scholarly journals The Southern Ocean Exchange: porous boundaries between humpback whale breeding populations in southern polar waters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. C. C. Marcondes ◽  
T. Cheeseman ◽  
J. A. Jackson ◽  
A. S. Friedlaender ◽  
L. Pallin ◽  
...  
Keyword(s):  
Southern Ocean ◽  
High Latitude ◽  
Prey Availability ◽  
Humpback Whale ◽  
Humpback Whales ◽  
West Antarctic ◽  
Breeding Populations ◽  
Commercial Whaling ◽  
Feeding Area ◽  
New Evidence

AbstractHumpback whales (Megaptera novaeangliae) are a cosmopolitan species and perform long annual migrations between low-latitude breeding areas and high-latitude feeding areas. Their breeding populations appear to be spatially and genetically segregated due to long-term, maternally inherited fidelity to natal breeding areas. In the Southern Hemisphere, some humpback whale breeding populations mix in Southern Ocean waters in summer, but very little movement between Pacific and Atlantic waters has been identified to date, suggesting these waters constituted an oceanic boundary between genetically distinct populations. Here, we present new evidence of summer co-occurrence in the West Antarctic Peninsula feeding area of two recovering humpback whale breeding populations from the Atlantic (Brazil) and Pacific (Central and South America). As humpback whale populations recover, observations like this point to the need to revise our perceptions of boundaries between stocks, particularly on high latitude feeding grounds. We suggest that this “Southern Ocean Exchange” may become more frequent as populations recover from commercial whaling and climate change modifies environmental dynamics and humpback whale prey availability.

scholarly journals A description and summary of the Antarctic Humpback Whale Catalogue

2020 ◽  
pp. 95-99
Author(s):  
Judith Allen ◽  
Carole Carlson ◽  
Peter T. Stevick
Keyword(s):  
South America ◽  
Southern Ocean ◽  
Antarctic Peninsula ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Western Coast ◽  
Long Distance ◽  
Dorsal Fin ◽  
Feeding Area ◽  
The Antarctic

The Antarctic Humpback Whale Catalogue (AHWC) is an international collaborative project investigating movement patterns of humpback whales in the Southern Ocean and corresponding lower latitude waters. The collection contains records contributed by 261 researchers and opportunistic sources. Photographs come from all of the Antarctic management areas, the feeding grounds in southern Chile and also most of the known or suspected low-latitude breeding areas and span more than two decades. This allows comparisons to be made over all of the major regions used by  Southern Hemisphere humpback whales. The fluke, left dorsal fin/flank and right dorsal fin/flank collections represent 3,655, 413 and 407 individual whales respectively. There were 194 individuals resighted in more than one year, and 82 individuals resighted in more than one region. Resightings document movement along the western coast of South America and movement between the Antarctic Peninsula and western coast of South America and Central America. A single individual from Brazil was resighted off South Georgia, representing the first documented link between the Brazilian breeding ground and any feeding area. A second individual from Brazil was resighted off Madagascar, documenting long distance movement of a female between non-adjacent breeding areas. Resightings also include two matches between American Samoa and the Antarctic Peninsula, documenting the first known feeding site for American Somoa and setting a new long distance seasonal migration record. Three matches between Sector V and eastern Australia support earlier evidence provided by Discovery tags. Multiple resightings of individuals in the Antarctic Peninsula during more than one season indicate that humpback whales in this area show some degree of regional feeding area fidelity. The AHWC provides a powerful non-lethal and non-invasive tool for investigating the movements and population structure of the whales utilising the Southern Ocean Sanctuary. Through this methodical, coordinated comparison and maintenance of collections from across the hemisphere, large-scale movement patterns may be examined, both within the Antarctic, and from the Antarctic to breeding grounds at low latitudes.

scholarly journals Large-scale spatial variabilities in the humpback whale acoustic presence in the Atlantic sector of the Southern Ocean

2020 ◽  
Vol 7 (12) ◽  
pp. 201347
Author(s):  
Elena Schall ◽  
Karolin Thomisch ◽  
Olaf Boebel ◽  
Gabriele Gerlach ◽  
Stefanie Spiesecke ◽  
...  
Keyword(s):  
Southern Ocean ◽  
High Latitude ◽  
Large Scale ◽  
Austral Summer ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Stock Management ◽  
Atlantic Sector ◽  
Acoustic Activity ◽  
Passive Acoustic

