Observations on the migrations of North Pacific humpback whales (Megaptera novaeangliae)

Migratory destinations of northeast Pacific humpback whales (Megaptera novaeangliae) were determined by repeat sightings of photographically identified individuals, using the black and white pigment patterns on the ventral side of the flukes. Individuals identified between 1975 and 1982 included 1056 in Hawaii, 420 in southeast Alaska, 54 in Prince William Sound, Alaska, 8 in British Columbia, and 12 in the Revillagigedo Islands, Mexico. Of these, 51 were found in Hawaii and southeast Alaska, 8 in Hawaii and Prince William Sound, 1 in Hawaii and British Columbia, and 1 in Mexico and Hawaii. Some travelled for four, five, and six successive seasons between Hawaii and southeast Alaska. One whale was found in British Columbia one summer and in southeast Alaska the next; the same individuals were commonly found off both Kona, Hawaii, and West Maui in winter. The study suggests that separate summer feeding areas may exist in the northeast Pacific where individuals prefer to feed. Migratory connections suggest that all humpbacks in the eastern North Pacific are of the same stock.

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Humpback Whale (Megaptera novaeangliae) observations in Laskeek Bay, western Hecate Strait, in spring and early summer, 1990–2018

The Canadian Field-Naturalist ◽

10.22621/cfn.v133i3.2231 ◽

2020 ◽

Vol 133 (3) ◽

pp. 263-269

Author(s):

Anthony J. Gaston ◽

Neil G. Pilgrim ◽

Vivian Pattison

Keyword(s):

British Columbia ◽

Humpback Whale ◽

Early Summer ◽

Megaptera Novaeangliae ◽

Humpback Whales ◽

The West ◽

Peak Period ◽

West Side

We describe observations of Humpback Whales (Megaptera novaeangliae) made along the west side of central Hecate Strait, British Columbia, during the spring and summer of 1990–2018. From none in March, the frequency of sightings increased from early April to a peak in May, then fell in June with few in July. The frequency of sightings during the peak period (1 May–20 June) increased over the course of the study at a mean rate of 6% a year, similar to increases recorded elsewhere in British Columbian waters. The frequency of sightings was highest in years when the Oceanic Niño Index for January–March was low and peaked earlier in years when the Oceanic Niño Index was high. Both of these relationships suggest a connection between Humpback Whale sightings in western Hecate Strait and the larger oceanographic context, with sightings more frequent in years of lower water temperatures.

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Possible Sexing Technique for Humpback Whales (Megaptera novaeangliae)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f80-284 ◽

1980 ◽

Vol 37 (12) ◽

pp. 2362-2364 ◽

Cited By ~ 2

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

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

Canadian Journal of Zoology ◽

10.1139/z99-005 ◽

1999 ◽

Vol 77 (3) ◽

pp. 504-508 ◽

Cited By ~ 11

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.

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

Royal Society Open Science ◽

10.1098/rsos.181463 ◽

2019 ◽

Vol 6 (3) ◽

pp. 181463 ◽

Cited By ~ 10

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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