, don't you think? I'm sitting her watching her sleeping soundly right now :) It's actually more entertaining than any "entertainment" on television!

Stephen H. Watson

Here's Blakeman's helpful response:


As it happens, I worked with probably a dozen or so American kestrels along with my red-tails in my undergraduate research on raptor caloric requirements at varying temps. I know the species well.

Each bird will be different, with unique feather patterns on the head and chest. Detailed close-up pictures of these can reveal individual IDs. But even as an experienced expert, this gets too far beyond tedious . Occasionally a bird will have a feather or two that is quickly diagnostic, but in most cases it's going to be lengthy periods of time comparing jpeg after jpeg. I don't recommend it. It's frustrating and ultimately confusing.

The far better approach --one that can really work -- is to get the eyasses banded. Check with the California wildlife authority, or a local US Fish and Wildlife Service office and ask for a raptor bander. Tell them the unique situation you have. Banding of eyass kestrels causes no problems. The adults are back feeding the young just about as soon as the bander closes the door on the nestbox. An ornithologist at any of the local universities should know of a bander.

You might ask the bander to apply colored bands, for easier ID. This may not be authorized by USFWS, as they prefer to do this only with important research birds but give it a try).

As always, I'm very interested in what the adults are feeding the eyasses. I have no idea what Pasadena kestrels feed their young. I presume insects are a notable fraction of the prey, but what mammals are being fed? I don't think you have the common vole (Microtus spp.) there. I may be wrong.

Keep me posted.


John A. Blakeman

PS: In the next communication, Watson informed Blakeman that the kestrels seemed to be eating mainly lizards.

Here's a link for Steve Watson's Kestrel Webcam

Birder Bob Brooks writes:

On Sunday 3/27/05] a 2nd winter Icelandic Gull, in amongst the herring gulls out on the island in the reservoir, gave us a great show through my scope. I never would have seen it but not for the other person since I usually ignore the gulls. I was looking at the hooded mergansers through my scope when he approached and got the gull in my sights. We then zoomed to 45 power and had a great show. We watched it for about 30 minutes. We verified all the points in Peterson and Sibley. My first Icelandic and very excited to see this beautiful creature and I will never again ignore the gulls.

Bob Brooks