Lipotes vexillifer (Baiji, Yangtze River Dolphin)

[Melly]

This is the candidate for the rarest waterliving mammal of the world. Between 13 and 60 individuals are occurs in the Yangtse River in China.

www.environmental-expert.com/magazine/wiley/1052-7613/pdf5.pdf

[Peter]

Extract from Reeves et al. (2003, p. 51): "The Baiji is considered the most endangered cetacean, and its prospects for survival are extremely doubtful (IWC 2001). The species’ recent distribution has been limited to the main channel of the Yangtze River, principally the middle reaches between the two large tributary lakes, Dongting and Poyang. In the past, it also occurred as far upstream as Tonglu in the Fuchun River (referred to as Quantangjiang in Chen 1989), a separate drainage situated just south of the lower Yangtze, and also in the two aforementioned lakes (Zhou et al. 1977). The upper range limit used to be 50km above Gezhouba Dam, near Yichang (Zhou et al. 1977), but it is now 150km downstream of the dam site, near Jingzhou or Shashi (Liu et al. 2000). The present downstream limit in the Yangtze is near Fuanzhou, 135km upstream of the river mouth (Chen and Hua 1987). On the basis of surveys conducted in 1985 and 1986, Chen and Hua (1989) estimated that the total population was around 300 individuals. Numbers are thought to be much lower today. An intensive survey in November 1997 produced a total count of only 13 dolphins (Wang 2000). There may be no more than a few tens of Yangtze dolphins in existence today.

Deaths from entanglement in fishing gear (especially bottom-set, snagging longlines called "rolling hooks"), electrocution from electric fishing, collisions with vessels, and underwater blasting for channel maintenance are at least partially responsible for the declines in Baiji range and abundance. In addition, the damming of tributaries, drainage for land "reclamation," dredging, overfishing, and the noise and congestion caused by vessel traffic in the river have substantially degraded the Yangtze environment (Zhou et al. 1998). The species disappeared from the Qiantang (Liu et al. 2000) and Fuchun Rivers after construction of a high dam in the Xinan River (a tributary of the Fuchun upstream of Tonglu) in 1957. Construction of the controversial Three Gorges Dam began in 1994. Erosion from the clear water released below the dam (Kondolf 1997) is expected to eliminate counter-currents for approximately 200km downstream and to degrade them in another long stretch downstream to Chenglingji (Chen and Hua 1987). The increase in large ship traffic, resulting from improved navigation in the upper reaches after the Three Gorges Dam is completed, will likely increase the incidence of ship-strikes."

[sebbe67]

BEIJING: A nearly monthlong joint Chinese-foreign expedition has failed to spot a rare dolphin in a sign that its Yangtze River habitat is becoming increasingly despoiled by pollution and human activity, the Xinhua News Agency said Saturday.

The 30 Chinese and foreign scientists spent 26 days scouring 1,700 kilometers (1,000 miles) of the Yangtze for the baiji or white-flag dolphin to no avail, Xinhua said. A previous expedition in 1997 found 13 baiji, it said.

An online diary kept by foreign expedition members from the Swiss-based Baiji.org Foundation largely confirmed the Xinhua account. Its occasional entries describe a fruitless search for the baiji, a long, narrow dolphin that the foundation calls the rarest mammal in the world.

"We can't say the white-flag dolphin is extinct," Xinhua quoted Wang Ding, an expedition leader and a hydrobiologist with the Chinese Academy of Sciences. "However, the population has dropped dramatically."

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Wang estimated that the baiji currently number "no more than 50," Xinhua said.

The expedition covered a heavily traveled section of the Yangtze, from Yichang — site of the massive Three Gorges Dam — to Shanghai. Pollution, overfishing, shipping and dam-building are degrading the baiji's habitat and likely causing the decline in its numbers, Xinhua and the foundation's Web site said.

If the situation is not corrected, Wang projected extinction for the baiji within a decade, Xinhua said.

[Melanie]

Rare Yangtze dolphin may be extinct
After a month, scientists fail to locate species; pollution named as main culprit




The rare white-flag dolphin, called baiji, has seemingly disappeared from the Yangtze River, its only habitat. If true, the estimated three-million-year-old species is now extinct.


