Interchange of humpback whales (Megaptera novaeangliae) between northern Philippines and Ogasawara, Japan, has implications for conservation

2020 ◽  
Vol 26 (4) ◽  
pp. 378
Author(s):  
Shotaro Nakagun ◽  
Laetitia I. Smoll ◽  
Takayuki Sato ◽  
Cynthia A. A. Layusa ◽  
Jo Marie V. Acebes
Keyword(s):  
North Pacific ◽  
Site Fidelity ◽  
Western North Pacific ◽  
The Philippines ◽  
Scientific Data ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Breeding Grounds ◽  
High Site ◽  
Pass Through

Humpback whales (Megaptera novaeangliae) in the western North Pacific breed in the Philippines and Japan, where there is relatively little scientific data available, leading to uncertainty about their population status and structure. This study investigates links between humpback whale populations in northern Philippines and Ogasawara, Japan, through a comparison of the most recent fluke identification catalogues. The Philippines catalogue (1999–2016) included 234 individuals, and the Ogasawara catalogue (1987–2014), 1389 individuals. The number of matched individuals was 86 (including 14 known females and 40 known males), corresponding to 36.8% of the Philippines and 6.2% of the Ogasawara catalogues. The findings included four within-season matches, with travel times as short as 25 days. The results suggest that a considerable portion of whales utilising Philippine waters pass through and also utilise the Ogasawara region, but the majority of whales found off Ogasawara either stay in that location, move to different breeding grounds, or remain out of the sampling area. Nevertheless, in light of the high site fidelity of individuals in the Philippines and Ogasawara area, as well as constant evidence of breeding activities, these regions are of importance to the lesser known western North Pacific subpopulation. Humpback whales migrating to this part of the world are estimated to be in relatively low abundance, therefore continued conservation attention is needed.

scholarly journals Interchange and movements of humpback whales (Megaptera novaeangliae) between western North Pacific winter breeding grounds in northern Luzon, Philippines and Okinawa, Japan

2021 ◽  
Vol 22 (1) ◽  
pp. 39-53
Author(s):  
Jo Marie Acebes ◽  
Haruna Okabe ◽  
Nozomi Kobayashi ◽  
Shotaro Nakagun ◽  
Naoto Higashi ◽  
...  
Keyword(s):  
North Pacific ◽  
Western North Pacific ◽  
The Philippines ◽  
Humpback Whales ◽  
Distinct Population Segment ◽  
Breeding Grounds ◽  
Different Seasons ◽  
The Relationship ◽  
Population Segment ◽  
Winter Breeding

Humpback whales wintering in the northern Philippines and Okinawa, Japan, belong to the western North Pacific subpopulation, now recognised as a distinct population segment. The numbers for this subpopulation are low hence it is being proposed to be listed as endangered. Although previous research revealed movements between breeding grounds, the relationship between these areas remain little understood. Recent survey efforts in the Philippines resulted in a total of 234 photo-identified individuals from 1999-2016 while Okinawa had 1,445 from 1991-2014. Within the seasons a total of 100 matches were found between the two breeding grounds including 38 males and 24 females while the rest were unknown. Within these matches, eight individuals were recorded moving within seasons, including two individuals moving across seasons multiple times. The two whales were both males, where one was recorded in both breeding grounds in three different seasons (2005, 2008 and 2012). The shortest duration of recorded sightings between grounds was one whale seen in the Philippines in late March 2012 and in Okinawa 13 days later. More females with calves were sighted in the Philippines than in Okinawa and this may indicate the Philippines as a preferred nursing ground.

The diets of humpback whales (Megaptera novaeangliae) on the shelf and oceanic feeding grounds in the western North Pacific inferred from stable isotope analysis

2012 ◽  
Vol 29 (3) ◽  
pp. E253-E265 ◽  
Author(s):  
Olga A. Filatova ◽  
Briana H. Witteveen ◽  
Anton A. Goncharov ◽  
Alexei V. Tiunov ◽  
Maria I. Goncharova ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
North Pacific ◽  
Western North Pacific ◽  
Isotope Analysis ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Feeding Grounds

Site fidelity and residence times of humpback whales (Megaptera novaeangliae) on the Brazilian coast

2012 ◽  
Vol 92 (8) ◽  
pp. 1783-1791 ◽  
Author(s):  
Clarêncio G. Baracho-Neto ◽  
Elitieri Santos Neto ◽  
Marcos R. Rossi-Santos ◽  
Leonardo L. Wedekin ◽  
Mariana C. Neves ◽  
...  
Keyword(s):  
Residence Time ◽  
Site Fidelity ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Brazilian Coast ◽  
Northern Coast ◽  
Occupancy Rate ◽  
Breeding Grounds ◽  
Minimum Number ◽  
Using Data

Humpback whales (Megaptera novaeangliae) migrate between their feeding grounds, located in high latitudes, and their breeding grounds, located in low latitudes, exhibiting certain levels of site fidelity to their migratory destinations. The residence time, also known as occupancy rate, can be defined as the minimum number of days that those individuals remained in the same area. In this paper, site fidelity and residence time of humpback whales that breed off the northern coast of Bahia, Brazil were investigated. Data were collected between 2000 and 2009 on-board research cruises and whale watching vessels. This paper also studies possible differences between males and females with respect to site fidelity off the Brazilian coast, using data collected since 1989. A total of 841 whales were photo-identified. The vast majority of the whales (96%, N = 809) were seen only once in the studied area, while 4% (32 individuals) were seen twice. Most of the resights occurred within the same season (72%, N = 23), while 9 resights (28%) occurred in different years. None of the individuals were seen more than twice. The average site fidelity rate was 1% and the occupancy rate varied from one up to 21 days (mean = 5.3; SD = 5.4, N = 23).

