Ecological niche partitioning between baleen whales inhabiting Icelandic waters

Stable isotope analyses offer a useful means for quantifying ecological niche dimensions, though few studies have examined isotopic response of an ecological community with respect to resource gradients such as fluctuations in prey availability. Stable carbon and nitrogen isotopes were measured for Lake Michigan salmonines and their prey collected from 2014 to 2016. Bayesian ellipse and mixing model analyses were used to quantify isotopic niche characteristics and diets, respectively, among species and years. During the three-year study period, abundance and size structure of preferred alewife prey changed substantially and offered an opportunity to explore predator isotopic niche response and diet shifts along a prey resource gradient. Results suggested increased reliance on alewives, especially small alewives, over the study period and were consistent with greater availability of this prey. However, differential use of alewife size classes and alternative prey sources by salmonine predators was apparent, which suggested possible resource partitioning. Characterization of ecological niche overlap using stable isotopes likely requires consideration of shared resource availability as well as specific prey and habitat preferences.

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Independent evolution of baleen whale gigantism linked to Plio-Pleistocene ocean dynamics

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.0546 ◽

2017 ◽

Vol 284 (1855) ◽

pp. 20170546 ◽

Cited By ~ 77

Author(s):

Graham J. Slater ◽

Jeremy A. Goldbogen ◽

Nicholas D. Pyenson

Keyword(s):

Body Size ◽

Evolutionary Dynamics ◽

Niche Partitioning ◽

Ocean Dynamics ◽

Baleen Whales ◽

The Past ◽

Large Size ◽

Size Evolution ◽

Primary Determinant ◽

Quantitative Examination

Vertebrates have evolved to gigantic sizes repeatedly over the past 250 Myr, reaching their extreme in today's baleen whales (Mysticeti). Hypotheses for the evolution of exceptionally large size in mysticetes range from niche partitioning to predator avoidance, but there has been no quantitative examination of body size evolutionary dynamics in this clade and it remains unclear when, why or how gigantism evolved. By fitting phylogenetic macroevolutionary models to a dataset consisting of living and extinct species, we show that mysticetes underwent a clade-wide shift in their mode of body size evolution during the Plio-Pleistocene. This transition, from Brownian motion-like dynamics to a trended random walk towards larger size, is temporally linked to the onset of seasonally intensified upwelling along coastal ecosystems. High prey densities resulting from wind-driven upwelling, rather than abundant resources alone, are the primary determinant of efficient foraging in extant mysticetes and Late Pliocene changes in ocean dynamics may have provided an ecological pathway to gigantism in multiple independent lineages.

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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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New insight into trophic niche partitioning and diet of mackerel (Scomber scombrus) and herring (Clupea harengus) in Icelandic waters

ICES Journal of Marine Science ◽

10.1093/icesjms/fsaa100 ◽

2021 ◽

Author(s):

Cecilia Kvaavik ◽

Gudmundur J Óskarsson ◽

Hildur Pétursdóttir ◽

Gudrun Marteinsdóttir ◽

Anna Kristín Daníelsdóttir

Keyword(s):

Trophic Position ◽

Niche Partitioning ◽

Clupea Harengus ◽

Isotopic Niche ◽

Similar Species ◽

Calanoid Copepods ◽

Fish Prey ◽

Scomber Scombrus ◽

Prey Preferences ◽

Icelandic Waters

Abstract Understanding the competitive interactions of ecological similar species is essential to determine their role and niche in the ecosystem. Using both conventional dietary methods and stable isotope analysis, we examined the feeding ecology, trophic position and possible niche partitioning of Northeast Atlantic mackerel (Scomber scombrus), Icelandic summer spawning (ISS) herring (Clupea harengus), and Norwegian spring spawning (NSS) herring from Icelandic waters during the spring and summer 2012 and 2014. The stomach analysis showed differences in prey preferences among the species during summer, where mackerel diets were almost exclusively calanoid copepods, while herring ate larger zooplankton, i.e. euphausiids and amphipods. Analysis of isotopic diet contribution of mackerel and herring using Bayesian mixing models, representing mainly the spring consumption, revealed that euphausiids were the main dietary contributor of both mackerel and herring. Fish prey were also an important dietary source for ISS herring, and amphipods were important to the diet of NSS herring. In addition, mackerel encompassed a broad isotopic niche, whereas the two herring stocks had narrower and separated niches from each other. The results from this analysis reveal new and holistic information into the diet of these species, which have various ecological implications.

