scholarly journals More of the same: allopatric humpback whale populations share acoustic repertoire

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5365 ◽  
Author(s):  
Michelle E.H. Fournet ◽  
Lauren Jacobsen ◽  
Christine M. Gabriele ◽  
David K. Mellinger ◽  
Holger Klinck

Background Humpback whales (Megaptera novaeangliae) are a widespread, vocal baleen whale best known for producing song, a complex, repetitive, geographically distinct acoustic signal sung by males, predominantly in a breeding context. Humpback whales worldwide also produce non-song vocalizations (“calls”) throughout their migratory range, some of which are stable across generations. Methods We looked for evidence that temporally stable call types are shared by two allopatric humpback whale populations while on their northern hemisphere foraging grounds in order to test the hypothesis that some calls, in strong contrast to song, are innate within the humpback whale acoustic repertoire. Results Despite being geographically and genetically distinct populations, humpback whales in Southeast Alaska (North Pacific Ocean) share at least five call types with conspecifics in Massachusetts Bay (North Atlantic Ocean). Discussion This study is the first to identify call types shared by allopatric populations, and provides evidence that some call types may be innate.

2012 ◽  
Vol 14 (2) ◽  
pp. 175-183 ◽  
Author(s):  
ET Vu ◽  
D Risch ◽  
CW Clark ◽  
S Gaylord ◽  
LT Hatch ◽  
...  

2021 ◽  
Vol 118 (38) ◽  
pp. e2111205118
Author(s):  
Chun-Mao Tseng ◽  
Shin-Jing Ang ◽  
Yi-Sheng Chen ◽  
Jen-Chieh Shiao ◽  
Carl H. Lamborg ◽  
...  

Bluefin tuna (BFT), highly prized among consumers, accumulate high levels of mercury (Hg) as neurotoxic methylmercury (MeHg). However, how Hg bioaccumulation varies among globally distributed BFT populations is not understood. Here, we show mercury accumulation rates (MARs) in BFT are highest in the Mediterranean Sea and decrease as North Pacific Ocean > Indian Ocean > North Atlantic Ocean. Moreover, MARs increase in proportion to the concentrations of MeHg in regional seawater and zooplankton, linking MeHg accumulation in BFT to MeHg bioavailability at the base of each subbasin's food web. Observed global patterns correspond to levels of Hg in each ocean subbasin; the Mediterranean, North Pacific, and Indian Oceans are subject to geogenic enrichment and anthropogenic contamination, while the North Atlantic Ocean is less so. MAR in BFT as a global pollution index reflects natural and human sources and global thermohaline circulation.


Paleobiology ◽  
2012 ◽  
Vol 38 (1) ◽  
pp. 162-179 ◽  
Author(s):  
Moriaki Yasuhara ◽  
Gene Hunt ◽  
Thomas M. Cronin ◽  
Natsumi Hokanishi ◽  
Hodaka Kawahata ◽  
...  

There is growing evidence that changes in deep-sea benthic ecosystems are modulated by climate changes, but most evidence to date comes from the North Atlantic Ocean. Here we analyze new ostracod and published foraminiferal records for the last 250,000 years on Shatsky Rise in the North Pacific Ocean. Using linear models, we evaluate statistically the ability of environmental drivers (temperature, productivity, and seasonality of productivity) to predict changes in faunal diversity, abundance, and composition. These microfossil data show glacial-interglacial shifts in overall abundances and species diversities that are low during glacial intervals and high during interglacials. These patterns replicate those previously documented in the North Atlantic Ocean, suggesting that the climatic forcing of the deep-sea ecosystem is widespread, and possibly global in nature. However, these results also reveal differences with prior studies that probably reflect the isolated nature of Shatsky Rise as a remote oceanic plateau. Ostracod assemblages on Shatsky Rise are highly endemic but of low diversity, consistent with the limited dispersal potential of these animals. Benthic foraminifera, by contrast, have much greater dispersal ability and their assemblages at Shatsky Rise show diversities typical for deep-sea faunas in other regions.Statistical analyses also reveal ostracod-foraminferal differences in relationships between environmental drivers and biotic change. Rarefied diversity is best explained as a hump-shaped function of surface productivity in ostracods, but as having a weak and positive relationship with temperature in foraminifera. Abundance shows a positive relationship with both productivity and seasonality of productivity in foraminifera, and a hump-shaped relationship with productivity in ostracods. Finally, species composition in ostracods is influenced by both temperature and productivity, but only a temperature effect is evident in foraminifera. Though complex in detail, the global-scale link between deep-sea ecosystems and Quaternary climate changes underscores the importance of the interaction between the physical and biological components of paleoceanographical research for better understanding the history of the biosphere.


