scholarly journals Population abundance of recovering humpback whales (Megaptera novaeangliae) and other baleen whales in the Scotia Arc, South Atlantic

2021 ◽  
Author(s):  
M Baines ◽  
N Kelly ◽  
M Reichelt ◽  
C Lacey ◽  
S Pinder ◽  
...  
Keyword(s):  
South Atlantic ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Population Abundance ◽  
Baleen Whales ◽  
Scotia Arc

scholarly journals Social survival: humpback whales (Megaptera novaeangliae) use social structure to partition ecological niches within proposed critical habitat

2020 ◽  
Author(s):  
Janie Wray ◽  
Eric Keen ◽  
Éadin N. O’Mahony
Keyword(s):  
Habitat Use ◽  
Social Structure ◽  
Niche Partitioning ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Baleen Whales ◽  
Fjord System ◽  
The Social ◽  
Social Niche

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.

scholarly journals ‘Megapclicks’: acoustic click trains and buzzes produced during night-time foraging of humpback whales ( Megaptera novaeangliae )

2007 ◽  
Vol 3 (5) ◽  
pp. 467-470 ◽  
Author(s):  
Alison K Stimpert ◽  
David N Wiley ◽  
Whitlow W.L Au ◽  
Mark P Johnson ◽  
Roland Arsenault
Keyword(s):  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Baleen Whale ◽  
Night Time ◽  
Baleen Whales ◽  
Acoustic Behaviour ◽  
Suction Cup ◽  
Form Part ◽  
Acoustic Tags ◽  
Feeding Area

Humpback whales ( Megaptera novaeangliae ) exhibit a variety of foraging behaviours, but neither they nor any baleen whale are known to produce broadband clicks in association with feeding, as do many odontocetes. We recorded underwater behaviour of humpback whales in a northwest Atlantic feeding area using suction-cup attached, multi-sensor, acoustic tags (DTAGs). Here we describe the first recordings of click production associated with underwater lunges from baleen whales. Recordings of over 34 000 ‘megapclicks’ from two whales indicated relatively low received levels at the tag (between 143 and 154 dB re 1 μPa pp), most energy below 2 kHz, and interclick intervals often decreasing towards the end of click trains to form a buzz. All clicks were recorded during night-time hours. Sharp body rolls also occurred at the end of click bouts containing buzzes, suggesting feeding events. This acoustic behaviour seems to form part of a night-time feeding tactic for humpbacks and also expands the known acoustic repertoire of baleen whales in general.

scholarly journals Social survival: Humpback whales (Megaptera novaeangliae) use social structure to partition ecological niches within proposed critical habitat

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0245409
Author(s):  
Janie Wray ◽  
Eric Keen ◽  
Éadin N. O’Mahony
Keyword(s):  
Habitat Use ◽  
Social Structure ◽  
Niche Partitioning ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Baleen Whales ◽  
Fjord System ◽  
The Social ◽  
Social Niche

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.

Net Entanglements of Baleen Whales in the Inshore Fishery of Newfoundland

1979 ◽  
Vol 36 (5) ◽  
pp. 521-528 ◽  
Author(s):  
J. S. Perkins ◽  
P. C. Beamish
Keyword(s):  
Key Words ◽  
Newfoundland And Labrador ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Balaenoptera Acutorostrata ◽  
Balaenoptera Physalus ◽  
Baleen Whales ◽  
Minke Whales ◽  
Capelin Mallotus Villosus ◽  
Inshore Waters

This paper documents net entrapments of baleen whales in the inshore waters of Newfoundland and Labrador. The species involved are principally minke whales (Balaenoptera acutorostrata) and humpback whales (Megaptera novaeangliae). Finback whales (Balaenoptera physalus) are also caught in nets but far less frequently. The timing of these entrapments corresponds with the spawning season for capelin (Mallotus villosus) on the beaches around the province. The magnitude and implications of this problem, both to the whales and the fisherman, are assessed. Key words: baleen whales, net entrapments, mortality assessment, capelin, Balaenoptera acutorostrata, B. physalus, Megaptera novaeangliae

scholarly journals Norrisanima miocaena, a new generic name and redescription of a stem balaenopteroid mysticete (Mammalia, Cetacea) from the Miocene of California

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7629 ◽  
Author(s):  
Matthew S. Leslie ◽  
Carlos Mauricio Peredo ◽  
Nicholas D. Pyenson
Keyword(s):  
Phylogenetic Analyses ◽  
Original Description ◽  
Type Specimen ◽  
Megaptera Novaeangliae ◽  
Morphological Data ◽  
Humpback Whales ◽  
Phylogenetic Position ◽  
Data Sets ◽  
Baleen Whales ◽  
Size Evolution

