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Phillip J. Clapham - One of the best experts on this subject based on the ideXlab platform.
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Humpback Whale abundance in the north pacific estimated by photographic capture recapture with bias correction from simulation studies
Marine Mammal Science, 2011Co-Authors: Jay Barlow, Christine M Gabriele, Phillip J. Clapham, John Calambokidis, Scott C Baker, Erin A Falcone, Alexander M Burdin, John K B Ford, Richard G Leduc, David K MattilaAbstract:We estimated the abundance of Humpback Whales in the North Pacific by capture-recapture methods using over 18,000 fluke identification photographs collected in 2004–2006. Our best estimate of abundance was 21,808 (CV = 0.04). We estimated the biases in this value using a simulation model. Births and deaths, which violate the assumption of a closed population, resulted in a bias of +5.2%, exclusion of calves in samples resulted in a bias of −10.5%, failure to achieve random geographic sampling resulted in a bias of −0.4%, and missed matches resulted in a bias of +9.3%. Known sex-biased sampling favoring males in breeding areas did not add significant bias if both sexes are proportionately sampled in the feeding areas. Our best estimate of abundance was 21,063 after accounting for a net bias of +3.5%. This estimate is likely to be lower than the true abundance due to two additional sources of bias: individual heterogeneity in the probability of being sampled (unquantified) and the likely existence of an unknown and unsampled breeding area (−8.7%). Results confirm that the overall Humpback Whale population in the North Pacific has continued to increase and is now greater than some prior estimates of prewhaling abundance.
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Humpback Whale: Megaptera novaeangliae
Encyclopedia of Marine Mammals, 2009Co-Authors: Phillip J. ClaphamAbstract:Publisher Summary This chapter discusses the characteristics, taxonomy, distribution, abundance, and ecology of the Humpback Whale or Megaptera novaeangliae. The Humpback Whale is one of the best known and easily recognizable of the large Whales. It is known for its frequent acrobatic behavior and its occasional tendency to approach vessels. At close range, Humpback Whales are easily distinguished from any other large Whale by their remarkably long flippers, which are approximately one-third the length of the body. The flippers are ventrally white and can be either white or black dorsally depending on the population and the individual; the flippers of North Atlantic Humpbacks tend to be white, while those in the North Pacific are usually black. Humpback Whales are found in all oceans of the world. They are a highly migratory species, spending spring through fall on feeding grounds in mid- or high-latitude waters, and wintering on calving grounds in the tropics, where they do not eat. They are typically found in coastal or shelf waters in summer and close to islands or reef systems in winter. The Humpback Whale is heavily exploited by the whaling industry for several centuries. Because of its coastal distribution, it is often the first species to be hunted in a newly discovered area. As a result, the Humpback is considered as an endangered species.
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acoustic monitoring on a Humpback Whale megaptera novaeangliae feeding ground shows continual singing into late spring
Proceedings of The Royal Society B: Biological Sciences, 2004Co-Authors: Christopher W Clark, Phillip J. ClaphamAbstract:Singing by males is a major feature of the mating system of Humpback Whales, Megaptera novaeangliae (Borowski). Although a few songs have been opportunistically recorded on the Whales' high-latitude feeding grounds, singing in these regions was thought to be only sporadic. We report results from the first continuous acoustic monitoring of a Humpback Whale feeding ground (off Cape Cod, MA, USA) in spring. Using autonomous sea-floor recording systems, we found singing on a daily basis over the entire 25 day monitoring period, from 14 May to 7 June 2000. For much of the period, song was recorded 24 h per day. These results, combined with evidence for aseasonal conceptions in whaling catch data, suggest that the Humpback Whale breeding season should no longer be considered as confined to lower-latitude regions in winter. Rather, we suggest breeding extends geographically and temporally onto feeding grounds into at least spring and early summer. Singing at these times represents either low-cost opportunistic advertising by (perhaps relatively few) males to court females that failed to conceive during the winter, and/or possibly an intrasexual display.
