100 Under 100

by Scott Leslie

  BLACK STILT

  Shorebirds, in contrast to typically solitary raptors such as the white-collared kite, are usually observed in massive flocks, turning this way and that through the air as they move like a single organism just above the beach. But imagine a shorebird so rare that just a decade ago you could count the number of breeding pairs on your two hands with enough fingers left to call a strikeout. Seven pairs, that is how close the black stilt of New Zealand came to extinction.

  Typically elegant like other species of stilts and avocets around the world, this all-black species, 40 centimetres in length, is an ebony plumaged, lanky, fragile-looking shorebird with long skinny red legs, a long neck, and a delicately pointed, slightly up-turned bill. Like others in its family, it feeds by probing under rocks and in muddy water for insects and the occasional tiny fish. Atypical for its family, the black stilt generally doesn’t migrate.

  It was widespread across New Zealand’s North and the South Islands in the late 18th century. By the early 20th century, however, it had disappeared from the North Island and had dwindled to dangerously low numbers on the South Island. Decades of predation by introduced species such as ferrets, minks, and brown rats had decimated the species. A successful government program that killed off a plague of introduced rabbits in the 1940s eliminated a major food source for the South Island’s large feral cat population, which in turn switched to eating the native birds to survive. The black stilt, a ground nester, was one of the species most affected. Not all of the stilt’s problems can be blamed on introduced species, however. Large-scale hydroelectric development in its last nesting stronghold, the MacKenzie Basin of South Canterbury, destroyed much of the braided river bottom habitat where it nested. The projects resulted in flooding in some areas and draining of wetlands in others, neither of which are good conditions for a bird that lays its four eggs in a scraped-out hollow on a braided gravel bar in the middle of a riverbed.

  By the time the New Zealand government began a recovery program for the black stilt in the early 1980s, only 32 were left. Had it not been for a captive breeding program begun then, plus predator-control programs to get rid of the introduced species that kill the shorebird and eat its eggs, the black stilt would likely be extinct now. Fortunately, although the growth in its population has been slow, today, thanks to the recovery program, there are almost 100 birds living in the wild.

  Not every rare shorebird is so fortunate to have its population increased because of a sustained recovery effort. In fact, two of the northern hemisphere’s curlews have become so rare in recent decades that their very existence is questioned.

  ESKIMO CURLEW

  On October 7, 1492, after a month out of the sight of land, Christopher Columbus’s crew spotted a flock of what are thought to be Eskimo curlew shorebirds flying westward over the sea. Taking their cue from the birds, the sailors of the Niña, the Pinta, and the Santa Maria changed direction in the hope of making landfall. It turned out to be a good idea. A few days later, on October 12, Juan Rodrigo Bermejo, on the Pinta, spotted land. Columbus named it San Salvador Island (now a district of the Bahamas). The first contact with the New World had been made.

  It seems only fitting that it was a flock of Eskimo curlews (possibly along with some lesser golden plovers, a species with which they often migrated) that led Columbus to land. October was the peak of their southward migration. As one of the most abundant bird species in the western hemisphere, millions of them would have been on their way south along the Atlantic coast of North America, having recently left behind autumn feeding areas in Nova Scotia and Newfoundland. So enormous was the fall migration of curlews that vast single flocks of hundreds of thousands of them would cast shadows on the earth, living clouds blotting out the sun.

  A stilt-legged shorebird with a long, thin, downward-curving bill; a 70-centimetre wingspan; and mottled brown plumage, the Eskimo curlew is easily confused in the field with the closely related, more numerous whimbrel; only by their calls can the two be reliably told apart. This similarity is one of the reasons it’s hard to conclusively say the curlew is gone or is still with us—there may be a few still mixed in with groups of whimbrels and lesser golden plovers, species with which it was known to flock. On the other hand, the odds are that any Eskimo curlews reported—and reports are few and far between—may in fact be whimbrels. Declaring a species extinct is a serious step, so any report of their continued survival, however unlikely that might be, could cast some doubt on the decision.

