Aggressive behavior between humpback whales (Megaptera novaeangliae) wintering in Hawaiian waters

1984 ◽  
Vol 62 (10) ◽  
pp. 1922-1937 ◽  
Author(s):  
C. Scott Baker ◽  
Louis M. Herman
Keyword(s):  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Pair Bonds ◽  
The Social ◽  
Newborn Calves ◽  
Males And Females ◽  
Peak Abundance ◽  
Physical Displacement ◽  
Sexually Mature ◽  
Winter Breeding

Humpback whales (Megaptera novaeangliae) wintering in Hawaiian waters engage in strenuous aggression toward con-specifics. The social context and sex of individuals involved suggest that aggression is the result of male–male competition for sexually mature females, including cows with newborn calves. Characteristic behaviors associated with aggression occur in a roughly hierarchical scaling of intensity and include broadside displays, underwater exhalations, head lunges (in which the throat is inflated and enlarged), physical displacement, and charge–strikes. Humpback whales do not form stable pair bonds during the winter breeding season; females are seen serially and simultaneously with multiple males and males are seen serially with multiple females. Repeated observations of individually identified whales indicate that escorting and singing are interchangeable reproductive roles of mature males. Incidents of aggression show a seasonal increase and decrease that parallel changes in abundance and average pod size. A seasonal peak in the frequency of aggression is probably related to an increase in population density and to changes in the reproductive physiology of mature males and females. It is suggested that singing may function, in part, to synchronize ovulation in females with the peak abundance of mature males on the wintering grounds.

scholarly journals Social Behaviour of Humpback Whales (Megaptera novaeangliae) in Hervey Bay, Eastern Australia, a Preferential Female Stopover During the Southern Migration

2021 ◽  
Vol 8 ◽  
Author(s):  
Trish Franklin ◽  
Wally Franklin ◽  
Lyndon Brooks ◽  
Peter Harrison ◽  
Adam A. Pack ◽  
...  
Keyword(s):  
Social Behaviour ◽  
Humpback Whale ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Site Specific ◽  
Factors Influencing ◽  
The Social ◽  
Eastern Australia ◽  
Competitive Behaviour ◽  
Males And Females

Agonistic competitive social behaviour in humpback whales [Megaptera novaeangliae (Borowski, 1781)] has been extensively studied and reported in previous research. However, non-agonistic social behaviour in humpback whale pods has not been systematically studied. We investigated the social behaviour of 3,949 humpback whale pods over a period of 14 years during August, September, and October in Hervey Bay (Queensland, eastern Australia), a preferential female stopover early in the southern migration. Modelling and analyses of the data examined the factors influencing the occurrence and timing of non-agonistic social behaviour pods, agonistic competitive pods and newly associated pods. Non-agonistic social behaviour was observed more frequently during August when mature females, including early pregnant and resting females, co-occur and socially interact with immature males and females. Overall, relatively few mature males visit Hervey Bay. Agonistic competitive behaviour was observed with increasing frequency during September and October when mother-calf pods, with few escorts predominated. Mother-calf pods in Hervey Bay spent most of their time alone involved in maternal care. Agonistic competitive behaviour is related to the decreasing numbers of potentially oestrous females toward the end of the season. Non-agonistic social behaviour and agonistic competitive behaviour were more frequently observed in larger and newly associated pods. Overall, non-agonistic social behaviour pods were more prevalent than agonistic competitive social behaviour pods. The results of this study substantiate that non-agonistic social behaviour may be more prevalent than aggressive agonistic social behaviour in site-specific locations and habitats, depending upon the classes and timings of humpback whales using such habitats.

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.

Transience of social affiliations among humpback whales (Megaptera novaeangliae) on the Hawaiian wintering grounds

1985 ◽  
Vol 63 (4) ◽  
pp. 762-772 ◽  
Author(s):  
Joseph R. Mobley Jr. ◽  
Louis M. Herman
Keyword(s):  
Mating Systems ◽  
Megaptera Novaeangliae ◽  
Rate Of Change ◽  
Humpback Whales ◽  
New Members ◽  
Transient Nature ◽  
Social Affiliations ◽  
Shore Station ◽  
Sexually Mature ◽  
Modal Size

Observations were made from an elevated shore station and from small boats of membership and of changes in membership in pods of humpback whales, Megaptera novaeangliae, assembling in Hawaiian waters during the winter–spring season of 1980. Pod sizes were small, with many singletons, pairs, and triplets, and a few larger sized pods. For pods having a calf present, the modal size was three: the mother, her calf, and an adult "escort" animal. When the calf was absent the modal size was two animals. On the average, 14% of the pods per hour changed membership, either losing or gaining members; for both pods with and without calf, the modal sizes showed the lowest rate of change. The rate of change was seasonally dependent and was at its maximum between mid-February and mid-March, when the relative abundance of whales was also at its maximum. Pods with calf were much more likely to attract new members than to lose members; pods without calf were equally likely to attract or lose members. Twelve cases of photographic resightings of individuals documented changes in affiliations with intervals as short as 1 h. The driving force for the transient nature of pod membership was hypothesized to be the prospecting behavior of mature males searching for sexually mature, receptive females. The overall pattern and duration of social affiliations was consistent with characteristics of polygynous or promiscuous mating systems.

