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Shabangu FW, Daniels R, Jordaan RK, de Bruyn PJN, van den Berg MA, Lamont T. Killer whale acoustic patterns respond to prey abundance and environmental variability around the Prince Edward Islands, Southern Ocean. ROYAL SOCIETY OPEN SCIENCE 2024; 11:230903. [PMID: 38179079 PMCID: PMC10762440 DOI: 10.1098/rsos.230903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 12/01/2023] [Indexed: 01/06/2024]
Abstract
Killer whales are apex predators with temporally and spatially varying distributions throughout the world's oceans. Their ecology and behaviour are poorly understood in most regions due to limited research, often because of logistical challenges. Here, we used a passive acoustic monitoring device to investigate the seasonal acoustic occurrence and diel vocalizing behaviour of killer whales around the remote sub-Antarctic Prince Edward Islands (PEIs), Southern Ocean. Killer whales showed diel vocalizing patterns that varied seasonally in relation to their prey abundance and social activities. Killer whale calls were intermittently detected year-round with a high number of hours containing calls in October to December, and a secondary peak in February to May, corresponding to seal prey abundance. Random forest modelling identified wind speed as the primary predictor of the occurrence of killer whale calls (with a negative correlation) while sea surface height, chlorophyll-a and sea surface temperature were moderately important. We provide the first acoustic evidence that killer whale occurrence around the PEIs might coincide with variability in environmental conditions and prey abundance. Our results provide the first indication of diel vocalizing pattern of killer whales in the Southern Ocean. This knowledge is important for understanding killer whale ecology and adaptation to the changing oceans.
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Affiliation(s)
- Fannie W. Shabangu
- Fisheries Management Branch, Department of Forestry, Fisheries and the Environment, Foreshore, Cape Town, South Africa
- Mammal Research Institute, University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa
| | - Robyn Daniels
- Department of Oceanography, University of Cape Town, Cape Town, South Africa
| | - Rowan K. Jordaan
- Mammal Research Institute, University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa
| | - P. J. Nico de Bruyn
- Mammal Research Institute, University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa
| | - Marcel A. van den Berg
- Oceans and Coasts Research Branch, Department of Forestry, Fisheries and the Environment, Foreshore, Cape Town, South Africa
| | - Tarron Lamont
- Department of Oceanography, University of Cape Town, Cape Town, South Africa
- Nansen–Tutu Centre for Marine Environmental Research, University of Cape Town, Cape Town, South Africa
- Oceans and Coasts Research Branch, Department of Forestry, Fisheries and the Environment, Foreshore, Cape Town, South Africa
- Bayworld Centre for Research and Education, Cape Town, South Africa
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Jouma'a J, Orgeret F, Picard B, Robinson PW, Weimerskirch H, Guinet C, Costa DP, Beltran RS. Contrasting offspring dependence periods and diving development rates in two closely related marine mammal species. ROYAL SOCIETY OPEN SCIENCE 2024; 11:230666. [PMID: 38179081 PMCID: PMC10762441 DOI: 10.1098/rsos.230666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 11/23/2023] [Indexed: 01/06/2024]
Abstract
Understanding the ontogeny of diving behaviour in marine megafauna is crucial owing to its influence on foraging success, energy budgets, and mortality. We compared the ontogeny of diving behaviour in two closely related species-northern elephant seals (Mirounga angustirostris, n = 4) and southern elephant seals (Mirounga leonina, n = 9)-to shed light on the ecological processes underlying migration. Although both species have similar sizes and behaviours as adults, we discovered that juvenile northern elephant seals have superior diving development, reaching 260 m diving depth in just 30 days, while southern elephant seals require 160 days. Similarly, northern elephant seals achieve dive durations of approximately 11 min on their first day of migration, while southern elephant seals take 125 days. The faster physiological maturation of northern elephant seals could be related to longer offspring dependency and post-weaning fast durations, allowing them to develop their endogenous oxygen stores. Comparison across both species suggests that weaned seal pups face a trade-off between leaving early with higher energy stores but poorer physiological abilities or leaving later with improved physiology but reduced fat stores. This trade-off might be influenced by their evolutionary history, which shapes their migration behaviours in changing environments over time.
