Migratory round-trip of individually identified humpback whales at the Strait of Magellan: clues on transit times and phylopatry to destinations Ciclo migratorio de ballenas jorobadas individualizadas del estrecho de Magallanes: indicios sobre la duración de la migración y filopatría en los destinos

• Published in: Revista chilena de historia natural 2008-12, Vol.81 (4), p.547-560
• Main Authors: JUAN J CAPELLA, JORGE GIBBONS, LILIÁN FLÓREZ-GONZÁLEZ, MARTHA LLANO, CARLOS VALLADARES, VALERIA SABAJ, YERKO A VILINA
• Format: Article
• Language: English
• Subjects: ADNmt; ballenas jorobadas; Colombia; estrecho de Magallanes; foto identificación; humpback whales; migración; migration; photo-identification; Strait of Magellan
• ISSN: 0716-078X; 0717-6317

Humpback whales undertake seasonal migration between productive high-latitude areas where they feed in summer and low-latitude tropical waters where mating and calving occur during winter. In the eastern south Pacific, the species breeds off Colombia and Ecuador, and feeds primarily in the western Antarctic Peninsula and in the waters of the Strait of Magellan (SM), recently described as a new feeding ground for humpback whales. Comparison of fluke photographs of 62 individuals from the SM obtained during the austral summer from 1999 to 2005 and 1,042 individuals from Colombia, provided conclusive matches for six individuals, with an overall interchange Índex of 0.093. Eight migratory trips between summer and winter grounds were registered for four whales during a complete migratory round-trip in consecutive years. The mínimum distance traveled in a one-way trip ranged from 6,650 to 7,000 km. The duration of the two fastest trips between these migratory destinations was 88 and 99 days, with a mean speed of migration of 76 and 67 km day-1 respectively. Five of the whales present in both areas were males and three mitochondrial DNA haplotypes were identified: EM-1 for three individuals, EM-2 for two and EM-3 for the last one, all of which have been previously described for humpback whales from Colombia. All six individuals were seen several days in each season in the SM (as many as 39 days in one case), with an average stay of 72 ± 40 days (n = 20) per year, ranging from 3 to 125 days. On average, each of the six individuals was seen in the SM during 71 ± 18 % of the seven monitored summers. Three individuals were re-sighted in the SM six out of the seven surveyed years, during four to six consecutive years. These results provide the first direct evidence to include humpback whales that feed in the Strait of Magellan as part of the eastern south Pacific population of whales that feed off Colombian waters.La ballena jorobada migra estacionalmente entre latitudes altas donde se alimenta en verano y latitudes bajas donde cría y se aparea en invierno. En el Pacífico sureste, la especie se reproduce en Colombia y Ecuador y se alimenta principalmente al oeste de la península Antartica, y en el estrecho de Magallanes (EM) recientemente descrito como nueva área de alimentación. Al comparar las fotografías de las colas de 62 ballenas individualizadas en el EM durante el verano austral entre 1999 y 2005 con 1.042 individuos de Colombia, se encontró a seis individuos c