Wednesday, November 28, 2007

A Few Hawaiian Birds

Here are a few Hawaiian birds that I probably will not be writing about in my regular Brattleboro Reformer column, but which deserve at least one mention and photo.

First, two endemic honeycreepers.

The I'iwi is an icon for endemic Hawaiian forest birds.

The Apapane is the honeycreeper which I saw most often while in the islands, but it rarely stayed still long enough for a photo. It's red, like the I'iwi, but the black bill in the photo betrays its identity.

The Red-crested Cardinal was common on Maui, Hawaii, and Kaua'i. While non-native (introduced from South America), it is still a stunning bird.

Also from South America, also a stunning bird, but found only on Hawaii, is the Yellow-billed Cardinal.

The Spotted Dove, also known as the Lace-necked Dove and on the islands as the Mountain Dove, was introduced from Asia in the mid 1800s.

Saturday, November 17, 2007

A First Encounter with Birds in Hawai’i

I just got back from Hawaii. I did not go to the islands to watch birds. I went to help with grandchildren, handle luggage, cook, and to be a tourist. Nevertheless, whenever possible I paid attention to the birds.

When I travel to a new place, I learn about the place, and its bird life, in advance. In the case of Hawaii’s birds, this book knowledge came from two slim volumes. From these guides, I learned that the birds most sought after by birders would be very difficult to see. These endemic species are largely confined to mountainous forests; they are often rare, many are endangered, and some may be extinct. On the other hand, in the areas where human impact is the greatest, Hawaii’s bird life has become an avian melting pot, with alien species from around the world having found open ecological niches where they can thrive. Since even most these alien species were birds I had never seen before, I approached the islands with anticipation and expectation.

A good rule of thumb in this journey of life is to keep limits on one’s anticipation level. To wit: the first bird I saw after traveling some five thousand miles was in the Maui airport’s baggage claim area. While corralling luggage, and recounting the checked bags of six people, I noticed birds flying about. With no glass walls or electronically controlled doors, and oblivious to all security stations, House Sparrows scavenged the terminal for crumbs dropped by weary travelers. Yes, House Sparrows - those ubiquitous little brown birds that occupy the ecological barrens in our cities and towns, and even wander into the lush gardens of the rural village where I live.

Ah well. I was still in anticipation. The next morning I was up at dawn. With coffee in hand, I stood on the lanai (the Hawaiian word for porch or deck, in case you’ve never been to the islands), watched the sky lighten, saw the cloud caught on the mountain peak of West Maui turn pink, and listened to the cacophony of bird song. It was wild, noisy ... and new. It seemed like some thirty or more birds were greeting the new day. Through several more cups of coffee, I listened and watched, and began to impose some order and make identifications.

None of the birds I saw that first morning were endemics. All are native to somewhere else in the world. The rooster that was crowing may have the best claim to being a true Hawaiian bird. It was a Red Junglefowl, a chicken brought to the islands by the first Polynesian settlers a millennium and a half ago. Occasionally during our time in Hawaii, we saw one that was tethered, but most were free ranging, feral or semi-feral, and in the jungles, truly wild birds. And stunningly beautiful! Just as noisy, but much plainer, was the Gray Francolin, a game bird introduced from India, that was foraging on a nearby lawn and flew briefly to the roof of our house.

During the course of the morning, I identified new birds and sorted out the many songs and calls I was hearing. Eventually, I thought I was recognizing some familiar sounds - a mimic who was repeating songs in triplet, a clear “chip” call, and snatches of a warble. They seemed familiar because they were familiar: Northern Mockingbird, Northern Cardinal, and House Finch. Each behaved just as I would expect them to behave on any day of the year in Vermont. The mockingbird sang from the tip-top of a palm tree. The cardinal skulked through the lower thicket, his presence betrayed by his brilliance.

There were doves, the Spotted and the Zebra, both Asian natives, both occupying the niche we might associate with our Mourning Dove, both with haunting coos like our dove.

Two small songbirds were common in our yard. The Java Sparrow was unlike any bird with the “sparrow” name in North America. Far from being a little brown bird, this sparrow is warm gray with a black cap, a bold white cheek, and a large beak (proportionately bigger than a cardinal’s) that is bright red at the base, fading to white at the tip. The Japanese White-eye is a green, warbler-like bird with a bright white eye ring. Both are beautiful birds, but as alien species in Hawaii, they often move into the habitats of native species and pose a threat to those species.

