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Kailua-Kona, HI, United States

Kiszka J.,CNRS Coastal and Marine Environment Laboratory | Oremus M.,University of Auckland | Richard P.,CNRS Coastal and Marine Environment Laboratory | Poole M.,Marine Mammal Research Program | And 2 more authors.
Journal of Experimental Marine Biology and Ecology | Year: 2010

Defining trophic relationships among organisms of a community is critical in ecology. However, the access to data is sometimes difficult, particularly in remote environments. Ecological niche segregation among the most common delphinid species was investigated: the spinner dolphin (Stenella longirostris), the roughed-toothed dolphin (Steno bredanensis), the short-finned pilot whale (Globicephala macrorhynchus), and the melon-headed whale (Peponocephala electra). Resource partitioning was explored by analysing δ13C (reflecting foraging habitats) and δ15N stable isotopes (reflecting trophic level) from skin biopsies collected around Moorea from July to October 2002 to 2004. Results revealed that spinner dolphins had the lowest trophic level. The three other species had similar δ15N signatures. The most significant result is the differentiation of S. longirostris from S. bredanensis and G. macrorhynchus but not from the P. electra. For the latter three species, some degrees of overlap were apparent. For S. longirostris, S. bredanensis and G. macrorhynchus, variation of δ13C and δ15N stable isotope was not significant between sexes. This study suggests that stable isotopes reveal some degree of segregation and overlap within this delphinid community. However, fine-scale segregation processes may be concealed by stable isotope analyses, meaning that traditional dietary analyses investigations are complementary in answering questions related to niche segregation. © 2010 Elsevier B.V.

Garland E.C.,University of Queensland | Noad M.J.,University of Queensland | Goldizen A.W.,University of Queensland | Lilley M.S.,IBM | And 6 more authors.
Journal of the Acoustical Society of America | Year: 2013

Humpback whales have a continually evolving vocal sexual display, or "song," that appears to undergo both evolutionary and "revolutionary" change. All males within a population adhere to the current content and arrangement of the song. Populations within an ocean basin share similarities in their songs; this sharing is complex as multiple variations of the song (song types) may be present within a region at any one time. To quantitatively investigate the similarity of song types, songs were compared at both the individual singer and population level using the Levenshtein distance technique and cluster analysis. The highly stereotyped sequences of themes from the songs of 211 individuals from populations within the western and central South Pacific region from 1998 through 2008 were grouped together based on the percentage of song similarity, and compared to qualitatively assigned song types. The analysis produced clusters of highly similar songs that agreed with previous qualitative assignments. Each cluster contained songs from multiple populations and years, confirming the eastward spread of song types and their progressive evolution through the study region. Quantifying song similarity and exchange will assist in understanding broader song dynamics and contribute to the use of vocal displays as population identifiers. © 2013 Acoustical Society of America.

Oremus M.,University of Auckland | Oremus M.,British Petroleum | Poole M.M.,Marine Mammal Research Program | Albertson G.R.,Oregon State University | And 2 more authors.
Journal of Experimental Marine Biology and Ecology | Year: 2012

Pelagic species of dolphins are generally assumed to be nomadic, while coastal/insular species often show strong site fidelity. Rough-toothed dolphins (Steno bredanensis) are characteristically described as pelagic, but studies based on individual identification have shown some level of site fidelity near oceanic islands. Here, we collected photographs for individual identification (n=108 unique individuals) and biopsy samples (n=64) to assess genetic diversity, population structure and abundance of rough-toothed dolphins around Moorea and Raiatea (170km apart) in the Society Islands, French Polynesia. Genotype (14 microsatellite loci) and photo-identification recaptures over two to 12years indicated long-term site fidelity around Moorea and a high probability of demographic partitioning between Moorea and Raiatea. There was also a marked genetic differentiation between the two islands for both control region mitochondrial haplotypes (450 base pairs, FST=0.58, p<0.001) and microsatellite allele frequencies (FST=0.07, p<0.001), a pattern confirmed by Bayesian clustering analysis. Around Moorea, estimates of census and current effective population size support a population size in the low hundreds. These results suggest a pattern of small, resident community structure, raising important implications for the management of this species known for depredation issues with local fisheries. Such pattern may be found in other species of pelagic dolphins around oceanic islands, extending the need to conduct similar studies in order to highlight potential conservation issues. © 2012 Elsevier B.V.