  Little is known of the Eskimo curlew’s life history. They spend (spent?) their summers nesting on the arctic tundra west of Canada’s Mackenzie River and into Alaska. The female lays four olive-brown eggs in a depression on a carefully chosen hammock of soft moss. The downy chicks emerge from the shells after about four weeks of incubation by both the male and female. In the fall, young and adults begin an epic migration that is surpassed by few birds. After flying east across the top of the continent to Labrador, they turn down into Atlantic Canada before heading due south to the Lesser Antilles of the Caribbean (Columbus would have seen them on this leg of their migration). Finally, there’s a long flight deep into South America, where they winter on the great grasslands of the pampas. The following spring they take a much more direct route straight through the centre of North America to their breeding grounds in the western Arctic. Throughout their migratory peregrinations, the birds continuously communicate by twittering soft, melodious whistles to each other, said by some to resemble bluebird songs.

  Known as doughbirds for the thick layer of fat carried during fall migration, they weigh over 400 grams, making them popular with hunters. Running a deadly migratory gauntlet every year that covered 30,000 kilometres, Eskimo curlews were shot in the fall along the US Eastern Seaboard, blasted on grassland wintering grounds in Argentina, and ambushed by gunners in Texas and the Great Plains while returning north to breed in the spring. Slaughtered both for the market and for the sport, like the ill-fated passenger pigeon, they were treated as though their numbers were infinite.

  Like most shorebirds, Eskimo curlews are gregarious. The loyalty they show to their own kind is extreme, and the way hunters exploited this is heartbreaking. Flocks had a habit of circling back time after time to the scene of a shooting, drawn by the sight of their recently downed flock mates on the ground. And an almost complete lack of fear of humans—even when being fired upon—plus a propensity to clump together en masse in huge flocks, rendered them easy pickings, even for short-range shotguns. Little thought was given to the fate of the species as dozens at a time were taken down by single shotgun blasts. They were scooped up dead from the ground by the wagonload.

  Big congregations of Eskimo curlews were a thing of the past by the late 19th century. The last large flock anywhere was observed in 1890 on the Magdalen Islands in the Gulf of St. Lawrence. Since then, there have been sporadic reports of mostly single or a few birds at a time throughout the 20th century. Some were confirmed sightings, most weren’t. Given the aforementioned difficulty in telling this species apart from the whimbrel, we’ll never know exactly how many sightings were actually of Eskimo curlews.

  By the time Canadian author Fred Bodsworth’s classic Last of the Curlews was published in 1954, nearly five centuries after Columbus’s landfall, the Eskimo curlew had been extremely rare for decades. No flock of more than 25 birds had been seen since 1916, and when the curlews were by chance observed, it was only one or two birds at a time.

  Bodsworth wrote about how close they had come to extinction in his day (the 1950s): “The odd survivor still flies the long and perilous migration from the wintering grounds of Argentine’s Patagonia, to seek a mate of its kind on the sodden tundra plains which slope to the Arctic sea. But the Arctic is vast. Usually they seek in vain. The last of a dying race, they now fly alone.”7

  An American birding magazine reported the sighting of a single bird on a rocky headland near Peggys Cove in Nova Scotia in 2007. The purported Eskimo curlew was observ
ed by a very experienced birder and professional biologist, who took great pains to arrive at an accurate identification of the bird before reporting it. Unfortunately, he wasn’t able to take a photograph or record its call, so the sighting remains unconfirmed. The IUCN Red List still lists the Eskimo curlew as critically endangered and possibly extinct. So even today, over 500 years after they helped an explorer from the Old World discover the New, there might be a few Eskimo curlews out there somewhere, following age-old tracks across the sky from the tundra to the pampas and back again in search of a future.

