Central Park in the Dark
PARTY-CRASHERS AND FLYING MAMMALS
The Loeb Boathouse, located at 74th Street along Central Park's East Drive, is a popular place for partiesyou have to book the space months or, for certain holidays, years in advance. Though a shuttle bus is available at the corner of Fifth Avenue and 72nd Street to take infirm or three-inch-high-heeled or merely nervous-Nelly partygoers to the Boathouse at night, some still choose to go by foot. It's a short and romantic stroll along the well-lit drive, with Pilgrim Hill and the model-boat pond visible to the east and glimpses of the rowboat lake to the west.
On most balmy summer evenings these strollers might notice an odd sighta small band of men, women, and sometimes a few children shining flashlights into a scraggly tree on the drive's east side, just past the point where the 72nd Street transverse goes straight ahead and the drive curves to the north. Indeed, on most summer nights you'll find me there too. Few stop to ask us what we're doing, perhaps because New Yorkers are trained to mind their own business. But the question hangs in the air. The answer: we're watching large, beautiful moths arriving to feed on a special tree.
On a certain summer night a few years ago, just a little after sunset, I happened to be one of those gussied-up partygoers myself.Though it was hard to walk right by the gang at the Moth Tree, I couldn't miss this particular bash. It was being held in honor of a romantic couple close to my heart: Pale Male and Lola, the red-tailed hawks that had been nesting on the twelfth floor of a nearby Fifth Avenue apartment house for more than a decade.
My attachment to Pale Male began in the early 1990s, when red-tailed hawks were rare in big cities. Though hawks passed over Central Park every year during the spring and fall migrations, none had ever nested there. When a light-colored redtail settled in as a year-round resident, hooked up with a mate, and then proceeded to build a nest on an elegant limestone building at Fifth Avenue and 74th Street, it was a newsworthy event. That year I wrote the first of a series of articles about Pale Male in The Wall Street Journal, and I continued to cover the redtail beat for years.
Pale Male, the first avian superstar. Pale Male, the red-tailed hawk that tour guides pointed out as he made lazy circles above the model-boat pond. Pale Malethe very name was a crucial ingredient in creating this hawk's celebrity. It fell trippingly from the tongue. Even the echo of Pall Mallpronounced either as Americans do, to rhyme with ball, or as the upper-class British do, Pell Mellgave the name a special zing. People liked to say itPale Male. Pale Male and Lola, his third and probably last true love. The names could pull the emotion lever all by themselves.
Over the years twenty-three redtail chicks had hatched and fledged from the Fifth Avenue nest. Later, when this same species of hawk began to proliferate in New York City and other urban centers in the Northeast, Central Park's dedicated hawkwatchers began to half believe that all the other city redtails nesting on buildings and ledges were Pale Male's offspring: the Pale Male dynasty.
Early one rainy morning in December, just as the twice-widowed hawk patriarch and Lola were preparing for a newbreeding season, the hawks' huge messy nest was summarily removed from its twelfth-floor ledge by workers ascending on a window-washers' platform. The building's fastidious owners had deemed the accumulation of sticks an unsightly mess and consigned it to the garbage bin.
The ensuing public furor, with crowds parading outside the building chanting, "Bring back the nest!" and car horns honking on Fifth Avenue in support of Hawks' Rights, inspired newspaper headlines and television news stories around the world. Intense public attention was brought to bear on the building's residents, who became public pariahs, while the Fifth Avenue hawks won the city's sympathy and even love. The building's board of directors swiftly relented, and New York City Audubon, the city's leading bird conservation group, helped broker a deal that would allow the hawks to rebuild their nest, or at least to try. In celebration of their success andwhy not?to raise some much-needed funds, the worthy organization was throwing a party at the Boathouse, smack in the heart of Pale Male's territory.
Among the bird-loving guests at the party were three who not only loved birds but loved to eat them. They were raccoons. Thick-tailed members of the Procyonidae family, close relatives of kinkajous, coatis, cacomistles, ringtails, and olingos, raccoons are far from uncommon in Central Park. Some park officials suggest that up to fifty of the black-masked mammals are permanent, year-round residents, and their real population may be twice as high.