Southern Hemisphere humpback whales ( Megaptera novaeangliae ) inhabit a wide variety of ecosystems including both low- and high-latitude areas. Understanding the habitat selection of humpback whale populations is key for humpback whale stock management and general ecosystem management. In the Atlantic sector of the Southern Ocean ( ASSO ), the investigation of baleen whale distribution by sighting surveys is temporally restricted to the austral summer. The implementation of autonomous passive acoustic monitoring, in turn, allows the study of vocal baleen whales year-round. This study describes the results of analysing passive acoustic data spanning 12 recording positions throughout the ASSO applying a combination of automatic and manual analysis methods to register humpback whale acoustic activity. Humpback whales were present at nine recording positions with higher acoustic activities towards lower latitudes and the eastern and western edges of the ASSO . During all months, except December (the month with the fewest recordings), humpback whale acoustic activity was registered in the ASSO . The acoustic presence of humpback whales at various locations in the ASSO confirms previous observations that part of the population remains in high-latitude waters beyond austral summer, presumably to feed. The spatial and temporal extent of humpback whale presence in the ASSO suggests that this area may be used by multiple humpback whale breeding populations as a feeding ground.

Multiple visits of individual humpback whales (Megaptera novaeangliae) between the Hawaiian and Japanese winter grounds

1999 ◽  
Vol 77 (3) ◽  
pp. 504-508 ◽  
Author(s):  
Dan R Salden ◽  
Louis M Herman ◽  
Manami Yamaguchi ◽  
Fumihiko Sato
Keyword(s):  
Genetic Variability ◽  
North Pacific ◽  
Humpback Whale ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Winter Ground ◽  
The Third ◽  
Breeding Populations ◽  
Published Report

We document through photographic identifications three humpback whale (Megaptera novaeangliae) winter ground interchanges between Hawai'i and Japan. Two of these whales, identified as male by their behavioral roles, made multiple interchanges across years; i.e., they were initially seen in Hawai'i, were later observed in Japan, and subsequently, returned to Hawai'i. The third whale was seen in only 2 different years, once in Japan and then in Hawai'i. Prior to this report, there has been only one published report of a Hawai'i-Japan interchange and only eight between Hawai'i and Mexico. None of these involved multiple interchanges. The current findings demonstrate that individual whales may be highly flexible in their annual choice of widely separated winter destinations and suggest that these wanderers may be mainly males. The occurrence of wanderers provides a mechanism for increasing genetic variability in the breeding populations and also suggests a mechanism for noted song similarities across different North Pacific winter grounds.

scholarly journals Humpback whale song recordings suggest common feeding ground occupation by multiple populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elena Schall ◽  
Karolin Thomisch ◽  
Olaf Boebel ◽  
Gabriele Gerlach ◽  
Sari Mangia Woods ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Behavioral Plasticity ◽  
Prey Availability ◽  
Humpback Whale ◽  
Sea Ice Concentration ◽  
Atlantic Sector ◽  
Feeding Ground ◽  
Breeding Grounds ◽  
Spatio Temporal ◽  
Feeding Grounds

AbstractHumpback whale males are known to sing on their low-latitude breeding grounds, but it is well established that songs are also commonly produced ‘off-season’ on the feeding grounds or during migration. This opens exciting opportunities to investigate migratory aggregations, study humpback whale behavioral plasticity and potentially even assign individual singers to specific breeding grounds. In this study, we analyzed passive acoustic data from 13 recording positions and multiple years (2011–2018) within the Atlantic sector of the Southern Ocean (ASSO). Humpback whale song was detected at nine recording positions in five years. Most songs were recorded in May, austral fall, coinciding with the rapid increase in sea ice concentration at most recording positions. The spatio-temporal pattern in humpback whale singing activity on Southern Ocean feeding grounds is most likely shaped by local prey availability and humpback whale migratory strategies. Furthermore, the comparative analyses of song structures clearly show a differentiation of two song groups, of which one was solely recorded at the western edge of the ASSO and the other song group was recorded throughout the ASSO. This new finding suggests a common feeding ground occupation by multiple humpback whale populations in the ASSO, allowing for cultural and potentially even genetic exchange among populations.

scholarly journals Very low numbers of endangered Oceania humpback whales seen in Fijian waters

2015 ◽  
Vol 33 (2) ◽  
pp. 39 ◽  
Author(s):  
C. Miller ◽  
A. Batibasiga ◽  
S. Sharma-Gounder ◽  
P. Solomona
Keyword(s):  
Southern Hemisphere ◽  
Humpback Whale ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Large Decrease ◽  
The South ◽  
Migration Routes ◽  
Antarctic Waters ◽  
Commercial Whaling

