100 Under 100

by Scott Leslie

  A huge right whale “critical habitat” area of about 95,000 square kilometres in the southeastern Bering Sea was established in 2007 by the federal government under the US Endangered Species Act and the Marine Mammal Protection Act. A smaller area was later designated in the Gulf of Alaska. But even in these areas the whales face potential conflict with humans. Commercial fisheries and shipping both occur within the designated habitats. And in a world of shrinking oil supplies, it may only be a matter of time before offshore petroleum and gas exploration begins here. The hard reality is that it’s difficult to imagine a few whales standing in the way of an energy-hungry nation expanding its domestic oil supply. How much of a difference these designated habitats will ultimately make in the fate of the last eastern North Pacific right whales is anybody’s guess.

  A little less guesswork—and a little more success—is involved in the conservation of the world’s smallest cetacean (it would take a thousand of them to make up the weight on one right whale), a well-studied species found a quarter of a world away, off the coast of New Zealand.

  MAUI’S DOLPHIN

  Few would argue that dolphins are exquisitely built for the sea, from the blowhole for breathing to the torpedo-shaped body to the powerful tail to the streamlined flippers and dorsal fin. But look closely at any dolphin embryo and you’ll see something unexpected and telling: the beginnings of hind legs. Although they stop developing early in the embryonic stage, tiny limb bones remain part of every dolphin’s skeleton. This vestige of terrestrial locomotion is evidence of a land-based ancestor for the ancient Delphinidae family: an otter-like land animal that first took to the sea some 50 million years ago. What drove this incipient dolphin into the ocean?

  Perhaps there was more food there. Maybe the sea was safer. It is safe no longer. We need look no farther for evidence of this than the world’s rarest dolphin, the Maui’s dolphin of New Zealand.

  It’s easy to understand why it might be harder to get a good population estimate of a marine species compared with a land-dwelling one. The sea is very large and its creatures are usually hidden beneath it in three-dimensional space. The Maui’s dolphin is an exception whose numbers can be estimated well because it lives within a small, defined area along the shallow waters of the west coast of New Zealand’s North Island. Possibly fewer than 100 to 150 animals survive.

  At a metre and a half long and weighing just 50 kilograms, the Maui’s dolphin is the smallest of the 40 species of dolphins worldwide. Named for Te Ika a Maui, a Maori term for North Island, it is physically and genetically distinct from the more numerous Hector’s dolphin of the South Island. The two have been isolated from one another for thousands of years and are considered separate subspecies.

  This chunky-bodied, grey and white dolphin, with its black dorsal fin shaped like Mickey Mouse’s ear and its black tail, flippers, and eye patches, is usually found in water no deeper than 20 metres. Here, small pods of up to five to eight individuals are seen engaging in mock chases, leaping and lobtailing; the young dolphins often blow bubbles and frolic with seaweed. Such antics may be more than simply play, perhaps filling an important role in learning, communication, and social bonding. Females don’t reproduce until they are seven to nine years old, and even then have only one baby every two to four years. The young stay with their mothers and other females in small nursery pods for protection. Such a slow reproductive rate means population recovery won’t be swift. It’s been estimated that even one human-caused death of a Maui’s dolphin every seven years would be enough to stymie any growth in their numbers.

  The single biggest threat to this intelligent marine mammal is entanglement in fishing gear. Like other dolphin species, Maui’s dolphins have evolved sophisticated sonar for hunting fish and navigating. But they seem to have trouble detecting the thin nylon filaments used in commercial and recreational gillnets, often becoming ensnared in them while on their way to the surface to breathe. Many drown. To prevent this, the New Zealand government has imposed a ban on setting nets in dolphin habitat along the North Island’s west coast. Other protective measures include a very slow “no wake” speed for boaters when in the vicinity of the animals, a ban on swimming with or feeding them, and a strict no-trash policy. These are positive steps. However, the dolphins’ near-shore habitat exposes them to a more insidious threat much harder to control: runoff of land-based farming pesticides and industrial pollution. Many of these nasty chemicals bioaccumulate, which means they get more toxic each step up the ocean food chain, a problem for species at the top, like dolphins. Young animals get a dose of these toxins through their mother’s milk, which may lead to reproductive problems and weak immune systems in adulthood. To complicate matters, very small populations of organisms often have reduced genetic diversity. The Maui’s dolphin is no exception. Today, only one of its three known genetic lineages of the past survives, possibly the result of inbreeding. This raises questions about its future ability to adapt to diseases or a changing environment.

