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Barceló G, Perrig PL, Dharampal P, Donadio E, Steffan SA, Pauli JN. More than just meat: Carcass decomposition shapes trophic identities in a terrestrial vertebrate. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gonzalo Barceló
- Department of Forest and Wildlife Ecology University of Wisconsin‐Madison Madison WI USA
| | - Paula L. Perrig
- Department of Forest and Wildlife Ecology University of Wisconsin‐Madison Madison WI USA
- Grupo de Investigaciones en Biología de la Conservación INIBIOMA (Universidad Nacional del Comahue ‐ CONICET) Bariloche Argentina
| | | | | | - Shawn A. Steffan
- Department of Entomology University of Wisconsin‐Madison Madison WI USA
- USDA‐ARS Vegetable Crop Research Unit Madison WI USA
| | - Jonathan N. Pauli
- Department of Forest and Wildlife Ecology University of Wisconsin‐Madison Madison WI USA
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2
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Williams CL, Hindle AG. Field Physiology: Studying Organismal Function in the Natural Environment. Compr Physiol 2021; 11:1979-2015. [PMID: 34190338 DOI: 10.1002/cphy.c200005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Continuous physiological measurements collected in field settings are essential to understand baseline, free-ranging physiology, physiological range and variability, and the physiological responses of organisms to disturbances. This article presents a current summary of the available technologies to continuously measure the direct physiological parameters in the field at high-resolution/instantaneous timescales from freely behaving animals. There is a particular focus on advantages versus disadvantages of available methods as well as emerging technologies "on the horizon" that may have been validated in captive or laboratory-based scenarios but have yet to be applied in the wild. Systems to record physiological variables from free-ranging animals are reviewed, including radio (VHF/UFH) telemetry, acoustic telemetry, and dataloggers. Physiological parameters that have been continuously measured in the field are addressed in seven sections including heart rate and electrocardiography (ECG); electromyography (EMG); electroencephalography (EEG); body temperature; respiratory, blood, and muscle oxygen; gastric pH and motility; and blood pressure and flow. The primary focal sections are heart rate and temperature as these can be, and have been, extensively studied in free-ranging organisms. Predicted aspects of future innovation in physiological monitoring are also discussed. The article concludes with an overview of best practices and points to consider regarding experimental designs, cautions, and effects on animals. © 2021 American Physiological Society. Compr Physiol 11:1979-2015, 2021.
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Affiliation(s)
- Cassondra L Williams
- National Marine Mammal Foundation, San Diego, California, USA.,Department of Ecology and Evolutionary Biology, School of Biological Science, University of California Irvine, Irvine, California, USA
| | - Allyson G Hindle
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, Nevada, USA
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Orgeret F, Reisinger RR, Carpenter-Kling T, Keys DZ, Corbeau A, Bost CA, Weimerskirch H, Pistorius PA. Spatial segregation in a sexually dimorphic central place forager: Competitive exclusion or niche divergence? J Anim Ecol 2021; 90:2404-2420. [PMID: 34091891 DOI: 10.1111/1365-2656.13552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 05/29/2021] [Indexed: 12/11/2022]
Abstract
Sexual competition is increasingly recognized as an important selective pressure driving species distributions. However, few studies have investigated the relative importance of interpopulation versus intrapopulation competition in relation to habitat availability and selection. To explain spatial segregation between sexes that often occurs in non-territorial and central place foragers, such as seabirds, two hypotheses are commonly used. The 'competitive exclusion' hypothesis states that dominant individuals should exclude subordinate individuals through direct competition, whereas the 'niche divergence' hypothesis states that segregation occurs due to past competition and habitat specialization. We tested these hypotheses in two populations of an extreme wide-ranging and sexually dimorphic seabird, investigating the relative role of intrapopulation and interpopulation competition in influencing sex-specific distribution and habitat preferences. Using GPS loggers, we tracked 192 wandering albatrosses Diomedea exulans during four consecutive years (2016-2019), from two neighbouring populations in the Southern Ocean (Prince Edward and Crozet archipelagos). We simulated pseudo-tracks to create a null spatial distribution and used Kernel Density Estimates (KDE) and Resource Selection Functions (RSF) to distinguish the relative importance of within- versus between-population competition. Kernel Density Estimates showed that only intrapopulation sexual segregation was significant for each monitoring year, and that tracks between the two colonies resulted in greater overlap than expected from the null distribution, especially for the females. RSF confirmed these results and highlighted key at-sea foraging areas, even if the estimated of at-sea densities were extremely low. These differences in selected areas between sites and sexes were, however, associated with high interannual variability in habitat preferences, with no clear specific preferences per site and sex. Our results suggest that even with low at-sea population densities, historic intrapopulation competition in wide-ranging seabirds may have led to sexual dimorphism and niche specialization, favouring the 'niche divergence' hypothesis. In this study, we provide a protocol to study competition within as well as between populations of central place foragers. This is relevant for understanding their distribution patterns and population regulation, which could potentially improve management of threatened populations.
