Saturday, January 13, 2007

A slip of the nuthatch caught by a large Gotcha gang

Red-breasted nuthatch -- photo by Lloyd Spitalnik --

I'm redfaced, but also gratified. I d1d misidentify a White-breasted Nuthatch on Lincoln's website and call it a Red-breasted in my posting yesterday. That was pretty stupid and hence the red face. But, my! how many letters came in!

I'm gratified that so many good birdwatchers read my website! Though if I bother I can find out how many readers I have, I don't know much about them. Now I know more. An astute, discriminating bunch, that's what you are.

The nicest letter came from Joyce Eagles, who not only said something nice about my site, but tried to be merciful about the mistake. She wrote:

Dear Marie, I have spent many happy hours enjoying your web site. The photo by Lincoln posted today is not a Red-breasted Nuthatch. It is a female White-breasted Nuthatch. The usual reddish wash on the undercarriage seems more extensive than is usual. joyce eagles

Friday, January 12, 2007

Redtails booming: Esford and Blakeman

Before we go back to red-tailed hawks:
Yesterday in Central Park, a Red-breasted Nuthatch
Photo by Lincoln Karim

Website correspondent John Esford writes:

Yesterday while travelling along I87 (NYS Thruway) south from Albany we counted no less than a dozen red-tailed hawks perched near the roadway from Albany County south to Ulster. Growing up in Saratoga County (and travelling extensively throughout NYS) the sight of any raptor has been an unusual (and thrilling) sight. I've researched your observations in Manhattan, and just to confirm your observations, the "upstate" areas bordering metro NYC are "booming" with red-tail populations. It was a most unusual series of spottings indeed. Gook luck, John E

John Blakeman comments:

The correspondent's recounting of numerous red-tails along a New York Interstate is typical. It substantiates my observations that red-tails are everywhere today, having saturated all available habitats.

Two factors come into play. First---and I've encountered this numerous times---the hawk watcher may have seen so many red-tails because he finally began to look for them. They may have been there for a long time. Most people drive down the freeway and keep their eyes and attention on the road ahead, failing to see the numerous red-tails perched on utility poles, fence posts, and adjacent trees.

But once one begins to learn where red-tails typically perch, they are easily spotted in a momentary glance. We scan the usual spots and search for the bright breasts. After you've seen a few of these, the following birds are quickly and easily spotted.
The second factor is the extremely mild, snow-free winter. Without a snow cover, the vole populations in the grasses along highways are easily seen by perched hawks. With lots of available voles in the grass, many red-tails lose their autumnal impulse to migrate southward. Many of these birds may remain in upstate NY because of good hunting conditions. If some heavy, persisting snow hits, the birds can still go south of the snow line and locally disappear until March.

--John Blakeman

Wednesday, January 10, 2007

Lewis & Clark saw Osage Oranges: last of a series

But first owl news. One year after a Great Horned Owl was photographed in Central Park, almost to the day, another GHO was seen in the Ramble. That was on Tuesday, Jan 9, 2007. Last year's owl stayed more than a month. Day before yesterday's owl stayed the usual one day. Yesterday it was gone. Now....on to Osage Oranges.
Great Horned Owl in Ramble, January 10, 2006
Photo by Cal Vornberger

First they repelled cockroaches. Next it was spiders. Now ants.
Here's the last osage orange posting, from Missouri. Too good to miss.


On the occasion of the bi-centennial of Lewis and Clark's Voyage of Discovery, an artist painted a mural on a wall in the Museum beneath the Gateway Arch showing Meriwether Lewis sitting outside Pierre Chouteau's home (a site now a part of the Arch grounds). Lewis was making sketches of a huge Osage Orange tree and its weird fruit to send to President Jefferson before the Voyage had left St Louis, some of many sketches he would complete of the strange plants, birds and animals he and Clark would find on the journey west. These included of course Lewis' Woodpecker and Clark's Nutcracker.

Today there are many such trees remaining in St Louis and across Missouri with their great whorls and rusty orange trunks, possibly because they were not commercially useful, but merely imposing and strangely beautiful. My mother had heard that the fruit was possibly repellent to the little ants that came in the kitchen after a rain...don't think they did much good, though.

Jacquelyn Chain
St Louis

Monday, January 08, 2007

Why woodpeckers' brains don't get addled and a Postscript

Riverside Park Red-headed Woodpecker
Photo by Scott Zevon

From the British Journal of Ophthalmology, 2002,86, 843:

To equip the bird for its ecological niche, evolution has provided the woodpecker with a thick bony skull with relatively spongy bone, especially at the occiput, and cartilage at the base of the mandible to partially cushion the incessant blows. Inside the skull, there is almost no cerebrospinal fluid in a very small subarachnoid space. The mandibles are attached to the skull by powerful muscles that contract a millisecond before strike, creating a tight, but cushioned structure at the moment of impact and distributing the force of the impact to the base and posterior aspects of the skull, thus bypassing the brain ( May et al, Lancet1976;1:454–5[Medline]).

