scholarly journals Assessment of the aerial behaviors of humpback whales, Megaptera novaeangliae (Borowski, 1781), in coastal areas in Northeastern Brazil

2017 ◽  
Vol 18 (3) ◽  
Author(s):  
Guilherme Maricato ◽  
Liliane Ferreira Lodi ◽  
Daniela Rodrigues Abras

The aim of this study was to analyze the aerial behaviors of humpback whales (Megaptera novaeangliae) in Northeastern Brazil. From July to October 2013, 113 groups, totaling 272 individuals (x̄ = 2.41; ± 1.52), were observed, including possible double counts. Groups consisting of more than three individuals showed a significantly higher level of aerial behaviors (χ² = 0.03) and a more varied aerial behavioral repertoire (χ² = 0.00) compared to smaller groups. No significant differences in aerial behaviors were found in relation to month (χ² = 0.74), the presence of calves in groups (χ² = 0.14) or depth (χ² = 0.54). Long-term studies can provide valuable information about sociality in humpback whales since their communication system is not limited to sound and can differ according to the environment.

2008 ◽  
Vol 25 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Diana G. Lunardi ◽  
Márcia H. Engel ◽  
Regina H. F. Macedo

Behavior of humpback whales was observed during the reproductive period off the northern coast of the state of Bahia (NB, n = 378 groups) and at the Abrolhos Bank (AB, n = 919) to compare patterns and group composition between the two locations. Alone individuals and dyads were most often encountered in both areas, although mother-calf pairs were more common in AB. While these two regions comprise distinct concentrations of humpback whales, with intrinsic environmental differences, behavior patterns were quite similar. The only behavioral differences found where for "tail up" and "resting". The patterns found here may reflect differences in the protection status of the areas or intrinsic environmental differences.


2020 ◽  
Author(s):  
Janie Wray ◽  
Eric Keen ◽  
Éadin N. O’Mahony

ABSTRACTAnimal culture and social bonds are relevant to wildlife conservation because they influence patterns of geography, behavior, and strategies of survival. Numerous examples of socially-driven habitat partitioning and ecological-niche specialization can be found among vertebrates, including toothed whales. But such social-ecological dynamics, described here as ‘social niche partitioning’, are not known among baleen whales, whose societies -- particularly on foraging grounds -- are largely perceived as unstructured and incidental to matters of habitat use and conservation. However, through 16 years of behavioral and photo-identification observations of humpback whales (Megaptera novaeangliae) feeding within a fjord system in British Columbia, Canada, we have documented long-term pair bonds (lasting up to 12 years) as well as a complex societal structure, which corresponds closely to persistent patterns in feeding strategy, long-term site fidelity (extended seasonal occupancy and annual rate of return up to 75%), specific geographic preferences within the fjord system, and other forms of habitat use. Randomization tests of network congruency and clustering algorithms were used to test for overlap in patterns of social structure and habitat use, which confirmed the occurrence of social niche partitioning on the feeding grounds of this baleen whale. In addition, we document the extensive practice of group bubble net feeding in Pacific Canada. This coordinated feeding behavior was found to strongly mediate the social structure and habitat use within this humpback whale society. Additionally, during our 2004 – 2019 study, we observed a shift in social network structure in 2010 – 2012, which corresponded with environmental and demographic shifts including a sudden decline in the population’s calving rate. Our findings indicate that the social lives of humpback whales, and perhaps baleen whales generally, are more complex than previously supposed and should be a primary consideration in the assessment of potential impacts to important habitat.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0245409
Author(s):  
Janie Wray ◽  
Eric Keen ◽  
Éadin N. O’Mahony

Animal culture and social bonds are relevant to wildlife conservation because they influence patterns of geography, behavior, and strategies of survival. Numerous examples of socially-driven habitat partitioning and ecological-niche specialization can be found among vertebrates, including toothed whales. But such social-ecological dynamics, described here as ‘social niche partitioning’, are not known among baleen whales, whose societies—particularly on foraging grounds—are largely perceived as unstructured and incidental to matters of habitat use and conservation. However, through 16 years of behavioral observations and photo-identifications of humpback whales (Megaptera novaeangliae) feeding within a fjord system in the Canadian Pacific (primarily within Gitga’at First Nation waters), we have documented long-term pair bonds (up to 12 years) as well as a complex societal structure, which corresponds closely to persistent patterns in feeding strategy, long-term site fidelity (extended occupancy and annual rate of return up to 75%), specific geographic preferences within the fjord system, and other forms of habitat use. Randomization tests of network congruency and clustering algorithms were used to test for overlap in patterns of social structure and habitat use, which confirmed the occurrence of social niche partitioning on the feeding grounds of this baleen whale species. In addition, we document the extensive practice of group bubble net feeding in Pacific Canada. This coordinated feeding behavior was found to strongly mediate the social structure and habitat use within this humpback whale society. Additionally, during our 2004–2019 study, we observed a shift in social network structure in 2010–2012, which corresponded with environmental and demographic shifts including a sudden decline in the population’s calving rate. Our findings indicate that the social lives of humpback whales, and perhaps baleen whales generally, are more complex than previously supposed and should be a primary consideration in the assessment of potential impacts to important habitat.


