Friday, July 18, 2008

At the Moth Tree and a PS

The Moth Tree


Wednesday night 7/16/08
Girlfriend Underwing [Catocala amica] with Armyworm Moth [Mythimna unipuncta]


below: Ilia Underwing [Catocala ilia]
above, right: Girlfriend Underwing

Last night 7/18/08 -- 8:55pm to 10:10pm
Reported by Marianne Girards

Armyworms [50+]
Coppers Underwings [5]
Ipsilon Darts [10+]
Idias [10+]
Lunate Zale [1]
Large Yellow Underwing[1]

PS
Those of you who have read Central Park in the Dark may be surprised to hear reports of moths at the Moth Tree in 2008. Hadn't the last chapter of the book implied that the Moth Tree was a thing of the past? Well, as Mark Twain once quipped about his own demise, so reports of the Moth Tree's death turned out to be hugely exaggerated. While last year was a moth-less disaster at the tree, this year, to the delight of the Central Park Mothers [rhymes with frothers] it is copiously oozing its insect-attracting sap once again.

Underwings and a Black Skimmer on Wednesday

Black Skimmer at the Model-boat Pond, 10pm 7/16/08
Photo by Bruce Yolton http://www.urbanhawks.blogs.com

Good moths at the Moth Tree on Wednesday -- a large Ilia Underwing and another Girlfriend Underwing. But the star of the evening was a Black Skimmer fishing at the Model-boat Pond within sight of the Moth Tree. It seemed impossible, but Bruce Yolton managed to get the thrilling shot of it above.

Tracking Hoots in the Night

Photo by Bruce Yolton in today's NY Times-- story begins on p E 27
first page of the Weekend Section - Fine Arts& Leisure

I've put the link to the story on this websites new page devoted to book news: http://www.cpind.blogspot.com

Here is the story without all the ads:
July 18, 2008

In Urban Wilderness, Tracking Hoots in the Night

ONE night in Central Park, when the screech owls were teaching their babies how to fly, a group of birders were scanning the canopy of a white oak tree at the Loch, the stream that meanders through Frederick Law Olmsted’s designed wilderness.

“I’ve got them,” Caroline Greenleaf said in a low voice. Her two little dogs, Zoe and Willa, trained not to bark, sat at her feet.

“Three of them, all together on that thin branch out to the right.” Marie Winn handed me her binoculars, and pointed to the shadowy mass of branches and leaves.

Ms. Winn, who chronicled Pale Male and Lola, the hawks that nested on the 12th floor of a Fifth Avenue apartment building, in her 1998 book, “Red-Tails in Love,” has been exploring the lives of owls, bats, moths, slugs and the people who love them, resulting in a new book, “Central Park in the Dark: More Mysteries of Urban Wildlife.”

Humans are hard-wired to avoid dark places, especially the forest. “We are daytime mammals, after all,” Ms. Winn writes, “and evolution has programmed us to respond to failing light by crawling into a safe, snug place and going to sleep.”

Except for New Yorkers.

Here, on that warm night, with Ms. Winn and some of the humans she writes about, I was among a few people who were not only defying evolution, but who were perfectly at home in the urban forest after dusk. Central Park had its dangerous days, to be sure, but restoration projects and cultural programs administered by the Central Park Conservancy since its founding in 1980 have brought it a long way. And as any urban dweller or hiker knows, the more people who enjoy a place, the safer it becomes.

We had met at Central Park West and 103rd Street, and made our way down the hill, along the north side of the Pool, into the North Woods. I was struck by how much light there was, even in the trees, with the city rising all around us.

“It never really gets dark here,” Ms. Winn said. “There’s always so much ambient light. And when it’s overcast, light bounces off the clouds.”

That night a half-moon glimmered through the trees as we made our way to the Pool, where we passed a family of raccoons, their masked faces illuminated by a street lamp.