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Affiliation(s)
- Joffrey Jouma'a
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
| | - Florian Orgeret
- Marine Apex Predator Research Unit, Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Gqeberha 6031, South Africa
| | - Baptiste Picard
- Centre d'Etudes Biologiques de Chizé, UMR 7372 La Rochelle University-CNRS, La Rochelle, France
| | - Patrick W. Robinson
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
| | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé, UMR 7372 La Rochelle University-CNRS, La Rochelle, France
| | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé, UMR 7372 La Rochelle University-CNRS, La Rochelle, France
| | - Daniel P. Costa
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, CA, USA
| | - Roxanne S. Beltran
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
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Jordaan RK, Oosthuizen WC, Reisinger RR, de Bruyn PJN. The effect of prey abundance and fisheries on the survival, reproduction, and social structure of killer whales ( Orcinus orca) at subantarctic Marion Island. Ecol Evol 2023; 13:e10144. [PMID: 37284666 PMCID: PMC10239896 DOI: 10.1002/ece3.10144] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/08/2023] [Accepted: 05/15/2023] [Indexed: 06/08/2023] Open
Abstract
Most marine apex predators are keystone species that fundamentally influence their ecosystems through cascading top-down processes. Reductions in worldwide predator abundances, attributed to environmental- and anthropogenic-induced changes to prey availability and negative interactions with fisheries, can have far-reaching ecosystem impacts. We tested whether the survival of killer whales (Orcinus orca) observed at Marion Island in the Southern Indian Ocean correlated with social structure and prey variables (direct measures of prey abundance, Patagonian toothfish fishery effort, and environmental proxies) using multistate models of capture-recapture data spanning 12 years (2006-2018). We also tested the effect of these same variables on killer whale social structure and reproduction measured over the same period. Indices of social structure had the strongest correlation with survival, with higher sociality associated with increased survival probability. Survival was also positively correlated with Patagonian toothfish fishing effort during the previous year, suggesting that fishery-linked resource availability is an important determinant of survival. No correlation between survival and environmental proxies of prey abundance was found. At-island prey availability influenced the social structure of Marion Island killer whales, but none of the variables explained variability in reproduction. Future increases in legal fishing activity may benefit this population of killer whales through the artificial provisioning of resources they provide.
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Affiliation(s)
- Rowan K. Jordaan
- Mammal Research Institute, Department of Zoology and EntomologyUniversity of PretoriaPretoriaSouth Africa
| | - W. Chris Oosthuizen
- Centre for Statistics in Ecology, the Environment (SEEC)University of Cape TownCape TownSouth Africa
| | - Ryan R. Reisinger
- Ocean and Earth ScienceUniversity of Southampton, National Oceanography Centre SouthamptonSouthamptonUK
| | - P. J. Nico de Bruyn
- Mammal Research Institute, Department of Zoology and EntomologyUniversity of PretoriaPretoriaSouth Africa
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Jordaan RK, Reisinger RR, Oosthuizen WC, de Bruyn PN. Seasonal fission and fusion of killer whale, Orcinus orca, social structure at sub-Antarctic Marion Island. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Jordaan RK, Oosthuizen WC, Reisinger RR, Nico De Bruyn PJ. Abundance, survival and population growth of killer whales Orcinus orca at subantarctic Marion Island. WILDLIFE BIOLOGY 2020. [DOI: 10.2981/wlb.00732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
| | | | - Ryan R. Reisinger
- R. R. Reisinger (https://orcid.org/0000-0002-8933-6875), Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS-La Rochelle Univ., Villiers-en-Bois, France, and: Inst. of Marine Sciences, Univ. of California Santa Cruz, Santa Cruz, California, US
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Morphometric Characterization of the Lidia Cattle Breed. Animals (Basel) 2020; 10:ani10071180. [PMID: 32668614 PMCID: PMC7401559 DOI: 10.3390/ani10071180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 11/17/2022] Open
Abstract
