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Grainger R, Raoult V, Peddemors VM, Machovsky-Capuska GE, Gaston TF, Raubenheimer D. Integrating isotopic and nutritional niches reveals multiple dimensions of individual diet specialisation in a marine apex predator. J Anim Ecol 2023; 92:514-534. [PMID: 36421071 PMCID: PMC10107186 DOI: 10.1111/1365-2656.13852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/23/2022] [Indexed: 11/27/2022]
Abstract
Dietary specialisations are important determinants of ecological structure, particularly in species with high per-capita trophic influence like marine apex predators. These species are, however, among the most challenging in which to establish spatiotemporally integrated diets. We introduce a novel integration of stable isotopes with a multidimensional nutritional niche framework that addresses the challenges of establishing spatiotemporally integrated nutritional niches in wild populations, and apply the framework to explore individual diet specialisation in a marine apex predator, the white shark Carcharodon carcharias. Sequential tooth files were sampled from juvenile white sharks to establish individual isotopic (δ-space; δ13 C, δ15 N, δ34 S) niche specialisation. Bayesian mixing models were then used to reveal individual-level prey (p-space) specialisation, and further combined with nutritional geometry models to quantify the nutritional (N-space) dimensions of individual specialisation, and their relationships to prey use. Isotopic and mixing model analyses indicated juvenile white sharks as individual specialists within a broader, generalist, population niche. Individual sharks differed in their consumption of several important mesopredator species, which suggested among-individual variance in trophic roles in either pelagic or benthic food webs. However, variation in nutrient intakes was small and not consistently correlated with differences in prey use, suggesting white sharks as nutritional specialists and that individuals could use functionally and nutritionally different prey as complementary means to achieve a common nutritional goal. We identify how degrees of individual specialisation can differ between niche spaces (δ-, p- or N-space), the physiological and ecological implications of this, and argue that integrating nutrition can provide stronger, mechanistic links between diet specialisation and its intrinsic (fitness/performance) and extrinsic (ecological) outcomes. Our time-integrated framework is adaptable for examining the nutritional consequences and drivers of food use variation at the individual, population or species level.
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Affiliation(s)
- Richard Grainger
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Vincent Raoult
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, New South Wales, Australia
| | - Victor M Peddemors
- New South Wales Department of Primary Industries, Fisheries, Sydney Institute of Marine Science, Mosman, New South Wales, Australia
| | - Gabriel E Machovsky-Capuska
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia.,Nutri Lens, East Ryde, New South Wales, Australia
| | - Troy F Gaston
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, New South Wales, Australia
| | - David Raubenheimer
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
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2
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Increased shark bite survivability revealed by two centuries of Australian records. Sci Rep 2022; 12:14121. [PMID: 35986014 PMCID: PMC9391475 DOI: 10.1038/s41598-022-16950-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 07/19/2022] [Indexed: 11/08/2022] Open
Abstract
AbstractThe perceived and real threat of shark bites have significant direct health and indirect economic impacts. Here we assess the changing odds of surviving an unprovoked shark bite using 200 years of Australian records. Bite survivability rates for bull (Carcharhinus leucas), tiger (Galeocerdo cuvier) and white (Carcharodon carcharias) sharks were assessed relative to environmental and anthropogenic factors. Survivability of unprovoked bull, tiger and white shark bites were 62, 75 and 53% respectively. Bull shark survivability increased over time between 1807 and 2018. Survivability decreased for both tiger and white sharks when the person was doing an in water activity, such as swimming or diving. Not unsurprisingly, a watercraft for protection/floatation increased survivability to 92% from 30%, and 88% from 45%, for tiger and white sharks respectively. We speculate that survival may be related to time between injury and treatment, indicating the importance of rapid and appropriate medical care. Understanding the predictors of unprovoked bites, as well as survivability (year and water activity), may be useful for developing strategies that reduce the number of serious or fatal human-shark interactions without impacting sharks and other marine wildlife.