“They’re waiting for the Russian woman, who arrives every night in her wheelchair to feed them pasta and pizza,” Ms. Winn said. “I asked her one time, ‘How do you say raccoon in Russian,’ and she said, ‘Rrrrrraaaccoon.’ ” We laughed, because there are probably very few raccoons in Russia. They are native to North America.

The stately trees, the way our voices echoed against the stones of the Glen Span Arch as we walked beneath the West Drive, and the rocks and waterfalls of the Loch were all familiar. Yet the shapes of things were all in shadow, almost dreamlike, as we made our way deeper into the woods. Joggers ran by. Some even asked about the owls in that hushed, conspiratorial tone that people use when they know about something that might be ruined if too many others knew its pleasures.

Tramping down a dark path, speaking in low voices, stopping at the sound of a bird: “Hear that?” Ms. Winn interrupted herself in the middle of a sentence. “That’s the oriole. That would be the male.

“I’ve been studying the songs. I’m not good at spotting, so I compensate by listening.”

I’d heard the haunting, melodic song hundreds of times calling from the woods in Maryland, but never knew what it was. Here, in the middle of the city, Ms. Winn had put a name to it. I longed to see this oriole, but it was hidden in the night.

Now we stood in a swampy glade, trying to locate the three screech owls that Ms. Greenleaf could see, way up in the tree. “They’re all together on a very thin branch out toward the right,” she said.

Which thin branch? It always amazes me how birders give directions, but this is how you learn.

“See those three branches that make a big triangle?” she kept on. “O.K. now, go to the top of the triangle, follow that branch up and just below the next branch that goes to the left, you’ll see a little brown mound.”

I found the triangle and focused Ms. Winn’s binoculars on the branch that went out to the left. Nope, nope, nothing. Then. Oh, yes! A baby screech owl stared back at me, its big eyes like dark pools, ringed in yellow. Its feathers were fuzzy and soft, with horizontal stripes across his gray chest.

“Oh, he’s playing with his foot,” said D. Bruce Yolton, a photographer. “That’s adorable.”

I could hear his camera clicking away like mad.

We could see the horizontal stripes on the kids’ gray, fuzzy chests, and the vertical stripes on the parents, whose markings look more like bark, which is why they are nearly impossible to see, perched in the cavity of an old tree.

“Ooh, somebody dropped down from above,” Mr. Yolton said. “They’re bouncing!”

Owls sleep most of the day, so as night falls, they slowly wake up.

“They’re half asleep, so they’re doing some stretching, getting ready for school,” Mr. Yolton said.

They stretched their necks, way up, then down, into their chests.

They stretched their wings. First, one long wing, leaning way over to the side. Then the other.

These birders have been following this family of screech owls since December, when Mr. Yolton found them nesting in a cavity in a black walnut tree. He has been documenting the owlets’ growth and education on a blog, urbanhawks.blogs.com.

That night in the woods we heard the hoot-hoot-hoot of the parents warning their children of raccoons, which like to eat baby owls.

“The father is the policeman,” Mr. Yolton said. “Two weeks before they fledged, he terrorized the raccoons. He scratched them when they came down the tree. He made them know they weren’t welcome.”

It was early April when the group first saw the baby owls venture from their nest.

“They climb up the tree like monkeys, using their bills to help them get to the top,” Ms. Winn said.

They can fly pretty well right off the bat, but landing, they said, is tricky.

“It was very funny,” Ms. Winn said. “We would see an owl landing, then hanging upside down, then falling to the next branch.”

By the time the young have fledged, I learned, they are the same size as their parents, which is only about eight inches tall. The same thing holds true for most songbirds.

But enough of these little screech owls. I admit I love them more than the tiny moths I saw one night in June with Ms. Winn and her friends, who call themselves mothers (pronounced MOTH-ers) when they are stalking these fragile creatures of the night. The moths are drawn by the black light the mothers shine on a white sheet laid over a bench by the Delacorte Theater, where we could hear Hamlet declaiming on the other side of the hydrangea bushes.