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.

Temporal pattern of humpback whale (Megaptera novaeangliae) group structure around Abrolhos Archipelago breeding region, Bahia, Brazil

2007 ◽  
Vol 87 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Maria E. Morete ◽  
Tatiana L. Bisi ◽  
Sergio Rosso
Keyword(s):  
Social Status ◽  
Temporal Pattern ◽  
Group Composition ◽  
Group Structure ◽  
Temporal Patterns ◽  
Humpback Whale ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Migration Patterns ◽  
The Social

To characterize temporal patterns of humpback group structure around Abrolhos Archipelago, Brazil, seven years (1998–2004) of data obtained from July through November were analysed. During one-hour scans, observers determined group composition within 9.3 km around a land-based station. A total of 930 scans, comprising 4288 groups were analysed. Seven group categories were identified and their frequencies were 14.6% of 1AD (lone whale), 25.2% of DYAD (two adult whales), 7.3% of TRIO (three adult whales), 5.2 of TRIO+ (more than three adults), 24.9% of MOC (mother and calf), 19.6% of MOCE (mother, calf and one escort), and 3.1% of MOCE+ (mother, calf and more than one escort). Proportions of whale-group categories did not change between morning and afternoon, nor among years. However, as the season progressed, groups with calves increased while groups without calves decreased. This progression may be explained by the segregated migration patterns of humpback whales and also by changes in the social status of individuals. The Abrolhos Reef provides protection from the prevailing winds, which may explain the higher proportion of groups with calves in the area.

Cytogenetic determination of sex among individually identified humpback whales (Megaptera novaeangliae)

1988 ◽  
Vol 66 (6) ◽  
pp. 1243-1248 ◽  
Author(s):  
Richard H. Lambertsen ◽  
C. Scott Baker ◽  
Deborah A. Duffield ◽  
Jan Chamberlin-Lea
Keyword(s):  
Population Biology ◽  
Marine Species ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Dermal Tissue ◽  
Behavioral Observations ◽  
The Social

Using a small biopsy dart, samples of living dermal tissue were collected from individually identified humpback whales (Megaptera novaeangliae) in southeastern Alaskan waters. In vitro culture of these samples provided enough chromosomal material to karyotype 10 individuals. Examination of the sex chromosomes in the karyotypes demonstrated the sex of each of the 10 whales. In two cases, cytogenetic findings verified previous inferences of sex based on behavioral observations. In another two cases, karyotyping allowed the determination of sex when even long-term sighting histories and behavioral observations had been insufficient. For the rest of the whales, sex determination by cytogenetic findings has preceded long-term sightings and will facilitate the interpretation of future behavioral observations. We conclude that in vitro culturing of dermal tissue collected from naturally marked humpback whales, coupled with karyology, promises to be a powerful technique in future studies of the social behavior and population biology of this marine species.

Site-specific female-biased sex ratio of humpback whales (Megaptera novaeangliae) during a stopover early in the southern migration

2018 ◽  
Vol 96 (6) ◽  
pp. 533-544 ◽  
Author(s):  
Trish Franklin ◽  
Wally Franklin ◽  
Lyndon Brooks ◽  
Peter Harrison
Keyword(s):  
Sex Ratio ◽  
Habitat Preferences ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Site Specific ◽  
Breeding Grounds ◽  
Biased Sex Ratio ◽  
Males And Females ◽  
Using Data ◽  
Migration Modeling

Previous research on humpback whales (Megaptera novaeangliae (Borowski, 1781)), in both the Northern and Southern hemispheres, has reported site-specific male-biased sex ratios in breeding grounds and along migratory corridors. However, one recent Southern Hemisphere study reported a female-biased sex ratio in a feeding area within a coastal migratory corridor, indicating that females may preferentially occupy some habitats. We investigated the classes and relative seasonal timing of humpback whales using Hervey Bay (Queensland, Australia) as a stopover early in the southern migration. Modeling and analyzes were undertaken using data from resighting histories of 361 individually identified whales between 1992 and 2009. The data consisted of 2131 sightings categorized by either sex, age, reproductive status, or maturational status. A female-biased sex ratio of 2.94:1 indicates that Hervey Bay is a preferential stopover for females. The data revealed that the bay is important for mature females who co-occur with immature males and females during August. During September and October, mothers with calves accompanied by a few escorts dominate the Bay. Immature males and females socialize with mature females during August and September. The data support the hypothesis that habitat preferences and differential migration of females and males provide a plausible explanation for site-specific sex-bias in breeding grounds, migratory stopovers, and along migratory corridors.

scholarly journals The social vocalization repertoire of east Australian migrating humpback whales (Megaptera novaeangliae)

2007 ◽  
Vol 122 (5) ◽  
pp. 2893 ◽  
Author(s):  
Rebecca A. Dunlop ◽  
Michael J. Noad ◽  
Douglas H. Cato ◽  
Dale Stokes
Keyword(s):  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
The Social
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