A 30-member expedition made up of both Chinese and foreign researchers conducted a nearly month-long survey of the river, but they failed to spot even one of the dolphins, China's Xinhua News Agency said on December 4. The white-flag dolphin, which lives only in the Chinese river, is called a "living fossil'' because it maintains the same appearance as when it came to the Yangtze from the sea an estimated three million years ago. In a 1997 survey, 13 baiji were confirmed to be living in the river.


If this dolphin is extinct, it would bear the sad distinction of being the first whale to disappear due to human action. Scientists say that pollution and massive development destroyed the white-flag dolphin's Yangtze River habitat, as well as overfishing methods using poisonous substances and explosives. In addition, noise from ships on the river seemed to disturb the baiji, as porpoises make sound waves as they swim.


The expedition surveyed the 1,700-meter-long river using special equipment to detect the sound of dolphins. They do have a faint hope left, as some sounds gathered have yet to be identified.

Wang Ding, one of the expedition's leaders and a hydrobiologist with the Chinese Academy of Sciences said, "We can't say for sure that the white-flag dolphin is extinct. However, the population has dropped dramatically.'' According to Wang, there were about 6,000 white-flag dolphins in the 1950s.

Posted on : Dec. 5, 2006 14:25 KST
© 2006 The Hankyoreh Media Company.
english.hani.co.kr/arti/english_edition/e_entertainment/176223.html

Well, i would like to move this thread to extinct. What do you think?

[RSN]

But, no captive specimens??

[Melanie]

Not at all. Only 13 individuals have survived in the past 10 years but it is possible that even that few animals haved died in the past years as suitable habitat is so much polluted that a survival on the long term was no more possible.

rsn said:

But, no captive specimens??

[another specialist]

rsn said:

But, no captive specimens??

Efforts to breed the baiji in captivity have failed. All potential mates for QiQi, the lone baiji male at the Institute of Hydrobiology in Wuhan, have died in the transition to captivity.

www.pbs.org/itvs/greatwall/controversy2.html

[another specialist]

Qi Qi, the only baiji in captivity and one of the few surviving representatives of this Critically Endangered species, died in his tank at the Wuhan Institute of Hydrobiology in 2002. Earlier hope that the species might be rescued by an ex-situ breeding program has waned, and much of the attention of Chinese scientists and conservationists has shifted to the sympatric freshwater population of finless porpoises. Photo: Steve Leatherwood, 7 March 1995.

www.iucn.org/bookstore/HTML-books/SSC-Dolphins-wales-porpoises/Chapter%206.html

[another specialist]

In 1994, the CSG and others urged that all surviving dolphins in the wild be brought into a “seminatural reserve” to establish a captive breeding population, but only after removal of finless porpoises from the reserve (Zhou et al. 1994; Reeves and Leatherwood 1994a). The Chinese government began the capture and translocation program, but despite extensive efforts, only one dolphin was captured and placed in the reserve (together with finless porpoises). This animal died in 1996 of causes that remain unclear (Perrin 1999). Many recent deaths of dolphins in the wild (5 of 12 documented in the 1990s) have been attributed to electrofishing, and this fishing method is now viewed as the most important threat to the species' survival (Zhang et al. 2001). Previously, the main cause of mortality was considered the use of a snagline fishing gear called “rolling hooks.” Although at least some types of “rolling hooks” are illegal, their use continues within the limited remaining range of the baiji. Efforts are underway to end electrofishing within the baiji's range (D. Wang, pers. comm.).

Remaining issues: The “semi-natural reserve” initiative has apparently failed, although the concept is still alive in conservation circles in China, and progress has been made in improving the reserve by replacement of net barriers with earthen dams and elimination of fishing (Zhang et al. 2001). Extinction seems inevitable in the absence of effective protection of the baiji in its wild habitat.

www.iucn.org/bookstore/HTML-books/SSC-Dolphins-wales-porpoises/Chapter%206.html

[RSN]

But is not possible to try make clones with a female of the closest related species? Or the genetics of they are so different? Or it is just inviable?

