1
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van Neer A, Nachtsheim D, Siebert U, Taupp T. Movements and spatial usage of harbour seals in the Elbe estuary in Germany. Sci Rep 2023; 13:6630. [PMID: 37095305 PMCID: PMC10125962 DOI: 10.1038/s41598-023-33594-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 04/15/2023] [Indexed: 04/26/2023] Open
Abstract
Harbour seals are top predators in the North Sea and regarded as sentinels for ecosystem health. A few hundred also occur in adjacent estuaries, such as the Elbe estuary, Germany. However, only little is known about how these animals use this dynamic tidally influenced habitat, which has been under high anthropogenic pressure for decades. In this context, nine harbour seals (Phoca vitulina) from the Elbe estuary were equipped with biotelemetry devices to track their movements over multiple months. Harbour seal movements were characterised by short trips (trip length outside pupping season for females: 9.0 ± 1.12 km, males: 7.0 ± 1.24 km) as well as small home ranges (median 50% home range for females: 16.3 km2, males: 36.1 km2) compared to harbour seals from marine regions. Within the estuary, the animals utilised the fairway, river branches and tributaries. During the pupping season in June and July, four seals showed strongly reduced trip lengths and durations, increased daily haul out durations as well as smaller home ranges. Even though a continuous exchange with harbour seals from the Wadden Sea likely occurs, most individuals in this study spent the entire deployment duration inside the estuary. This indicates that the Elbe estuary provides a suitable habitat for harbour seals, despite extensive anthropogenic usage, calling for further studies on the consequences of living in such an industrialised habitat.
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Affiliation(s)
- Abbo van Neer
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany
| | - Dominik Nachtsheim
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany.
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany
| | - Thomas Taupp
- Department of Animal Ecology, Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068, Koblenz, Germany
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2
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Nachtsheim DA, Johnson M, Schaffeld T, van Neer A, Madsen PT, Findlay CR, Rojano-Doñate L, Teilmann J, Mikkelsen L, Baltzer J, Ruser A, Siebert U, Schnitzler JG. Vessel noise exposures of harbour seals from the Wadden Sea. Sci Rep 2023; 13:6187. [PMID: 37061560 PMCID: PMC10105764 DOI: 10.1038/s41598-023-33283-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 04/11/2023] [Indexed: 04/17/2023] Open
Abstract
The North Sea faces intense ship traffic owing to increasing human activities at sea. As harbour seals (Phoca vitulina) are abundant top predators in the North Sea, it is hypothesised that they experience repeated, high-amplitude vessel exposures. Here, we test this hypothesis by quantifying vessel noise exposures from deployments of long-term sound and movement tags (DTAGs) on nine harbour seals from the Wadden Sea. An automated tool was developed to detect intervals of elevated noise in the sound recordings. An assessment by multiple raters was performed to classify the source as either vessels or other sounds. A total of 133 vessel passes were identified with received levels > 97 dB re 1µPa RMS in the 2 kHz decidecade band and with ambient noise > 6 dB below this detection threshold. Tagged seals spent most of their time within Marine Protected Areas (89 ± 13%, mean ± SD) and were exposed to high-amplitude vessel passes 4.3 ± 1.6 times per day. Only 32% of vessel passes were plausibly associated with an AIS-registered vessel. We conclude that seals in industrialized waters are exposed repeatedly to vessel noise, even in areas designated as protected, and that exposures are poorly predicted by AIS data.
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Affiliation(s)
- Dominik André Nachtsheim
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany.