“See that little white stigma on its wing,” Ms. Winn said, pointing to a tiny moth, hardly a half-inch in size. “It’s a celery looper, Anagrapha falcifera.” She added, “The common name usually refers to what the larvae eat.”

It was slim pickings on that night, but by now there are many catocalas, or underwings, moths with colorful markings on their hind wings that vary from about an inch to three inches. They come to sip the sap that oozes from the Moth Tree, an English oak near the East Drive just past 72nd Street.

That’s where they saw the black witch, a rarely seen moth, seven inches across. It’s the largest moth in North America, and it’s only been sighted this far north a few times, said Jim Lewis, another regular who showed me a very handsome slug. (The slugs refused to perform for us that night, but their romantic mating is fully recounted in Ms. Winn’s book.)

The screech owl children have finally left to find their own way in the world. And the mothers are immersed in underwing sightings at the old English oak. “We’ve seen a girlfriend, though it could be a he, a once-married, an ilia and a little,” Ms. Winn said, using the oddball common names of the moths.

The moths open their wings to reveal striking patterns of orange, yellow and black. But only for those who venture into Central Park in the dark.

##########

Here's a link to a little audio story on today's NYTimes website:
http://www.nytimes.com/interactive/2008/07/16/arts/moth-audioslideshow2/index.htm



Thursday, July 17, 2008

A bathing bird, a dining wasp

Eleanor Tauber has sent in some great photos from yesterday's Early Birder walk:
Great Golden Digger Wasp dining on Swamp Milkweed at Turtle Pond

A Black-crowned Night-heron taking a bath in The Lake

Wednesday, July 16, 2008

New discovery about songbirds

Photo by Lloyd Spitalnik

Fastest Known Muscles Found in Songbirds' Throats

Matt Kaplan
for _National Geographic News_ (http://news.nationalgeographic.com/)
July 10, 2008 [via e-birds]

The fastest muscles known lie within the throats of songbirds, according to new research on how birds vibrate their vocal cords.

Experts have long wondered whether bird song is caused by passive interactions as air moves between the vocal muscles or direct neuromuscular control.

"I had been looking at the muscles in a pigeon species and was amazed by how fast they were moving," said lead study author Coen Elemans at the University of Utah in Salt Lake City.

"[Pigeons] have really boring, slow songs, and it made me wonder what the muscles in songbirds were like, so I decided to find out."

What Elemans and colleagues discovered is that zebra finches and European starlings can change their tunes at frequencies as high as 250 hertz via direct muscle control.

This means that they are moving their muscles a hundred times faster than a blink of the human eye.


To find out how songbirds make their quick-fire modulations, the researchers first measured muscle activity in freely singing starlings and found that muscle motion corresponded to changes in song tone.

The team then exposed vocal muscle fibers from starlings and zebra finches to electrical stimulation in the lab to see just how fast the muscles can expand and contract.

The vocal muscles of male and female starlings both conntracted at about 3.2 milliseconds. Male zebra finch muscles, meanwhile, twitched at roughly 3.7 milliseconds while females' moved at 7.1.

Tiny twitching muscles on either side of rattlesnake rattles, along with muscles in the swim bladders of some fish, have been recorded approaching these speeds. But Elemans's team concludes that songbird vocal cords move faster than any muscle in any other known vertebrate.

Since most songbirds have the same general type of vocal cords, the discovery could mean that extremely fast-moving muscles are more common in nature than was previously thought.

Daniel Margoliash, a biologist at the University of Chicago who was not involved with the study, called the paper "as elegant as it is exciting."

"We've been fascinated by bird songs for so long, and this gives us a very important insight into the vocal organs behind them," he said.

"We had no idea muscles could work at these superfast rates," he added. "That they can and do is just amazing."

Daniel Mennill, an avian biologist at the University of Windsor in Canada, noted that fieldwork has shown songbird vocalizations to be among the most precisely timed behaviors in the animal kingdom.

"The synchronized duets and choruses of wrens, for example, are the most highly coordinated animal behaviors ever recorded," he said.

"These [new] results explain a lot about how birds actually achieve such amazing technical feats."