[another specialist]

From The Times
October 26, 2005

Last gasp for Yangtze dolphins doomed by industrial revolution
By Jane Macartney in Tian’ezhou

THE Yangtze River dolphin enjoys a rare and unwanted distinction. The grey-white, long-beaked animal looks likely to become the world’s first cetacean — the family of whales, dolphins and porpoises — to be made extinct by man.

In the 1950s as many as 6,000 baiji, as the dolphins are known in Chinese, still swam in the Yangtze. Today fewer than 50 may survive. None has been seen since July last year when a pair were spotted in Honghu Lake, part of a huge water system that winds out across the Yangtze plain.

In a dusty specimen room at the Hydrobiology Institute in the central Chinese city of Wuhan, the stuffed, enamelled body of the only Yangtze River dolphin (Lipotes vexillifer) to have lived in captivity lies forlornly among empty glass jars and cases displaying the bodies of infant dolphins and porpoises floating in formaldehyde.

Qiqi spent 22 lonely years swimming around a 300sq m (3,230 sq ft) pool at the institute after he was found badly bruised, the victim of illegal fishing, in a lake off the Yangtze in 1980. Scientists tried many times to catch a mate or companion for him. Their failure reflects the march of modernisation along the Yangtze that has transformed the dolphin’s muddy river home into its graveyard.

With little need to see in the turbid Yangtze waters, the dolphin — for centuries called the Goddess of the Yangtze and the subject of myths and legend — evolved a highly effective sonar above its beak. But the roar of marine traffic along one of China’s premier waterways effectively blinded it.

Fishermen trapped the baiji in their nets, ships and tourist boats sucked them into their propellers, pollution poisoned their river home and the huge Three Gorges Dam blocked their passage and altered their environment — perhaps permanently. “I am a little pessimistic,” Hao Yujiang, a researcher at the Institute, said. “It is not possible to improve the environment of the river in the foreseeable future.”

Having virtually abandoned hope of saving the baiji, scientists and environmentalists are now focusing on saving its cousin, the finless porpoise (Neophocaena phocaenoides). About 2,700 porpoises lived along the Yangtze in 1991. Now they are believed to number fewer than 1,000, although researchers lack the funds to carry out a proper census.

Five of the porpoises, which are grey-brown and snub-nosed, swim in tanks at the Wuhan Institute. One is a new arrival, the first to be born in captivity. The three-month-old male clings to his mother as she arches back and forth in her tank. His keepers purr like proud parents over his watery feats. The porpoises receive fresh carp several times a day and they eagerly pop their heads above the surface for a pat. The baby, still unname d, is likely to spend his life in the aquarium.

After years of campaigning, the Institute, working with the World Wide Fund for Nature (WWF), has persuaded local government departments to designate the nearby Tian’ezhou oxbow lake as a nature reserve. Already 23 porpoises have been moved to the crescent-shaped lake. The WWF hopes that the porpoises will have a chance to thrive in its cleaner, less populated waters.

But the porpoises are at a disadvantage in a country that is destroying its environment almost faster than it is developing its economy. “The Yangtze is a very busy waterway and the noise of the ships is badly disturbs their sonar system so they hit ships and jump against dykes,” Mr Hao said.

The construction of the huge Three Gorges Dam has dealt a serious blow, lowering the water level in many lakes fed by the Yangtze. Wei Zhou, secretary of the Wuhan Baiji Conservation Foundation, said that the porpoises’ habitat was getting smaller. He could not cite specific data, but said: “I feel more individuals have died.”

Drastic measures are needed, and soon, argue the WWF and researchers. Mr Hao said: “We need to protect the oxbow as a whole. Not just one species, but a whole ecosystem.”

The main obstacle is man —residents and government. About 500 families live around the oxbow and make a living from its waters. The aim now is to move them out, or at least out of the water, away from fishing to farming. But opposition can be fierce. “What is more important, the survival of man or animals?” one farmer said, with a dismissive gesture towards the Yangtze.

www.timesonline.co.uk/article/0,,3-1843247,00.html

[Meaghan]

How sad My fingers are crossed for the finless porpoises.

[sebbe67]

Rare white dolphin declared as extinct
¨
BEIJING - A rare, nearly blind white dolphin that survived for millions of years is effectively extinct, an international expedition declared Wednesday after ending a fruitless six-week search of its Yangtze River habitat.