2001 ◽  
Vol 79 (4) ◽  
pp. 589-600 ◽  
Author(s):  
Christine M Gabriele ◽  
Janice M Straley ◽  
Sally A Mizroch ◽  
C Scott Baker ◽  
Alison S Craig ◽  
...  

Sighting histories of individually identified female humpback whales (Megaptera novaeangliae) in their winter and summer ranges were used to investigate mortality of North Pacific humpback whale calves. We compiled records collected between 1979 and 1995 by eight independent research groups, which yielded 29 cases where 25 different mothers sighted in Hawai'i were identified later the same year in Alaska. In 7 of 29 cases, a calf sighted with its mother in Hawai'i was missing from its mother's Alaska sighting(s). After investigating many factors, we determined that the largest potential bias would occur in late-autumn observations, when calf absences might indicate weaning or temporary mother–calf separation rather than calf mortality. Our minimal and most robust estimate excluded all mortalities and survivals based on sightings of the mother after October 31; 3 of 20 cases or 0.150 (95% confidence intervals (CI) = 0.032, 0.378). The maximal calf mortality rate, derived from all the available data, was 7 of 29 cases or 0.241 (95% CI = 0.103, 0.434). An intermediate estimate that excluded all cases based on single Alaska sightings and omitted late-season sightings (2 of 11 cases or 0.182; 95% CI = 0.023, 0.518) is perhaps closest to the actual first-year mortality rate for humpback whale calves, although it is compromised by its small sample size. Our results demonstrate both the value and the limitations of using longitudinal data to determine the life-history parameters that are essential for documenting the recovery of endangered populations.


1987 ◽  
Vol 65 (12) ◽  
pp. 2853-2863 ◽  
Author(s):  
Phillip J. Clapham ◽  
Charles A. Mayo

Humpback whale mother–calf pairs from a currently unexploited population were observed in Massachusetts Bay between 1979 and 1985. During this period, 44 individually identified mature females were observed, with a total of 72 calves. Of the 20 mothers observed with more than one calf during the study period, 12 had two calves and 8 had three calves. The observed calving intervals were 1 year (n = 1), 2 years (n = 16), 3 years (n = 10), and 4 years (n = 1). The crude birth rate varied from a low of 0.045 in 1981 to a high of 0.103 in 1983 (mean = 0.075). An alternative calculation of reproductive rate yielded a range of 0.30–0.43 calves per mature female per year. Mature females were observed significantly more frequently in years when they had a calf than in years when they did not. Females with calves associate with other whales less frequently than females without calves. Observations of calves feeding suggest that weaning may begin when calves are 5–6 months of age. Forty-five of the 49 calves born before 1985 separated from their mothers during the calf's second winter, while 37 of the 49 were observed to return to the study area in 1 or more years after separation from their mothers. One calf is known to have died. Two females born during the study period returned with calves of their own in later years. The high return rate of calves in years after separation strongly suggests that the composition of a humpback whale feeding stock is determined matrilineally.


2016 ◽  
Vol 94 (7) ◽  
pp. 517-527 ◽  
Author(s):  
M.M. MacKay ◽  
B. Würsig ◽  
C.E. Bacon ◽  
J.D. Selwyn

North Atlantic humpback whales (Megaptera novaeangliae (Borowski, 1781)) are increasing in number, necessitating current data from winter areas for assessing potential interactions with humans. Occurrence patterns of humpback whales wintering off Puerto Rico were investigated to predict where whales aggregate in nearshore areas. Here we describe the relationship between group associations of humpback whales and bathymetric features off western Puerto Rico. Data were collected from 2011 to 2014. Effort consisted of 240.9 vessel h, 13.0 aerial h, and 303.6 h of land observations conducted over 165 days. A total of 197 humpback whale groups were observed with n = 331 individuals: 91 (46.2%) singletons, 67 (34%) dyads, 17 (8.6%) mother–calf pairs, 8 (4.1%) competitive groups, 8 (4.1%) mother–calf–escort groups, and 6 (3.1%) mixed-species associations. A linear regression model supported that group composition correlated with hotspots associated with four bathymetric features. Dyads and competitive groups were dispersed among features in deeper water. Singletons were observed farther from a shelf edge, whereas singing males were closely associated with a shelf edge. Mother–calf pairs occurred nearshore in shallow water; however, when mother–calf pairs were sighted with an escort, they were offshore. This study is especially important ahead of possible removal from the Endangered Species list.


2014 ◽  
Vol 92 (1) ◽  
pp. 9-18 ◽  
Author(s):  
A.S. Kennedy ◽  
A.N. Zerbini ◽  
O.V. Vásquez ◽  
N. Gandilhon ◽  
P.J. Clapham ◽  
...  