| | - Mark Johnson
- Aarhus Institute of Advanced Studies, Aarhus University, 8000, Aarhus, Denmark
- Zoophysiology, Department of Biology, Aarhus University, 8000, Aarhus, Denmark
| | - Tobias Schaffeld
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany
| | - Abbo van Neer
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany
| | - Peter T Madsen
- Zoophysiology, Department of Biology, Aarhus University, 8000, Aarhus, Denmark
| | - Charlotte R Findlay
- Zoophysiology, Department of Biology, Aarhus University, 8000, Aarhus, Denmark
| | - Laia Rojano-Doñate
- Zoophysiology, Department of Biology, Aarhus University, 8000, Aarhus, Denmark
- Marine Mammal Research, Department of Ecoscience, Aarhus University, 4000, Roskilde, Denmark
| | - Jonas Teilmann
- Marine Mammal Research, Department of Ecoscience, Aarhus University, 4000, Roskilde, Denmark
| | - Lonnie Mikkelsen
- Marine Mammal Research, Department of Ecoscience, Aarhus University, 4000, Roskilde, Denmark
- Norwegian Polar Institute, Fram Centre, 9296, Tromsö, Norway
| | - Johannes Baltzer
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany
| | - Andreas Ruser
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany
| | - Joseph G Schnitzler
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761, Büsum, Germany
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3
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Booth CG, Guilpin M, Darias-O’Hara AK, Ransijn JM, Ryder M, Rosen D, Pirotta E, Smout S, McHuron EA, Nabe-Nielsen J, Costa DP. Estimating energetic intake for marine mammal bioenergetic models. CONSERVATION PHYSIOLOGY 2023; 11:coac083. [PMID: 36756464 PMCID: PMC9900471 DOI: 10.1093/conphys/coac083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 11/08/2022] [Accepted: 12/21/2022] [Indexed: 06/18/2023]
Abstract
Bioenergetics is the study of how animals achieve energetic balance. Energetic balance results from the energetic expenditure of an individual and the energy they extract from their environment. Ingested energy depends on several extrinsic (e.g prey species, nutritional value and composition, prey density and availability) and intrinsic factors (e.g. foraging effort, success at catching prey, digestive processes and associated energy losses, and digestive capacity). While the focus in bioenergetic modelling is often on the energetic costs an animal incurs, the robust estimation of an individual's energy intake is equally critical for producing meaningful predictions. Here, we review the components and processes that affect energy intake from ingested gross energy to biologically useful net energy (NE). The current state of knowledge of each parameter is reviewed, shedding light on research gaps to advance this field. The review highlighted that the foraging behaviour of many marine mammals is relatively well studied via biologging tags, with estimates of success rate typically assumed for most species. However, actual prey capture success rates are often only assumed, although we note studies that provide approaches for its estimation using current techniques. A comprehensive collation of the nutritional content of marine mammal prey species revealed a robust foundation from which prey quality (comprising prey species, size and energy density) can be assessed, though data remain unavailable for many prey species. Empirical information on various energy losses following ingestion of prey was unbalanced among marine mammal species, with considerably more literature available for pinnipeds. An increased understanding and accurate estimate of each of the components that comprise a species NE intake are an integral part of bioenergetics. Such models provide a key tool to investigate the effects of disturbance on marine mammals at an individual and population level and to support effective conservation and management.
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Affiliation(s)
- Cormac G Booth
- Corresponding author: SMRU Consulting, Scottish Oceans Institute, University of St Andrews, East Sands, St Andrews, KY16 8LB, UK.
| | | | - Aimee-Kate Darias-O’Hara
- SMRU Consulting, Scottish Oceans Institute, University of St Andrews, East Sands, St Andrews, KY16 8LB, UK
| | - Janneke M Ransijn
- Sea Mammal Research Unit, Scottish Oceans Institute, East Sands, University of St. Andrews, St. Andrews, KY16 8LB, UK
| | - Megan Ryder
- SMRU Consulting, Scottish Oceans Institute, University of St Andrews, East Sands, St Andrews, KY16 8LB, UK
| | - Dave Rosen
- Institute for the Oceans and Fisheries, University of British Columbia, 2202 Main Mall,
Vancouver, BC V6T 1Z4, Canada
| | - Enrico Pirotta
- Centre for Research into Ecological and Environmental Modelling,
The Observatory, Buchanan
Gardens, University of St. Andrews, St. Andrews,
KY16 9LZ, UK
| | - Sophie Smout
- Sea Mammal Research Unit, Scottish Oceans Institute, East Sands, University of St. Andrews, St. Andrews, KY16 8LB, UK
| | - Elizabeth A McHuron
- Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington, 3737 Brooklyn Ave NE, Seattle, WA, 98105, USA
| | - Jacob Nabe-Nielsen
- Marine Mammal Research, Department of Ecoscience, Aarhus University, Aarhus, DK-4000
Roskilde, Denmark
| | - Daniel P Costa
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, 130
McAlister Way, Santa Cruz, CA, 95064, USA
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4
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Boyi JO, Heße E, Rohner S, Säurich J, Siebert U, Gilles A, Lehnert K. Deciphering Eurasian otter (
Lutra lutra
L.) and seal (
Phoca vitulina
L.;
Halichoerus grypus
F.) diet: metabarcoding tailored for fresh and saltwater fish species. Mol Ecol 2022; 31:5089-5106. [DOI: 10.1111/mec.16635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 07/13/2022] [Accepted: 07/25/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Joy Ometere Boyi
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
| | - Eileen Heße
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
| | - Simon Rohner
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
| | - Josefin Säurich
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Foundation Hannover Germany
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
| | - Anita Gilles
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
| | - Kristina Lehnert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation Büsum Germany
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5
