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本帖最后由 批一啊pia 于 2010-10-14 13:38 编辑
【纽约时报】法国在国内外均面临恐怖威胁
【今日话题】 一切为了爱!母鲸鱼求偶拼速度狂飙近万公里打破世界纪录
Record-breaking whale swims 9800km in search of a mate
原文链接
原文大意:海洋生物学家称,一头座头鲸打破了哺乳动物的记录,从大西洋游到印度洋,狂飙9800公里只为了寻觅佳偶。这头座头鲸因其奇特的身形和带有斑点的尾巴,在马达加斯加附近被观察员们认出,两年前曾在巴西的东南海岸出现过。她游过的距离比一般的季节性迁徙要多400公里。距离长短不是问题,问题在于这头母鲸鱼竟然为了求偶游这么远,一般来说这是雄性鲸鱼才做的事情。不过也有可能,它们只知道从西游到东,跟纬度没有什么关系。
A HUMPBACK whale has broken the world record for travel by any mammal, swimming at least 9800km from the Atlantic to the Indian Ocean in search of a mate, marine biologists reported.
The female humpback was first photographed among a group of whales at a breeding ground on Abrolhos Bank, off Brazil's southeastern coast, on August 7, 1999.
By sheer chance, it was photographed more than two years later, on September 21, 2001, by a commercial whale-watching tour at a breeding ground near the Ile Sainte Marie off the eastern coast of Madagascar.
The whale was identified thanks to the distinctive shape of its tail and a pattern of spots on it.
"It is the longest documented movement by a mammal, about 250 miles (400 km) longer than the longest seasonal migration that has been reported," according to the research, headed by Peter Stevick of the College of the Atlantic in Bar Harbor, Maine.
The trip is not just remarkable for the distance the whale covered, Mr Stevick said.
It also raises exciting questions about the breeding habits of humpbacks (Megaptera novaeangliae), a species of which relatively little is known.
Until now, it was thought that only males, rather than females, would be likely to wander such extreme distances in quest of a partner.
Humpbacks are known to be long-distance swimmers, but until now their migration patterns were thought to be between northern and southerly latitudes.
For instance, a whale might head to feeding area in a far southern latitude in the Atlantic, then return to a tropical latitude in the Atlantic in order to breed.
But this discovery suggests that humpbacks may also have a migratory pattern that straddles longitudes, not latitudes. In other words, they could swim east-west to breed.
Further work is needed to investigate such theories, as this is just a solitary sighting.
But if more marathon humpbacks are found, it could lead to a rethink of the species' genetic profile, which in turn has an impact on conservation.
So far scientists have been able to identify seven distinct breeding stocks and several sub-stocks of humpbacks in the Southern Hemisphere. Their perceived isolation and entrenched breeding habits raised fears of a restricted gene pool, which is bad news for a species.
Humpbacks were driven close to extinction through over-hunting but are now staging a comeback.
In 2008, the International Union for the Conservation of Nature (IUCN) moved humpbacks from the category of Vulnerable to that of Least Concern, meaning the species is at low risk of extinction. Two subpopulations remained classified as Endangered, however.
The study appears in Biology Letters, published by Britain's Royal Society. |
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