Photo-identification matches of humpback whales (Megaptera novaeangliae ) from feeding areas in Russian Far East seas and breeding grounds in the North Pacific

2017 ◽  
Vol 34 (1) ◽  
pp. 100-112 ◽  
Author(s):  
Olga V. Titova ◽  
Olga A. Filatova ◽  
Ivan D. Fedutin ◽  
Ekaterina N. Ovsyanikova ◽  
Haruna Okabe ◽  
...  
Keyword(s):  
North Pacific ◽  
Russian Far East ◽  
Far East ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Photo Identification ◽  
The North ◽  
Breeding Grounds ◽  
The North Pacific

Humpback whales, Megaptera novaeangliae (Cetaceaa : Balaenopteridae), in Hervey Bay, Queensland .

1994 ◽  
Vol 21 (3) ◽  
pp. 293 ◽  
Author(s):  
PJ Corkeron ◽  
M Brown ◽  
RW Slade ◽  
MM Bryden
Keyword(s):  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Eastern Coast ◽  
Western Coast ◽  
Photo Identification ◽  
Breeding Grounds ◽  
Pass Through ◽  
The Antarctic ◽  
The Impact ◽  
Final Cohort

Humpback whales, Megaptera novaeangliae, of the Antarctic Area V stock, pass through Hervey Bay, Queensland, during their southward migration. As part of an investigation of the impact of commercial whalewatching in the bay, aerial surveys were conducted during the 1988-90 whalewatching seasons, and a photo-identification project was run over the 1988 season. In 1988,60 pods containing 127 whales were observed. All pods were sighted on the transects in the eastern section of Hervey Bay, so surveys in 1989 and 1990 were confined to this area. In 1989, 223 whales in 121 pods were counted, and in 1990, 105 whales in 60 pods were observed. There was annual variation in the temporal pattern of the migration through Hervey Bay. Pods tended to occur in shallow water close to the western coast of Fraser Island and, on days when several whales were observed in the bay, pods were not distributed in a regular fashion. Mother-calf pods were the final cohort to migrate through the Bay. The recorded sizes of whale pods varied between observation platforms and averaged 1.75-2.81. In all, 100 whales were identified from photographs of natural marks. Most were photographed once only, although individual whales were sighted up to seven times. Of the 34 whales identified on more than one occasion, 24 were observed over a one- or two-day period. Pod sizes and residence times of whales in Hervey Bay resemble those of whales recorded at tropical breeding grounds. However, there are no data suggesting that Hervey Bay is of particular importance to any class of the humpback whale population migrating off the eastern coast of Australia.

Possible Sexing Technique for Humpback Whales (Megaptera novaeangliae)

1980 ◽  
Vol 37 (12) ◽  
pp. 2362-2364 ◽  
Author(s):  
V. P. Jurasz ◽  
D. McSweeney ◽  
C. M. Jurasz
Keyword(s):  
Morphological Feature ◽  
Megaptera Novaeangliae ◽  
Pregnant Female ◽  
Humpback Whales ◽  
Reasonable Accuracy ◽  
Southeast Alaska ◽  
Dorsal Fin ◽  
Breeding Grounds

By comparing photographs of humpback whales (Megaptera novaeangliae) photographed at the peak of their arch during a dive, we found some to be smooth and others to be scalloped middorsally caudal to the dorsal fin. Out of 410 photographs taken in southeast Alaska and Hawaii, 66% were found to be smooth and 34% scalloped. All females with calves were smooth. One pregnant female was smooth and only one female who was pregnant was slightly scalloped. One known male was scalloped and one "singer" on the Hawaiian breeding grounds was scalloped. We suggest that the smoothness or scalloping of this region is a morphological feature and can be used with reasonable accuracy to determine sex in humpback whales.Key words: humpback whales, morphology, sex

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.

