The movements of individual humpback whales (Megaptera novaeangliae) can be tracked by matching p... more The movements of individual humpback whales (Megaptera novaeangliae) can be tracked by matching photographs of the distinctive markings on the ventral sides of their tail flukes. During the winter-spring seasons of 1990, 1991, 1995, 1996, 1999, 2000, 2001 and 2002 a total of 42 individual humpbacks were identified by fluke photographs from the waters of the Cape Verde Islands. These were compared with photographs taken elsewhere in the North Atlantic. One match was made with a whale previously photographed in the Denmark Strait off Iceland, providing the first direct evidence of a link between the humpbacks in tropical waters of the eastern North Atlantic and a high-latitude feeding ground. This finding is consistent with the mitochondrial DNA evidence of at least two distinct breeding populations of humpback whales in the North Atlantic. The presence of cows with young calves as well as singers during the humpback mating and calving season implies that waters surrounding the Cape Verde archipelago constitute a breeding and calving ground for an eastern North Atlantic population of humpback whales.
The ability to recognize individual animals has substantially increased our knowledge of the biol... more The ability to recognize individual animals has substantially increased our knowledge of the biology and behaviour of many taxa. However, not all species lend themselves to this approach, either because of insufficient phenotypic variation or because tag attachment is not feasible. The use of genetic markers ('tags') represents a viable alternative to traditional methods of individual recognition, as they are permanent and exist in all individuals. We tested the use of genetic markers as the primary means of identifying individuals in a study of humpback whales in the North Atlantic Ocean. Analysis of six microsatellite loci among 3,060 skin samples collected throughout this ocean allowed the unequivocal identification of individuals. Analysis of 692 'recaptures', identified by their genotype, revealed individual local and migratory movements of up to 10,000 km, limited exchange among summer feeding grounds, and mixing in winter breeding areas, and also allowed the f...
Two minke whales were tagged with satellite-linked radio transmitters off the coast of northern N... more Two minke whales were tagged with satellite-linked radio transmitters off the coast of northern Norway in order to obtain data on daily locations, movements and swimming speed. One whale was tagged in September 1994, south of Lofoten at the entrance to the Vestfj orden, and one whale was tagged in August 1999 just north of Vesterålen. The whale tagged in
Proceedings of the Royal Society B: Biological Sciences, 1996
It has been speculated that humpback whales, Megaptera novaeangliae, from the northeastern North ... more It has been speculated that humpback whales, Megaptera novaeangliae, from the northeastern North Atlantic breed in tropical waters off the coast of West Africa and therefore that they represent a separate breeding population from that which winters in the West Indies. We determined the genotype at six microsatellite loci as well as the sequence of the first 288 nucleotides in the mitochondrial control region of 133 skin biopsies collected from humpback whales in the central North Atlantic (Iceland and Jan Mayen) and the northeastern North Atlantic (Bear Island and the northern coast of Norway). We detected no significant deviations from Hardy-Weinberg proportions nor any differences in genotype frequencies between localities at the nuclear loci. However, the mitochondrial analyses revealed two distinct matrilineal aggregations: the central and the northeastern North Atlantic. Our findings were not compatible with the idea of a separate eastern North Atlantic breeding ground unless one has been established recently. The proposed alternative hypothesis of a common North Atlantic panmictic population (wintering primarily in the West Indies) in which individual whales display maternally directed site-fidelity to specific feeding grounds was supported by re-sightings of two northeastern North Atlantic humpback whales in the West Indies.