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Affiliation(s)
- Florian Orgeret
- Marine Apex Predator Research Unit (MAPRU), Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa
| | - Ryan R Reisinger
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Tegan Carpenter-Kling
- Marine Apex Predator Research Unit (MAPRU), Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa.,DST-NRF Centre of Excellence at the FitzPatrick, Institute of African Ornithology, Nelson Mandela University, Port Elizabeth, South Africa
| | - Danielle Z Keys
- Marine Apex Predator Research Unit (MAPRU), Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa
| | - Alexandre Corbeau
- Centre d'Etudes Biologiques de Chizé, UMR 7372 du CNRS-Université de La Rochelle, Villiers-en-Bois, France
| | - Charles-André Bost
- Centre d'Etudes Biologiques de Chizé, UMR 7372 du CNRS-Université de La Rochelle, Villiers-en-Bois, France
| | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé, UMR 7372 du CNRS-Université de La Rochelle, Villiers-en-Bois, France
| | - Pierre A Pistorius
- Marine Apex Predator Research Unit (MAPRU), Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa.,DST-NRF Centre of Excellence at the FitzPatrick, Institute of African Ornithology, Nelson Mandela University, Port Elizabeth, South Africa
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4
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Morris G, Conner LM. Assessment of accuracy, fix success rate, and use of estimated horizontal position error (EHPE) to filter inaccurate data collected by a common commercially available GPS logger. PLoS One 2017; 12:e0189020. [PMID: 29190686 PMCID: PMC5708763 DOI: 10.1371/journal.pone.0189020] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 11/18/2017] [Indexed: 11/18/2022] Open
Abstract
Global positioning system (GPS) technologies have improved the ability of researchers to monitor wildlife; however, use of these technologies is often limited by monetary costs. Some researchers have begun to use commercially available GPS loggers as a less expensive means of tracking wildlife, but data regarding performance of these devices are limited. We tested a commercially available GPS logger (i-gotU GT-120) by placing loggers at ground control points with locations known to < 30 cm. In a preliminary investigation, we collected locations every 15 minutes for several days to estimate location error (LE) and circular error probable (CEP). Using similar methods, we then investigated the influence of cover on LE, CEP, and fix success rate (FSR) by constructing cover over ground control points. We found mean LE was < 10 m and mean 50% CEP was < 7 m. FSR was not significantly influenced by cover and in all treatments remained near 100%. Cover had a minor but significant effect on LE. Denser cover was associated with higher mean LE, but the difference in LE between the no cover and highest cover treatments was only 2.2 m. Finally, the most commonly used commercially available devices provide a measure of estimated horizontal position error (EHPE) which potentially may be used to filter inaccurate locations. Using data combined from the preliminary and cover investigations, we modeled LE as a function of EHPE and number of satellites. We found support for use of both EHPE and number of satellites in predicting LE; however, use of EHPE to filter inaccurate locations resulted in the loss of many locations with low error in return for only modest improvements in LE. Even without filtering, the accuracy of the logger was likely sufficient for studies which can accept average location errors of approximately 10 m.
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Affiliation(s)
- Gail Morris
- Joseph W. Jones Ecological Research Center, Jones Center Dr., Newton, Georgia, United States of America
| | - L. Mike Conner
- Joseph W. Jones Ecological Research Center, Jones Center Dr., Newton, Georgia, United States of America
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Kühn S, van Werven B, van Oyen A, Meijboom A, Bravo Rebolledo EL, van Franeker JA. The use of potassium hydroxide (KOH) solution as a suitable approach to isolate plastics ingested by marine organisms. MARINE POLLUTION BULLETIN 2017; 115:86-90. [PMID: 27912918 DOI: 10.1016/j.marpolbul.2016.11.034] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/15/2016] [Accepted: 11/15/2016] [Indexed: 05/26/2023]
Abstract
In studies of plastic ingestion by marine wildlife, visual separation of plastic particles from gastrointestinal tracts or their dietary content can be challenging. Earlier studies have used solutions to dissolve organic materials leaving synthetic particles unaffected. However, insufficient tests have been conducted to ensure that different categories of consumer products partly degraded in the environment and/or in gastrointestinal tracts were not affected. In this study 63 synthetic materials and 11 other dietary items and non-plastic marine debris were tested. Irrespective of shape or preceding environmental history, most polymers resisted potassium hydroxide (KOH) solution, with the exceptions of cellulose acetate from cigarette filters, some biodegradable plastics and a single polyethylene sheet. Exposure of hard diet components and other marine debris showed variable results. In conclusion, the results confirm that usage of KOH solutions can be a useful approach in general quantitative studies of plastic ingestion by marine wildlife.