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Patterson A, Gilchrist HG, Benjaminsen S, Bolton M, Bonnet-Lebrun AS, Davoren GK, Descamps S, Erikstad KE, Frederiksen M, Gaston AJ, Gulka J, Hentati-Sundberg J, Huffeldt NP, Johansen KL, Labansen AL, Linnebjerg JF, Love OP, Mallory ML, Merkel FR, Montevecchi WA, Mosbech A, Olsson O, Owen E, Ratcliffe N, Regular PM, Reiertsen TK, Ropert-Coudert Y, Strøm H, Thórarinsson TL, Elliott KH. Foraging range scales with colony size in high-latitude seabirds. Curr Biol 2022; 32:3800-3807.e3. [PMID: 35870447 DOI: 10.1016/j.cub.2022.06.084] [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] [Received: 09/21/2021] [Revised: 02/26/2022] [Accepted: 06/28/2022] [Indexed: 11/28/2022]
Abstract
Density-dependent prey depletion around breeding colonies has long been considered an important factor controlling the population dynamics of colonial animals.1-4 Ashmole proposed that as seabird colony size increases, intraspecific competition leads to declines in reproductive success, as breeding adults must spend more time and energy to find prey farther from the colony.1 Seabird colony size often varies over several orders of magnitude within the same species and can include millions of individuals per colony.5,6 As such, colony size likely plays an important role in determining the individual behavior of its members and how the colony interacts with the surrounding environment.6 Using tracking data from murres (Uria spp.), the world's most densely breeding seabirds, we show that the distribution of foraging-trip distances scales to colony size0.33 during the chick-rearing stage, consistent with Ashmole's halo theory.1,2 This pattern occurred across colonies varying in size over three orders of magnitude and distributed throughout the North Atlantic region. The strong relationship between colony size and foraging range means that the foraging areas of some colonial species can be estimated from colony sizes, which is more practical to measure over a large geographic scale. Two-thirds of the North Atlantic murre population breed at the 16 largest colonies; by extrapolating the predicted foraging ranges to sites without tracking data, we show that only two of these large colonies have significant coverage as marine protected areas. Our results are an important example of how theoretical models, in this case, Ashmole's version of central-place-foraging theory, can be applied to inform conservation and management in colonial breeding species.
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Affiliation(s)
- Allison Patterson
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Boulevard, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada.
| | - H Grant Gilchrist
- National Wildlife Research Centre, Environment and Climate Change Canada, Ottawa, ON, Canada
| | - Sigurd Benjaminsen
- Norwegian Institute for Nature Research, Fram Centre, 9296 Tromsø, Norway
| | - Mark Bolton
- RSPB Centre for Conservation Science, Royal Society for the Protection of Birds, Sandy, UK
| | | | - Gail K Davoren
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Sébastien Descamps
- Norwegian Polar Institute, Fram Centre, PO Box 6606 Langnes, 9296 Tromsø, Norway
| | - Kjell Einar Erikstad
- Norwegian Institute for Nature Research, Fram Centre, 9296 Tromsø, Norway; Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Morten Frederiksen
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Anthony J Gaston
- Laskeek Bay Conservation Society, Queen Charlotte, PO Box 867, Queen Charlotte, BC V0T 1S0, Canada
| | - Julia Gulka
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Jonas Hentati-Sundberg
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - Nicholas Per Huffeldt
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Greenland Institute of Natural Resources, Kivioq 2, 3900 Nuuk, Greenland
| | | | - Aili Lage Labansen
- Greenland Institute of Natural Resources, Kivioq 2, 3900 Nuuk, Greenland
| | | | - Oliver P Love
- Department of Integrative Biology, University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada
| | - Mark L Mallory
- Biology, Acadia University, 15 University Avenue, Wolfville, NS B4P 2R6, Canada
| | - Flemming Ravn Merkel
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - William A Montevecchi
- Psychology and Biology Departments, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Anders Mosbech
- Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Olof Olsson
- Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden
| | - Ellie Owen
- RSPB Centre for Conservation Science, Royal Society for the Protection of Birds, Sandy, UK
| | - Norman Ratcliffe
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, UK
| | - Paul M Regular
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | | | - Yan Ropert-Coudert
- Centre d'Etudes Biologiques de Chizé, CNRS - La Rochelle Université, Villiers-en-Bois, France
| | - Hallvard Strøm
- Norwegian Polar Institute, Fram Centre, PO Box 6606 Langnes, 9296 Tromsø, Norway
| | | | - Kyle H Elliott
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Boulevard, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada
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6
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Iorio-Merlo V, Graham IM, Hewitt RC, Aarts G, Pirotta E, Hastie GD, Thompson PM. Prey encounters and spatial memory influence use of foraging patches in a marine central place forager. Proc Biol Sci 2022; 289:20212261. [PMID: 35232237 PMCID: PMC8889173 DOI: 10.1098/rspb.2021.2261] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Given the patchiness and long-term predictability of marine resources, memory of high-quality foraging grounds is expected to provide fitness advantages for central place foragers. However, it remains challenging to characterize how marine predators integrate memory with recent prey encounters to adjust fine-scale movement and use of foraging patches. Here, we used two months of movement data from harbour seals (Phoca vitulina) to quantify the repeatability in foraging patches as a proxy for memory. We then integrated these data into analyses of fine-scale movement and underwater behaviour to test how both spatial memory and prey encounter rates influenced the seals' area-restricted search (ARS) behaviour. Specifically, we used one month's GPS data from 29 individuals to build spatial memory maps of searched areas and archived accelerometery data from a subset of five individuals to detect prey catch attempts, a proxy for prey encounters. Individuals were highly consistent in the areas they visited over two consecutive months. Hidden Markov models showed that both spatial memory and prey encounters increased the probability of seals initiating ARS. These results provide evidence that predators use memory to adjust their fine-scale movement, and this ability should be accounted for in movement models.