Appearing in the bushes behind the Boathouse's outdoor terrace at about 9:45 p.m., the three rather underdressed party-crashers consumed large quantities of chicken and pasta furtively offered them by a few of the invited guests. The raccoons ate noisily, but their benefactors managed to close the terrace doors. Thus they kept the animals' little growls of bestial contentment from disturbing the benefit's co-honorees, Mary Tyler Moore and Parks Commissioner Adrian Benepe. Togetherwith the local Audubon chapter each had helped to resolve the nest-removal crisis. Indeed, Mary Tyler Moore was a resident of the Hawk Building at the time and a vital liaison between the bird lovers and the building's board. Her prepared remarks were being delivered just as the raccoons began feasting.
Five years earlier, more than twenty-five raccoons had been found dead in the northern part of the park. Necropsies revealed multiple lacerations and puncture wounds, probably inflicted by dogs. There were rumors that two large, muscular canines, possibly Rottweilers or Doberman pinschers, had been seen ranging through the northern end of the park. Once, the rumors continued, the dogs had been seen running out of the park and into a waiting car, suggesting that the vicious pair had been loosed in the park to kill for their sadistic owner's amusement. It was a bizarre scenario.
Perhaps the killers were simply feral dogs who belonged to no one. But no stray dog was deemed capable of winning a fight with a strong, aggressive fifteen- or twenty-pound raccoon. Raccoons are known to defend themselves savagely when attacked. They pose no danger to people, howeverthere has never been a case of a human attacked by a raccoon in Central Park. It's as unlikely an event as a squirrel biting the hand that feeds, and feeds and feeds, it. Fortunately, the dog attacks ceased as mysteriously as they started, and the park's raccoon population seemed to return to its normal number, whatever that might be.
Though they are classified as nocturnal mammals, raccoons are often seen by day in Central Park. Tourists in particular are charmed to come across a wild woodland creature in the parkit's a little nature experience in the heart of the city. Birdwatchers too enjoy raccoon encounters, especially on days when birds are "quiet"that is, nowhere to be seen. Scanning the trees with binoculars, the park's birders often come upon a raccoon sleeping at the entrance to one of its densthey have manyor sprawled out on a horizontal branch with its legs and tail dangling.Sightings are less common in winter; though raccoons don't actually hibernate, they go into an energy-conserving winter sleep during the cold-weather months, living off stored fat reserves. Even then they'll emerge on sunny, warmish days for an evening stroll. By ones or twos, and sometimes by nines or tens, they'll venture forth at dusk to harvest the treasure trove of discarded hot dogs, pretzels, half-eaten sandwiches, apple cores, and other goodies available in every garbage can.
The three raccoons who attended the benefit at the Boathouse seemed to like the chocolate petits fours and the miniature cheesecakes from the dessert table above all. They picked up each little pastry with their hands and delicately placed it in their mouths, a behavior that a widely used text describes as characteristic of the speciesthe manual dexterity, that is, not the consumption of baked goods.
"Procyon has a well-developed sense of touch ... the hands are regularly used almost as skillfully as monkeys use theirs," say the authors of Walker's Mammals of the World (none of them, oddly enough, named Walker), adding an observation that seriously undermines the raccoon's scientific name, Procyon lotor ("washing bear"): "Although raccoons have sometimes been observed to dip food in water, especially under captive conditions, the legend that they actually wash their food is without foundation."
The raccoon's versatile hands (actually the front feet) are a useful adaptation that allows these highly successful animals to reach into small spaces or turn over stones while looking for prey, as well as to catch and hold on to small animals, fish, and a variety of invertebrates. They enable raccoons to perform the single act for which they are most famous (or infamous) in the human community: opening garbage cans, no matter how securely closed. Raccoons don't have to exert themselves much in Central Parkmany of the garbage cans have no lids at all. The nimble animals just climb in and carry off their booty to eat innearby trees. Sometimes a couple of animals will work in concert to knock over a large garbage can. Then they can dine on the spot. They just crawl in and chow down.
At the Boathouse Pale Male shindig, the three raccoons didn't have to lift a finger. But after the bandit-masked, ring-tailed, pointy-muzzled omnivores had eaten a truly awesome number of rich little confections, some partygoers became concerned for their health. These fears were groundless. Raccoons show up regularly at private Boathouse functions and employees reported that the three were seen again the evening after the Audubon benefit. They were in fine fettle, the men reported, though they seemed a little peckish, if not downright hungry.