Simple Summary The Lidia breed has great economic and social importance and is one of the most interesting breeds worldwide from a genetic point of view. The economic, social, and genetic impact has not been reflected in zootechnical studies carried out on it because the difficulty of handling and approaching of this type of animal makes measurement of live individuals almost impossible. For this reason, the first morphological characterization of Lidia breed was carried out using photogrammetry. This technology facilitates measurements of animals at a distance from 3-dimensional photographs. In the present work, 264 adult individuals (males and females) were studied to determine 20 morphological measurements, 5 zootechnical indexes, and individual phaneroptic information. The results show a considerable internal variability, sexual dimorphism, and the zoomometric differentiation of various genetic lines, thus improving value and complexity of this breed. Abstract Morphometric studies in Lidia cattle are scarce due to the challenges of handling and approaching this breed of cattle. For this reason, the first morphological characterization of the Lidia breed was carried out using photogrammetry. In the present work, 264 adult individuals (184 males and 80 females), belonging to 21 different herds, were studied. A total of 20 morphological measurements and five indexes were determined in every individual. There were many positive correlations between the measures, giving the model great morphostructural harmony. Considerable internal variability of the studied parameters was observed. This breed reflected significant sexually dimorphic features and internal morphological differences between the different genetic lines of the breed. Lidia cattle are small and mostly have a sub-concave profile (58.4% males and 69.7% females). The male proportionality indexes and the relative depth of the thorax indicated great muscular development of the anterior third and high thoracic capacity. The phaneroptic information describes a mostly black animal with black mucous and hooves and an outstanding development of the dewlaps and the tail in the males.
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Aspects of the ecology of killer whale (Orcinus orca Linn.) groups in the near-shore waters of Sub-Antarctic Macquarie Island. Polar Biol 2018. [DOI: 10.1007/s00300-018-2361-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Postma M, Tordiffe ASW, Hofmeyr MS, Reisinger RR, Bester LC, Buss PE, de Bruyn PJN. Terrestrial mammal three-dimensional photogrammetry: multispecies mass estimation. Ecosphere 2015. [DOI: 10.1890/es15-00368.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Reisinger RR, Oosthuizen WC, Péron G, Cory Toussaint D, Andrews RD, de Bruyn PJN. Satellite tagging and biopsy sampling of killer whales at subantarctic Marion Island: effectiveness, immediate reactions and long-term responses. PLoS One 2014; 9:e111835. [PMID: 25375329 PMCID: PMC4222950 DOI: 10.1371/journal.pone.0111835] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 10/01/2014] [Indexed: 11/19/2022] Open
Abstract
Remote tissue biopsy sampling and satellite tagging are becoming widely used in large marine vertebrate studies because they allow the collection of a diverse suite of otherwise difficult-to-obtain data which are critical in understanding the ecology of these species and to their conservation and management. Researchers must carefully consider their methods not only from an animal welfare perspective, but also to ensure the scientific rigour and validity of their results. We report methods for shore-based, remote biopsy sampling and satellite tagging of killer whales Orcinus orca at Subantarctic Marion Island. The performance of these methods is critically assessed using 1) the attachment duration of low-impact minimally percutaneous satellite tags; 2) the immediate behavioural reactions of animals to biopsy sampling and satellite tagging; 3) the effect of researcher experience on biopsy sampling and satellite tagging; and 4) the mid- (1 month) and long- (24 month) term behavioural consequences. To study mid- and long-term behavioural changes we used multievent capture-recapture models that accommodate imperfect detection and individual heterogeneity. We made 72 biopsy sampling attempts (resulting in 32 tissue samples) and 37 satellite tagging attempts (deploying 19 tags). Biopsy sampling success rates were low (43%), but tagging rates were high with improved tag designs (86%). The improved tags remained attached for 26±14 days (mean ± SD). Individuals most often showed no reaction when attempts missed (66%) and a slight reaction–defined as a slight flinch, slight shake, short acceleration, or immediate dive–when hit (54%). Severe immediate reactions were never observed. Hit or miss and age-sex class were important predictors of the reaction, but the method (tag or biopsy) was unimportant. Multievent trap-dependence modelling revealed considerable variation in individual sighting patterns; however, there were no significant mid- or long-term changes following biopsy sampling or tagging.