  But the good news for the Maui’s dolphin is that critical steps to save it are being taken. Continued research and a public dolphin-reporting program are giving scientists better data that are so vital for conservation. Besides the all-important fishing net bans (which continue to be expanded and adjusted as new information is collected), public and school awareness programs are teaching New Zealanders that they are custodians of the one of the world’s rarest dolphins, a distinction I’m sure they’d be happy to relinquish.

  BAIJI (YANGTZE) DOLPHIN

  As rare as the Maui’s dolphin is, there are doubts whether the Baiji dolphin of China’s Yangtze River exists at all.

  This small cetacean was venerated in Chinese mythology as the reincarnation of a princess who was drowned in the Yangtze River because she wouldn’t consent to marry someone she didn’t love. Known as the Goddess of the Yangtze, the Baiji was once seen as a symbol of peace and prosperity.

  Found only in the Yangtze, where it grows up to two and a half metres long, the light-coloured dolphin is a sleek, hydrodynamic animal with a long rostrum (snout). Because it typically lives in murky waters, its eyesight is quite poor, so it uses highly developed sonar for navigating and finding fish. It is one of four species of river dolphins worldwide; the others are found in the Ganges and Indus Rivers in India and the Amazon and Rio de la Plata in South America. Baijis are known to reach speeds of 60 kilometres per hour when fleeing danger, something that they’ve likely had to do a lot while dodging the juggernaut of modern China’s economic, industrial, and population expansion along the Yangtze.

  Much of the respect shown this animal for centuries came to an abrupt end during the Great Leap Forward of the late 1950s and early 1960s, when China’s cruel Communist leadership outlawed the veneration of animals and mandated an ethos of brutal exploitation of nature. People living along the Yangtze complied and began hunting the defenceless animal. This marked the beginning of the end for the intelligent mammal with a perpetual smile, which according to fossil evidence had lived in the river for 20 million years. The Yangtze had been the Baiji’s home for 100 times as long as Homo sapiens have walked the earth.

  Just before the Great Leap Forward, the Baiji’s population was estimated at a healthy 6,000 animals within its historic range along 1,700 kilometres of the Yangtze’s middle reaches, almost as far south as Shanghai. Although it became illegal to kill the dolphins in the 1970s and several protected areas were established by the early 1990s, it was too little too late. In 1997, an organized search for the Baiji was able to come up with only 13 dolphins. Fast-forward less than a decade to 2006, when the last organized search for the Baiji took place. Not a single dolphin was found. Five decades of losing habitat to megadams, being drowned in fishing nets, struck and killed by ships, deafened by underwater shipping noise, poisoned by pollution, electrocuted by electro-fishing (whereby a powerful electrical charge is passed through water to kill fish), and being butchered for their meat may have been too much.

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p; Nevertheless, some are not ready to give up on the Baiji just yet. Still categorized as critically endangered, it has yet to be declared officially extinct. A few conservationists feel that the search conducted in 2006 may have not lasted long enough to cover the vast stretch of potential Baiji habitat in the Yangtze. Maybe they were right, because in August 2007 a large white animal was filmed swimming in the river. It was later tentatively identified as a Baiji. Perhaps there are a few left, but if they are isolated from potential mates by dams, or too old and too sick to reproduce, it might still be too late. If so, the Goddess of the Yangtze will have become the ghost of the Yangtze.

  GILBERT’S POTOROO

  Kangaroos with little joeys and baby koalas riding around in their mothers’ backs are icons of Australian fauna. In one of the great quirks of evolution, all the mammals Down Under are marsupials, the young famously carried in a parent’s pouch while they develop. The marsupials encompass an impressive diversity of species that parallel that of placental mammals living on other continents. The most endangered one of all is the Gilbert’s potoroo.

  Weighing in at about a kilogram or less and reaching 30 centimetres in length, the potoroo is categorized as a rat kangaroo. Cute in a quirky way, it has a chubby body and long rat-like tail. Like a kangaroo, its powerful rear legs and long hind feet work like springs to bounce it along the ground. When sitting or standing still, it looks hunched over, a bit like a giant squirrel. It uses its short front legs only when manoeuvring very slowly and when foraging. The front feet are tipped by long, sharp claws for digging and are dextrous enough to manipulate objects it brings to its mouth.