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3
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Benites-Palomino A, Velez-Juarbe J, Altamirano-Sierra A, Collareta A, Carrillo-Briceño JD, Urbina M. Sperm whales (Physeteroidea) from the Pisco Formation, Peru, and their trophic role as fat sources for late Miocene sharks. Proc Biol Sci 2022; 289:20220774. [PMID: 35765834 PMCID: PMC9240678 DOI: 10.1098/rspb.2022.0774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Shark-cetacean trophic interactions, preserved as bite marks in the fossil record, mostly correspond to isolated or fragmentary findings that bear limited information about major trophic patterns or roles. Here, we provide evidence of focalized foraging by sharks in the form of tooth bite marks over physeteroids fossil bones from the late Miocene of Peru. These findings indicate that sharks were targeting the forehead of coeval physeteroids to actively feed on their lipid-rich nasal complexes. Miocene physeteroids displayed a broad diversity, including giant predatorial forms, small benthic foragers and suction feeders. Like their extant relatives, these animals exhibited enlarged fatty forehead organs responsible for their sound production capabilities, thus evolving taxon-specific cranial architecture. Bite marks are found on the cranial bones where these structures were attached, indicating that sharks actively targeted this region; but also, in areas that would only be accessible following the consumption of the surrounding soft tissues. The shape of the bite marks and their distribution suggests a series of consecutive scavenging events by individuals of different shark species. Similar bite patterns can be recognized on other Miocene physeteroids fossils from across the globe, suggesting that sharks actively exploited physeteroid carcasses as fat sources.
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Affiliation(s)
- Aldo Benites-Palomino
- Paläontologisches Institut und Museum, Universität Zürich, Karl-Schmid-Strasse 4, 8006 Zürich, Switzerland,Departamento de Paleontología de Vertebrados, Museo de Historia Natural-Universidad Nacional Mayor de San Marcos, Avenida Arenales 1256, Lima 11, Peru
| | - Jorge Velez-Juarbe
- Department of Mammalogy, Natural History Museum of Los Angeles County, 900 Exposition Blvd, Los Angeles, CA 90007, USA,Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Ali Altamirano-Sierra
- Departamento de Paleontología de Vertebrados, Museo de Historia Natural-Universidad Nacional Mayor de San Marcos, Avenida Arenales 1256, Lima 11, Peru
| | - Alberto Collareta
- Dipartimento di Scienze della Terra, Università di Pisa, via Santa Maria 53, 56126 Pisa, Italy
| | - Jorge D. Carrillo-Briceño
- Paläontologisches Institut und Museum, Universität Zürich, Karl-Schmid-Strasse 4, 8006 Zürich, Switzerland
| | - Mario Urbina
- Departamento de Paleontología de Vertebrados, Museo de Historia Natural-Universidad Nacional Mayor de San Marcos, Avenida Arenales 1256, Lima 11, Peru
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4
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Bosio G, Collareta A, Di Celma C, Lambert O, Marx FG, de Muizon C, Gioncada A, Gariboldi K, Malinverno E, Malca RV, Urbina M, Bianucci G. Taphonomy of marine vertebrates of the Pisco Formation (Miocene, Peru): Insights into the origin of an outstanding Fossil-Lagerstätte. PLoS One 2021; 16:e0254395. [PMID: 34264979 PMCID: PMC8282071 DOI: 10.1371/journal.pone.0254395] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 06/28/2021] [Indexed: 11/23/2022] Open
Abstract
The Miocene Pisco Formation, broadly exposed in the Ica Desert of southern Peru, is among the most outstanding Cenozoic marine Fossil-Lagerstätten worldwide. It is renowned for its exceptional preservation and abundance of vertebrate fossils, including a rich assemblage of whales and dolphins (Cetacea). Here, we integrate taphonomic data on 890 marine vertebrate fossils, gathered through 16 different localities. Our observations range from the taxonomic distribution, articulation, completeness, disposition and orientation of skeletons, to the presence of bite marks, associations with shark teeth and macro-invertebrates, bone and soft tissue preservation, and the formation of attendant carbonate concretions and sedimentary structures. We propose that the exceptional preservation characterising many Pisco vertebrates, as well as their exceptionally high abundance, cannot be ascribed to a single cause like high sedimentation rates (as proposed in the past), but rather to the interplay of several favourable factors including: (i) low levels of dissolved oxygen at the seafloor (with the intervention of seasonal anoxic events); (ii) the early onset of mineralisation processes like apatite dissolution/recrystallisation and carbonate mineral precipitation; (iii) rapid burial of carcasses in a soupy substrate and/or a novel mechanism involving scour-induced self-burial; and (iv) original biological richness. Collectively, our observations provide a comprehensive overview of the taphonomic processes that shaped one of South America’s most important fossil deposits, and suggest a model for the formation of other marine vertebrate Fossil-Lagerstätten.