  SLENDER-BILLED CURLEW

  The plight of the slender-billed curlew echoes that of its closely related New World cousin. A hundred years ago, tens of thousands of slender-billed curlews migrated from Siberia in a southwesterly direction across eastern and central Europe. These large (40 centimetres in length), grey-brown, mottled shorebirds, sporting long necks, long legs, and long, slender down-curving bills, made their way to wintering grounds in coastal and inland wetlands around the Mediterranean and in North Africa. Despite their abundance, only a few nests of this species were ever discovered. These were found between 1900 and 1925 in subarctic scrub forest in the vicinity of Novosibirsk in southwest Siberia. Typically shorebird like, the nests were simple cups on the ground made of grasses and moss and holding four eggs. Very little else is known about the ecology of this enigmatic shorebird. And that’s too bad, because today we need every bit of knowledge we can garner on the slender-billed curlew to save it from extinction; but it just might be too late.

  Listed as critically endangered on the IUCN Red List, the population of this shorebird is estimated to be fewer than 50. And even that might be optimistic. There hasn’t been a confirmed observation of a group of more than 100 slender-billed curlews since a flock was seen in Morocco in 1974. In 1995, a handful of curlews were videotaped in Morocco, the last time more than one bird was seen at the same time. And there is no irony in the fact that this particular little group of birds was apparently later shot, since it was unrestrained hunting of the species during its migration and on its wintering grounds that has put it on the edge of extinction, if not over it.

  The last time an individual was confirmed was during migration in 2001 in Hungary. With the exception of this single bird, several search expeditions across the slender-billed curlew’s range over the past two decades have come up empty-handed.

  Despite many human eyes watching for it over the massive span of the slender-billed curlew’s range, it’s conceivable the bird might be missed. It is a difficult species to positively identify. Because it is similar in size to the relatively abundant whimbrel and similar in appearance to the still common Eurasian curlew, both of which it historically mingled with, a single or even a few slender-billeds travelling among a throng of these birds might easily go unnoticed. To this end, in 2008, the Slender-billed Curlew Working Group, established under the Convention on Migratory Species, created what’s being called “the greatest Western Palearctic birding challenge” (“Palearctic” is the biogeographical term applied to species nesting in northern Eurasia).

  The idea was to rally teams of volunteers living in the 35 countries for which records of the species exist to scour every last potential habitat of the slender-billed curlew. It’s the biggest effort ever to confirm the existence of a species feared extinct. So far (as of 2011), no luck. However, those who truly love nature are a stubborn lot and refuse to admit defeat; there’s just too much at stake.

  There is still reason to hope that somewhere out there a few remaining slender-billed curlews continue to pair up, build their nests, breed, rear downy chicks, and utter their soft cour-lee, cour-lee call as they migrate in autumn across Europe to warmer climes in the Mediterranean, then return home in spring to the taiga of Siberia to do it all over again.

  PINK-HEADED DUCK

  Compared with the two hapless curlews, both of which are well known in birding and conservation circles, the pink-headed duck is rather a mystery. Formerly found in India, Bangladesh, Nepal, and possibly Myanmar, it is a poorly known waterfowl, last conclusively observed in the wild in 1949.

  First discovered in 1790, this striking chocolate brown–bodied diving duck, with its bright pink head, long pink neck, and pink bill is extremely shy of humans and lives in lowland forest swamps and secluded pools in tall grass jungles. It may also be nocturnal, further enhancing its mystique.

  Living in pairs during the breeding season, they would congregate in small flocks of 30 to 40 birds through the rest of the year. About the size of a domestic duck, the species was hunted throughout its range. How big a factor hunting was in their demise isn’t clear, especially since, like other diving ducks, they may not have made a particularly tasty meal. On the other hand, their spectacular colour made them a popular ornamental bird and relatively large, almost perfectly round eggs were attractive to collectors as well. Of course, with nowhere to live, a species’ population is going to plummet, so the lion’s share of the blame for the precarious status of the pink-headed duck goes to the cutting of lowland forests within its range and the draining of wetlands for farming.

  Though rare by the late 1800s in India, a few would nevertheless turn up for sale in the markets of Calcutta into the early 20th century. In 1956, it became illegal to hunt the bird in India, but as usual, it was too little, too late—the pink-headed species was already a dead duck on the subcontinent.