  The potoroo lives almost entirely on fungi, a unique trait among mammals. In fact, over 90 percent of its food is made up of truffles. It snuffles through the undergrowth, nose to the ground, until it smells the tasty morsels buried just beneath the surface. After digging them up, it eats the cherry-sized truffles, which are fungi’s fruiting bodies. This is exactly what the fungi “wants” the potoroo to do, so it produces an odour that is irresistible to the little marsupial. In exchange for a meal, the potoroo helps spread the fungi’s spores to new sites when it later defecates. It is a simple yet elegant example of the mutualism that occurs in nature.

  At one time, the little Gilbert’s potoroo was abundant in southwestern Western Australia, prompting the namesake of the species, naturalist John Gilbert, to write in the 1800s that “immense numbers could be captured by aborigines in a single afternoon.” Alas, much has changed. By the late 1870s, it was thought to be extinct, but like so many species currently surviving on the edge of oblivion, it was rediscovered. In 1994, a small colony was found living on a single promontory in the Two Peoples Bay Nature Reserve near Albany, Western Australia. Between 30 and 40 Gilbert’s potoroos currently survive there. Despite searches, the species hasn’t been found outside this small area, where it is limited to a few dense patches of vegetation that hasn’t been burnt in over 50 years, a rare commodity in this part of Australia. However, 10 of the original potoroos were translocated to two additional conservation colonies between 2005 and 2007. They have reproduced very well since their move. Today, these colonies hold between 40 and 50 of the cute marsupials, in addition to the originally discovered colony.

  SEYCHELLES SHEATH-TAILED BAT

  Pity the bats. They don’t have the benefit of being cute like potoroos, a trait of real utility when it comes to garnering support for conservation. Of all the mammals, none is more misunderstood or unjustly maligned than the bat. Ignorance of bats runs deep, and nowhere is this more evident than when one gets loose inside a house or flies around the backyard during a barbecue. Fear is struck into the hearts of helpless humans, and a code-red state of panic ensues. Everybody makes for whichever door puts them on the side of the wall not occupied by the bat. There’s usually one brave soul who stays behind to deal with the beast, courageously stalking the intimidating canary-sized menace with a broom. Flailing in futility with the makeshift weapon, the intrepid would-be bat wrangler ducks like a hitter dodging a fastball every time the tiny animal swoops near. Faces pressed against the window watching the struggle blanch at the sight of the beast flitting, butterfly-like, around the room.

  The truth about bats is far less dramatic. Bats don’t get in the hair, they don’t carry disease (except rarely, like any animal), they don’t suck blood (well, some that live in faraway places do, but not humans’ blood), and they don’t turn into vampires. What bats are is the largest order of mammals on the planet with 1,150 species; warm-blooded creatures that give birth to live young, suckle them, and mother them; the owners of a sonar system so sophisticated they can see with sound as well as we can see with light; highly social animals with tight-knit communities and complex communications; the planet’s most effective and withal cheapest method of mosquito control; barometers of the state of the environment thanks to their sensitivity to chemicals and changes in their insect food supply; and one of the most important pollinators of plants on earth, including more than a few human-grown crops. The most tragic fact about bats is that nearly one-tenth of them are endangered or critically endangered.

  One of the rarest bats on earth lives on the remote Seychelles Islands in the Indian Ocean, off Africa. Named for a membrane that stretches between its hind legs, which is used for flight manoeuvring, the reddish-brown, 10-gram Seychelles sheath-tailed bat lives on two small islands: Silhouette and Mahe. Here, it roosts among boulder fields in woodland along the coast, where it also breeds, giving birth to a single pup late in the year. It feeds using echolocation to locate insects in mature woodland near the coast.

  Already extirpated from several other islands in the Seychelles, where it was once quite common, the bat now numbers about 60. The causes for its decline haven’t been pinpointed, but the best guess is a combination of human disturbance of the roost sites, hunting by introduced barn owls and feral cats, invasive kudzu vine, loss of habitat, and a decline of important food items such as beetles and moths due to pesticides. And so goes the common refrain in the realm of endangered species: there isn’t one but many reasons for decline.