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Invertebrate Trace Fossils: The Backbone of Continental Ichnology

Short Courses in Paleontology ◽

10.1017/s2475263000002294 ◽

1992 ◽

Vol 5 ◽

pp. 64-104 ◽

Cited By ~ 10

Author(s):

Stephen T. Hasiotis ◽

Thomas M. Bown

Keyword(s):

Water Table ◽

Ecological Niche ◽

Niche Partitioning ◽

Trace Fossils ◽

Future Research ◽

Animal Kingdom ◽

New Concepts ◽

Depositional Systems ◽

Genetic Responses

The purpose of this chapter is to evoke new concepts, provide guidelines and new frontiers for future research, and demonstrate that invertebrate traces actually comprise the “backbone” of continental (as well as marine) ichnology. Invertebrate organisms that inhabit the continental, nonmarine realm include some of the most diverse and populous classes in the animal kingdom. For example, both the Insecta and Crustacea exhibit burrowing behaviors unique to subaqueous freshwater and subaerial systems. Because of the sheer biomass of burrowing pupae, larvae, juvenile, and adult stages of these organisms, invertebrates dependent on the position of the water table form the basis for ecological niche-partitioning of depositional systems within all of the continental realm. A distinction must be made here between continental and marine ichnocoenoses because they represent distinctly different styles of living. These in turn dictate different behavioral and genetic responses of the organisms that inhabit them. Burrow architectures that occur in both continental and marine ichnocoenoses can be differentiated by subtle differences in morphology that are due to convergence of the burrowing mechanisms of the respective organisms.

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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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Ecological niche partitioning of the invasive dinoflagellate Prorocentrum minimum and its native congeners in the Baltic Sea

Harmful Algae ◽

10.1016/j.hal.2016.09.006 ◽

2016 ◽

Vol 59 ◽

pp. 100-111 ◽

Cited By ~ 14

Author(s):

Irena V. Telesh ◽

Hendrik Schubert ◽

Sergei O. Skarlato

Keyword(s):

Baltic Sea ◽

Ecological Niche ◽

Niche Partitioning ◽

Prorocentrum Minimum ◽

The Baltic Sea ◽

The Baltic

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Morphological specializations of baleen whales associated with hydrodynamic performance and ecological niche

Journal of Morphology ◽

10.1002/jmor.10474 ◽

2006 ◽

Vol 267 (11) ◽

pp. 1284-1294 ◽

Cited By ~ 83

Author(s):

Becky L. Woodward ◽

Jeremy P. Winn ◽

Frank E. Fish

Keyword(s):

Ecological Niche ◽

Hydrodynamic Performance ◽

Baleen Whales

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A small whale reveals diversity of the Eocene cetacean fauna of Antarctica

Antarctic Science ◽

10.1017/s0954102020000516 ◽

2020 ◽

pp. 1-8

Author(s):

Svitozar Davydenko ◽

Thomas Mörs ◽

Pavel Gol'din

Keyword(s):

Twentieth Century ◽

Ecological Niche ◽

Niche Partitioning ◽

Ventral Side ◽

Late Eocene ◽

Neural Arch ◽

Early Diversification ◽

Swimming Style ◽

Seymour Island

Abstract Cetacean fossils have been recorded from middle and late Eocene deposits on Seymour Island since the beginning of the twentieth century and include fully aquatic Basilosauridae and stem Neoceti. Here, we report a small cetacean vertebra tentatively referred to as Neoceti from the late Eocene of Seymour Island. It shows a mosaic of traits, some of which are characteristic of early Neoceti (anteroposteriorly long transverse processes; a ventral keel on the ventral side of the centrum; thin pedicles of the neural arch), whereas others are shared with Basilosauridae (low-placed bases of the transverse processes). However, some traits are unique and may be autapomorphic: presence of separate prezygapophyses on the vertebra at the thoracic/lumbar boundary and a proportionally short centrum. Both traits imply a fast swimming style, which is characteristic of modern dolphins rather than Eocene cetaceans. Thus, this specimen can be identified as Neoceti indet., with some hypothetical odontocete affinities. Along with a few other Eocene whale taxa, it seems to be among the earliest known members of Neoceti on Earth. The finding of small and fast-swimming Neoceti in Antarctica also demonstrates early diversification of cetaceans and ecological niche partitioning by them dating back as early as the late Eocene.

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