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north atlantic Humpback Whale abundance and rate of increase four decades after protection from whaling
Marine Ecology Progress Series, 2003Co-Authors: Peter T Stevick, Phillip J. Clapham, Judith Allen, Steven K Katona, Finn Larsen, Jon Lien, David K Mattila, Per J Palsboll, Nancy A Friday, Johann SigurjonssonAbstract:Humpback Whales Megaptera novaeangliae in the North Atlantic Ocean were severely depleted by exploitation. With legal protection since 1955, substantial recovery is likely to have occurred, but information on abundance and rates of increase has been limited. We present an assessment of Humpback Whale abundance in the North Atlantic Ocean based upon capture- recapture estimates using naturally marked individuals. These data result from a long-term collabo- rative effort combining large-scale dedicated projects and incidental data collection, leading to extensive geographical coverage. The application of robust statistical techniques produces estimates of greater accuracy and precision than has previously been possible. Abundance estimates ranging from 5930 to 12 580 individuals, with coefficients of variation (CVs) from 0.07 to 0.39, were calculated for the West Indies breeding population using data from 1979 to 1993. The most precise estimate for the West Indies breeding population is 10 752 (CV = 0.068) for 1992 and 1993. Due to application of new analytical methods, these estimates are larger and more precise than those previously published from similar time periods. The average rate of increase for the West Indies breeding population over a 14 yr period was estimated to be 0.031 (SE = 0.005). The best available estimate for the entire North Atlantic population of Humpback Whales is 11 570 (95% CI 10 290 to 13 390) based upon samples from 1992 and 1993. However, this estimate may be biased downwards to an unknown extent due to heterogeneity in capture probabilities that do not influence the West Indies estimates.
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composition and dynamics of Humpback Whale competitive groups in the west indies
Behaviour, 1992Co-Authors: Phillip J. Clapham, David K Mattila, Per J Palsboll, Oswaldo VasquezAbstract:It has been hypothesized that Humpback Whale, Megaptera novaeangliae, competitive groups represent intrasexual competition by males for access to a mature female. The composition and dynamics of these groups was studied between 1989 and 1991 in Samana Bay, West Indies. The sex of group participants was determined by molecular analysis of skin biopsies. Groups showed similar characteristics of size and movement as those described from other breeding areas, except that only one group contained a calf. The sex was determined of 141 participants in 44 competitive groups. In 21 of these groups, we were able to biopsy all participants. No group contained more than one female, but seven of the wholly sampled groups (all of them small) consisted entirely of males. Of 22 animals who were ''positively'' assigned the role of Nuclear Animal, 17 were female, and five were male. Similarly, of 24 biopsied Principal Escorts, 23 were male and one female. All 24 biopsied Challengers were male. Of 55 animals who were either classified as Secondary Escort, or whose role could not be categorized, 51 were male and four female. In 8 cases, associated pairs of males exhibiting no aggression towards each other were observed to either enter or leave a competitive group together. Of 16 individuals resighted on more than one day, all but one were males. These data suggest that: 1. While most groups (as predicted) represent male-male competition for a single female, observers should be cautious in their assumptions; 2. All-male groups may represent dominance sorting by unfamiliar conspecifics; 3. Females may occasionally aggressively repel advances by unwanted males; 4. While unlikely in light of present knowledge, the possibility that males form coalitions cannot be dismissed. We suggest that competitive groups may be asymmetrical contests in which a female Nuclear Animal is of more value to the Principal Escort than to a Challenger, particularly if the former's defence of her represents mate-guarding.
David K Mattila - One of the best experts on this subject based on the ideXlab platform.
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Humpback Whale abundance in the north pacific estimated by photographic capture recapture with bias correction from simulation studies
Marine Mammal Science, 2011Co-Authors: Jay Barlow, Christine M Gabriele, Phillip J. Clapham, John Calambokidis, Scott C Baker, Erin A Falcone, Alexander M Burdin, John K B Ford, Richard G Leduc, David K MattilaAbstract:We estimated the abundance of Humpback Whales in the North Pacific by capture-recapture methods using over 18,000 fluke identification photographs collected in 2004–2006. Our best estimate of abundance was 21,808 (CV = 0.04). We estimated the biases in this value using a simulation model. Births and deaths, which violate the assumption of a closed population, resulted in a bias of +5.2%, exclusion of calves in samples resulted in a bias of −10.5%, failure to achieve random geographic sampling resulted in a bias of −0.4%, and missed matches resulted in a bias of +9.3%. Known sex-biased sampling favoring males in breeding areas did not add significant bias if both sexes are proportionately sampled in the feeding areas. Our best estimate of abundance was 21,063 after accounting for a net bias of +3.5%. This estimate is likely to be lower than the true abundance due to two additional sources of bias: individual heterogeneity in the probability of being sampled (unquantified) and the likely existence of an unknown and unsampled breeding area (−8.7%). Results confirm that the overall Humpback Whale population in the North Pacific has continued to increase and is now greater than some prior estimates of prewhaling abundance.