There are many more bats than raccoons to be found in Central Park, but the flying mammals' more reclusive hunting habits usually keep them out of human sight. That may be a good thing, since many people are deeplyand needlesslyterrified of bats. Late strollers in the park may glimpse the dark shapes of hunting bats circling over one or another of the park's bodies of water, but unthinkingly they assume the creatures are birds. Being crepuscularactive at dusk and at dawnas well as nocturnal, bats are rarely seen by Central Park visitors in broad daylight. Rarely, however, does not mean never.
One of these rare daytime bat encounters was enjoyed by Kellye Rosenheim, a fairly recent addition to Central Park's roster of expert birders. A pretty and stylish young woman, Kellye had been a beginner ten years earlier when she'd gone on one of Wendy Paulson's Nature Conservancy bird walks in Central Park. She just wanted a few hours away from the kids. But those few hours changed her life.
Once bitten by the birding bug, a gifted person can moveahead quickly. Kellye advanced at breakneck speed. She went on bird walks. She went on birding trips. She studied bird books and field guides and tapes of birdsong. Today she leads the Nature Conservancy1 walks in Central Park whenever Wendy is in Washington. This happened frequently after her husband, Henry Paulson, was appointed secretary of the treasury in June 2006.
One late October morning Kellye had a serendipitous encounter with a red bat in the Ramble and sent me a detailed note about it. When I compared some of her observations with scientific accounts of the same species, I appreciated the precision of her description. That ability to observe carefully and remember tiny details, even ones that might seem insignificant, is the sign of unusual talent.
Picture this: 8:30 a.m., Sunday, October 22, a little chilly. A friend and I walked up the hill from the Boathouse and turned toward the Point, where that little path begins. Just where a low railing on the right begins, we stepped out onto the rock cliff there. You know the spot, it's where most birdwatchers begin their watching. Looking down, you see the swampy area below.
As you're standing there, if you look out at eye level, you see the willows on the left. But straight ahead there's a treeit has oval leaves, pointed at the end, about four inches long, which hang down vertically from the twig branches they grow on. They grow in a line down the branch.
Well, we were watching a cardinal moving around on that tree. All of a sudden something hissed at the bird and I thought it was a snake coming out of the leaves to strike at it. But I put my binoculars on it and saw it was a bat, with its side to me. The "snake's body" that I thought I saw was its wing extended out.
I could see its face. Its little mouth was open with the teethshowing. It was hanging upside down, not, I believe, from the branch, but clinging to a big leaf, kind of hiding behind it. The fur was red all over its body (about four inches long) and the skin on its wing was black except where the bones underneath werethere it was reddish, like its fur. That's how I figured it was a Red Bat. It was just awesome. Eventually it retracted its wing and went back into hiding, but not before a hermit thrush dove at it as it would at an owl.
The bat was hanging on to the leaf of that tree near its stem, or so it appeared. I should mention that the leaves on its tree were all still green. The bat itself was at eye level, if you're standing on the cliff there. It looked kind of like a dead leaf behind some green leaves.
The image of a bat looking like a dead leaf in the midst of a cluster of green ones jogged my memory. I looked in a file folder of references to bats in Central Park and there I found what I was looking for: an article in the August 1956 issue of the Journal of Mammalogy entitled "Migration Records of the Red Bat," by the late ornithologist John K. Terres. He wrote:
On September 1, 1955, I caught a live female red bat with my hands that I saw hanging from the branch of a wild black cherry tree in Central Park, New York City. The bat was only about eight feet above the ground, and bore a striking resemblance to a dead brown leaf. It hung from a twig among a cluster of green leaves, and was asleep when I caught it. I examined it for ectoparasites but found none. I returned it to its perch by putting its feet to the twig, which it clutched, and after a momentary shuffling of its wings, seemed to go back to sleep. When I came back to look for it the next day it was gone.
As I reread the old clipping, an odd question struck me: How had John Terres managed to reach a bat hanging eight feetabove the ground? I called an old friend who'd worked with the noted bird expert on his magnum opus, The Audubon Society's Encyclopedia of North American Birds, and asked: "Was John Terres an exceptionally tall man?" "No," she answered, "he wasn't particularly tall. Sort of average height." How had he nabbed his bat, then? I wondered. Had he climbed the tree?