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Affiliation(s)
- Giulia Bosio
- Dipartimento di Scienze dell’Ambiente e della Terra, Università degli Studi di Milano-Bicocca, Milan, Italy
| | - Alberto Collareta
- Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy
- * E-mail:
| | - Claudio Di Celma
- Scuola di Scienze e Tecnologie, Università di Camerino, Camerino, Italy
| | - Olivier Lambert
- D.O. Terre et Histoire de la Vie, Institut Royal des Sciences Naturelles de Belgique, Bruxelles, Belgium
| | - Felix G. Marx
- Museum of New Zealand Te Papa Tongarewa, Wellington, New Zealand
- Department of Geology, University of Otago, Dunedin, New Zealand
| | - Christian de Muizon
- Département Origines et Evolution, CR2P UMR 7207, (MNHN, CNRS, UPMC, Sorbonne-Université), Muséum national d’Histoire naturelle, Paris, France
| | - Anna Gioncada
- Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy
| | - Karen Gariboldi
- Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy
| | - Elisa Malinverno
- Dipartimento di Scienze dell’Ambiente e della Terra, Università degli Studi di Milano-Bicocca, Milan, Italy
| | - Rafael Varas Malca
- Departamento de Paleontologia de Vertebrados, Museo de Historia Natural-UNMSM, Lima, Peru
| | - Mario Urbina
- Departamento de Paleontologia de Vertebrados, Museo de Historia Natural-UNMSM, Lima, Peru
| | - Giovanni Bianucci
- Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy
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Abstract
Over the past decade, drones have become a popular tool for wildlife management and research. Drones have shown significant value for animals that were often difficult or dangerous to study using traditional survey methods. In the past five years drone technology has become commonplace for shark research with their use above, and more recently, below the water helping to minimise knowledge gaps about these cryptic species. Drones have enhanced our understanding of shark behaviour and are critically important tools, not only due to the importance and conservation of the animals in the ecosystem, but to also help minimise dangerous encounters with humans. To provide some guidance for their future use in relation to sharks, this review provides an overview of how drones are currently used with critical context for shark monitoring. We show how drones have been used to fill knowledge gaps around fundamental shark behaviours or movements, social interactions, and predation across multiple species and scenarios. We further detail the advancement in technology across sensors, automation, and artificial intelligence that are improving our abilities in data collection and analysis and opening opportunities for shark-related beach safety. An investigation of the shark-based research potential for underwater drones (ROV/AUV) is also provided. Finally, this review provides baseline observations that have been pioneered for shark research and recommendations for how drones might be used to enhance our knowledge in the future.
