Age-specific behavior and habitat use in humpback whales: Implications for vessel strike

Most studies of cetacean habitat use do not consider the influence of anthropogenic activities. We investigated the influence of environmental and anthropogenic variables on habitat use by humpback Megaptera novaeangliae and Bryde’s whales Balaenoptera brydei off the coast of the Brazilian city of Rio de Janeiro. Although there are 2 marine protected areas (MPAs) in this area, few data are available on cetacean habitat use or on the overlap of different cetacean species within these MPAs. Our aim was to evaluate the effectiveness of the MPAs and propose a buffer zone to better protect the biodiversity of the study area. We conducted systematic surveys and developed spatial eigenvector generalized linear models to characterize habitat use by the species in the study area. Habitat use by humpback whales was influenced only by depth, whereas for Bryde’s whales there was the additional influence of anthropogenic variables. For Bryde’s whales, which use the area for feeding, sea surface temperature and the distance to anchorages had a major influence on habitat use. We also showed that neither of the MPAs in the study area adequately protects the hotspots of either whale species. Most of the humpback whale grid cells with high sighting predictions were located within 2 km of the MPAs, while areas of high sighting prediction of Bryde’s whales were located up to 5 km from the MPAs, closer to beaches. Our findings provide important insights for the delimitation of protected areas and zoning of the MPAs.

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Movements and Habitat Use by Southeast Pacific Humpback Whales (Megaptera novaeangliae) Satellite Tracked at Two Breeding Sites

Aquatic Mammals ◽

10.1578/am.43.2.2017.139 ◽

2017 ◽

Vol 43 (2) ◽

pp. 139-155 ◽

Cited By ~ 6

Author(s):

Héctor M. Guzman ◽

Fernando Félix

Keyword(s):

Habitat Use ◽

Megaptera Novaeangliae ◽

Humpback Whales ◽

Breeding Sites ◽

Southeast Pacific

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Low latitude habitat use patterns of a recovering population of humpback whales

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315418000255 ◽

2018 ◽

Vol 98 (5) ◽

pp. 1087-1096 ◽

Cited By ~ 1

Author(s):

Maria Isabel Carvalho Gonçalves ◽

Renata Santoro De Sousa-Lima ◽

Niel Nascimento Teixeira ◽

Maria Emilia Morete ◽

Gustavo Henrique De Carvalho ◽

...

Keyword(s):

Habitat Use ◽

Cost Effective ◽

Humpback Whales ◽

Anthropogenic Activity ◽

Small Scale ◽

Nursery Ground ◽

Social Strategies ◽

Low Latitude ◽

Use Patterns ◽

Key Factor

The coast of Brazil is an important low latitude nursery ground for humpback whales (Megaptera novaeangliae). The number of humpback whales in this region has increased and its population is reoccupying areas where it has been depleted during the whaling period. The goal of this study was to conduct land-based observations during 2014 and 2015 to characterize patterns of habitat use and relative abundance of humpback whales that migrate to one of these reoccupation areas: Serra Grande, Bahia state. The observed mean group size was 2.12 ± 0.96 individuals and did not vary through the reproductive season nor between years. Dyads (32.9%) and singletons (26.7%) were more frequently observed, and groups with calves represented 21.2% of the sightings. The mean number of whales counted per hour increased from 2014 (3.44 ± 3.35) to 2015 (5.12 ± 4.18). Habitat use varied during the season; whales used shallower waters closer to shore as the season progressed. The spatial distribution of groups with calves was dependent on the presence and number of escorts. Spatial segregation of groups with calves closer to shore is a key factor in understanding the overall distribution of whales in the area, suggesting that social strategies are affected by environmental factors, as seen in other wintering grounds. Small-scale studies from land-based stations, in areas such as this where there is no previous knowledge about the species, are cost effective. They provide information about the overall behavioural and spatial patterns while anthropogenic activity is still low, allowing habitat protection and management decisions before implementation and increase of human activities.

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Micro-scale habitat use of humpback whales around Maui Nui, Hawaii

The Journal of the Acoustical Society of America ◽

10.1121/1.4987956 ◽

2017 ◽

Vol 141 (5) ◽

pp. 3669-3669

Author(s):

Anke Kügler ◽

Marc Lammers

Keyword(s):

Habitat Use ◽

Humpback Whales ◽

Micro Scale

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Social survival: humpback whales (Megaptera novaeangliae) use social structure to partition ecological niches within proposed critical habitat

10.1101/2020.12.31.424937 ◽

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.

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Natural history, population dynamics, and habitat use of humpback whales over 30 years on an Alaska feeding ground

Ecosphere ◽

10.1002/ecs2.1641 ◽

2017 ◽

Vol 8 (1) ◽

pp. e01641 ◽

Cited By ~ 21

Author(s):

Christine M. Gabriele ◽

Janet L. Neilson ◽

Janice M. Straley ◽

C. Scott Baker ◽

Jennifer A. Cedarleaf ◽

...

Keyword(s):

Population Dynamics ◽

Natural History ◽

Habitat Use ◽

Humpback Whales ◽

Feeding Ground

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Social survival: Humpback whales (Megaptera novaeangliae) use social structure to partition ecological niches within proposed critical habitat

PLoS ONE ◽

10.1371/journal.pone.0245409 ◽

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.

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