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return movement of a Humpback Whale between the antarctic peninsula and american samoa a seasonal migration record
Endangered Species Research, 2011Co-Authors: Jooke Robbins, Judith Allen, David K Mattila, Luciano Dalla Rosa, Eduardo R Secchi, Ari S Friedlaender, Peter T Stevick, Douglas P Nowacek, Debbie SteelAbstract:Humpback Whales Megaptera novaeangliae are seasonal migrants that mate and calve at low latitudes and feed at mid- to high latitudes. Connections between most Southern Hemisphere breeding and feeding areas are not well understood, but are critical for assessing stock structure and human impacts. Photo-identification was performed to identify the feeding grounds of an Endan- gered sub-population that breeds in the central South Pacific Ocean (CSP). Identification pho- tographs were obtained from 159 ind. at American Samoa and compared to 3508 Southern Hemi- sphere Humpback Whales in the Antarctic Humpback Whale Catalogue (AHWC), including 1352 from Antarctic feeding grounds. Two individuals from American Samoa were seen on 3 occasions at the Antarctic Peninsula. This is the first known feeding site for American Samoa and one of few reli- ably identified for the CSP. AHWC #2950 was confirmed to have undertaken a round-trip movement of no less than 18 840 km, spanning 108 longitudinal degrees. This represents the largest mammalian migration known to date and a departure from historical assumptions about CSP migratory patterns. The frequency, causes, and fitness implications of such movements have yet to be determined. How- ever, distance is the only known extrinsic barrier to Humpback Whale movement within oceans, and so maximum individual range is 1 factor potentially affecting population exchange and colonization of new habitats. The movement documented here may place this Endangered sub-population at risk if conservation efforts are relaxed in unidentified parts of its range. Yet, the ability of Humpback Whales to undertake such extensive movements may have also contributed to the apparent recovery of some populations versus other historically exploited Whale species.
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north atlantic Humpback Whale abundance and rate of increase four decades after protection from whaling
Marine Ecology Progress Series, 2003Co-Authors: Peter T Stevick, Phillip J. Clapham, Judith Allen, Steven K Katona, Finn Larsen, Jon Lien, David K Mattila, Per J Palsboll, Nancy A Friday, Johann SigurjonssonAbstract:Humpback Whales Megaptera novaeangliae in the North Atlantic Ocean were severely depleted by exploitation. With legal protection since 1955, substantial recovery is likely to have occurred, but information on abundance and rates of increase has been limited. We present an assessment of Humpback Whale abundance in the North Atlantic Ocean based upon capture- recapture estimates using naturally marked individuals. These data result from a long-term collabo- rative effort combining large-scale dedicated projects and incidental data collection, leading to extensive geographical coverage. The application of robust statistical techniques produces estimates of greater accuracy and precision than has previously been possible. Abundance estimates ranging from 5930 to 12 580 individuals, with coefficients of variation (CVs) from 0.07 to 0.39, were calculated for the West Indies breeding population using data from 1979 to 1993. The most precise estimate for the West Indies breeding population is 10 752 (CV = 0.068) for 1992 and 1993. Due to application of new analytical methods, these estimates are larger and more precise than those previously published from similar time periods. The average rate of increase for the West Indies breeding population over a 14 yr period was estimated to be 0.031 (SE = 0.005). The best available estimate for the entire North Atlantic population of Humpback Whales is 11 570 (95% CI 10 290 to 13 390) based upon samples from 1992 and 1993. However, this estimate may be biased downwards to an unknown extent due to heterogeneity in capture probabilities that do not influence the West Indies estimates.