As I have already written, standing on the lanai with my cup of coffee that first morning, I heard at least thirty different birds. If you have been counting, you will realize that I have named nine species. The other twenty-one plus birds that I heard that morning were the Common Myna.

The Common Myna, native to India, is a close relative of our European Starling, and like our starling, is an adaptable and successful introduced species. It looks something like a juvenile starling with a dark head cap. It has a yellow teardrop behind the eye, bright yellow legs and beak, and shows large, splashy white patches on its wings when it flies.

The myna does not often mimic other sounds, but it doesn’t need to. Its repertoire of whistles, squawks, and chatter is diverse ... and loud ... and constant. Imagine the various calls and screams made by a flock of Blue Jays, then throw in the additional variability of the mockingbird, catbird, thrasher, and starling, and you begin to get a sense of the myna’s vocal presence.

I know that the myna is alien to Hawaii, and as such, probably poses threats to endemic species, but I liked the myna. It travels in pairs and gathers in flocks. It gleans insects - or anything else edible - around airports and hotels, on golf courses and lawns, in landscaped gardens and dense tropical jungles. And all the time, it is chattering.

The Common Myna was simply entertaining - a starling with the roguish love-ability of a Blue Jay. That first morning a pair landed on the lanai and hopped toward me. When I stepped tentatively in their direction, they hopped back. When I took two more steps, they flew to the railing, then the roof. One more step on my part, and they flew to a palm. They chattered to one another, then changed trees and squawked some more. When I ignored them, they came back to the lanai and we replayed the whole scene.

It took me another day to formulate a theory about this behavior, and a third day to test the theory. With the help of our four-year old, we placed some stale bread crumbs on the railing of the lanai, then pretended to do something else. Sure enough, one myna came right to the crumbs, and a second one followed. We repeated the experiment. This time the pair came together and gulped down the crumbs. They also talked with each other, and it seemed to me that one of them said, “It took that dummy long enough to figure it out.” And the other one agreed. I tried to explain to them that back home the Blue Jays are too impatient to wait around and beg, while my chickadees thank me when I feed them. But the mynas didn’t seem to care about my explanations.

Which reminds me - I’d better go check my bird feeders.

Sunday, November 11, 2007

Turkey Vultures - Avian Victims of Prejudice

The Turkey Vulture is not one of my favorite birds. Like most people, I prefer the cuteness of the chickadee or titmouse, the comic antics of the nuthatch, the gaudiness of the Wood Duck or Harlequin, the majesty of the Bald Eagle, the power of the stooping Peregrine, the ethereal song of the thrushes, or the sheer endurance and metabolic efficiency of a long distant migrant, like the Blackpoll. The Blackpoll burns fat reserves in its one ounce body during a 2000 mile journey across open ocean at the equivalent rate of an automobile which would get 750,000 miles per gallon.

Nevertheless, the Turkey Vulture is a much maligned bird, and the victim of what can only be called ignorant and irrational prejudice (if you will excuse the unnecessary and redundant adjectives).

First, some background. The Turkey Vulture is a relatively new arrival in New England. In the first half of the nineteenth century, Audubon knew of the bird in New Jersey, but did not know anyone who had observed it in New York. The same was true in Massachusetts and Maine. “On my later northern journeys,” he wrote, “I nowhere saw it. A very few remain and spend the winter in New Jersey and Pennsylvania, where I have seen them only during summer, and where they breed. As we proceed farther south, they become more and more abundant.” In the early twentieth century, Forbush had occasional reports of the Turkey Vulture in New England. Today they are widespread throughout Vermont. Locally. thirty to fifty birds congregate around the Retreat Meadows in Brattleboro from Spring through Fall. In winter, they can be found in southern Connecticut. Although increasingly common in our neighborhood, I know no one who waxes eloquent about their presence.

Occasionally in our history, Turkey Vultures have been protected. In Charleston, South Carolina, Turkey Vultures were relied upon to clean up the offal and waste of the local slaughterhouses. It was a criminal offense to harm one of the birds, and the city officials rigorously enforced the law.

Such is not the case today. Today there is seldom much love expressed toward the Turkey Vulture. Much of the prejudice toward the Turkey Vulture is attributable to its diet - it feeds on carrion. Its diet is often referred to by such terms as filthy, foul, and malodorous. It is a scavenger, gathering where animal waste, scraps and garbage have been discarded.