The neurological mechanisms must be superb since these birds strike in a perfect perpendicular stroke to eliminate the torsional shear force that would otherwise tear the meninges or cause concussions ( May et al, Arch Neurol1979;36:370–3[Medline]).

Although not studied, this mechanism probably also protects against intraretinal haemorrhages and retinal detachment. Additionally, the woodpecker is protected, at least to some extent, by its size. Its brain is relatively small, resulting in a small ratio of brain weight to brain surface area. Any impact force would be spread out over a relatively large area making its brain somewhat more resistant to concussion than a human’s brain. Nevertheless, the woodpecker will use the leverage of its entire body weight to increase the force of impact of its bill, and it becomes a full body hammer.

of pileated woodpecker head. This sagittal section is at the approximate mid-point of the skull. The hyoid bone can be seen as small white opacities just inferior to the eyes as illustrated with the black arrow. (Scan by Erik R Wisner, DVM, School of Veterinary Medicine, University of California Davis.) Right: Woodpecker skull cut in A-P direction illustrates the dense, yet spongy, bone and the narrow subarachnoid space. Note the large eyes compared with the brain. (Photograph by

The same high speed photography that has documented its strike mechanism has revealed that in that millisecond before strike the thickened nictitans closes over the eye. This would protect the eye from flying debris and chips, but would also act as a "seat belt" to restrain the eyes from quite literally "popping out of its head."

Woodpeckers enjoy a cushioned choroid with an as yet unknown mucopolysaccharide filling the interstices. The pecten probably also has a role in maintaining an effective cushion as the pecten can fill with blood to briefly elevate intraocular pressure thus maintaining firm pressure on the lens and retina to prevent damage.

The woodpecker has other unique adaptations that deserve recognition and may contribute to the protection from intracranial injuries. The tongue is most unusual as it originates on the dorsum of the maxilla, passes through the right nostril, between the eyes, divides into two, arches over the superior portion of the skull and around the occiput passing on either side of the neck, coming forward through the lower mandible, and uniting into a single tongue in the oropharyngeal cavity. The muscles encase the bony hyoid throughout this muscular course into the oropharynx and are additionally secured in the floor of the mouth creating an apparatus that allows for extraordinary protrusion of the tongue of up to 4 inches beyond the tip of the bill! These musculotendinous bands create a curious sling-like structure that probably functions as an isometric shock absorber if contracted before each strike. This sling would also serve to distribute the potential shearing forces ( May et al, Lancet1976;1:454–5[Medline]).

Such length is useful for penetrating insect nests beneath the bark of trees. The sharp tongue (literally) is coated with sticky saliva for smaller insects such as ants and has backward pointing barbs that are useful in impaling larger insects and grubs. For added emphasis, the tongue is equipped with excellent tactile abilities to allow for recognition of smaller insects, such as ants. The chisel tipped mandibles are constructed of individual fused plates of keratin called rhamphotheca, and the longitudinal trabeculae are reinforced with calcium.

PS Today is TURNAROUND DAY for sunrise. From henceforth, sunrise will begin to get earlier. Yesterday sunrise was 7:20 a.m. Today it was 7:19 a.m! And, in case you're interested. Today the day [i.e. the period between sunrise and sunset] is 1 minute and 13 seconds longer than it was on December 21, the solstice. Why, if sunrise has continued to be later? Because sunset has been getting later too, since December 13th!

How red is his head?

Red-headed Woodpecker in Riverside Park - January 7, 2007
Photos by Scott Zevon --[Click on any photo to enlarge it]

Scott Zevon, a doctor with an office near Central Park , sent me these great photos of my Riverside Drive neighbor. They should resolve any doubts about whether this uncommon woodpecker who is attracting quite a following among Central Park birdwatchers, is really getting a red head..Too bad I'm working at my downtown office most daylight hours these days. I'd invite all the woodpecker fans up for tea and cookies! [This bird's roost is directly outside of my building .]

Sunday, January 07, 2007

They're not useless says Jan

Jan Lipert, a frequent website correspondent, responds to John Blakeman's comments about Osage Oranges posted yesterday

[This is a far richer subject than I imagined...]

Hi, Marie --
In the late 1950s, decades before the invention of paint-balls and water balloons, the boys in my grammar school in New Jersey discovered that the Osage oranges lying under the schoolyard hedge made wonderful 'bombs' to throw at each other. The ripe fruit would smash upon impact, to the great joy of the boys and the consternation of the the teachers -- and, I am sure, of their mothers, who had to clean their uniforms.
Please tell John that Osage oranges are not completely useless, after all!
Jan Lipert