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an ocean basin wide mark recapture study of the north atlantic Humpback Whale megaptera novaeangliae
Marine Mammal Science, 1999Co-Authors: Tim D Smith, Judith Allen, Phillip J Clapham, Philip S Hammond, Steven K Katona, Finn Larsen, Jon Lien, David K Mattila, Per J Palsboll, Johann SigurjonssonAbstract:Although much is known about the Humpback Whale, Megaptera novaeangliae, regional studies have been unable to answer several questions that are central to the conservation and management of this endangered species. To resolve uncertainties about population size, as well as the spatial and genetic structure of the Humpback Whale population in the North Atlantic, we conducted a two-year ocean-basin-wide photographic and biopsy study in 1992-1993. Photographic and skin-biopsy sampling was conducted of animals in feeding and breeding areas throughout most of the range of this species in the North Atlantic, from the West Indies breeding grounds through all known feeding areas as far north as arctic Norway. A standardized sampling protocol was designed to maximize sample sizes while attempting to ensure equal probability of sampling, so that estimates of abundance would be as accurate and as precise as possible. During 666 d at sea aboard 28 vessels, 4,207 tail fluke photographs and 2,326 skin biopsies were collected. Molecular analyses of all biopsies included determination of sex, genotype using six microsatellite loci, and mitochondrial control region sequence. The photographs and microsatellite loci were used to identify 2,998 and 2,015 individual Whales, respectively. Previously published results from this study have addressed spatial distribution, migration, and genetic relationships. Here, we present new estimates of total abundance in this ocean using photographic data, as well as overall and sex-specific estimates using biopsy data. We identify several potential sampling biases using only breeding-area samples and report a consistent mark-recapture estimate of oceanwide abundance derived from photographic identification, using both breeding and feeding-area data, of 10,600 (95% confidence interval 9,300-12,100). We also report a comparable, but less precise, biopsy-based estimate of 10,400 (95% confidence interval of 8,000-13,600). These estimates are significantly larger and more precise than estimates made for the 1980s, potentially reflecting population growth. In contrast, significantly lower and less consistent estimates were obtained using between-feeding-area or between-breeding-area sampling. Reasons for the lower estimates using the results of sampling in the same areas in subsequent years are discussed. Overall, the results of this ocean-basin-wide study demonstrate that an oceanwide approach to population assessment of baleen Whales is practicable and results in a more comprehensive understanding of population abundance and biology than can be gained from smaller-scale efforts.
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composition and dynamics of Humpback Whale competitive groups in the west indies
Behaviour, 1992Co-Authors: Phillip J. Clapham, David K Mattila, Per J Palsboll, Oswaldo VasquezAbstract:It has been hypothesized that Humpback Whale, Megaptera novaeangliae, competitive groups represent intrasexual competition by males for access to a mature female. The composition and dynamics of these groups was studied between 1989 and 1991 in Samana Bay, West Indies. The sex of group participants was determined by molecular analysis of skin biopsies. Groups showed similar characteristics of size and movement as those described from other breeding areas, except that only one group contained a calf. The sex was determined of 141 participants in 44 competitive groups. In 21 of these groups, we were able to biopsy all participants. No group contained more than one female, but seven of the wholly sampled groups (all of them small) consisted entirely of males. Of 22 animals who were ''positively'' assigned the role of Nuclear Animal, 17 were female, and five were male. Similarly, of 24 biopsied Principal Escorts, 23 were male and one female. All 24 biopsied Challengers were male. Of 55 animals who were either classified as Secondary Escort, or whose role could not be categorized, 51 were male and four female. In 8 cases, associated pairs of males exhibiting no aggression towards each other were observed to either enter or leave a competitive group together. Of 16 individuals resighted on more than one day, all but one were males. These data suggest that: 1. While most groups (as predicted) represent male-male competition for a single female, observers should be cautious in their assumptions; 2. All-male groups may represent dominance sorting by unfamiliar conspecifics; 3. Females may occasionally aggressively repel advances by unwanted males; 4. While unlikely in light of present knowledge, the possibility that males form coalitions cannot be dismissed. We suggest that competitive groups may be asymmetrical contests in which a female Nuclear Animal is of more value to the Principal Escort than to a Challenger, particularly if the former's defence of her represents mate-guarding.