But why should that be a cause for prejudice and distaste? Lots of birds do the same. Have you never seen crows feeding on a road killed squirrel, chipmunk, or opossum? Gulls are notorious scavengers. Some birders spend hours at town dumps, studying the feeding gulls in search of a rare species, while the gulls pick through the foul-smelling tons of human generated garbage.

A few years ago there was great excitement when an adult Bald Eagle was spotted on the ice in the West River. Traffic along Route 30 was slowed, even stopped, by people trying to get a look at the eagle. The eagle was feeding on a dead deer. Would the same kind of excitement be generated during the summer by vultures feeding on a deer carcass along the river bank? Perhaps if there was a Black Vulture among Turkey Vultures, it might attract the interest of some serious birders. The Black Vulture, a native of our Southeast, is extending its range northward. It is starting to show up in Vermont in the early Spring and mid-Fall. Birders will take notice of a Black Vulture. But the general public? They’ll only be annoyed at having to slow down.

Ah, someone says, the Turkey Vulture is disgusting because it feeds on disgusting, rancid, rotting flesh. If you think that, please read on.

John James Audubon (1785-1851) is synonymous with birds in America. He was a brilliant artist, an inveterate traveler, and a self-promoted frontier woodsman who sported long hair and fir-trimmed buckskins. He was also a superb naturalist with an abiding curiosity. Among the questions he asked was how does the Turkey Vulture find the carrion on which it feeds? By sight? Or smell? To answer the question, he first created a dummy deer carcass filled with straw and laid it in the open. Before long, Turkey Vultures appeared. That answered part of the question. Next he took a hog carcass and hid it under brush in a ravine. Vultures flew overhead but never came down to investigate or feed. Ergo, Turkey Vultures rely on sight, not smell. The authority had spoken.

Unfortunately, Audubon was wrong on two counts. He was wrong in his methodology, and as a result, wrong in his conclusion. In the 1960s, Audubon’s experiment was repeated with a carcass concealed in a box. A small fan blew gently across the carcass. Turkey Vultures soon gathered from many directions downwind and circled the area.

What had Audubon done wrong? The answer did not become clear until further experiments were conducted in the 1980s. Apparently Audubon had used a truly stinking, rotten carcass, presumably reasoning that what he would find odorously offensive would be appealing to Turkey Vultures. Not so. Turkey Vultures like their food properly aged - about one to four days. The Turkey Vultures could smell Audubon’s carcass, but it had the same appeal to them as it would have had to Audubon. None at all. It is now known that Turkey Vultures have a very acute sense of smell. A few straying molecules, often many miles from a carcass, can be detected by Turkey Vultures and lead them to their meal.

Turkey Vultures are one of the few birds which have a good sense of smell. Even their cousins, the Black Vultures, do not have a sense of smell. Black Vultures often travel with Turkey Vultures in order to take advantage of the latter’s ability to smell food. The Blacks follow the TVs to the food source.

So, why is there this prejudice toward the Turkey Vulture? Yes, it eats dead meat, but it is particular about its meat being properly aged, just as I am particular about my dead meat being properly cooked. Most humans eat carrion, though we don’t call it that, and, since we lack the proper beak for the job, we have a butcher cut it up for us. We may have prejudice toward some humans, but except for the odd misanthrope, we are not prejudiced toward all humans. I don’t have an answer for this prejudice toward the vulture, any more than I have an answer for prejudice toward other people - except that all the evidence I seem able to garner suggests that prejudice - avian or human - is ignorance. Which, as a basis for an opinion, is stupid!

Good Birding!

Saturday, November 03, 2007

Vultures Are Storks, Not Hawks

I don’t know anyone who would list the Turkey Vulture among their favorite birds. The Turkey Vulture is big. It is ugly. It has disgusting habits. It feeds entirely on carrion - dead meat, usually thought of as rotten and rancid. The Massachusetts ornithologist, Edward Forbush, described the buzzard (as it is known in folk-circles) as a “cowardly fowl .... They often gather, not only about dead animals, but also about the sick or disabled when death seems imminent. If the death of the victim seems assured they approach their prey. Over what follows let us draw the veil.” He refers to their diet as “filthy cargo,” “foul matter” and “malodorous decaying bodies.” Some four hundred years ago, the habits of vultures gave to our language (according to the Oxford English Dictionary) a noun which could be applied to “a person of vile and rapacious disposition.”