North Atlantic humpback whales (Megaptera novaeangliae (Borowski, 1781)) migrate from high-latitude summer feeding grounds to low-latitude winter breeding grounds along the Antillean Island chain. In the winters and springs of 2008 through 2012, satellite tags were deployed on humpback whales on Silver Bank (Dominican Republic) and in Guadeloupe (French West Indies) breeding areas. Whales were monitored, on average, for 26 days (range = 4–90 days). Some animals remained near their tagging location for multiple days before beginning their northerly migration, yet some visited habitats along the northwestern coast of the Dominican Republic, northern Haiti, the Turks and Caicos islands, and off Anguilla. Individuals monitored during migration headed towards feeding grounds in the Gulf of Maine (USA), Canada, and the eastern North Atlantic (Iceland or Norway). One individual traveled near Bermuda during the migration. This study provides the first detailed description of routes used by North Atlantic humpback whales towards multiple feeding destinations. Additionally, it corroborates previous research showing that individuals from multiple feeding grounds migrate to the Antilles for the breeding season. This study indicates that North Atlantic humpbacks use an area broader than the existing boundaries of marine mammal sanctuaries, which should provide justification for their expansion.


1994 ◽  
Vol 72 (2) ◽  
pp. 274-279 ◽  
Author(s):  
Judith M. Allen ◽  
Howard C. Rosenbaum ◽  
Steven K. Katona ◽  
Philip J. Clapham ◽  
David K. Mattila

The relative amount of pigmentation on the flukes of 3812 humpback whales from five feeding and three breeding regions in the western North Atlantic Ocean was ranked subjectively into categories 1 (white) through 5 (black). The distribution of rankings was examined to determine whether differences existed between regions or sexes. Fluke pigmentation differed significantly among whales photographed in the five northern feeding regions (Iceland, southwestern Greenland, Newfoundland (including the Labrador coast), the Gulf of St. Lawrence, and the Gulf of Maine). Whales photographed in the Gulf of Maine were characterized by a significantly higher proportion of dark-colored flukes than whales in all feeding regions except Iceland. Whales photographed near Greenland were characterized by significantly more light-colored flukes than other feeding regions. Fluke pigmentation also varied significantly among whales photographed in the three southern breeding regions (Virgin Bank, Puerto Rico, and the Dominican Republic). The flukes of whales photographed near Virgin Bank differed from those of whales near the Dominican Republic and included a higher proportion of light flukes. Fluke pigmentation of males and females differed significantly in the Gulf of Maine and in the Dominican Republic. Both areas showed higher proportions of dark-fluked females and light-fluked males. Sex bias differences in other regions were not examined because sample sizes were small. Fluke pigmentation of whales photographed only on the summer range did not differ significantly from the pigmentation of those photographed only on the winter range, supporting the belief that all northern feeding aggregations mix on the southern breeding grounds. Regional differences in fluke pigmentation suggest that the western North Atlantic humpback whale population includes a number of relatively isolated subunits, as suggested previously by photoidentification and DNA studies.


2021 ◽  
Vol 22 (1) ◽  
pp. 75-80
Author(s):  
Joana Castro ◽  
André Cid ◽  
Marina I Laborde

Brydes’s whale (Balaenoptera edeni) is a species of baleen whale known to live year-round in warm waters, although the distribution of the species in the North Atlantic Ocean is still poorly known. In this work we report the sighting of an adult individual during the summer of 2020 in the South coast of Portugal. The whale was observed 6.4 nautical miles from the shore at a depth of 50.6 metres. Initially this individual was associated with a group of bottlenose dolphins. This is the first record of this species for mainland Portugal.


2013 ◽  
Vol 94 (6) ◽  
pp. 1117-1125 ◽  
Author(s):  
Anita Murray ◽  
Aaron N. Rice ◽  
Christopher W. Clark

Humpback whales (Megaptera novaeangliae) are known to utilize Massachusetts Bay as a feeding ground in the spring and summer, during the annual migration of the Gulf of Maine sub-population. However, there is a limited understanding of the pattern of humpback whale occurrence in this region outside of the feeding period. Passive acoustic monitoring of Massachusetts Bay over a two-year period, revealed an extended presence of acoustically active humpback whales throughout a majority of the study period (87%; 633 days of presence out of 725 days of acoustic monitoring). Humpback whale presence oscillated between lengthy periods of consistent presence (April to December) and relatively shorter periods of variable presence (December to March). Seasonal variation in presence was evident during three distinct phases: (1) maximum-presence from spring to early winter; (2) variable-presence in early winter and early spring; and (3) minimum-presence mid-winter. The variation in seasonal presence was concurrent with coarse migratory patterns of humpback whales, and yearly variations in presence presumably reflect a shift in the influx and efflux of whales between years. The extended presence of humpbacks in this area suggests that Massachusetts Bay is an important, year-round habitat for the Gulf of Maine sub-population, and may warrant revision of management and regulatory practices to reflect this presence.


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