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Brunnschweiler JM, Vignaud TM, Côté IM, Maljković A. The costs of cohabiting: the case of sharksuckers (Echeneis naucrates) and their hosts at shark provisioning sites. Ecology 2020; 101:e03160. [PMID: 32799316 DOI: 10.1002/ecy.3160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/08/2020] [Accepted: 06/28/2020] [Indexed: 11/11/2022]
Affiliation(s)
| | - Thomas M Vignaud
- Independent Researcher, Residence TANZI, Apt 18, Racket Road, Grand Baie, 30549, Mauritius
| | - Isabelle M Côté
- Earth to Ocean Group, Department of Biological Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - Aleksandra Maljković
- Independent Researcher, 34 Evesham Road, Cheltenham, Gloucestershire, GL52 2AB, UK
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Abstract
The use of drones to study marine animals shows promise for the examination of numerous aspects of their ecology, behaviour, health and movement patterns. However, the responses of some marine phyla to the presence of drones varies broadly, as do the general operational protocols used to study them. Inconsistent methodological approaches could lead to difficulties comparing studies and can call into question the repeatability of research. This review draws on current literature and researchers with a wealth of practical experience to outline the idiosyncrasies of studying various marine taxa with drones. We also outline current best practice for drone operation in marine environments based on the literature and our practical experience in the field. The protocols outlined herein will be of use to researchers interested in incorporating drones as a tool into their research on marine animals and will help form consistent approaches for drone-based studies in the future.
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Jiang DY, Motani R, Tintori A, Rieppel O, Ji C, Zhou M, Wang X, Lu H, Li ZG. Evidence Supporting Predation of 4-m Marine Reptile by Triassic Megapredator. iScience 2020; 23:101347. [PMID: 32822565 PMCID: PMC7520894 DOI: 10.1016/j.isci.2020.101347] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/09/2020] [Accepted: 07/04/2020] [Indexed: 11/28/2022] Open
Abstract
Air-breathing marine predators have been essential components of the marine ecosystem since the Triassic. Many of them are considered the apex predators but without direct evidence-dietary inferences are usually based on circumstantial evidence, such as tooth shape. Here we report a fossil that likely represents the oldest evidence for predation on megafauna, i.e., animals equal to or larger than humans, by marine tetrapods-a thalattosaur (∼4 m in total length) in the stomach of a Middle Triassic ichthyosaur (∼5 m). The predator has grasping teeth yet swallowed the body trunk of the prey in one to several pieces. There were many more Mesozoic marine reptiles with similar grasping teeth, so megafaunal predation was likely more widespread than presently conceived. Megafaunal predation probably started nearly simultaneously in multiple lineages of marine reptiles in the Illyrian (about 242-243 million years ago).
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Affiliation(s)
- Da-Yong Jiang
- Laboratory of Orogenic Belt and Crustal Evolution, Ministry of Education; Department of Geology and Geological Museum, School of Earth and Space Sciences, Peking University, Yiheyuan Street. 5, Beijing 100871, People's Republic of China
| | - Ryosuke Motani
- Department of Earth and Planetary Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Andrea Tintori
- Dipartimento di Scienze della Terra, Università degli Studi di Milano, Via Mangiagalli, 34-20133 Milano, Italy
| | - Olivier Rieppel
- Integrative Research Center, The Field Museum, Chicago, IL 60605-2496, USA
| | - Cheng Ji
- Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Beijing East Road 39, Nanjing, Jiangsu 210008, People's Republic of China
| | - Min Zhou
- Laboratory of Orogenic Belt and Crustal Evolution, Ministry of Education; Department of Geology and Geological Museum, School of Earth and Space Sciences, Peking University, Yiheyuan Street. 5, Beijing 100871, People's Republic of China
| | - Xue Wang
- Laboratory of Orogenic Belt and Crustal Evolution, Ministry of Education; Department of Geology and Geological Museum, School of Earth and Space Sciences, Peking University, Yiheyuan Street. 5, Beijing 100871, People's Republic of China
| | - Hao Lu
- Laboratory of Orogenic Belt and Crustal Evolution, Ministry of Education; Department of Geology and Geological Museum, School of Earth and Space Sciences, Peking University, Yiheyuan Street. 5, Beijing 100871, People's Republic of China
| | - Zhi-Guang Li
- The Geoscience Museum, Hebei GEO University, No. 136 East Huai'an Road, Shijiazhuang, Hebei 050031, People's Republic of China
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