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Affiliation(s)
- Ryan R. Reisinger
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- * E-mail:
| | - W. Chris Oosthuizen
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Guillaume Péron
- Centre for Statistics in Ecology, Environment and Conservation, Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa
| | - Dawn Cory Toussaint
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Russel D. Andrews
- School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
- Alaska SeaLife Center, Seward, Alaska, United States of America
| | - P. J. Nico de Bruyn
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
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“Photozoometer”: A new photogrammetric system for obtaining morphometric measurements of elusive animals. Livest Sci 2014. [DOI: 10.1016/j.livsci.2014.03.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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de Bruyn PJN, Tosh CA, Terauds A. Killer whale ecotypes: is there a global model? Biol Rev Camb Philos Soc 2012; 88:62-80. [DOI: 10.1111/j.1469-185x.2012.00239.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Killer whale predation on subantarctic fur seals at Prince Edward Island, Southern Indian Ocean. Polar Biol 2012. [DOI: 10.1007/s00300-012-1216-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Reisinger RR, de Bruyn PJN, Bester MN. Predatory impact of killer whales on pinniped and penguin populations at the Subantarctic Prince Edward Islands: fact and fiction. J Zool (1987) 2011. [DOI: 10.1111/j.1469-7998.2011.00815.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Postma M, Wege M, Bester M, van der Merwe D, Bruyn PD. Inshore Occurrence of Southern Right Whales ( Eubalaena australis) at Subantarctic Marion Island. AFRICAN ZOOLOGY 2011. [DOI: 10.3377/004.046.0112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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McMahon CR, Bester MN, Hindell MA, Brook BW, Bradshaw CJA. Shifting trends: detecting environmentally mediated regulation in long-lived marine vertebrates using time-series data. Oecologia 2008; 159:69-82. [PMID: 18987892 DOI: 10.1007/s00442-008-1205-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Accepted: 10/07/2008] [Indexed: 11/30/2022]
Abstract
Assessing the status and trends in animal populations is essential for effective species conservation and management practices. However, unless time-series abundance data demonstrate rapid and reliable fluctuations, objective appraisal of directionality of trends is problematic. We adopted a multiple-working hypotheses approach based on information-theoretic and Bayesian multi-model inference to examine the population trends and form of intrinsic regulation demonstrated by a long-lived species, the southern elephant seal. We also determined the evidence for density dependence in 11 other well-studied marine mammal species. (1) We tested the type of population regulation for elephant seals from Marion Island (1986-2004) and from 11 other marine mammal species, and (2) we described the trends and behavior of the 19-year population time series at Marion Island to identify changes in population trends. We contrasted five plausible trend models using information-theoretic and Bayesian-inference estimates of model parsimony. Our analyses identified two distinct phases of population growth for this population with the inflexion occurring in 1998. Thus, the population decreased between 1986 and 1997 (-3.7% per annum) and increased between 1997 and 2004 (1.9% per annum). An index of environmental stochasticity, the Southern Oscillation Index, explained some of the variance in r and N. We determined analytically that there was good evidence for density dependence in the Marion Island population and that density dependence was widespread among marine mammal species (67% of species showed evidence for population regulation). This approach demonstrates the potential functionality of a relatively simple technique that can be applied to short time series to identify the type of regulation, and the uncertainty associated with the phenomenon, operating in populations of large mammals.
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Affiliation(s)
- Clive R McMahon
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, Gauteng, Republic of South Africa.
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Bester MN, de Clercq H, Hofmeyr GJG, de Bruyn PJN. Leucistic southern elephant seal at Marion Island? Polar Biol 2007. [DOI: 10.1007/s00300-007-0380-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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