  The removal of introduced kudzu and introduced cinnamon plants to allow native flora to flourish again on Silhouette Island has helped restore the insect population there. This appears to have helped the bats. After hitting a low of as few as 14 animals in the 1990s, the population had bounced back to 40 by 2010. Meanwhile on Mahe, where 90 percent of the people in the Seychelles live, three small roosts are home to just a handful of bats. Unfortunately, living as they do in woodlands along the coasts on both islands, there’s the inevitable and ever-present threat of housing and tourism development. To complicate matters further for the little bat, they have no legal protection in the Seychelles. Gaining full protection for the species is a conservation priority. Control of feral cats and barn owls, public education, and continued management of the bat’s habitat are also critical if the Seychelles sheath-tailed bat is to be rescued from extinction.

  1. A burgeoning human population is an acute problem in East Africa. Growing faster than any other country in the world, it took only eight decades for Kenya’s population to swell from about 3 million to nearly 40 million today. For an idea of how rapid that growth is, if the population of the United States had expanded at the same rate over that time, it would now be home to almost 1.6 billion people.

  2. The exploitation of the “scientific research” loophole in the International Whaling Commission’s ban on commercial whaling continues to this day. Japan “legally” hunts whales using massive factory ships, satellite tracking, and grenade-tipped harpoons. There is little, if any, scientific value in it. It is condemned by whale biologists around the world, who see it for what it really is: a scientifically worthless and cynical justification for the mass killing of whales. Between 1988 and 2009, Japan has thus taken over 12,000 whales in the North Pacific and around Antarctica. None of them (at least that we know of) was a northern hemisphere right whale, since those a
re just too rare to be hunted profitably. Despite Japan’s insistence that the hunt is done strictly for research, the meat ends up being sold in its restaurants and markets. Mercifully, the Japanese public appears to be losing its taste for eating cetacean flesh. In fact, demand has dropped so much that by 2011, some 6,000 tonnes of whale meat were stockpiled in warehouses throughout Japan. Yet, despite this glut, Japan will resume its “scientific research” whaling in the western North Pacific in the summer of 2011. Although it isn’t targeting the eastern North Pacific right whale, since it is endangered, Japan hopes to kill some 200 smaller minke whales in the name of science. The question must once again be asked, what exactly will be accomplished by such slaughter?

  FRAYING FEATHERS: BIRDS

  Birds are a paradox of conservation. On one hand, as brightly coloured, often musical creatures that are generally active during daylight hours, they are an ever-present visual and audible part of our everyday world, the single most popular group of wild animals on earth. Hundreds of millions of bird aficionados around the world are only too ready to support the protection of their feathered friends. On the other hand, the enormous diversity of birds (there are about 10,000 species) means they are spread across the globe, on every continent and island, in every nook and cranny, often remote and therefore difficult to help. The majority of the threatened ones are located on small oceanic islands and in the tropical forests of continents and large islands such as New Guinea and Borneo. Currently, there are 1,253 bird species on the IUCN Red List of Threatened Species.

  SÃO TOMÉ FISCAL

  What pops into your head when you think of a songbird? A canary, a warbler, a robin, a sparrow? Whichever it is, probably the last thing that comes to mind is a ruthless predator. But that’s exactly what the São Tomé fiscal is. Like other members of the family of birds known as shrikes, the São Tomé fiscal has a reputation as an efficient, albeit diminutive, hunter. As if it were a tiny hawk, it swoops down on a potential meal and plucks it from the ground with its bill. That’s the predatory part. The ruthless part comes next: even when it’s no longer hungry, this bird keeps hunting for more. So, when it can’t stuff anything else into its full belly, it takes its prey—which might be anything from a small insect to a nestling bird to a small lizard—and impales it on a big thorn or a spike on a barbed-wire fence to save it for later. And sometimes, larger quarry, like a writhing lizard, might be too much for the shrike to handle, so the thorn also comes in handy as a vice to hold the animal while the bird pecks and tears at it until it’s dead. Not surprisingly, the nickname “butcherbird” has stuck for members of the shrike family. So have other unflattering names, such as the “hangman” or “the murderer.” The name “shrike” comes from “shriek,” for the shrill call made by these unusual songbirds. Naturally, one member of the family has to be the rarest, and that distinction falls to the São Tomé fiscal.