Franklin W.,Southern Cross University of Australia | Franklin W.,South Pacific Whale Research Consortium | Franklin T.,Southern Cross University of Australia | Franklin T.,South Pacific Whale Research Consortium | And 30 more authors.
Journal of Cetacean Research and Management | Year: 2012

Discovery mark tagging provided the first evidence of linkages between eastern Australian and Oceania Humpback whale breeding grounds and the Antarctic Area V feeding areas. Early investigation of movements of humpback whales in the Western Pacific led to the view that the Balleny Islands and the Ross Sea were the summer destinations for humpback whales from eastern Australia and the Oceania breeding grounds. Recent photo-identification (ID) studies provided further evidence of low levels of migratory interchange and complex linkages within Oceania and between eastern Australia and Oceania. We report here the migratory movement of three humpback whales (Megaptera novaeangliae) between Eastern Australia (E(i) breeding stock) and the Area V Antarctic feeding area in the vicinity of the Balleny Islands. Using photo-ID techniques, comparisons between a Balleny Island fluke catalogue (n = 11 individuals) and existing fluke catalogues from eastern Australia (n = 3,120 individuals) and Oceania (n = 725 individuals), yielded three matches to Hervey Bay, Byron Bay and Ballina in eastern Australia and no matches to Oceania. The eastern Australia catalogue (n = 3,120) was made up of Hervey Bay (n = 1,556), Byron Bay, (n = 916) and Ballina (n = 648). The Oceania catalogue (n = 725) is made up of Tonga (n = 282); New Caledonia (n = 160); French Polynesia (n = 159); New Zealand (n = 41); Cook Islands (n = 36); American Samoa (n = 31); Vanuatu, Niue, Samoa and Fiji (n = 11) and Norfolk Island (n = 5). Only three previous individual photo-ID matches have been reported between eastern Australia Breeding Stock E(i) and Antarctic Area V feeding areas in the vicinity of the Balleny Islands and the Ross Sea. Only one genotype match has been reported between Antarctic Area V feeding areas and Oceania breeding grounds. An analysis of the frequencies of whales seen and not seen in the Balleny Islands, Oceania and eastern Australia, relative to the expected frequencies, based on the estimated population sizes and the sizes of the catalogues, supports the hypothesis that Antarctic Area V waters, in the vicinity of the Balleny islands, is a summer feeding area for some eastern Australian humpback whales.

Garland E.C.,University of Queensland | Garland E.C.,South Pacific Whale Research Consortium | Goldizen A.W.,University of Queensland | Rekdahl M.L.,University of Queensland | And 11 more authors.
Current Biology | Year: 2011

Cultural transmission, the social learning of information or behaviors from conspecifics [1-5], is believed to occur in a number of groups of animals, including primates [1, 6-9], cetaceans [4, 10, 11], and birds [3, 12, 13]. Cultural traits can be passed vertically (from parents to offspring), obliquely (from the previous generation via a nonparent model to younger individuals), or horizontally (between unrelated individuals from similar age classes or within generations) [4]. Male humpback whales (Megaptera novaeangliae) have a highly stereotyped, repetitive, and progressively evolving vocal sexual display or "song" [14-17] that functions in sexual selection (through mate attraction and/or male social sorting) [18-20]. All males within a population conform to the current version of the display (song type), and similarities may exist among the songs of populations within an ocean basin [16, 17, 21]. Here we present a striking pattern of horizontal transmission: multiple song types spread rapidly and repeatedly in a unidirectional manner, like cultural ripples, eastward through the populations in the western and central South Pacific over an 11-year period. This is the first documentation of a repeated, dynamic cultural change occurring across multiple populations at such a large geographic scale. © 2011 Elsevier Ltd.

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