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Affiliation(s)
- Virginia Iorio-Merlo
- School of Biological Sciences, Lighthouse Field Station, University of Aberdeen, Cromarty, Ross-shire IV11 8YJ, UK
| | - Isla M Graham
- School of Biological Sciences, Lighthouse Field Station, University of Aberdeen, Cromarty, Ross-shire IV11 8YJ, UK
| | - Rebecca C Hewitt
- School of Biological Sciences, Lighthouse Field Station, University of Aberdeen, Cromarty, Ross-shire IV11 8YJ, UK
| | - Geert Aarts
- Wildlife Ecology and Conservation Group and Wageningen Marine Research, Wageningen University and Research, Ankerpark 27, 1781 AG Den Helder, The Netherlands.,Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands
| | - Enrico Pirotta
- Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, Fife KY16 9LZ, UK.,School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - Gordon D Hastie
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife KY16 8LB, UK
| | - Paul M Thompson
- School of Biological Sciences, Lighthouse Field Station, University of Aberdeen, Cromarty, Ross-shire IV11 8YJ, UK
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7
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Philipp C, Unger B, Siebert U. Occurrence of Microplastics in Harbour Seals ( Phoca vitulina) and Grey Seals ( Halichoerus grypus) from German Waters. Animals (Basel) 2022; 12:ani12050551. [PMID: 35268122 PMCID: PMC8908825 DOI: 10.3390/ani12050551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 11/21/2022] Open
Abstract
The level of knowledge on microplastic exposure in marine mammals is limited by the access to dead and alive individuals. Focusing on the Northeast Atlantic area, some studies already confirmed the microplastic presence in free-ranging marine mammals, such as harbour porpoises or harbour seals inhabiting the North Sea (NS). In contrast, knowledge on the exposure to grey seals and particularly on specimen inhabiting the Baltic Sea (BS) are scarce. This study examined 63 gastrointestinal tracts (GIT) of harbour seals and grey seals originating from German waters (NS and BS) found between 2014 and 2019. Besides the documentation of microplastic findings, this study is dealing with life history and health parameters, attempting to identify correlations with microplastic presence. This study confirmed beside the presence, the egestion of microplastics (>100 µm; MPs) in the examined seals, without correlations in parasite infestations or inflammation responses. 540 suspected MPs were identified in 62 intestinal samples (42% fibres, 58% fragments), and 228 MPs in seven stomachs (28% fibres, 72% fragments). In accordance, first evidence of the retainment of fragments in the GIT were given. However, no significant difference in MP occurrence was indicated for different sex or age groups.
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8
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Maaß E, Hanke FD. How harbour seals (Phoca vitulina) encode goals relative to landmarks. J Exp Biol 2022; 225:274185. [DOI: 10.1242/jeb.243870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/24/2022] [Indexed: 11/20/2022]
Abstract
Visual landmarks are defined as object with prominent shape or size that distinguish themselves from the background. With the help of landmarks, animals can orient themselves in their natural environment. Yet, the way in which landmarks are perceived and encoded has previously only been described in insects, fish, birds, reptilians and terrestrial mammals. The present study aimed to provide insight into how a marine mammal, the harbour seal, is encoding goals relative to landmarks. In our expansion test, three harbour seals were trained to find a goal inside an array of landmarks. After diagonal, horizontal or vertical expansion of the landmark array, the search behaviour displayed by the animals was documented and analyzed regarding the underlying encoding strategy. The harbour seals mainly encoded directional vector information from landmarks and did neither search arbitrarily around a landmark nor used a rule-based approach. Depending on the number of landmarks available within the array, the search behaviour of some harbor seals changed, indicating flexibility in landmark-based search. Our results present first insight in how a semi-aquatic predator could encode landmark information when swimming along the coastline in search for a goal-location.
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Affiliation(s)
- Eric Maaß
- University of Rostock, Institute for Biosciences, Neuroethology, Albert-Einstein-Str. 3, 18059 Rostock, Germany
| | - Frederike D. Hanke
- University of Rostock, Institute for Biosciences, Neuroethology, Albert-Einstein-Str. 3, 18059 Rostock, Germany
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