Rarotonga, Cook Islands
Rarotonga, Cook Islands

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Paton D.A.,Southern Cross University of Australia | Paton D.A.,South Pacific Whale Research Consortium | Paton D.A.,Jamison Center | Brooks L.,Southern Cross University of Australia | And 10 more authors.
Journal of Cetacean Research and Management | Year: 2011

The humpback whales (Megaptera novaeangliae) that migrate along the east coast of Australia were hunted to near extinction during the last century. This remnant population is part of Breeding Stock E. Previous abundance estimates for the east Australian portion of Breeding Stock E have been based mainly on land-based counts. Here we present a capture-recapture abundance estimate for this population using photo-identification data. These data were collected at three locations on the migration route (Byron Bay - northern migration, Hervey Bay and Ballina - southern migration) in order to estimate the population of humpback whales that migrated along the east coast of Australia in 2005. The capture-recapture data were analysed using a variety of closed population models with a model-averaged estimate of 7,041 (95% CI 4,075-10,008) whales.

Paton D.A.,Jamison Center | Paton D.A.,South Pacific Whale Research Consortium | Paton D.A.,Southern Cross University of Australia | Kniest E.,South Pacific Whale Research Consortium | Kniest E.,University of Newcastle
Journal of Cetacean Research and Management | Year: 2011

Humpback whales (Megaptera novaeangliae) that migrate past the east coast of Australia comprise part of Group V (E(i) breeding stock). From 1995 to 2004 an annual 16 day survey was conducted from Cape Byron (28°37'S, 153°38'E), the most easterly point on the Australian mainland, monitoring the peak of the humpback whale northern migration. The annual rate of increase between 1998 and 2004 of humpback whales observed off Cape Byron is 11.0% (95% CI 2.3-20.5%). This rate of increase is consistent with that recorded from other studies of the humpback whale population off the east coast of Australia. The large confidence intervals associated with this estimate are due to considerable inter-annual variation in counts. The most likely explanation for this being the short survey period, which may not have always coincided with the peak of migration, and in some years a large proportion of whales passed Cape Byron at a greater distance out to sea, making sightability more difficult.

Garrigue C.,British Petroleum | Garrigue C.,South Pacific Whale Research Consortium | Zerbini A.N.,National Oceanic and Atmospheric Administration | Zerbini A.N.,Instituto Aqualie | And 5 more authors.
Journal of Mammalogy | Year: 2010

Knowledge of the local and migratory movements of humpback whales (Megaptera novaeangliae) from New Caledonia is very limited. To investigate this topic, we attached satellite-monitored tags to 12 whales off southern New Caledonia. Tag longevity ranged from 1 to 52 days (X̄ 22.5 days). Tagged whales generally moved to the south or southeast, with several spending time in a previously unknown seamount habitat named Antigonia before resuming movement, generally toward Norfolk Island or New Zealand. However, 1 female with a calf traveled the entire length of the western coast of New Caledonia (∼450 km) and then west in the direction of the Chesterfield Reefs, a 19th century American ("Yankee") whaling ground. None of the New Caledonia whales traveled to or toward eastern Australia, which is broadly consistent with the low rate of interchange observed from photo-identification comparisons between these 2 areas. The connections between New Caledonia and New Zealand, together with the relatively low numbers of whales seen in these places generally, support the idea that whales from these 2 areas constitute a single population that remains small and unrecovered. © 2010 American Society of Mammalogists.

Clapham P.J.,National Oceanic and Atmospheric Administration | Clapham P.J.,South Pacific Whale Research Consortium | Zerbini A.N.,National Oceanic and Atmospheric Administration | Zerbini A.N.,Cascadia Research Collective
Marine Biology | Year: 2015

Humpback whales (Megaptera novaeangliae) in the Southern Hemisphere were heavily exploited by commercial whaling. Today, their recovery is variable: Humpbacks remain surprisingly scarce in some formerly populous areas (e.g., New Zealand, Fiji), while in other regions (such as eastern Australia), they appear to be rebounding at or even above the maximum plausible rate of annual increase. Here, we propose that this phenomenon cannot be explained solely in demographic terms. Through simulation, we test the hypothesis that reported high rates of increase represent a combination of true intrinsic growth rates and temporary immigration, driven by a strong tendency to aggregate for mating. We introduce the idea that overexploitation diminished density at major breeding grounds such that these were no longer viable; then, during subsequent population recovery, a critical mass was attained in certain areas which drew in whales that formerly bred elsewhere. The simulations show that, to maintain high increase rates, the contribution to that rate by temporary immigration from a second, “source” population would have to represent a larger and larger proportion of the source stock and would require relatively high (but quite plausible) intrinsic rates of increase for each population. In the modeling scenarios, the demand for immigrants would eventually exceed the supply and exhaust the source population, but the simulations demonstrated that high increase rates can be sustained over periods of more than 20 years. This hypothesis, if correct, would not only explain excessively high rates of increase in current “hotspots” such as eastern Australia, but also imply that formerly important areas (e.g., Fiji) host few whales today not necessarily because of a failure to recover, but because the species’ mating system leads the whales concerned to migrate to higher-density breeding grounds elsewhere. Overall, we caution that assessments of depleted animal populations that do not consider the social behavior of a species are missing a potentially vital component of the picture. © 2015, Springer-Verlag Berlin Heidelberg (outside the USA).