  Over the years its continued existence has been speculated and even occasionally reported by birders, biologists, and writers. There was even a travel-adventure book dedicated to the search for the duck along India’s Brahmaputra River published in 1988. Although the author claims to have spotted the duck during his search, this, along with several other earlier sightings, are unconfirmed, though intriguing. Cryptozoologists—enthusiasts who often rely on anecdotes to prove the existence of mythical creatures like the sasquatch, the yeti, and the Loch Ness monster—have entered the fray to promote the existence of the duck. A cryptozoology website featured birder Richard Thorns’s photograph of what might be a pink-headed duck. It was apparently taken in northern Myanmar, near an area thought by scientists to be the last potential stronghold of the species if it still survives. Although the bird in the photo looks similar to illustrations of the duck, the resolution is low so it’s inconclusive. Adding to the difficulty of confirming the species’ existence is the fact that the spot-billed duck and the red-crested pochard, similar species living in the same region, could be easily mistaken for the pink-headed duck.

  Yet there’s still a glimmer of hope for the species’ survival in the vast, remote swamps of northern Myanmar. Between 2003 and 2006, five official scientific searches there resulted in a possible sighting by a scientist and two credible reports by local fishers in 2004, as well as a convincing description by a fisher in 2006. Still, nobody has yet to come up with actual proof—a good photo, a clear video, a pink feather, an actual duck. But there is also some doubt that it doesn’t still exist. Given the ambiguity of it all, even unconfirmed reports such these can’t be dismissed out of hand, no matter how sketchy they are, so it remains listed as critically endangered on the IUCN Red List. And even as we look for it, there’s much about the bird to keep it hidden from our curious, probing eyes: extreme shyness, a tiny population, nocturnal habits, inaccessible habitat. In fact, there’s little you could add to this list that would make it harder to find—except, of course, extinction.

  As mysterious as a pink-headed duck might be, even stranger is a flightless one.

  CAMPBELL ISLAND TEAL

  Rats. Rats. And more rats. That is what nearly wiped the Campbell Island teal off the face of the earth. When sealing and whaling ships landed in 1810 on the remote subantarctic island located 700 kilometres south of New Zealand, they unleashed a rodential plague, which exponentially multiplied to become the worst on earth. More on this later.

  The Campbell Island teal is a flightless duck found nowhere else in the world. Like many sp
ecies of birds that inhabit isolated, oceanic islands, these small, 48-centimetre-long, dark brown waterfowl (the males sport a dark green iridescence on their head and necks) lost over countless generations the ability to fly, since a lack of natural predators meant they didn’t need to get airborne for escape. The opportunity to occupy an ecological niche that would be normally filled by a mammal—none of which ever naturally inhabited the remote island—may have also contributed to the loss of flight. This doesn’t mean Campbell Island teals are slow on their feet. Just ask any biologist who has tried to capture one. They move with speed and agility and apparently have a knack of deliberately disappearing into the surrounding vegetation. It helps that they frequent the chest-tall, dense tussock grass that grows so abundantly on subantarctic islands like Campbell. Oddly enough for a duck, the teals are also thought to take refuge in nesting burrows made by the island’s storm petrels. They are nocturnal, too, perhaps because the aquatic invertebrates they feed on offshore are more abundant at night. During the day, the ducks forage on the shore, picking insects and other delicacies from the rotting seaweed.

  Little is known of their ecology in the wild. However, captive Campbell Island teals lay a small clutch—for a duck—of an average of three to four eggs during the Austral spring, beginning in October. Brown skuas and northern giant petrels (both predatory seabirds, the latter of which must rank among the ugliest of birds) are their natural predators. Kelp gulls also occasionally prey on teal chicks. But the species likely evolved to deal with these avian threats by using its speed on the ground and the ability to find cover, so a population balance between predator and prey was maintained over the centuries. Dealing with the rats was a different story.