Biennial and Lower-Frequency Variability Observed in the Early Summer Climate in the Western North Pacific

2004 ◽  
Vol 17 (21) ◽  
pp. 4254-4266 ◽  
Author(s):  
Tomohiko Tomita ◽  
Takao Yoshikane ◽  
Tetsuzo Yasunari
Keyword(s):  
North Pacific ◽  
Western North Pacific ◽  
Southern Oscillation ◽  
The Philippines ◽  
Early Summer ◽  
Tropical Pacific ◽  
Western Pacific ◽  
Spatial Phase ◽  
Summer Climate ◽  
Baiu Front

Abstract Early summer climate in the western North Pacific is largely represented by the baiu phenomenon. The meridional fluctuations of the baiu front on interannual time scales and the associated large-scale circulations are examined using the empirical orthogonal function (EOF) analysis and composite or correlation analyses based on the EOF time coefficients. The first EOF mode indicates a 5- or 6-yr low-frequency fluctuation (LF mode) appearing south of 35°N. The development is concurrent with horseshoe sea surface temperature anomalies (SSTAs) in the entire tropical Pacific that are associated with the El Niño–Southern Oscillation (ENSO). SSTAs in the western North Pacific control the anomalous southward expansion of the baiu front through a modification of the convection at around 20°–35°N. The LF mode is negatively correlated with the south-southeast Asian summer monsoon. The second EOF mode is characterized by a meridional seesawlike fluctuation with a node at around 28°N and a time scale of biennial oscillation (BO mode). The horseshoe SSTAs again control the anomalous meridional circulations, but with a different spatial phase through a convection off the Philippines. The spatial phase difference between the two horseshoe patterns is about 90° in both the zonal and meridional directions. The BO mode is negatively correlated with the tropical western North Pacific monsoon. SSTAs associated with the BO mode tend to be confined to the tropical western Pacific, while the signals of the LF mode extend rather broadly in the tropical Pacific–Indian Ocean sector, suggesting that the tropical BO is an aborted ENSO in the tropical central–western Pacific. The spatial phase of horseshoe SSTAs adjusts the interannual variability of the meridional fluctuation of the baiu front in the western North Pacific.

scholarly journals Attribution of Decadal Variability in Tropical Cyclone Passage Frequency over the Western North Pacific: A New Approach Emphasizing the Genesis Location of Cyclones

2013 ◽  
Vol 26 (3) ◽  
pp. 973-987 ◽  
Author(s):  
Satoru Yokoi ◽  
Yukari N. Takayabu
Keyword(s):  
Tropical Cyclone ◽  
Time Scales ◽  
North Pacific ◽  
Western North Pacific ◽  
Decadal Variability ◽  
The Philippines ◽  
Ocean Basin ◽  
New Approach ◽  
Equal Degree ◽  
Analysis Application

Abstract Variability in tropical cyclone (TC) activity is a matter of direct concern for affected populations. On interannual and longer time scales, variability in TC passage frequency can be associated with total TC frequency over the concerned ocean basin [basinwide frequency (BF)], the spatial distribution of TC genesis in the basin [genesis distribution (GD)], and the preferable track (PT) that can be considered as a function of genesis locations. To facilitate investigation of mechanisms responsible for the variability, the authors propose an approach of decomposing anomalies in the passage frequency into contributions of variability in BF, GD, and PT, which is named the Integration of Statistics on TC Activity by Genesis Location (ISTAGL) analysis. Application of this approach to TC best track data in the western North Pacific (WNP) basin reveals that overall distribution of the passage frequency trends over the 1961–2010 period is mainly due to the PT trends. On decadal time scales, passage frequency variability in midlatitudes is primarily due to PT variability, while the BF and GD also play roles in the subtropics. The authors further discuss decadal variability over the East China Sea in detail. The authors demonstrate that northward shift of the PT for TCs generated around the Philippines Sea and westward shift for TCs generated in the eastern part of the WNP contribute the variability with almost equal degree. The relationships between these PT shifts and anomalies in environmental circulation fields are also discussed.

scholarly journals Fluctuating reproductive rates in Hawaii's humpback whales, Megaptera novaeangliae , reflect recent climate anomalies in the North Pacific

2019 ◽  
Vol 6 (3) ◽  
pp. 181463 ◽  
Author(s):  
R. Cartwright ◽  
A. Venema ◽  
V. Hernandez ◽  
C. Wyels ◽  
J. Cesere ◽  
...  
Keyword(s):  
Climate Change ◽  
North Pacific ◽  
Megaptera Novaeangliae ◽  
Anthropogenic Climate Change ◽  
Humpback Whales ◽  
Encounter Rates ◽  
The North ◽  
The Impact ◽  
The North Pacific ◽  
Population Segment

Alongside changing ocean temperatures and ocean chemistry, anthropogenic climate change is now impacting the fundamental processes that support marine systems. However, where natural climate aberrations mask or amplify the impacts of anthropogenic climate change, identifying key detrimental changes is challenging. In these situations, long-term, systematic field studies allow the consequences of anthropogenically driven climate change to be distinguished from the expected fluctuations in natural resources. In this study, we describe fluctuations in encounter rates for humpback whales, Megaptera novaeangliae , between 2008 and 2018. Encounter rates were assessed during transect surveys of the Au'Au Channel, Maui, Hawaii. Initially, rates increased, tracking projected growth rates for this population segment. Rates reached a peak in 2013, then declined through 2018. Specifically, between 2013 and 2018, mother–calf encounter rates dropped by 76.5%, suggesting a rapid reduction in the reproductive rate of the newly designated Hawaii Distinct Population Segment of humpback whales during this time. As this decline coincided with changes in the Pacific decadal oscillation, the development of the NE Pacific marine heat wave and the evolution of the 2016 El Niño, this may be another example of the impact of this potent trifecta of climatic events within the North Pacific.

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