from the NYTimesThe image above, taken in 2001, was used to identify a female humpback
whale who traveled more than 6,000 miles from Brazil to Madagascar.
By SINDYA N. BHANOO
If you cruise the Web you can find long-lost friends, high school sweethearts and ... far-traveling humpback whales.
With the help of Flickr, a photo-sharing site, Peter Stevick, a biologist at the College of the Atlantic, in Bar Harbor, Me., and colleagues have identified a whale that made an unprecedented journey, an epic 6,000 miles from Brazil to Madagascar, about 10 years ago. The whale’s adventure is described in Biology Letters.
Gale McCullough, a research assistant in Dr. Stevick's lab, often checks Flickr for whale photos because humpbacks can be identified by their tails, which are as individual as fingerprints. An amateur photographer had taken a photo on a film camera in 2001 and only recently posted it. That photo matched one taken by researchers of a whale off the coast of Brazil in 1999.
There is no way to know what the humpback’s exact journey was, but the shortest route it could have taken would have been across the south Atlantic Ocean and around Africa to arrive in Madagascar, in the Indian Ocean, said Dr. Stevick, the study’s lead author.
During the course of a year, humpback whales spend their summers in cooler climates and focus their efforts on getting as much nourishment as possible. In the winter, they travel to warm tropical areas where they mate and give birth to their calves. It is not uncommon for the whales to travel close to 4,000 miles in a single year.
But this female’s journey was unprecedented. “It traveled between two different breeding habitats, which is something that is virtually unseen,” Dr. Stevick said. Just why this particular whale made the unusual journey is unclear. It is possible that it was in search of a better habitat, or that it simply got lost, he said.
Reference
Stevick PT, Neves MC, Johansen F, Engel MH, Allen J, Marcondes MCC, Carlson C (2010) A quarter of a world away: female humpback whale moves 10 000 km between breeding areas. Biology Letters doi: 10.1098/rsbl.2010.0717
ABSTRACT
Fidelity of individual animals to breeding sites is a primary determinant of population structure. The degree and scale of philopatry in a population reflect the fitness effects of social facilitation, ecological adaptation and optimal inbreeding. Patterns of breeding-site movement and fidelity are functions of social structure and are frequently sex biased. We report on a female humpback whale (Megaptera novaeangliae) first identified by natural markings off Brazil that subsequently was photographed off Madagascar. The minimum travel distance between these locations is greater than 9800 km, approximately 4000 km longer than any previously reported movement between breeding grounds, more than twice the species' typical seasonal migratory distance and the longest documented movement by a mammal. It is unexpected to find this exceptional long-distance movement between breeding groups by a female, as models of philopatry suggest that male mammals move more frequently or over longer distances in search of mating opportunities. While such movement may be advantageous, especially in changeable or unpredictable circumstances, it is not possible to unambiguously ascribe causality to this rare observation. This finding illustrates the behavioural flexibility in movement patterns that may be demonstrated within a typically philopatric species.
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