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The baiji would be the first large aquatic mammal driven to extinction since hunting and overfishing killed off the Caribbean monk seal in the 1950s.

For the baiji, the culprit was a degraded habitat — busy ship traffic, which confounds the sonar the dolphin uses to find food, and overfishing and pollution in the Yangtze waters of eastern China, the expedition said.

"The baiji is functionally extinct. We might have missed one or two animals but it won't survive in the wild," said August Pfluger, a Swiss economist turned naturalist who helped put together the expedition. "We are all incredibly sad."

The baiji dates back 20 million years. Chinese called it the "goddess of the Yangtze." For China, its disappearance symbolizes how unbridled economic growth is changing the country's environment irreparably, some environmentalists say.

"It's a tremendously sad day when any species goes extinct. It becomes more of a public tragedy to lose a large, charismatic species like the river dolphin," said Chris Williams, manager of river basin conservation for the World Wildlife Fund in Washington.

"The loss of a large animal like a river dolphin is often a harbinger for what's going on in the larger system as whole. It's not only the loss of a beautiful animal but an indication that the way its habitat is being managed, the way we're interacting with the natural environment of the river is deeply flawed ... if a species like this can't survive."

Randall Reeves, chairman of the Swiss-based World Conservation Union's Cetacean Specialist Group, who took part in the Yangtze mission, said expedition participants were surprised at how quickly the dolphins disappeared.

"Some of us didn't want to believe that this would really happen, especially so quickly," he said. "This particular species is the only living representative of a whole family of mammals. This is the end of a whole branch of evolution."

The damage to the baiji's habitat is also affecting the Yangtze finless porpoise, whose numbers have fallen to below 400, the expedition found.

"The situation of the finless porpoise is just like that of the baiji 20 years ago," the group said in a statement citing Wang Ding, a Chinese hydrobiologist and co-leader of the expedition. "Their numbers are declining at an alarming rate. If we do not act soon they will become a second baiji."

Pfluger said China's Agriculture Ministry, which approved the expedition, had hoped the baiji would be another panda, an animal brought back from the brink of extinction in a highly marketable effort that bolstered the country's image.

The expedition was the most professional and meticulous ever launched for the mammal, Pfluger said. The team of 30 scientists and crew from China, the United States and four other countries searched a 1,000-mile heavily trafficked stretch of the Yangtze, where the baiji once thrived.

The expedition's two boats, equipped with high-tech binoculars and underwater microphones, trailed each other an hour apart without radio contact so that a sighting by one vessel would not prejudice the other. When there was fog, he said, the boats waited for the mist to clear to make sure they took every opportunity to spot the mammal.

Around 400 baiji were believed to be living in the Yangtze in the early 1980s, when China was just launching the free-market reforms that have transformed its economy. The last full-fledged search, in 1997, yielded 13 confirmed sightings, and a fisherman claimed to have seen a baiji in 2004.

At least 20 to 25 baiji would now be needed to give the species a chance to survive, said Wang.

For Pfluger, the baiji's demise is a personal defeat. A member of the 1997 expedition, he recalls the excitement of seeing a baiji cavorting in the waters near Dongting Lake.

"It marked me," he said. He went on to set up the baiji.org Foundation to save the dolphin. In recent years, Pfluger said, scientists like the eminent zoologist George Schaller told him to stop his search, saying the baiji's "lost, forget it."

During the latest expedition, an online diary kept by team members traced a dispiriting situation, as day after day they failed to spot a single baiji.

Even in the expedition's final days, members believed they would find a specimen, trolling a "hotspot" below the industrial city of Wuhan where Baiji were previously sighted, Pfluger said.

"Hope dies last," he said.

news.yahoo.com/s/ap/20061213/ap_on_sc/china_dolphin_extinction

[sebbe67]

Maybe should be moved to the extinct category, and a name change on the topic?

[another specialist]

femmdraven said:

Unfortunately, we can add another to the list:
news.yahoo.com/s/ap/20061213/ap_on_sc/china_dolphin_extinction

[another specialist]

sebbe67 said:

Maybe should be moved to the extinct category, and a name change on the topic?

I agree to the move and name change.