Study leader Elemans said he is keen to continue his search for creatures with superfast muscles, and he thinks bats will be good candidates.

"Bats echolocate with an auditory sweep that rapidly moves from very highpitch to very low," he said.

"I'm convinced that there are fast-moving muscles behind this sonic sweep."

Reminder: new page with book news at http://www.cpind.blogspot.com

Monday, July 14, 2008

So far at the Moth Tree -- East Drive near 74th St.

new blog at http://www.cpind.blogspot.com

Large Yellow Underwing [an increasingly common exotic species]revealing it's colorful and rarely revealed hind wings


Once-married Underwing [ Catocala unijuga]

American Idia

Ilia Underwing [conspicua form]


Lunate Zale [pronounced zah-lay by lepidopterists, though we still say Zale rhymes with Snail.]

PS, At 10:30 pm last night, as Jim Lewis and I were heading out of the park, we saw a Black Skimmer zigzagging back and forth over the Model-boat Pond.

Sunday, July 13, 2008

Drunk as a skunk? and PS from Marie

Nessus Sphinx in an altered state of consciousness

Beth Bergman describes her first reaction to the sight of a Nessus Sphinx moth on the
Carousel sap tree, and then what happened when she came back to get her second set of photos.:

It's a bird. It's a plane. It's SUPER BUG. . . My brain screamed, "hummingbird!" It was small with wings that hummed and it was hovering at the sweet spot at the oozy tree (sap).So I did what every law abiding person would do, jump the fence for a closer look. This wasn't a hummingbird, but it looked like something I saw once in Colorado, also resembled a hummingbird and wasn't.

When confused, take pictures, ID will follow, but this was a hard subject, -low light, moving subject, dark-on-bark. I got the ID that evening from expert, Marie Winn, a Nessus Sphinx moth. Wow! What a fascinating thing.

Today I went back to the oozy tree, this time with a strobe and diffuser. If the moth was there again I might get better pictures. Lo and behold it was there, perched at the sap spot sucking up the stuff non-stop. The best plan is always to take pictures first, get a few shots, and then do adjustments, because anything in nature can fly away in a split second. I got the few shots then got out the extra gear. The moth never left...... suck, suck, suck, suck, suck.... enough time to shoot from several angles.

Then all of a sudden it fell off the tree, not fly, FELL, plop, thud, as if dead. I couldn't find it. Where did it go? Is this "drink-till-you-drop"? It seemed so. And then I saw it on the grass, found it by looking for its tail bands. It was moving slightly. Drunk? And then it turned, face up. The camera got the face better than what my eyes saw, because I was trying to predict what would happen next. What a great face! It flew back to the sap spot and resumed drinking.

P.S. from Marie

In the last chapter of Central Park in the Dark I finally find out why the Moth Tree [There was only one until Beth Bergman discovered another one near the Carousel] oozes that insect-attracting sap. Here's a passage from page 267, just after a tree expert tells the Central Park Mothers [rhymes with authors] that the tree is suffering from a disease called Slime Flux.:

Slime flux! A quick Internet search confirmed the diagnosis.
Many websites included photos of diseased trees that looked just like the Moth Tree. Many sites mentioned a symptom that left us no doubt that Kane had nailed it: “Various types of insects are attracted to the slime flux,” wrote the authors of “Ornamental Disease Note No. 8” from the North Carolina State University Plant Pathology Extension. “Insects feed on the slime,” observed a tree expert at Colorado State University. Walter Reeves, a gardening commentator on Georgia Public Radio, wrote that “the ooze is usually surrounded by insects,” adding a bit censoriously, “some of whom seem inebriated!”
PPS Last night at the Moth Tree:
1 Yellow-striped Armyworm
1 Ilia Underwing [conspicua form]
Many Lunate Zales
2 Large Yellow Underwings [an exotic]
Many Copper Underwings


PPS Don't forget there's a new page devoted to news of Central Park in the Dark
Http://www.cpind.blogspot.com