2020 ◽  
Vol 110 ◽  
Author(s):  
Leidiane P. Diniz ◽  
Cláudio S. de Morais Júnior ◽  
Ittalo L.S. Medeiros ◽  
Alef J. da Silva ◽  
Alan P. Araújo ◽  
...  

Abstract The present study aimed to inventory the biodiversity of planktonic microcrustaceans (Cladocera and Copepoda) in 44 environments from the semiarid region of Brazil, increasing the knowledge about zooplankton community, including phytophilous species. Between 2011 and 2017, organisms were collected in a non - systematic way in the states of Rio Grande do Norte, Pernambuco, Ceará and Paraíba. A total of 60 species of planktonic microcrustaceans were identified, of which 52 were cladocerans and eight were copepods. The basin that presented the highest richness was Pajeú River with 41 species. Nevertheless, the extrapolated number of species shows an increasing tendency for this basin. The genus composition was different between the basins, with Moxotó basin (Pernambuco) being isolated from the others, probably since lagoons were the only type of environment sampled in this basin. Richness and abundance patterns were higher for the basins where sampling was mainly performed in lentic environments, such as Pajeú and Moxotó. Microcrustacean inventories and long-term studies need to be conducted more frequently to better understand the biodiversity of continental aquatic ecosystems in the semiarid region of Brazil.


1988 ◽  
Vol 66 (6) ◽  
pp. 1243-1248 ◽  
Author(s):  
Richard H. Lambertsen ◽  
C. Scott Baker ◽  
Deborah A. Duffield ◽  
Jan Chamberlin-Lea

Using a small biopsy dart, samples of living dermal tissue were collected from individually identified humpback whales (Megaptera novaeangliae) in southeastern Alaskan waters. In vitro culture of these samples provided enough chromosomal material to karyotype 10 individuals. Examination of the sex chromosomes in the karyotypes demonstrated the sex of each of the 10 whales. In two cases, cytogenetic findings verified previous inferences of sex based on behavioral observations. In another two cases, karyotyping allowed the determination of sex when even long-term sighting histories and behavioral observations had been insufficient. For the rest of the whales, sex determination by cytogenetic findings has preceded long-term sightings and will facilitate the interpretation of future behavioral observations. We conclude that in vitro culturing of dermal tissue collected from naturally marked humpback whales, coupled with karyology, promises to be a powerful technique in future studies of the social behavior and population biology of this marine species.


2020 ◽  
Vol 36 (2) ◽  
pp. 472-485 ◽  
Author(s):  
Vanessa Pirotta ◽  
Wayne Reynolds ◽  
Geoffrey Ross ◽  
Ian Jonsen ◽  
Alana Grech ◽  
...  

2008 ◽  
Author(s):  
Lawrence J. Schweinhart ◽  
Elena V. Malofeeva ◽  
Lawrence J. Schweinhart ◽  
Michelle M. Englund ◽  
Arthur J. Reynolds ◽  
...  

Phlebologie ◽  
2010 ◽  
Vol 39 (03) ◽  
pp. 133-137
Author(s):  
H. Partsch

SummaryBackground: Compression stockings are widely used in patients with varicose veins. Methods: Based on published literature three main points are discussed: 1. the rationale of compression therapy in primary varicose veins, 2. the prescription of compression stockings in daily practice, 3. studies required in the future. Results: The main objective of prescribing compression stockings for patients with varicose veins is to improve subjective leg complaints and to prevent swelling after sitting and standing. No convincing data are available concerning prevention of progression or of complications. In daily practice varicose veins are the most common indication to prescribe compression stockings. The compliance depends on the severity of the disorder and is rather poor in less severe stages. Long-term studies are needed to proof the cost-effectiveness of compression stockings concerning subjective symptoms and objective signs of varicose veins adjusted to their clinical severity. Conclusion: Compression stockings in primary varicose veins are able to improve leg complaints and to prevent swelling.


Author(s):  
Yelena I. Polyakova ◽  
Yekaterina I. Novichkova ◽  
Tatiana S. Klyuvitkina ◽  
Elizaveta A. Agafonova ◽  
Irina M. Kryukova

Presented the results of long-term studies of diatoms and aquatic palynomorphs in surface sediments of the Arctic seas and the possibility of their use for the reconstructions of paleocirculation water masses, advection of Atlantic and Bering sea water into the Arctic ocean, changes in the river runoff to the seas, sedimentary processes in the marginal filter of the largest rivers, seasonal sea ice cover and other hydrological parameters.


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