[Carlos]

Carwardine (1995). Whales, Dolphins and Porpoises.DK

A sad memory of this unique animal

[another specialist]

Animal Info - Baiji
(Other Names: °×ôßëà, Changjiang Dolphin, Chinese Lake Dolphin, Chinesischer Flussdelphin, Dauphin Fluviatile de Chine, Delf¨ªn de China, Pei Ch'i, White-fin Dolphin, White-flag Dolphin, Yangtze or Yangzi River Dolphin)
Lipotes vexillifer

Profile
Pictures: Baiji #1 (7 Kb JPEG) (Cetacea); Baiji #2 (68 Kb JPEG) (Terrambiente.org)

The baiji is a graceful animal, with a long, narrow and slightly upturned beak and a flexible neck. As opposed to some other freshwater dolphins, like the Indus River dolphin, its eyes are functional, although greatly reduced. Its coloration is bluish-gray to gray above and white to ashy-white below. It weighs 135 - 230 kg (300 - 510 lb) and measures as much as 2.5 m (8.2') in length.

The baiji only occurs in freshwater rivers and lakes. It favors large eddy counter-currents such as are found below meanders; channel convergences; and areas in a river with structure, such as sandbars. In the Yangtze River, the baiji generally lives in the deeper sections, swimming to shallow water only to catch small fish. Any available species of small (less than 6.5 cm (2.5") in width) freshwater fish is eaten. Feeding activity is primarily diurnal.

A group may congregate in the quiet area of an eddy for 5 - 6 hours. At night the baiji often rests in areas of very slow current. Several underwater acoustic signals are apparently used for communication and echolocation. Baijis generally live in small groups of 3 - 4 animals, which may come together to make up a larger social unit of 9 - 16 dolphins.

The distribution of the baiji originally included not only the lower and middle reaches of the Yangtze River down to the river¡¯s mouth, but also the Qiantang and Fuchun Rivers and Dongting and Poyang Lakes. It no longer occurs in the lakes or branches of the Yangtze but only in the mainstem, and the extent of its distribution is significantly reduced. The baiji is considered the most endangered cetacean, and its prospects for survival are extremely doubtful.

Deaths from entanglement in or electrocution by fishing gear, collisions with vessels, blasting for channel maintenance, and illegal harvesting of the baiji are at least partially responsible for the decline of its range and abundance. In addition, the damming of tributaries, drainage for land "reclamation," dredging, depletion of the baiji's prey by over-fishing, and noise and congestion caused by vessel traffic in the river have substantially degraded the Yangtze's environment. The Three Gorges Dam will produce further stress on the baiji population by altering the Yangtze's hydrological regime. The baiji generally occurs in large eddy counter-currents which are expected to be eliminated for approximately 200 km (120 mi) downstream by the water released below the dam.

Tidbits
*** The baiji is one of the world's rarest mammals.

*** In the past, the baiji had been protected by custom, since the Chinese considered it to be an incarnation of a drowned princess (Burton & Pearson 1987). It also has a nickname in China - "Giant Panda of the Yangtze River" - that may reflect the general affection for this aquatic mammal (Tan 1996).

*** In one area where the baiji is most common (Anhui Province) a council has been set up called the ¡®Lipotes vexillifer Conservation Association.' The association is to spread information about the baiji, especially among fishermen along the Yangtze River. An increased awareness of the baiji may have accounted for the rescue of several animals which had been hit by propellers. (Klinowska 1991)

Status and Trends
IUCN Status:
1970's: Indeterminate
1980's - 1994: Endangered
1996 - 2004: Critically Endangered (Criteria: A1bc, C2b, D) (Population Trend: Decreasing) (IUCN 2004)
2006: Critically Endangered (Criteria: C2a(ii), D) (Population Trend: Decreasing) (IUCN 2006)
Countries Where the Baiji Is Currently Found:
2006: Occurs in China (Yangtze River) (IUCN 2006).

Population Estimates:
[Note: Figures given are for wild populations only.]