Rorqual whales are among the most species rich group of baleen whales (or mysticetes) alive today, yet the monophyly of the traditional grouping (i.e., Balaenopteridae) remains unclear. Additionally, many fossil mysticetes putatively assigned to either Balaenopteridae or Balaenopteroidea may actually belong to stem lineages, although many of these fossil taxa suffer from inadequate descriptions of fragmentary skeletal material. Here we provide a redescription of the holotype of Megaptera miocaena, a fossil balaenopteroid from the Monterey Formation of California, which consists of a partial cranium, a fragment of the rostrum, a single vertebra, and both tympanoperiotics. Kellogg (1922) assigned the type specimen to the genus Megaptera Gray (1846), on the basis of its broad similarities to distinctive traits in the cranium of extant humpback whales (Megaptera novaeangliae (Borowski, 1781)). Subsequent phylogenetic analyses have found these two species as sister taxa in morphological datasets alone; the most recent systematic analyses using both molecular and morphological data sets place Megaptera miocaena as a stem balaenopteroid unrelated to humpback whales. Here, we redescribe the type specimen of Megaptera miocaena in the context of other fossil balaenopteroids discovered nearly a century since Kellogg’s original description and provide a morphological basis for discriminating it from Megaptera novaeangliae. We also provide a new generic name and recombine the taxon as Norrisanima miocaena, gen. nov., to reflect its phylogenetic position outside of crown Balaenopteroidea, unrelated to extant Megaptera. Lastly, we refine the stratigraphic age of Norrisanima miocaena, based on associated microfossils to a Tortonian age (7.6–7.3 Ma), which carries implications for understanding the origin of key features associated with feeding and body size evolution in this group of whales.

scholarly journals Whale, Whale, Everywhere: Increasing Abundance of Western South Atlantic Humpback Whales (Megaptera novaeangliae) in Their Wintering Grounds

PLoS ONE ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. e0164596 ◽  
Author(s):  
Guilherme A. Bortolotto ◽  
Daniel Danilewicz ◽  
Artur Andriolo ◽  
Eduardo R. Secchi ◽  
Alexandre N. Zerbini
Keyword(s):  
South Atlantic ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Wintering Grounds

scholarly journals A Bayesian assessment of the conservation status of humpback whales (Megaptera novaeangliae) in the western South Atlantic Ocean

2020 ◽  
pp. 131-144
Author(s):  
Alexandre N. Zerbini ◽  
Eric J. Ward ◽  
Paul G. Kinas ◽  
Marcia H. Engel ◽  
Artur Andriolo
Keyword(s):  
Population Size ◽  
Probability Distributions ◽  
Conservation Status ◽  
South Atlantic ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Eastern Coast ◽  
Base Case ◽  
Model Parameters ◽  
Quantities Of Interest

The population of humpback whales (Megaptera novaeangliae) wintering off the eastern coast of South America is referred to by the International Whaling Commission as ‘Breeding Stock A’ (BSA). This population was heavily exploited in 20th century modern commercial whaling operations. After more than 30 years of protection, its present status remains unknown. A deterministic sex and age-aggregated population dynamics model was used to estimate the pre-exploitation population size (K), the maximum net recruitment rate (rmax), the maximum depletion level (Nmin/K), and other quantities of interest of BSA. Input data included modern whaling catch series, absolute estimates of abundance, observed growth rates and indices of relative abundance. A Bayesian statistical method was used to calculate probability distributions for the model parameters. Prior distributions were set on rmax – an uninformative (Uniform [0, 0.106]) and an informative (Normal [0.067, 0.042]) – and on the population size in 2005 – N2005 (Uniform [500, 22,000]). A total of 10,000 samples were used to compute the joint posterior distribution of the model parameters using the Sampling-Importance-Resampling algorithm. Sensitivity of model outputs to the priors on rmax, a genetic constraint, data inclusion and catch allocation scenarios was investigated. Medians of the posterior probability distributions of quantities of interest for the base case scenario were: rmax = 0.069 (95% probability intervals [PI] = 0.013–0.104), K = 24,558 (95% PI = 22,791–31,118), Nmin/K = 2% (PI = 0.31%–12.5%), N2006/ K = 27.4% (PI = 18.3%–39.5%), N2020/K = 61.8% (PI = 23.8%–88.6%), and N2040/K = 97.3% (PI = 31.6%–99.9%). Despite apparent recovery in the past three decades, the western South Atlantic humpback whale population is still low relative to its pre-exploitation size and requires continued conservation efforts.

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