A week later I visited the spot Kellye had described, the rocky cliff looking down on a swampy area Central Park's birders call, for unknown reasons, the Oven. It's a favorite birdwatching location, especially during the spring migration, and for a simple reason: you can look down into the treetops and see warblers easilyno neck-craning necessary.
Now, with the willows on the left, I faced directly ahead as Kellye had done. I could see two trees that were taller than the rest: an old black cherry and a hackberry. Based on her description of the leaves and the twig arrangement, Kellye's bat tree had to be the black cherry. And John Terres's tree had been a black cherry too! Eureka. If he'd been standing on that same ledge fifty years earlier he could easily have reached out and removed a sleeping bat, though the creature was actually eight feet above the ground. A coincidence? Or another example of nature's mystery? Just thinking about it gave me a chill.
Discovering a sleeping bat by day requires no unusual equipmentjust unusual luck. Finding bats at night is a different matter. Just as binoculars are crucial to a birder's success, so the bat-detector, a device that translates ultrasonic bat songs into frequencies people can hear, is indispensable to Central Park's bat hunters.
Today it's widely known that bats zero in on their insect prey by emitting ultrasonic sounds and then listening to their echoes when they bounce off objects in the air, a process called echolocation. Yet the very existence of ultrasonic sound was not proveduntil the twentieth century. How bats manage to operate in complete darkness remained a mystery until then.2
More than two hundred years ago Lazzaro Spallanzani, an Italian scientist, came close to solving the mystery. In a series of experiments he compared how bats and owls function at various levels of light. When placed in a partially darkened room, both the bird and the mammal oriented perfectly. In complete darkness, however, only the bat continued to navigate successfully. The owl collided with the wall and with objects in the room. It was evident that when the use of eyesight is no longer possible, bats resort to some other sense to navigate, one that owls do not possess.
In subsequent experiments, Spallanzani demonstrated that while bats he had blinded (alas) continued to hunt as well as those with perfect eyesight, when their ears were plugged they became disoriented and collided with obstacles set in their way. He came to the reasonable conclusion that hearing is the sense crucial to bats' navigation. But the idea was widely ridiculed. "Since bats see with their ears do they hear with their eyes?" a fellow scientist wisecracked.
Spallanzani himself was confounded by his findings. His experiments had shown that bats use their ears to hunt successfully, but how in the world did it work? Without understanding that the seemingly silent flying mammals were actually producing sounds that helped them navigate and hunt, he couldn't make sense of his discovery. His dilemma came to be known as "Spallanzani's bat problem."
Many decades before the discovery of ultrasonic sound, an American poet hinted at its existence. In her poem "The Bat Is Dun," Emily Dickinson wrote, "And not a song pervade his Lips," describing a bat in flight, but she modified the observation by adding, "Or none perceptible." A keen observer of nature,Dickinson had somehow understood that bats make sounds imperceptible to human ears.
Finally, in 1938, a young man named Donald Griffin solved Spallanzani's bat problem. Griffin, a Harvard graduate student, heard that G. W. Pierce, an eminent Harvard physics professor, had just developed an apparatus able to detect sounds above the human hearing range. It was the first of its kind.
Fascinated by bats from childhood, Griffin was familiar with Spallanzani's enigmatic experiments. Like Emily Dickinson, he had a hunch that bats were not really silent but made sounds that were simply not "perceptible." He applied to Pierce for permission to try the ultrasonic detector on a cageful of bats; until then the apparatus had been used only to detect high-pitched insect sounds. Permission was granted.
In his book Echoes of Bats and Men, Griffin describes the moment when his hunch was proved true: "Just as soon as I brought some bats to Pierce's apparatus, it became obvious that they were emitting plenty of sound, but that it was almost entirely above the frequencies that we could hear." For the young bat student it was an auspicious moment and the beginning of the end of Spallanzani's bat mystery. Griffin continues:
Further experiments showed that covering the mouth of a bat and thus preventing its emission of these high-frequency sounds was just as effective as plugging its ears. Both treatments made bats quite unable to detect large objects or small and they bumped against the walls of the room or anything else in their path. In short, their whole orientation during flight depended on echoes of the high-frequency sounds that they emitted almost continuously while flying about. Because these sounds had shorter wave lengths and consequently higher frequencies than those to which our ears respond, the ability of bats to fly in total darkness had seemed a complete mystery. But once this simple fact became known, all seemed clear.