Johann Sigurjonsson - One of the best experts on this subject based on the ideXlab platform.
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north atlantic Humpback Whale abundance and rate of increase four decades after protection from whaling
Marine Ecology Progress Series, 2003Co-Authors: Peter T Stevick, Phillip J. Clapham, Judith Allen, Steven K Katona, Finn Larsen, Jon Lien, David K Mattila, Per J Palsboll, Nancy A Friday, Johann SigurjonssonAbstract:Humpback Whales Megaptera novaeangliae in the North Atlantic Ocean were severely depleted by exploitation. With legal protection since 1955, substantial recovery is likely to have occurred, but information on abundance and rates of increase has been limited. We present an assessment of Humpback Whale abundance in the North Atlantic Ocean based upon capture- recapture estimates using naturally marked individuals. These data result from a long-term collabo- rative effort combining large-scale dedicated projects and incidental data collection, leading to extensive geographical coverage. The application of robust statistical techniques produces estimates of greater accuracy and precision than has previously been possible. Abundance estimates ranging from 5930 to 12 580 individuals, with coefficients of variation (CVs) from 0.07 to 0.39, were calculated for the West Indies breeding population using data from 1979 to 1993. The most precise estimate for the West Indies breeding population is 10 752 (CV = 0.068) for 1992 and 1993. Due to application of new analytical methods, these estimates are larger and more precise than those previously published from similar time periods. The average rate of increase for the West Indies breeding population over a 14 yr period was estimated to be 0.031 (SE = 0.005). The best available estimate for the entire North Atlantic population of Humpback Whales is 11 570 (95% CI 10 290 to 13 390) based upon samples from 1992 and 1993. However, this estimate may be biased downwards to an unknown extent due to heterogeneity in capture probabilities that do not influence the West Indies estimates.
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an ocean basin wide mark recapture study of the north atlantic Humpback Whale megaptera novaeangliae
Marine Mammal Science, 1999Co-Authors: Tim D Smith, Judith Allen, Phillip J Clapham, Philip S Hammond, Steven K Katona, Finn Larsen, Jon Lien, David K Mattila, Per J Palsboll, Johann SigurjonssonAbstract:Although much is known about the Humpback Whale, Megaptera novaeangliae, regional studies have been unable to answer several questions that are central to the conservation and management of this endangered species. To resolve uncertainties about population size, as well as the spatial and genetic structure of the Humpback Whale population in the North Atlantic, we conducted a two-year ocean-basin-wide photographic and biopsy study in 1992-1993. Photographic and skin-biopsy sampling was conducted of animals in feeding and breeding areas throughout most of the range of this species in the North Atlantic, from the West Indies breeding grounds through all known feeding areas as far north as arctic Norway. A standardized sampling protocol was designed to maximize sample sizes while attempting to ensure equal probability of sampling, so that estimates of abundance would be as accurate and as precise as possible. During 666 d at sea aboard 28 vessels, 4,207 tail fluke photographs and 2,326 skin biopsies were collected. Molecular analyses of all biopsies included determination of sex, genotype using six microsatellite loci, and mitochondrial control region sequence. The photographs and microsatellite loci were used to identify 2,998 and 2,015 individual Whales, respectively. Previously published results from this study have addressed spatial distribution, migration, and genetic relationships. Here, we present new estimates of total abundance in this ocean using photographic data, as well as overall and sex-specific estimates using biopsy data. We identify several potential sampling biases using only breeding-area samples and report a consistent mark-recapture estimate of oceanwide abundance derived from photographic identification, using both breeding and feeding-area data, of 10,600 (95% confidence interval 9,300-12,100). We also report a comparable, but less precise, biopsy-based estimate of 10,400 (95% confidence interval of 8,000-13,600). These estimates are significantly larger and more precise than estimates made for the 1980s, potentially reflecting population growth. In contrast, significantly lower and less consistent estimates were obtained using between-feeding-area or between-breeding-area sampling. Reasons for the lower estimates using the results of sampling in the same areas in subsequent years are discussed. Overall, the results of this ocean-basin-wide study demonstrate that an oceanwide approach to population assessment of baleen Whales is practicable and results in a more comprehensive understanding of population abundance and biology than can be gained from smaller-scale efforts.