WORLD (China)
Before 1900: 3000 - 5000 (Ellis 1993, Leatherwood & Genthe 1995)
1980: 400 (Ellis 1993)
1985-6: 300 (Reeves et al. 2003)
1993: 150 - 240 (Ellis 1993)
1995: Probably fewer than 100 (Leatherwood & Genthe 1995)
2003: Maybe no more than a few tens of individuals (Reeves et al. 2003)
2006: Recent informed guesses range from "there may be only a few dozen" to "there are very likely less than a hundred" (IUCN 2006)
History of Distribution:
Currently, the baiji is endemic to the Yangtze River of China (See Figure 1 (126 Kb PDF) (IUCN 2006)). The baiji also occurred historically in Dongting and Poyang Lakes, both appended water bodies of the Yangtze, but apparently it is no longer found in either lake. The baiji¡¯s upstream limit in the Yangtze has changed from the Three Gorges area - approximately 35 km (22 mi) above Gezhouba Dam near Yichang - in the 1940's to approximately 170 km (105 mi) below the dam site near Jingzhou in the 1990's. This dolphin was once observed as far downstream as the Yangtze River mouth near Shanghai, but it is now rare below Nanjing. No baiji were found downstream of Jiangyin, located 256 km (160 mi) upstream of the mouth, during surveys in 1997 - 99. During the most recent surveys the baiji has been found mainly in several segments of the Yangtze between Tongling and Dongting Lake, such as the Tongling section, the Poyang Lake mouth area, and the Honghu section. (IUCN 2006) (See Figure 1 showing the Yangtze River and locations used to describe the distribution of the baiji.)

Distribution Map #1S (1980's) (24 Kb JPEG) (WCMC/CMS) (smaller map)
Distribution Map #1L (1980's) (71 Kb JPEG) (WCMC/CMS) (larger map)

Threats and Reasons for Decline:
Deaths from entanglement in fishing gear (especially bottom-set, snagging longlines called "rolling hooks"), electrocution from electric fishing, collisions with vessels, underwater blasting for channel maintenance, and illegal hunting of the baiji for its meat and for its body parts (used in traditional medicines) are at least partially responsible for the declines in baiji range and abundance. In addition, the damming of tributaries, drainage for land "reclamation," dredging, depletion of the baiji's prey by over-fishing, and noise and congestion caused by vessel traffic in the river have substantially degraded the Yangtze's environment. (Burnie & Wilson 2001, Reeves et al. 2003)

The Three Gorges Dam on the Yangtze River will produce further stress on the baiji population. Although the Three Gorges Dam is upstream from the existing Gezhouba Dam, which already blocks the baiji from swimming further upstream, operation of the Three Gorges Dam will cause alteration of the Yangtze's hydrological regime, which will affect the baiji's habitat. The baiji generally occurs in large eddy counter-currents, such as are found below meanders, channel convergences and sandbars. Erosion from the water released below the dam is expected to eliminate these counter-currents for approximately 200 km (120 mi) downstream and degrade them for another 160 km (100 mi) downstream (IWC 2000). It is predicted by local experts that the baiji will become extinct in the near future whether the Three Gorges Dam is built or not (YVWRPB 1999).

Data on Biology and Ecology
Size and Weight:
The baiji weighs 135 - 230 kg (300 - 510 lb). Its length is up to 2.5 m (8.2') in females and 2.3 m (7.5') in males.

Habitat:
The baiji only occurs in freshwater rivers and lakes. It favors large eddy counter-currents such as are found below meanders; channel convergences; and areas in a river with structure, such as sandbars and areas adjacent to islands. In the Yangtze River, the baiji generally lives in the deeper sections, swimming to shallow water only to catch small fish. In the past, it entered the large tributary lakes in summer when the water level was high and returned to the deep water of the Yangtze River to pass the winter. (Tan 1996, IWC 2000)

The baiji occurs in the Yangtze River & Lakes Global 200 Ecoregion. (Olson & Dinerstein 1998, Olson & Dinerstein 1999)

Age to Maturity:
More than 6 years in females; approximately 4 years in males (IWC 2000).

Gestation Period:
10 - 11 months.

Birth Season:
The baiji probably breeds and gives birth in the first half of the year. The peak calving season appears to be February to April. (Culik 2003)

Birth Rate:
The interbirth interval is 2 years. There is a single young at birth. (Nowak 1999)

Observed pregnancy rates are approximately 30% (IWC 2000).