Poor Spallanzaniclose, but no cigar. He blinded the bats, he plugged their ears, but he neglected to cover their mouths. Thus he failed to demonstrate the "simple fact" (as Griffin was unkind enough to remind us in his book) that the bats were not silent after all, that in reality they were making quite a din.
Griffin's fellow graduate student and collaborator Robert Galambos later recalled their historic discovery of echolocation:
Don divided a sound treated experimental room into equal parts by hanging a row of wires from the ceiling. We aimed the microphone of the Pierce device at this wire array and began to count the number of times a bat flying through the wires will hit them when normal, or deaf, or mute. (The impairments we produced, by plugging the ears or tying the mouth shut, were all reversible.) ... We also recorded the output of the Pierce device and correlated the bat's vocal output as it approached the barrier with whether it hit or missed the wires. Everything we predicted did happen. Nothing ever went wrong.
Expecting that their claims would be as controversial as Spallanzani's, the two young experimenters made a movie demonstration they hoped would silence the skeptics. And indeed it did. The short movie has been shown and continues to be shown to this day on science and nature television programs around the world. Thanks to Donald Griffin, the once-mysterious world of bats had opened up for nature lovers everywhere, even in Central Park.
I made my official entry into the bat world while taking part in Central Park's first bioblitz. The event is a twenty-four-hour census of all living things to be found in a designated area: insects, reptiles, amphibians, fish, birds, mammals as well as plantsand fungieverything. Volunteers are organized according to the various plant and animal groups, with teams going out at different times throughout the day and night. I picked the last time slot of the dayeight-thirty to midnightand signed up for the bat team.
On June 27, just before sunset, our team made its way to the Ramble in search of bats. In place of binoculars we used bat-detectors to make our sightings, handheld instruments that can pick up the high-frequency sounds bats emit, between 20 and 200 kilohertz (kHz), and translate them into levels audible to the human ear, frequencies below 20 kHz.
When a bat comes into range, the bat-detector begins to click loudly. And since different bat species emit sounds at different frequencies, the detectors can help identify the bats' species. The little brown bat (Myotis lucifugus),3 calls at 38 to 62 kHz, the Eastern red bat (Lasiurus borealis) at 39 to 50 kHz, and the big brown bat (Eptesicus fuscus) at 25 to 51 kHz. You can see there's some overlap. If the bat-detector registers 45 kHz the bat could be any of those three. That's when a quick look at the bat helps. There's usually enough artificial light in Central Park to help distinguish species by size.
The bioblitz team had another trick up their sleeve. Strips of fine nylon netting called mist nets were to be stretched out across some spot, preferably a stream or other body of water, where bats were likely to be hunting. Unable to see the almost invisible nets, or to detect them by means of echolocation, bats in the vicinity tend to fly into them and become tangled in the mesh. One team member would be a mist-net monitor, positioned there to gently untangle the bats and place them into a bat bag for later analysis. The Azalea Pond in the Ramble was the chosen water body. Brad Klein and his wife, Danielle Gustafson,both experienced bat-handlers, volunteered to be the mist-net monitors.
I always think of Evelyn Waugh's "bright young things" when I think of Brad and Danielle. Like Waugh's young aristocrats, Brad and Danielle are good-looking, smart, witty, and sharp-tongued. But unlike Waugh's feckless socialites, these two do not find that making a living is "too, too, weary-making." Danielle works for the New York Stock Exchange; Brad is a journalist. He was writing guided tours for museums and galleries at the time of the bioblitz.
Just before real dark descended, Brad's detector went off, clicking away at 40 kHz. Within a few minutes the first bat hit the netin the lowering light we could actually see it flying overheadthen two more. I was consumed with pity for the poor creatures who had set out to find their evening meal and landed in the mist net instead. This was the moment when our expert Rodrigo Medellin, the "bat guru of Mexico," took over. No harm would come to the animals as a result of their capture, he assured us. Moreover, the momentary interruption in their bat lives was well worth the educational value for humans, who might otherwise fear them and try to eradicate them. Nevertheless I and several others did not breathe easily until the moment came for their release.
