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Report of the Second Workshop on The Biology and Conservation of ...

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<strong>The</strong> Breeding Ground Distributi<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Humpback Whales (Megapteranovaeangliae) in <str<strong>on</strong>g>the</str<strong>on</strong>g> Western North Pacific <strong>and</strong> <strong>The</strong>ir Trans-Movementsam<strong>on</strong>g <str<strong>on</strong>g>the</str<strong>on</strong>g> Ogasawara Isl<strong>and</strong>s, <str<strong>on</strong>g>the</str<strong>on</strong>g> Ryukyu Isl<strong>and</strong>s <strong>and</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> Babuyan Isl<strong>and</strong>s,PhilippinesYamaguchi, M. 1 , Acebes, J.M. 2 <strong>and</strong> Miyamura, Y. 3(1) Ogasawara Marine Center, Chichi-jima, Ogasawara, Tokyo 100-2101 Japane-mail: manapua@f4.di<strong>on</strong>.ne.jp(2) WWF-Philippines, Diliman, Quez<strong>on</strong> City 1101 Philippines(3) Heart L<strong>and</strong>, 105 Zamami, Okinawa 901-3402 Japan<strong>The</strong> Ogasawara Isl<strong>and</strong>s (27°N, 142°E) <strong>and</strong> Ryukyu (Kerama) Isl<strong>and</strong>s (26°N, 127°E), which locatein <str<strong>on</strong>g>the</str<strong>on</strong>g> sou<str<strong>on</strong>g>the</str<strong>on</strong>g>rn part <str<strong>on</strong>g>of</str<strong>on</strong>g> Japan, have been known as major breeding grounds for <str<strong>on</strong>g>the</str<strong>on</strong>g> humpbackwhales (Megaptera novaeangliae). It is approved by c<strong>on</strong>tinuous researches showing existence<str<strong>on</strong>g>of</str<strong>on</strong>g> newborn calves <strong>and</strong> mating pods, <strong>and</strong> re-sightings <str<strong>on</strong>g>of</str<strong>on</strong>g> individual whales in <str<strong>on</strong>g>the</str<strong>on</strong>g> same seas<strong>on</strong>or over seas<strong>on</strong>s proved by fluke photo identificati<strong>on</strong>. <strong>The</strong> biological research <strong>on</strong> this species hasbeen operated in <str<strong>on</strong>g>the</str<strong>on</strong>g> Ogasawara <strong>and</strong> Ryukyu Isl<strong>and</strong>s since 1989 <strong>and</strong> in <str<strong>on</strong>g>the</str<strong>on</strong>g> Babuyan Isl<strong>and</strong>s,nor<str<strong>on</strong>g>the</str<strong>on</strong>g>rn Luz<strong>on</strong>, Philippines since 1999 respectively. During 1989-1994, 490 individuals wereidentified in <str<strong>on</strong>g>the</str<strong>on</strong>g> Ogasawara Isl<strong>and</strong>s (including photos taken in 1987-88) <strong>and</strong> 89 in <str<strong>on</strong>g>the</str<strong>on</strong>g> RyukyuIsl<strong>and</strong>s, <strong>and</strong> 28 individuals were found in both waters. <strong>The</strong> dense interchanges <str<strong>on</strong>g>of</str<strong>on</strong>g> speciesbetween <str<strong>on</strong>g>the</str<strong>on</strong>g>se two regi<strong>on</strong>s indicates that <str<strong>on</strong>g>the</str<strong>on</strong>g> species that migrate to both regi<strong>on</strong>s bel<strong>on</strong>g to <str<strong>on</strong>g>the</str<strong>on</strong>g>same populati<strong>on</strong> so-called “Asian stock”. Fur<str<strong>on</strong>g>the</str<strong>on</strong>g>rmore, to determine <str<strong>on</strong>g>the</str<strong>on</strong>g> sou<str<strong>on</strong>g>the</str<strong>on</strong>g>rn margin <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g>Asian stock distributi<strong>on</strong>, sighting surveys were c<strong>on</strong>ducted in <str<strong>on</strong>g>the</str<strong>on</strong>g> water <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Mariana Isl<strong>and</strong>s in1995 <strong>and</strong> 1996. Although no humpback whales were sighted in those surveys, some sightingswere reported by residents with photographs as evidence. Additi<strong>on</strong>ally, five <str<strong>on</strong>g>of</str<strong>on</strong>g> ten whales, whichhave been identified in <str<strong>on</strong>g>the</str<strong>on</strong>g> nor<str<strong>on</strong>g>the</str<strong>on</strong>g>rn part <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Philippines since 1999, were matched to <str<strong>on</strong>g>the</str<strong>on</strong>g> <strong>on</strong>esin Ogasawara-Ryukyu ID photo collecti<strong>on</strong>s. Of <str<strong>on</strong>g>the</str<strong>on</strong>g>se five whales, three were found in Ogasawara,<strong>on</strong>e was in Ryukyu <strong>and</strong> <strong>on</strong>e was in both regi<strong>on</strong>s. Although it is assumed that <str<strong>on</strong>g>the</str<strong>on</strong>g> humpbackwhales in <str<strong>on</strong>g>the</str<strong>on</strong>g> breeding ground <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> western North Pacific are still densely distributed in <str<strong>on</strong>g>the</str<strong>on</strong>g>Ogasawara <strong>and</strong> Ryukyu Isl<strong>and</strong>s, <str<strong>on</strong>g>the</str<strong>on</strong>g>ir recent distributi<strong>on</strong> extends to <str<strong>on</strong>g>the</str<strong>on</strong>g> waters <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Philippines<strong>and</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> Mariana Isl<strong>and</strong>s.<str<strong>on</strong>g>Sec<strong>on</strong>d</str<strong>on</strong>g> <str<strong>on</strong>g>Workshop</str<strong>on</strong>g> <strong>on</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> <strong>Biology</strong> <strong>and</strong> C<strong>on</strong>servati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> Small Cetaceans <strong>and</strong> Dug<strong>on</strong>gs <str<strong>on</strong>g>of</str<strong>on</strong>g> SE Asia 159

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