There’s not much in the way of endearing qualities to be found in the vultures.

But ... as masters of the air, the vultures have few equals. The soaring buteos, such as the Red-tailed Hawk, receive good notices as they ride the wind currents. Flocks of people gather on ridges and hill tops when the Broad-winged Hawks are at their peak during Fall migration. The feathered flocks kettle upward on invisible thermals with scarcely a movement of their wings - dozens of birds, in some places hundreds and even thousands - drawing oohs and aahs from the spectators below as they ride the currents, and then stream southward. Few people pay much mind to the nearby Turkey Vultures.

Yet the TVs, as they are cryptically known, could give flying lessons to most of the raptors. They are aloft when the thermals and winds are so weak that the buteos are grounded. With broad wings and a wingspan of five and a half feet, they can capture the faintest of rising thermal and the gentlest of air currents. At four pounds, they are relatively light. They fly with their wings in a “V”, or dihedral. They tip and teeter on their way, like an uncertain tight-rope walker. In heavy winds, they rush through the air, in total control. In the same winds, the smaller hawks are buffeted, and struggle to maintain control of their flight, or perhaps give up entirely and perch until conditions are calmer.

Turkey Vultures, along with the other New World vultures, are popularly grouped with the diurnal raptors - the day hunting birds of prey like the falcons, eagles and hawks. But scientists have long suspected that the relationship may be something very different. New World vultures, for example, have toes which are distinctly different from other birds of prey; the hind toe is small and weak. As such, they cannot carry away their food. When on foot, they are gawky, hopping clumsily. This is very different from the powerful toe and sharp talons of the hawks, which allow them to carry food, but not to walk with any grace.

DNA studies have finally confirmed what scientists have long suspected, with the result that our New World vultures have been reclassified. They are now known to be closely related to storks, and not to any of the hawks nor even the Old World vultures, which are classified in the same order as hawks. Like storks, New World vultures cool their relatively long (and un-hawk-like) legs by defecating on them, which is what gives the vultures the appearance of having white legs. The cooling is affected by the evaporation of the liquid in the feces. (This is yet another of the less appealing characteristics of our vultures.) They also have a vestige of webbing between their toes, suggesting that they once waded in muddy ponds like the storks. Unlike Old World vultures, the New World vultures do not build stick nests, do not have true vocalizations (they lack a syrinx and can only hiss and grunt), and do not nest colonially. The similarities between Old World and New World vultures, such as bald heads, beaks which can tear meat, and regurgitating food to feed young, are the result of what scientists call “convergent evolution.” These adaptations for feeding on carrion evolved independently.

When I lived in Pennsylvania, the pine trees across the street from my home were a roosting place for Turkey Vultures in the late Fall. In the waning afternoon sun, they drifted in from all directions, the low rays turning these big black birds into golden brown. They settled into the tree tops where they were all but invisible, but still wary and skittish. A nearby barking dog might spook them into flight, and then the trees seemed to come alive with the thunderous flapping of wings. In the morning, they perched on the leafless branches of the maples and oaks, their wings open to capture the warmth of the morning sun. Then they lifted off and were gone for the day. Until one day in November day, they did not return at night, and were gone for the season.

A few years ago, I was in southern New Jersey in early November, having wiggled my way into a group of hawk banders who were spending a week as volunteers with the Cape May Bird Observatory’s hawk banding project. Bird movement was quiet when we first settled into the blind in the early morning. But as the fog slowly burned off and the air began to warm, large birds started to rise out of the distant trees. Through the morning, I watched and photographed several kettles of these birds. In mid-September on Putney Mountain I would have known with a certainty that these kettles were flocks of Broad-winged Hawks. But the Broad-wings were long gone to the tropics. The weak rays of the late year sun warmed the air but the warmth was fleeting. Yet the birds in those November kettles circled steadily higher and higher. The rocking of their large, v-shaped wings were subtle adjustments to barely moving air currents and feeble thermals. The Turkey Vultures were moving southward.

A week later at home, I carefully marked the photographs of the Turkey Vulture kettles, so that I would not confuse their black dots with the kettles of Broad-winged Hawks I had photographed in September. Two months separated the buteo kettles and the vulture kettles. The Turkey Vultures can migrate with much less help from the thermals and ridge deflected winds than the broad-wings. They are masters of the aerial currents.

Good Birding.


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