It took Brad and Danielle quite a long time to disentangle the bats from the mist nets. Danielle had an anxious look on her face the whole time she worked, and I imagined that, like me, she was afraid of harming the animals. But it wasn't the bats that caused her to furrow her brow. She knew the bats were fine. As she held each hissing and snarling creature in one gloved hand while unraveling the knots with the other, she was worried about damaging the net.
As we watched the mist-net extractions, the tension was broken when first Brad and ten minutes later Danielle managed to fall into the pond. They held the mist net above the water, thuskeeping the bats perfectly dry, but they got completely drenched themselves. I'm afraid that I and the other bat-happiness worriers chuckled as the soaked pair pulled themselves out of the pond.
In an e-mail the next day Brad described his experience in detail:
I went to the pair in my net, and the little guy clamped his teeth down on the fingertip of my cotton glove and just started chewing with ardor. I scooted my finger clear of the teethbut in all the excitement I forgot the first rule of mist nettingdetermine from which side the bat entered the net before trying to get him out. Plus, he wasn't fully in a pocket of the net so I was afraid of losing him. The idea with these little ones is to grab the body below the head with the gloved hand, then untangle each wing with the bare hand. I learned this on our trip to the Amazon, where some bats have really big teeth and a bite that can take off part of your finger!
The mud in the Azalea Pond was surprisingly glue-like, and I sank in halfway to my knees while working on getting the bat out. It was great fun to mimic the field scientists I've watched in the past, taking care and responsibility not to hurt the animal and taking slight risks (mugging, sprained ankle, rabies) to do the job well.
Our bats here are in many ways less sexy than in the tropics, where they eat fruit, disperse seeds, drink nectar and pollinate plants, build little houses out of leaves, cling to the sides of trees, and drink your blood as you sleep in the hammock on the boat's deck. But to think that a little creature like that could spend 10 to 20 years living in New York City, hibernating in a building during the winternegotiating traffic and urban lighting during the summer ... amazing!
Two years later another bioblitz was held in Central Park. This time the bat team's destination was the North Woods.
I was happy that our bat expert that day, a wildlife technicianwith the New York State Department of Environmental Conservation named Carl Herzog, preferred to gather information by means of acoustical equipment and a computer rather than by mist-net trapping. Also on our team were three local experts familiar with the bat population of Central Park: Chanda Bennett of the American Museum of Natural History, her husband, Tare Gantt, a high school science teacher, and Danielle Gustafson againBrad was out of town. Then there were four or five amateurs like me, attracted by the romance of bats and the allure of the park in the dark. We were not disappointed.
Thanks to our bat-detectors we were literally detectives. Carl carried a portable computer with a detector attached to it. The apparatus could record and analyze the particular bat emissions being picked up at any given moment, thereby giving a more precise indication of that bat's species.
At 8:30 p.m. the bat team set forth from bioblitz headquarters at the North Meadow Recreation Center, which is just north of the 96th Street transverse. With all detectors turned on, we made our way to the Pool, a little pond between 100th and 103rd streets near Central Park West.
Along the way we inspected every black locust and shagbark hickory we passed. These trees have rough, flaking bark that offers nesting opportunities for local bats. But none had availed themselves, as far as we could see. We noticed several trees with large hollows visibleweren't these promising bat homes as well? No, said Carl, bats avoid large openings. Very small crevices offer better protection from predators. And what predators might bats encounter in Central Park? Raccoons, among others, said Carl. Bad news for Central Park bats given the abundant raccoon population.
At 8:45 we were nearing the Pool when our bat-detectors began clicking wildly. Stopping near a streetlamp, we caught a few fleeting glimpses of dark, erratically flying shapes swooping between trees and water. They looked like birds. But even in thedark something about the creatures' flight pattern revealed that they were bats. They darted and swiveled and wheeled about in the air much more actively than even the most acrobatic avian species, the flycatchers, for instance.
Observers have long distinguished bats from birds simply by the gestalt of their flight, but only recently have scientists succeeded in defining the aerodynamic differences between bat flight and bird flight. In an experiment as inventive as Griffin's landmark study, researchers watched both birds and bats as they navigated in wind tunnels that were filled with manufactured fog. By tracking the displacement of fog particles as the animals flew, the experimenters found that while birds generate thrust using only the downstroke of their wings, bats have developed a twisting wing path that increases the lift during the upstroke as well.