Maximum Age:
Based on dentition, a wild individual was estimated to have lived 24 years (Nowak 1999).

Diet:
Any available species of freshwater fish is eaten. The only selection criterion appears to be size: smaller than 6.5 cm (2.5") in width. Both surface- and bottom-feeders are taken as prey.

Behavior:
Feeding activity is primarily diurnal. At night the baiji often rests in areas of very slow current. Baijis surface without splashing and breathe smoothly. Short breathing intervals of 10 - 30 sec alternate with a longer one of up to 200 sec.

Several underwater acoustic signals are emitted, including a whistle, which apparently function in communication. There also are series of clicks that probably are used for echolocation. (Nowak 1999)

It has been shown from photographic identification and sighting records that baiji groups make both local and long-range movements, although these movements are not believed to indicate periodic migration. The longest recorded distance traveled by an individually identifiable baiji was more than 200 km (120 mi) from the initial sighting location. (Culik 2003)

Social Organization:
Baijis generally live in small groups of 3 - 4 animals, which may come together to make up a larger social unit of 9 - 16 dolphins. A group may congregate in the quiet area of an eddy for 5 - 6 hours.

Density and Range:
In the late 1970's an average density of 0.25 individuals/km (0.4 individuals/mi) was observed in the Yangtze (Nowak & Paradiso 1983).

www.animalinfo.org/species/cetacean/lipovexi.htm

[Melanie]

Feeling guilt over Chinese dolphins' demise
Yangtze baiji extinct after surviving for 20 million years

I'm feeling a bit empty.

The experts who have been following the fate of fewer than a dozen freshwater dolphins left in China's vast Yangtze River have declared them lost and the species extinct. Decades of searching the river's murky waters must pass before the sad news becomes official, but the Chinese and Swiss scientists who have been keeping their vigil over the nearly sightless, elusive dolphins are sadly certain.

After surviving 20 million years of shifting climates, which included ice ages and periods far warmer than today, the baiji (a Chinese name meaning "gray-white dolphin") is gone from the face of the earth.

No matter which story you accept about how people populated the Middle Kingdom, the Yangtze dolphin was there first, patrolling the river in family groups of fewer than a half dozen and snatching fish in its long, very toothy beak. Scientists say that even then, the river was seriously silted at some times of year, as the Amazon and the Nile are, and the dolphins found their prey more by echo location than sight.

The dolphins, while more numerous than in recent years, were probably never common. Ranging upwards of 7 feet and weighing nearly a half ton, a female gave birth to a single 3-foot calf, at most, every other year.

That's not the kind of birthrate that leads to high population numbers.

In spite of the Yangtze River's importance to maritime commerce, the Yangtze dolphin remained unknown to science until 80 years ago. There are records of them being sighted from the mouth of the Yangtze, near Shanghai, all the way upriver to the mountains above where the grand Three Gorges Dam was recently built, but they were never extensively studied.

Baiji favored slow-moving channels and lakes, and they were most often seen where smaller tributaries entered the main Yangtze. Most of what is known of Yangtze dolphin life is based on limited observations frustrated by their rarity during the short time they've been known to science.

In 1975, the Chinese government declared the dolphin a national treasure and tried to set up sanctuaries and captive breeding programs. But the only populations to survive were in the wild.

Conservation officials thought the dolphins had turned a corner in 1986, when dolphin calves were seen for the first time in many years, but it was too little, too late. Boat traffic on the Yangtze continued to increase, the fish populations declined and so did the dolphin's population.

Extinction is final.

Extinction is also the way of the world. Nothing lasts forever. So why does the passing of a dolphin matter?

I reckon guilt is part of the answer. Species guilt. We're good at it. Few of us may have personally participated in the human development along the Yangtze, but it was fellow humans who polluted the river, fished it out and zipped about in boats driven by dolphin-injuring propellers. That's all the reason we need for thinking we did it.

There's also the cuteness factor. We humans have totemically adopted whales and dolphins as spiritual brothers and sisters, and their recovery from the decimation visited on them by commercial whaling somehow gives us hope.