Horton T.W.,Geological science | Holdaway R.N.,Geological science | Holdaway R.N.,University of Canterbury | Holdaway R.N.,Palaecol Research Ltd | And 10 more authors.
Biology Letters | Year: 2011

Humpback whale seasonal migrations, spanning greater than 6500 km of open ocean, demonstrate remarkable navigational precision despite following spatially and temporally distinct migration routes. Satellite-monitored radio tag-derived humpback whale migration tracks in both the South Atlantic and South Pacific include constant course segments of greater than 200 km, each spanning several days of continuous movement. The whales studied here maintain these directed movements, often with better than 18 precision, despite the effects of variable seasurface currents. Such remarkable directional precision is difficult to explain by established models of directional orientation, suggesting that alternative compass mechanisms should be explored. © 2011 The Royal Society.

Garland E.C.,University of Queensland | Garland E.C.,South Pacific Whale Research Consortium | Garland E.C.,National Oceanic and Atmospheric Administration | Lilley M.S.,IBM | And 6 more authors.
Behaviour | Year: 2012

Animals can communicate using visual and acoustic displays to convey information to conspecifics. In some cases, such displays are produced in highly stereotyped and repetitive sequences. Here we use a quantitative analysis technique, the Levenshtein distance, to assess similarity in sequences of displays at both the population and individual levels. We review two existing variations of the method and present two new variations that complement and extend these existing techniques. Three of the methods include the use of a median string sequence and three use a normalisation of the original equation. Humpback whale song theme sequences from multiple populations, years and song types (different variations of the display) are used as examples to illustrate the application and success of each variation. A novel outcome of this technique is that it can produce a threshold measure of similarity to assess when behavioural sequences are so dissimilar that they must be considered different, with a measure of the probability of such clusters being distinct. The Levenshtein distance is applicable to all behavioural data produced in sequences and its use should not be limited to acoustical studies. © 2012 Koninklijke Brill NV, Leiden.

Clapham P.J.,South Pacific Whale Research Consortium
Marine Policy | Year: 2015

Since 1987, Japan has conducted extensive special permit whaling ("scientific whaling") in the Antarctic and North Pacific. This has been viewed by many as a way to circumvent the International Whaling Commission's (IWC) moratorium on commercial whaling, which was implemented in 1985. Recently, Australia took Japan to the International Court of Justice (ICJ) over this issue. Using various criteria, the Court ruled that Japan's whaling was not "for purposes of scientific research" as required by Article VIII of the International Convention for the Regulation of Whaling, and ordered Japan to immediately cease its JARPA II whaling program in the Antarctic. Despite optimism that the Court's ruling might spell the end of Japanese whaling in the Antarctic and even elsewhere, Japan has indicated that it will redesign its whaling programs and continue operations. Based upon Japan's history at the IWC, I argue here that this was an expected outcome; I predict the course of events over the next months, and suggest that the ICJ ruling, while satisfying as an independent vindication of Japan's critics, represents little more than a temporary setback for that nation's whaling enterprise. © 2014 Elsevier Ltd.

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.

PubMed | University of Queensland, South Pacific Whale Research Consortium and IBM
Type: Journal Article | Journal: Conservation biology : the journal of the Society for Conservation Biology | Year: 2015

For cetaceans, population structure is traditionally determined by molecular genetics or photographically identified individuals. Acoustic data, however, has provided information on movement and population structure with less effort and cost than traditional methods in an array of taxa. Male humpback whales (Megaptera novaeangliae) produce a continually evolving vocal sexual display, or song, that is similar among all males in a population. The rapid cultural transmission (the transfer of information or behavior between conspecifics through social learning) of different versions of this display between distinct but interconnected populations in the western and central South Pacific region presents a unique way to investigate population structure based on the movement dynamics of a song (acoustic) display. Using 11 years of data, we investigated an acoustically based population structure for the region by comparing stereotyped song sequences among populations and years. We used the Levenshtein distance technique to group previously defined populations into (vocally based) clusters based on the overall similarity of their song display in space and time. We identified the following distinct vocal clusters: western cluster, 1 population off eastern Australia; central cluster, populations around New Caledonia, Tonga, and American Samoa; and eastern region, either a single cluster or 2 clusters, one around the Cook Islands and the other off French Polynesia. These results are consistent with the hypothesis that each breeding aggregation represents a distinct population (each occupied a single, terminal node) in a metapopulation, similar to the current understanding of population structure based on genetic and photo-identification studies. However, the central vocal cluster had higher levels of song-sharing among populations than the other clusters, indicating that levels of vocal connectivity varied within the region. Our results demonstrate the utility and value of using culturally transmitted vocal patterns as a way of defining connectivity to infer population structure. We suggest vocal patterns be incorporated by the International Whaling Commission in conjunction with traditional methods in the assessment of structure.

PubMed | Ministry of Fisheries and Marine Resources of the Solomon Islands Government, South Pacific Whale Research Consortium and Oregon State University
Type: Journal Article | Journal: Royal Society open science | Year: 2015

The drive hunting of dolphins has a long history in the Solomon Islands, specifically at the island of Malaita. In 2010, the most active village, Fanalei, suspended hunting in exchange for financial compensation from an international non-governmental organization but resumed hunting again in early 2013. Here, we report on a visit to Fanalei in March 2013 to document the species and number of dolphins killed in the renewed hunting. Detailed records for the 2013 hunting, up to the time of our visit, included at least 1500 pantropical spotted dolphins (Stenella attenuata), 159 spinner dolphins (Stenella longirostris) and 15 bottlenose dolphins, probably Tursiops truncatus. Molecular identification confirmed two of the species, pantropical spotted and spinner dolphins. A summary of all available records from 1976 to 2013 documented a minimum total of 15454 dolphins killed by the Fanalei villagers alone. We also found the local price of a dolphin tooth had increased from about US$0.14 (SBD$1) in 2004 to about US$0.70 (SBD$5) in 2013. The large number of dolphins killed and the apparent incentive for future hunting offered by the increasing commercial value of teeth, highlight an urgent need to monitor hunts and assess the abundance and trends in local populations.

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