As indicated by our bat-detectors and also by our experts' visual assessment, all our bats at the Pool were little brown bats. Next we headed down a slope and under a handsome bridge called Glen Span Arch. Another water body was at handthe Loch, a meandering stream that flows through a densely wooded area known as the Ravine. The rivulet passes under the Huddle-stone Arch, another of Central Park's thirty historic bridges, and into the Harlem Meer at the park's northeast corner. We were beginning to expect bats in the vicinity of water, and sure enough, as we approached the Meer our detectors began clicking like Geiger counters at a uranium deposit.
When we came to the Meer twenty minutes later, another fusillade of clicks erupted from the detectors. But one bat here was a surprise. Based on a visual impression of the animal illuminated by a streetlamp, as well as by the computer report, Carl believed we had found a northern long-eared bat (Myotis septentrionalis ). The discovery of a species never before identified in Central Park is what a bioblitz is all about. Our team felt triumphant, as if we had found a new species of bird in the Amazonrainforest or, at least, an ivory-billed woodpecker in some lonesome bayou.
On our way back we ran into the reptile and amphibian team. They did not seem quite as elated. They had only one species on their list: an American bullfrog.
One early October Friday I came home to find a message on my answering machine from Starr Saphir, one of Central Park's most accomplished birders and bird-walk leaders. Even on a recording I could hear her excitement:
I led a walk for the Linnaean Society this morning in the Ramble. We had stopped at the benches on the east side of the Azalea Pond, and were just heading for the swampy pin oak when we saw a silver-haired bat! This was a life bat for me and for all of us. The bat was in the leaf litter on our left and then flew up to a nearby tree trunk where we all had a chance to observe it.
You know what day today is, don't you? I think having a bat of any species is very nice on Friday the 13th, but I know a silver-haired bat is even better. It's a most unusual species for Central Park. Thought you'd want to know.
A life bird, in birdwatchers' lingo, is a species seen for the first time in one's life. Like many other advanced birders, Starr has a long list of life birdsher grand total is 2,344. "That's on earth," she noted when I asked her for the number, adding in typical Starr fashion, "Of course I've never birded any other planet." In New York alone she has 397 state birds. As she was walking in the park a day earlier, a shorebird called a greater yellowlegs flew overhead on its way from somewhere to somewhere, Central Park definitely not its destination. But a flyover counts, and that brought Starr's Central Park bird list to 244.
But what about life bats? Her Central Park bat list increased by 33 percent with her sighting of the silver-haired bat, the otherthree being the little brown bat, red bat, and big brown bat. I told her about my only sighting of a silver-haired bat more than ten years earlier. One fall day as I was standing at Belvedere Castle looking down at Turtle Pond below, I saw Starr's future fourth life bat flying low over the water. It was easy to identify because its blackish hair looked as if the tips had just been frosted at the beauty parlor. When I added that the bat actually plunged into the pond and swam for some distance to reach the far shore, Starr didn't bat an eye. (When you talk or even write about Starr Saphir, the urge to pun becomes irresistible.) "He was probably doing the bat-stroke," she quipped instantly.
It's not a coincidence that Starr discovered her silver-haired bat near the Azalea Pond. Lasionycteris noctivagans (the scientific name derives from Greek and Latin words meaning "night wandering shaggy bat") prefers to forage near the edges of wooded streams. That's just what the Azalea Pond isa small enlargement of the Gill, Central Park's quintessential wooded stream. The Gill, to be sure, is not really a wooded stream; it turns on and off with a cleverly hidden faucet.
The Ramble retains much of its original Vaux and Olmsted design, but there's an essential difference in the scene today. In place of showy rose and rhododendron displays, you'll find a multitude of carefully chosen trees and shrubs where birds can feed and insects overwinter. At certain times of year you'll find hundreds of songbirdswarblers, vireos, tanagers, cuckoos, kinglets, and grosbeaksfor whom Central Park has become a crucial stopover place during migration. You'll find raccoons wandering and occasional bullfrogs croaking. And if you're lucky, you might come upon a silver-haired bat dozing in the leaf litter.
Copyright © 2008 by Marie Winn