Jacobsen, K.-O., Marx, M. and ØIen, N.(2004), TWO-WAY TRANS-ATLANTIC MIGRATION OF A NORTH ATLANTI... more Jacobsen, K.-O., Marx, M. and ØIen, N.(2004), TWO-WAY TRANS-ATLANTIC MIGRATION OF A NORTH ATLANTIC RIGHT WHALE (EUBALAENA GLACIALIS). Marine Mammal Science, 20: 161–166. doi: 10.1111/j. 1748-7692.2004. tb01147. x
The movements of individual humpback whales (Megaptera novaeangliae) can be tracked by matching p... more The movements of individual humpback whales (Megaptera novaeangliae) can be tracked by matching photographs of the distinctive markings on the ventral sides of their tail flukes. During the winter-spring seasons of 1990, 1991, 1995, 1996, 1999, 2000, 2001 and 2002 a total of 42 individual humpbacks were identified by fluke photographs from the waters of the Cape Verde Islands. These were compared with photographs taken elsewhere in the North Atlantic. One match was made with a whale previously photographed in the Denmark Strait off Iceland, providing the first direct evidence of a link between the humpbacks in tropical waters of the eastern North Atlantic and a high-latitude feeding ground. This finding is consistent with the mitochondrial DNA evidence of at least two distinct breeding populations of humpback whales in the North Atlantic. The presence of cows with young calves as well as singers during the humpback mating and calving season implies that waters surrounding the Cape Verde archipelago constitute a breeding and calving ground for an eastern North Atlantic population of humpback whales.
The ability to recognize individual animals has substantially increased our knowledge of the biol... more The ability to recognize individual animals has substantially increased our knowledge of the biology and behaviour of many taxa. However, not all species lend themselves to this approach, either because of insufficient phenotypic variation or because tag attachment is not feasible. The use of genetic markers ('tags') represents a viable alternative to traditional methods of individual recognition, as they are permanent and exist in all individuals. We tested the use of genetic markers as the primary means of identifying individuals in a study of humpback whales in the North Atlantic Ocean. Analysis of six microsatellite loci among 3,060 skin samples collected throughout this ocean allowed the unequivocal identification of individuals. Analysis of 692 'recaptures', identified by their genotype, revealed individual local and migratory movements of up to 10,000 km, limited exchange among summer feeding grounds, and mixing in winter breeding areas, and also allowed the f...
Two minke whales were tagged with satellite-linked radio transmitters off the coast of northern N... more Two minke whales were tagged with satellite-linked radio transmitters off the coast of northern Norway in order to obtain data on daily locations, movements and swimming speed. One whale was tagged in September 1994, south of Lofoten at the entrance to the Vestfj orden, and one whale was tagged in August 1999 just north of Vesterålen. The whale tagged in
Proceedings of the Royal Society B: Biological Sciences, 1996
It has been speculated that humpback whales, Megaptera novaeangliae, from the northeastern North ... more It has been speculated that humpback whales, Megaptera novaeangliae, from the northeastern North Atlantic breed in tropical waters off the coast of West Africa and therefore that they represent a separate breeding population from that which winters in the West Indies. We determined the genotype at six microsatellite loci as well as the sequence of the first 288 nucleotides in the mitochondrial control region of 133 skin biopsies collected from humpback whales in the central North Atlantic (Iceland and Jan Mayen) and the northeastern North Atlantic (Bear Island and the northern coast of Norway). We detected no significant deviations from Hardy-Weinberg proportions nor any differences in genotype frequencies between localities at the nuclear loci. However, the mitochondrial analyses revealed two distinct matrilineal aggregations: the central and the northeastern North Atlantic. Our findings were not compatible with the idea of a separate eastern North Atlantic breeding ground unless one has been established recently. The proposed alternative hypothesis of a common North Atlantic panmictic population (wintering primarily in the West Indies) in which individual whales display maternally directed site-fidelity to specific feeding grounds was supported by re-sightings of two northeastern North Atlantic humpback whales in the West Indies.
Jacobsen, K.-O., Marx, M. and ØIen, N.(2004), TWO-WAY TRANS-ATLANTIC MIGRATION OF A NORTH ATLANTI... more Jacobsen, K.-O., Marx, M. and ØIen, N.(2004), TWO-WAY TRANS-ATLANTIC MIGRATION OF A NORTH ATLANTIC RIGHT WHALE (EUBALAENA GLACIALIS). Marine Mammal Science, 20: 161–166. doi: 10.1111/j. 1748-7692.2004. tb01147. x
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