Intensive commercial whaling caused significant declines in Southern Hemisphere humpback whale (Megaptera novaeangliae) populations. In Fiji, land-based humpback whale surveys undertaken from 1956 to 1958 documented maximum weekly counts of more than 150 humpback whales in parts of the Bligh waters. These records provide an invaluable point of comparison to present-day observations as they occurred immediately prior to very large humpback whale catches in Antarctic waters to the south – and on potential migration routes – of humpback whales breeding in Fijian waters. We report here on a three-year (2010–2012) land-based survey also conducted in the Bligh waters during which a total of 33 individuals over 480 h were counted from Ovalau Island and 68 individuals over approximately 300 h were observed from Makogai Island. These findings suggest a large decrease in numbers of humpback whales seen in Fiji waters since commercial whaling operations.

scholarly journals New insights into prime Southern Ocean forage grounds for thriving Western Australian humpback whales

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sophie Bestley ◽  
Virginia Andrews-Goff ◽  
Esmee van Wijk ◽  
Stephen R. Rintoul ◽  
Michael C. Double ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Western Boundary ◽  
Boundary Current ◽  
Austral Spring ◽  
Partial Explanation ◽  
Migration Pathways ◽  
Western Australian ◽  
Feeding Grounds

Abstract Humpback whale populations migrate extensively between winter breeding grounds and summer feeding grounds, however known links to remote Antarctic feeding grounds remain limited in many cases. New satellite tracks detail humpback whale migration pathways from Western Australia into the Southern Ocean. These highlight a focal feeding area during austral spring and early summer at the southern Kerguelen plateau, in a western boundary current where a sharp northward turn and retroflection of ocean fronts occurs along the eastern plateau edge. The topographic steering of oceanographic features here likely supports a predictable, productive and persistent forage ground. The spatial distribution of whaling catches and Discovery era mark-recaptures confirms the importance of this region to Western Australian humpback whales since at least historical times. Movement modelling discriminates sex-related behaviours, with females moving faster during both transit and resident periods, which may be a consequence of size or indicate differential energetic requirements. Relatively short and directed migratory pathways overall, together with high-quality, reliable forage resources may provide a partial explanation for the ongoing strong recovery demonstrated by this population. The combination of new oceanographic information and movement data provides enhanced understanding of important biological processes, which are relevant within the context of the current spatial management and conservation efforts in the Southern Ocean.

scholarly journals Pectoral herding: an innovative tactic for humpback whale foraging

2019 ◽  
Vol 6 (10) ◽  
pp. 191104 ◽  
Author(s):  
Madison M. Kosma ◽  
Alexander J. Werth ◽  
Andrew R. Szabo ◽  
Janice M. Straley
Keyword(s):  
Foraging Behaviour ◽  
Prey Availability ◽  
New Technology ◽  
Humpback Whale ◽  
Ventral Side ◽  
Humpback Whales ◽  
Foraging Efficiency ◽  
Behavioural Plasticity ◽  
Southeast Alaska ◽  
And Shifts

Humpback whales ( Megaptera novaeangliae ) have exceptionally long pectorals (i.e. flippers) that aid in shallow water navigation, rapid acceleration and increased manoeuvrability. The use of pectorals to herd or manipulate prey has been hypothesized since the 1930s. We combined new technology and a unique viewing platform to document the additional use of pectorals to aggregate prey during foraging events. Here, we provide a description of ‘pectoral herding’ and explore the conditions that may promote this innovative foraging behaviour. Specifically, we analysed aerial videos and photographic sequences to assess the function of pectorals during feeding events near salmon hatchery release sites in Southeast Alaska (2016–2018). We observed the use of solo bubble-nets to initially corral prey, followed by calculated movements to establish a secondary boundary with the pectorals—further condensing prey and increasing foraging efficiency. We found three ways in which humpback whales use pectorals to herd prey: (i) create a physical barrier to prevent evasion, (ii) cause water motion to guide prey towards the mouth, and (iii) position the ventral side to reflect light and alter prey movement. Our findings suggest that behavioural plasticity may aid foraging in changing environments and shifts in prey availability. Further study would clarify if ‘pectoral herding’ is used as a principal foraging tool by the broader humpback whale population and the conditions that promote its use.

scholarly journals Humpback whales of the Persian Gulf

2017 ◽  
Author(s):  
Seyed Mohammad Hashem Dakhteh ◽  
Sharif Ranjbar ◽  
Mostafa Moazeni ◽  
Nazanin Mohsenian ◽  
Hossein Delshab ◽  
...  
Keyword(s):  
Coastal Waters ◽  
Persian Gulf ◽  
Arabian Sea ◽  
New Records ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Formal Description ◽  
Endangered Population ◽  
The Persian Gulf ◽  
New Evidence

