The Omura’s whale (Balaenoptera omurai) was described as a new species in 2003 and then soon after as an ancient lineage basal to a Bryde’s/sei whale clade. Currently known only from whaling and stranding specimens primarily from the western Pacific and eastern Indian Oceans, there exist no confirmed field observations or ecological/behavioural data. Here we present, to our knowledge, the first genetically confirmed documentation of living Omura’s whales including descriptions of basic ecology and behaviour from northwestern Madagascar. Species identification was confirmed through molecular phylogenetic analyses of biopsies collected from 18 adult animals. All individuals shared a single haplotype in a 402 bp sequence of mtDNA control region, suggesting low diversity and a potentially small population. Sightings of 44 groups indicated preference for shallow-water shelf habitat with sea surface temperature between 27.4°C and 30.2°C. Frequent observations were made of lunge feeding, possibly on zooplankton. Observations of four mothers with young calves, and recordings of a song-like vocalization probably indicate reproductive behaviour. Social organization consisted of loose aggregations of predominantly unassociated single individuals spatially and temporally clustered. Photographic recapture of a female re-sighted the following year with a young calf suggests site fidelity or a resident population. Our results demonstrate that the species is a tropical whale without segregation of feeding and breeding habitat, and is probably non-migratory; our data extend the range of this poorly studied whale into the western Indian Ocean. Exclusive range restriction to tropical waters is rare among baleen whale species, except for the various forms of Bryde’s whales and Omura’s whales. Thus, the discovery of a tractable population of Omura’s whales in the tropics presents an opportunity for understanding the ecological factors driving potential convergence of life-history patterns with the distantly related Bryde’s whales.

South Asia is a region of complex atmospheric dynamics and therefore changes resulting from increasing greenhouse gas concentrations, combined with existing vulnerability to extreme weather events such as flooding, could put the region at particular risk from climate change. However, current climate projections for the region show a range of uncertainty, particularly in terms of changes in the variability and extremes of precipitation. Focusing on Bangladesh and the region encompassing parts of the Ganges, Brahmaputra and Meghna river basins, we aim to explore and quantify climate model uncertainty in climate change projections for the 21(st) century. We use results from a 17-member perturbed physics ensemble of projections from a global climate model which have been used to drive a higher resolution (25 km) regional climate model over the south Asia region from 1971 to 2099. The range of temperature and precipitation responses across the ensemble are assessed including representation of the annual cycle, trends, and changes in precipitation extremes. The 17 ensemble members consistently simulate increasing annual mean temperatures by 2100 compared with present day, ranging between 2.6 °C and 4.8 °C. Additionally, all ensemble members indicate increasing annual precipitation by 2100 of between around 8% and 28%, though with interdecadal variability which results in one ensemble member showing a slight decrease in precipitation in the mid-century period. The frequency of light precipitation events is projected to decrease in the future, but with an increase in the frequency of heavy events. Three members of the climate model ensemble, representing a range of projected climate outcomes, have been selected for use in further impacts modelling for the region.

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BackgroundThe harpy eagle (Harpia harpyja) is the largest Neotropical bird of prey and is threatened by human persecution and habitat loss and fragmentation. Current conservation strategies include local education, captive rearing and reintroduction, and protection or creation of trans-national habitat blocks and corridors. Baseline genetic data prior to reintroduction of captive-bred stock is essential for guiding such efforts but has not been gathered previously.Methodology/FindingsWe assessed levels of genetic diversity, population structure and demographic history for harpy eagles using samples collected throughout a large portion of their geographic distribution in Central America (n = 32) and South America (n = 31). Based on 417 bp of mitochondrial control region sequence data, relatively high levels of haplotype and nucleotide diversity were estimated for both Central and South America, although haplotype diversity was significantly higher for South America. Historical restriction of gene flow across the Andes (i.e. between our Central and South American subgroups) is supported by coalescent analyses, the haplotype network and significant F ST values, however reciprocally monophyletic lineages do not correspond to geographical locations in maximum likelihood analyses. A sudden population expansion for South America is indicated by a mismatch distribution analysis, and further supported by significant (p<0.05) negative values of Fu and Li's DF and F, and Fu's F S. This expansion, estimated at approximately 60 000 years BP (99 000–36 000 years BP 95% CI), encompasses a transition from a warm and dry time period prior to 50 000 years BP to an interval of maximum precipitation (50 000–36 000 years BP). Notably, this time period precedes the climatic and habitat changes associated with the last glacial maximum. In contrast, a multimodal distribution of haplotypes was observed for Central America suggesting either population equilibrium or a recent decline.SignificanceHigh levels of mitochondrial genetic diversity in combination with genetic differentiation among subgroups within regions and between regions highlight the importance of local population conservation in order to preserve maximal levels of genetic diversity in this species. Evidence of historically restricted female-mediated gene flow is an important consideration for captive-breeding programs.