Ma Rcia H Engel - One of the best experts on this subject based on the ideXlab platform.
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multiple processes drive genetic structure of Humpback Whale megaptera novaeangliae populations across spatial scales
Molecular Ecology, 2017Co-Authors: Francine Kershaw, Salvatore Cerchio, Ines Carvalho, Jacqueline Loo, Cristina Pomilla, Peter B Best, K P Findlay, Tim Collins, Ma Rcia H EngelAbstract:Elucidating patterns of population structure for species with complex life histories, and disentangling the processes driving such patterns, remains a significant analytical challenge. Humpback Whale (Megaptera novaeangliae) populations display complex genetic structures that have not been fully resolved at all spatial scales. We generated a data set of nuclear markers for 3575 samples spanning the seven breeding stocks and substocks found in the South Atlantic and western and northern Indian Oceans. For the total sample, and males and females separately, we assessed genetic diversity, tested for genetic differentiation between putative populations and isolation by distance, estimated the number of genetic clusters without a priori population information and estimated rates of gene flow using maximum-likelihood and Bayesian approaches. At the ocean basin scale, structure is governed by geographical distance (IBD P < 0.05) and female fidelity to breeding areas, in line with current understanding of the drivers of broadscale population structure. Consistent with previous studies, the Arabian Sea breeding stock was highly genetically differentiated (FST 0.034–0.161; P < 0.01 for all comparisons). However, the breeding stock boundary between west South Africa and east Africa was more porous than expected based on genetic differentiation, cluster and geneflow analyses. Instances of male fidelity to breeding areas and relatively high rates of dispersal for females were also observed between the three substocks in the western Indian Ocean. The relationships between demographic units and current management boundaries may have ramifications for assessments of the status and continued protections of populations still in recovery from commercial whaling.
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a quarter of a world away female Humpback Whale moves 10 000 km between breeding areas
Biology Letters, 2011Co-Authors: Peter T Stevick, Judith Allen, Ma Rcia H Engel, Mariana C Neves, Freddy Johansen, Milton C C Marcondes, Carole CarlsonAbstract:Fidelity of individual animals to breeding sites is a primary determinant of population structure. The degree and scale of philopatry in a population reflect the fitness effects of social facilitation, ecological adaptation and optimal inbreeding. Patterns of breeding-site movement and fidelity are functions of social structure and are frequently sex biased. We report on a female Humpback Whale (Megaptera novaeangliae) first identified by natural markings off Brazil that subsequently was photographed off Madagascar. The minimum travel distance between these locations is greater than 9800 km, approximately 4000 km longer than any previously reported movement between breeding grounds, more than twice the species' typical seasonal migratory distance and the longest documented movement by a mammal. It is unexpected to find this exceptional long-distance movement between breeding groups by a female, as models of philopatry suggest that male mammals move more frequently or over longer distances in search of mating opportunities. While such movement may be advantageous, especially in changeable or unpredictable circumstances, it is not possible to unambiguously ascribe causality to this rare observation. This finding illustrates the behavioural flexibility in movement patterns that may be demonstrated within a typically philopatric species.