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Affiliation(s)
- Susanne Kühn
- Wageningen University and Research, Department Wageningen Marine Research, Ankerpark 27, 1781 AG, Den Helder, The Netherlands.
| | - Bernike van Werven
- Wageningen University and Research, Department Wageningen Marine Research, Ankerpark 27, 1781 AG, Den Helder, The Netherlands; University of Utrecht, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands
| | | | - André Meijboom
- Wageningen University and Research, Department Wageningen Marine Research, Ankerpark 27, 1781 AG, Den Helder, The Netherlands
| | - Elisa L Bravo Rebolledo
- Wageningen University and Research, Department Wageningen Marine Research, Ankerpark 27, 1781 AG, Den Helder, The Netherlands; Elisa Bravo - Ecological and Biological Research, Zwaluwlaan 17, 3722 CH Bilthoven, The Netherlands
| | - Jan A van Franeker
- Wageningen University and Research, Department Wageningen Marine Research, Ankerpark 27, 1781 AG, Den Helder, The Netherlands
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Beasley DE, Koltz AM, Lambert JE, Fierer N, Dunn RR. The Evolution of Stomach Acidity and Its Relevance to the Human Microbiome. PLoS One 2015. [PMID: 26222383 PMCID: PMC4519257 DOI: 10.1371/journal.pone.0134116] [Citation(s) in RCA: 179] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Gastric acidity is likely a key factor shaping the diversity and composition of microbial communities found in the vertebrate gut. We conducted a systematic review to test the hypothesis that a key role of the vertebrate stomach is to maintain the gut microbial community by filtering out novel microbial taxa before they pass into the intestines. We propose that species feeding either on carrion or on organisms that are close phylogenetic relatives should require the most restrictive filter (measured as high stomach acidity) as protection from foreign microbes. Conversely, species feeding on a lower trophic level or on food that is distantly related to them (e.g. herbivores) should require the least restrictive filter, as the risk of pathogen exposure is lower. Comparisons of stomach acidity across trophic groups in mammal and bird taxa show that scavengers and carnivores have significantly higher stomach acidities compared to herbivores or carnivores feeding on phylogenetically distant prey such as insects or fish. In addition, we find when stomach acidity varies within species either naturally (with age) or in treatments such as bariatric surgery, the effects on gut bacterial pathogens and communities are in line with our hypothesis that the stomach acts as an ecological filter. Together these results highlight the importance of including measurements of gastric pH when investigating gut microbial dynamics within and across species.
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Affiliation(s)
- DeAnna E. Beasley
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail:
| | - Amanda M. Koltz
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Joanna E. Lambert
- Department of Anthropology, University of Colorado, Boulder, Colorado, United States of America
| | - Noah Fierer
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado United States of America
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, United States of America
| | - Rob R. Dunn
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
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Soanes LM, Arnould JPY, Dodd SG, Milligan G, Green JA. Factors affecting the foraging behaviour of the European shag: implications for seabird tracking studies. MARINE BIOLOGY 2014; 161:1335-1348. [PMID: 24882884 PMCID: PMC4033789 DOI: 10.1007/s00227-014-2422-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 03/08/2014] [Indexed: 05/22/2023]
Abstract
Seabird tracking has become an ever more popular tool to aid environmental procedures such as the designation of marine protected areas and environmental impact assessments. However, samples used are usually small and little consideration is given to experimental design and sampling protocol. European shags Phalacrocorax aristotelis were tracked using GPS technology over three breeding seasons and the following foraging trip characteristics: trip duration, trip distance, maximum distance travelled from the colony, size of area used and direction travelled from colony were determined for each foraging trip. The effect of sex, year of study, breeding site, number and age of chicks and the timing of tracking on foraging behaviour were investigated using a General Estimation Equation model. A range of sampling scenarios reflecting likely field sampling were also tested to compare how foraging behaviour differed depending on composition of the sample of birds tracked. Trip distance, trip duration, maximum distance travelled and size of area used were all significantly affected by the breeding site, and the number of chicks a tracked adult was raising. The effect of sex was also seen when examining trip distance, trip duration and the maximum distance travelled. The direction travelled on a foraging trip was also significantly affected by breeding site. This study highlights the importance of sampling regime and the influence that year, sex, age, number of chicks and breeding site can have on the foraging trip characteristics for this coastal feeding seabird. Given the logistical and financial constraints in tracking large numbers of individuals, this study identifies the need for researchers to consider the composition of their study sample to ensure any identified foraging areas are as representative as possible of the whole colony's foraging area.
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Affiliation(s)
- L. M. Soanes
- School of Environmental Sciences, University of Liverpool, Liverpool, L69 3GP UK
| | - J. P. Y. Arnould
- School of Life and Environmental Sciences, Deakin University, Burwood, 3215 Australia
| | - S. G. Dodd
- Royal Society for the Protection of Birds, North Wales Office, Bangor, LL57 4FD UK
| | - G. Milligan
- School of Environmental Sciences, University of Liverpool, Liverpool, L69 3GP UK
| | - J. A. Green
- School of Environmental Sciences, University of Liverpool, Liverpool, L69 3GP UK
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