Juvenile Penguins Go Beyond Safe Area


Using satellite telemetry, scientists have tracked juvenile emperor penguins from their natal colony at the Ross Sea in Antarctica to distant ice-free waters in the Southern Ocean outside the area where they are protected under international agreements.

"It is disturbing to learn that em­peror penguins leave the relative safety of the Ross Sea during at least one critical stage in their life cycle and range in areas that are, and will become, more heavily exploited by commercial fisheries," said Dr. Ger­ald L. Kooyman, a researcher at the Scripps Institute of Oceanography in San Diego.

Dr. Kooyman expressed concern that large numbers of the penguins could be caught in the nets or long lines of fishing fleets, and that stocks of the marine animals on which they feed could be overfished.

The provisions of the Antarctic Treaty and the Convention on the Conservation of Antarctic Marine Living Resources extend only to the 60th parallel in the Ross Sea region. Dr Kooyman pointed out in a report in the current issue of the journal Nature. But four juvenile birds from an emperor penguin colony near Cape Washington were tracked well beyond that boundary, and one pen­guin was 1,775 miles from its birth­place when signals from its transmitter stopped at 56.9 degrees south latitude.

Dr. Kooyman said these findings suggested that the 60th parallel was "too limiting to adequately protect even the most familiar symbol of Antarctic wildlife, the emperor pen­guin." He urged that scientists investigate the dispersal patterns of Ade­lie and Chinstrap penguins, which also breed on the coast of Antarctica.

The satellite tracking of young em­peror penguins, using small trans­mitters glued to the feathers on their backs, is part of a continuing study of the species by Scripps scientists. The Ross sea birds,Dr. Kooyman said, are of special interest because they occur in the last marine frontier that has not been exploited by humans .

The geography of the Ross Sea, he added, provides the penguins with a safe haven compared with birds from breeding sites on the Antarctic continent's outer perimeter. About two dozen emperor penguin colonies are known and the species' breeding population is estimated at 135,000 to 175,000 pairs. The bird's numbers have declined at some colonies in recent years and disturbance from human activity, particularly helicop­ter flights, at nearby scientific bases, is cited as one likely cause.

The emperor is the world's largest penguin, standing nearly four feet tall and weighing as much as 90 pounds. Emperor penguins breed in the winter darkness after the sea ice forms, gathering in colonies either on the floes or the coast. The females lay a single egg each and then spend several weeks at sea while the incu­bating males fast and huddle for warmth in temperatures that hover around 40 degrees below zero. The parents reunite as the southern sky starts to lighten and the eggs hatch, and over the next five months they share the duty of raising the rapidly growing chicks.

The entire breeding cycle consumes nine months. The parent birds depart to put on weight and molt shortly before their chicks fledge, leaving the 25 pound juveniles to fend for themselves. Dr. Kooyman said the adult emperor penguins travel in ice-congested polar waters during the nonbreeding months, feeding on fish and squid at depths up to 1,500 feet. But the whereabouts of the juveniles and their food habits from the time they leave the colony until their return several years later are still a mystery.

Because transmitters and anten­nas were attached near the pen­guins' tails to reduce drag, satellite reception was possible only when the birds were out of the water, resting on pack ice or a drifting iceberg. The juvenile emperors left the Ross Sea colony in late December, and the researchers expected they would re­main in the pack ice like the adults The transmitter batteries would have lasted at least through June. but the last signal was received on March 6. By then, Dr. Kooyman said. the birds were in ice-free waters, where they were immersed at all times, traveling at an average rate of one mile an hour on a course that would have them circumnavigating Antarctica for the next few years.

Juvenile emperors, he added, are not as physiologically capable as the adults, and the availability of prey that can be caught in shallower dives "may be the key as to why they go so far north."


1,096 Mammal and 1,108 Bird Species Threatened By LES LINE

Since 1960, when it started a card file on 34 rare animals. the Species Survival Commission of the World Conservation Union has kept a rap­idly growing list of threatened wildlife on every continent. The Red List, as it became known to conservation­isits, was updated last week using revised criteria for determining the risk of extinction, and the news is grim: 1.096 mammals, nearly one fourth of all known species, are con­sidered threatened, as are 1,108 birds, more than 11 percent of the world's bird species.

The number of mammals listed as critically endangered (169), endan­gered (315) or vulnerable (612) is startling, since this is the first time that the organization, formerly known as the International Union for the Conservation of Nature, has fully assessed the status of each of the 4,630 or so species in the world's 26 orders of mammals. In the past only birds, which number 9,670 species. have been evaluated on a compre­hensive global scale.

The three risk categories are based in large part on the rate of a species' population decline over them last 10 years.  For example, animals whose num­bers have dropped by 80 percent are considered critically endangered­. Habitat loss, fragmentation and degradation, reflecting human popula­tion growth and economic develop­ment, were cited as the most signifi­cant threats to Red List animals. But the Species Survival Commission said the introduction of non-native species threatened entire ecological communities, especially in aquatic systems and in isolated environ­ments like oceanic Islands.

In a statement, interior Secretary Bruce Babbitt described the new Red List as "probably the most thor­ough scientific assessment of the state of the world's wildlife ever undertaken." Dr. Russell Mittermier, a primate expert who is president of Conservation international in Washington called the report proof that warnings about global biological loss haven't been exag­gerated."

And Dr. William Conway, directorof the Wildlife Conservation Society at the Bronx Zoo, said. "Few animals that lie in the path of human develop­nment and have limited ranges can bec exacted to survive without special efforts to protect them."

More than 500 scientists contribut­ed to the evaluations  which identity 5205 animals of all kinds as threat­ened.The document lists 253 reptile. 124 amphibian and 734 fish species as being at risk of extinction, but itemphasizes that thousands of spe­cies cies in those taxonomic groups have not been assessed. "It is impossible to make definitive statements about their overall conservation status," the report states. And 1,891 species of inverte­brates, mainly crustaceans, insects and mollusks. are threatened, but very few of the so-called lower ani­mals have been examined relative to their immense numbers.

Among the different orders of mammals.330 species of rodents. 231 bats. 152 shrews and moles. 653arni­vores (cats. bears, raccoons, wild dogs and weasels). 96 primates and 70 even-toed ungulates (hippopota­muses, pigs, deer, antelope, goats and sheep) are listed as threatened. In the case of primates, nearly half the world's monkeys and apes are on

the Red List, along with 11 of 18 species of hoofed mammals, a high­ profile group that includes rhinocer­oses, zebras, wild horses and tapirs.Among little-known mammals list­ed ed as critically endangered. the Gulf of California harbor porpoise or va­quita (Spanish for -little cow") has been reduced to around 100 individ­uals because of pollution, water di­version and entanglements in fishing nets. The pygmy hog, the world's smallest pig species, survives in two wildlife sanctuaries in India. And only 200 Tonkin snub-nosed monkeys exist in isolated forest fragments in northern Vietnam.

The countries with the largest number of threatened mammals are Indonesia (128 species) and China and India (75 each). The report notes that these countries are species-rich but also account for 43 percent of the world's human population, which puts tremendous pressure on critical habitats. Indonesia. Brazil and China have the highest number of threat­ened species of birds: 104,103 and 90,respectively.