AbstractThe humpback whale has long been considered a rare straggler into the Persian Gulf, however new evidence contradicts this concept. We here critically review published and new records forMegaptera novaeangliaeoccurrence in the Gulf for the period 1883-2017. Of eight authenticated records (6 specimens, 2 live-sightings), seven are contemporary cases while one is a mid-Holocene specimen from UAE. An additional four are possible but unsubstantiated reports. Four regional, current, range states are confirmed, i.e. Iran, Iraq, Kuwait and Qatar. Four of the five newly reported cases are from Iran’s coastal waters. We conclude that the Persian Gulf is part of the habitual range of the Arabian Sea humpback whale population, and has been since at least the mid-Holocene. It is unknown whether frequent passage occurs through the Strait of Hormuz or whether whales are (semi)resident. The low abundance of this endangered population and frequent deleterious anthropogenic events, particularly ship strikes and net entanglements, are cause for major concern. In view of its historical and taxonomic relevance, the formal description ofMegaptera indicaGervais, 1883, from Iraq, now thought to be a subspeciesM. novaeangliae indica, is here translated from French.

scholarly journals Combining Regional Habitat Selection Models for Large-Scale Prediction: Circumpolar Habitat Selection of Southern Ocean Humpback Whales

2021 ◽  
Vol 13 (11) ◽  
pp. 2074
Author(s):  
Ryan R. Reisinger ◽  
Ari S. Friedlaender ◽  
Alexandre N. Zerbini ◽  
Daniel M. Palacios ◽  
Virginia Andrews-Goff ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Predictive Models ◽  
Regional Variation ◽  
Large Scale ◽  
Predictive Performance ◽  
Humpback Whale ◽  
Machine Learning Algorithms ◽  
Humpback Whales ◽  
Environmental Covariates ◽  
Animal Habitat

Machine learning algorithms are often used to model and predict animal habitat selection—the relationships between animal occurrences and habitat characteristics. For broadly distributed species, habitat selection often varies among populations and regions; thus, it would seem preferable to fit region- or population-specific models of habitat selection for more accurate inference and prediction, rather than fitting large-scale models using pooled data. However, where the aim is to make range-wide predictions, including areas for which there are no existing data or models of habitat selection, how can regional models best be combined? We propose that ensemble approaches commonly used to combine different algorithms for a single region can be reframed, treating regional habitat selection models as the candidate models. By doing so, we can incorporate regional variation when fitting predictive models of animal habitat selection across large ranges. We test this approach using satellite telemetry data from 168 humpback whales across five geographic regions in the Southern Ocean. Using random forests, we fitted a large-scale model relating humpback whale locations, versus background locations, to 10 environmental covariates, and made a circumpolar prediction of humpback whale habitat selection. We also fitted five regional models, the predictions of which we used as input features for four ensemble approaches: an unweighted ensemble, an ensemble weighted by environmental similarity in each cell, stacked generalization, and a hybrid approach wherein the environmental covariates and regional predictions were used as input features in a new model. We tested the predictive performance of these approaches on an independent validation dataset of humpback whale sightings and whaling catches. These multiregional ensemble approaches resulted in models with higher predictive performance than the circumpolar naive model. These approaches can be used to incorporate regional variation in animal habitat selection when fitting range-wide predictive models using machine learning algorithms. This can yield more accurate predictions across regions or populations of animals that may show variation in habitat selection.

scholarly journals Multi-year presence of humpback whales in the Atlantic sector of the Southern Ocean but not during El Niño

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Elena Schall ◽  
Karolin Thomisch ◽  
Olaf Boebel ◽  
Gabriele Gerlach ◽  
Sari Mangia Woods ◽  
...  
Keyword(s):  
Southern Ocean ◽  
El Niño ◽  
El Nino ◽  
Humpback Whales ◽  
Low Latitude ◽  
Sea Ice Extent ◽  
Atlantic Sector ◽  
Acoustic Data ◽  
Breeding Grounds ◽  
Passive Acoustic

AbstractHumpback whales are thought to undertake annual migrations between their low latitude breeding grounds and high latitude feeding grounds. However, under specific conditions, humpback whales sometimes change their migratory destination or skip migration overall. Here we document the surprising persistent presence of humpback whales in the Atlantic sector of the Southern Ocean during five years (2011, 2012, 2013, 2017, and 2018) using passive acoustic data. However, in the El Niño years 2015 and 2016, humpback whales were virtually absent. Our data show that humpback whales are systematically present in the Atlantic sector of the Southern Ocean and suggest that these whales are particularly sensitive to climate oscillations which have profound effects on winds, sea ice extent, primary production, and especially krill productivity.

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