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mitochondrial dna diversity of the southwestern atlantic Humpback Whale megaptera novaeangliae breeding area off brazil and the potential connections to antarctic feeding areas
Conservation Genetics, 2008Co-Authors: Ma Rcia H Engel, Luciano Dalla Rosa, Eduardo R Secchi, Nelson J R Fagundes, Howard C Rosenbaum, Matthew S Leslie, Paulo Henrique Ott, R Schmitt, Sandro L BonattoAbstract:In the Southwestern Atlantic Ocean, Humpback Whales migrate every winter to the Brazilian coast for breeding and calving in the Abrolhos Bank. This breeding stock represents the remnants of a larger population heavily exploited during the beginning of the 20th century. Despite its relevance to conservation efforts, the degree of current genetic variation and the migratory relationship with Antarctic feeding areas for this population are still largely unknown. To examine these questions, we sequenced ∼400 bp of the mitochondrial DNA control region from samples taken off the Brazilian coast (n = 171) and near the Antarctic Peninsula (n = 77). The genetic variability of the Brazilian Humpback Whale breeding population was high and similar to that found in other Southern Hemisphere breeding grounds. Phylogenetic analysis suggested the existence of a new mitochondrial clade that exists at low frequency among Southern Hemisphere populations. Direct comparison between the Brazilian and the Colombia breeding populations and the Antarctic Peninsula feeding population showed no genetic differentiation between this feeding region and the Colombian breeding area or between feeding Areas I and II near the Antarctic Peninsula. In contrast, these populations were genetically distinct from the Brazilian population. Two Humpback Whales sampled off South Georgia Islands, in the Scotia Sea, shared identical haplotypes to Whales from Brazil. Our results, supported by photo-identification and satellite telemetry data, suggest that the main feeding area of the Southern Hemisphere Humpback Whale population is likely to be located near the South Georgia/South Sandwich Islands area and not in the Antarctic Peninsula.
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a note on the movement of a Humpback Whale from abrolhos bank brazil to south georgia
2006Co-Authors: Peter T S Tevick, Luiza Pacheco De Godoy, Megan Mcosker, Ma Rcia H Engel, Judith AllenAbstract:Most models of population structure for Southern Hemisphere Humpback Whales (Megaptera novaeangliae) assume that individuals feeding in the Scotia Sea migrate primarily to breeding and calving areas off Brazil. However data to support this are few and mostly indirect. Abrolhos Bank, Brazil, is the largest breeding and calving ground for Humpback Whales in the western South Atlantic O cean. Historically, the waters near South Georgia held the largest concentrations of Humpback Whales in Antarctic Area II and were amo ng the largest in the Southern Ocean. Photographs of individually distinctive natural markings on Humpback Whale flukes collected from the Scotia Sea (n=9) were compared with two collections of photographs from Brazilian waters ( n=829 and n=735) to identify re-sightings. A Humpback Whale photographed in August 2000 at Abrolhos Bank was subsequently photographed in December 2004 near Shag Rocks off South Georgia. The migratory distance between these sightings is 3,945km. This finding constitutes the first long-distance indi vidual resighting to be documented from either of these areas.
Marc Tollis - One of the best experts on this subject based on the ideXlab platform.
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return to the sea get huge beat cancer an analysis of cetacean genomes including an assembly for the Humpback Whale megaptera novaeangliae
Molecular Biology and Evolution, 2019Co-Authors: Marc Tollis, Jooke Robbins, Andrew E Webb, Lukas F K Kuderna, Aleah F Caulin, Jacinda D Garcia, Martine Berube, Nader Pourmand, Tomas MarquesbonetAbstract:Cetaceans are a clade of highly specialized aquatic mammals that include the largest animals that have ever lived. The largest Whales can have ∼1,000× more cells than a human, with long lifespans, leaving them theoretically susceptible to cancer. However, large-bodied and long-lived animals do not suffer higher risks of cancer mortality than humans-an observation known as Peto's Paradox. To investigate the genomic bases of gigantism and other cetacean adaptations, we generated a de novo genome assembly for the Humpback Whale (Megaptera novaeangliae) and incorporated the genomes of ten cetacean species in a comparative analysis. We found further evidence that rorquals (family Balaenopteridae) radiated during the Miocene or earlier, and inferred that perturbations in abundance and/or the interocean connectivity of North Atlantic Humpback Whale populations likely occurred throughout the Pleistocene. Our comparative genomic results suggest that the evolution of cetacean gigantism was accompanied by strong selection on pathways that are directly linked to cancer. Large segmental duplications in Whale genomes contained genes controlling the apoptotic pathway, and genes inferred to be under accelerated evolution and positive selection in cetaceans were enriched for biological processes such as cell cycle checkpoint, cell signaling, and proliferation. We also inferred positive selection on genes controlling the mammalian appendicular and cranial skeletal elements in the cetacean lineage, which are relevant to extensive anatomical changes during cetacean evolution. Genomic analyses shed light on the molecular mechanisms underlying cetacean traits, including gigantism, and will contribute to the development of future targets for human cancer therapies.