Losing a spiritual cousin like baiji feels personal. Maybe the environmental optimism seen in whale recovery isn't quite what we thought.

We'll probably hear stories about how baiji was a top predator, and that losing a top predator like that can fundamentally disturb the Yangtze's ecosystem. And the stories are true.

Losing a top predator like the wolf from the Yellowstone ecosystem caused elk numbers to soar and the hungry elk munched every willow in sight. Everything's connected.

But last summer, I took a boat ride down the coast. There was a lot of bait in the water. Where there are small fish, there are bigger fish and birds feeding on them.

There were brown pelicans everywhere we looked. Brown pelicans were once nearly as rare along California's coast as the Yangtze dolphins were in China 10 years ago, but since we quit using eggshell-thinning DDT, pelican populations have recovered. For hour after hour on that trip we watched the pelicans make their seemingly clumsy dives and raise their heads back out of the water with fish in their pouches. We got to know the brown pelican as we watched.

We, none of us, will ever have that opportunity with baiji.

Freelance writer "Digger" Jerry George sends his journal "letters" home to the Bay Area from Yellowstone National Park -- or wherever he happens to be observing nature. E-mail him at [e-mail].

[another specialist]

China's white dolphin called extinct after 20 million years
POSTED: 9:25 p.m. EST, December 13, 2006

BEIJING, China (AP) -- An expedition searching for a rare Yangtze River dolphin ended Wednesday without a single sighting and with the team's leader saying one of the world's oldest species was effectively extinct.

The white dolphin known as baiji, shy and nearly blind, dates back some 20 million years. Its disappearance is believed to be the first time in a half-century, since hunting killed off the Caribbean monk seal, that a large aquatic mammal has been driven to extinction.

A few baiji may still exist in their native Yangtze habitat in eastern China but not in sufficient numbers to breed and ward off extinction, said August Pfluger, the Swiss co-leader of the joint Chinese-foreign expedition.

"We have to accept the fact, that the Baiji is functionally extinct. We lost the race," Pfluger said in a statement released by the expedition. "It is a tragedy, a loss not only for China, but for the entire world. We are all incredibly sad."

Overfishing and shipping traffic, whose engines interfere with the sonar the baiji uses to navigate and feed, are likely the main reasons for the mammal's decline, Pfluger said. Though the Yangtze is polluted, water samples taken by the expedition every 30 miles did not show high concentrations of toxic substances, the statement said.

For nearly six weeks, Pfluger's team of 30 scientists scoured a 1,000-mile heavily trafficked stretch of the Yangtze, where the baiji once thrived. The expedition's two boats, equipped with high-tech binoculars and underwater microphones, trailed each other an hour apart without radio contact so that a sighting by one vessel would not prejudice the other.

Around 400 baiji were believed to be living in the Yangtze in the 1980s. The last full-fledged search, in 1997, yielded 13 confirmed sightings, and a fisherman claimed to have seen a baiji in 2004, Pfluger said in an earlier interview.

At least 20 to 25 baiji would now be needed to give the species a chance to survive, the group's statement said, citing Wang Ding, a hydrobiologist and China's foremost campaigner for the baiji.

Pfluger, an economist by training who later went to work for an environmental group, was a member of the 1997 expedition and recalls the excitement of seeing a baiji cavorting in the waters near Dongting Lake.

"It marked me," he said in an interview Monday. He went on to set up the baiji.org Foundation to save the dolphin.

That goal having evaporated, Pfluger said his foundation would turn to teaching sustainable fishing practices and trying to save other freshwater dolphins. The expedition also surveyed one of those dwindling species, the Yangtze finless porpoise, finding less than 400 of them.

"The situation of the finless porpoise is just like that of the baiji 20 years ago," Wang, the Chinese scientist, said in the statement. "Their numbers are declining at an alarming rate. If we do not act soon they will become a second baiji."

Pfluger and an occasional online diary kept by expedition members traced a dispiriting situation, as day after day team members engaged in a fruitless search for the baiji.

"At first the atmosphere was 'Let's go. Let's go save this damn species,"' Pfluger said. "As the weeks went on we got more desperate and had to motivate each other."

www.cnn.com/2006/TECH/science/12/13/china.dolphin.ap/index.html