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Persson-Sjodin E, Hernlund E, Pfau T, Andersen PH, Forsström KH, Byström A, Serra Bragança FM, Hardeman A, Greve L, Egenvall A, Rhodin M. Withers vertical movement symmetry is useful for locating the primary lame limb in naturally occurring lameness. Equine Vet J 2024; 56:76-88. [PMID: 37226583 DOI: 10.1111/evj.13947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 05/04/2023] [Indexed: 05/26/2023]
Abstract
BACKGROUND During orthopaedic assessment of lame horses, a head nod is commonly present in both primary forelimb and hindlimb lame horses. Additional motion metrics that could assist clinicians in correctly differentiating between these two scenarios would be of great clinical value. OBJECTIVES The primary objective of this study was to examine whether withers movement asymmetry can be used in a clinical setting to distinguish primary forelimb lameness from compensatory head movement asymmetry due to primary hindlimb lameness. STUDY DESIGN Retrospective, multicentre study. METHODS Movement asymmetry of head, withers and pelvis was measured using multi-camera optical motion capture, as part of routine lameness investigations at four European equine hospitals. Vertical movement asymmetry parameters from 317 horses trotting in a straight line were compared before and after successful diagnostic analgesia of a single limb. Descriptive statistics, t-tests and linear models were used to analyse the data. RESULTS In forelimb lame horses, 80%-81% showed head and withers asymmetry both indicating lameness in the same forelimb. In hindlimb lame horses, 69%-72% showed head asymmetry ipsilateral to the lame hindlimb and withers asymmetry diagonal to the lame hindlimb, thus, head and withers asymmetry indicated lameness in different forelimbs. A large (>15 mm) compensatory head nod was seen in 28%-31% of the hindlimb lame horses. In 89%-92% of these, head and withers asymmetry indicated lameness in different forelimbs. Withers asymmetry decreased linearly with reduced head or pelvic asymmetry for both forelimb and hindlimb lame horses. MAIN LIMITATIONS Compensatory strategies were evaluated on group level to identify common patterns, potentially ignoring uncommon individual strategies. CONCLUSIONS Withers vertical movement asymmetry metrics can be useful in helping to locate the primary lame limb during quantitative lameness assessment. Head and withers movement asymmetry parameters generally indicate the same forelimb in forelimb lame horses, but different forelimbs in hindlimb lame horses.
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Affiliation(s)
- Emma Persson-Sjodin
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Elin Hernlund
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Thilo Pfau
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Pia Haubro Andersen
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Karin Holm Forsström
- Equine Clinic, University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anna Byström
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Filipe M Serra Bragança
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Aagje Hardeman
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- DataHorse, Wierden, The Netherlands
| | - Line Greve
- Evidensia Specialist Equine Hospital Helsingborg, Helsingborg, Sweden
| | - Agneta Egenvall
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Marie Rhodin
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Mumme S, Middleton AD, Ciucci P, De Groeve J, Corradini A, Aikens EO, Ossi F, Atwood P, Balkenhol N, Cole EK, Debeffe L, Dewey SR, Fischer C, Gude J, Heurich M, Hurley MA, Jarnemo A, Kauffman MJ, Licoppe A, van Loon E, McWhirter D, Mong TW, Pedrotti L, Morellet N, Mysterud A, Peters W, Proffitt K, Saïd S, Signer J, Sunde P, Starý M, Cagnacci F. Wherever I may roam-Human activity alters movements of red deer (Cervus elaphus) and elk (Cervus canadensis) across two continents. Glob Chang Biol 2023; 29:5788-5801. [PMID: 37306048 DOI: 10.1111/gcb.16769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 03/29/2023] [Accepted: 04/02/2023] [Indexed: 06/13/2023]
Abstract
Human activity and associated landscape modifications alter the movements of animals with consequences for populations and ecosystems worldwide. Species performing long-distance movements are thought to be particularly sensitive to human impact. Despite the increasing anthropogenic pressure, it remains challenging to understand and predict animals' responses to human activity. Here we address this knowledge gap using 1206 Global Positioning System movement trajectories of 815 individuals from 14 red deer (Cervus elaphus) and 14 elk (Cervus canadensis) populations spanning wide environmental gradients, namely the latitudinal range from the Alps to Scandinavia in Europe, and the Greater Yellowstone Ecosystem in North America. We measured individual-level movements relative to the environmental context, or movement expression, using the standardized metric Intensity of Use, reflecting both the directionality and extent of movements. We expected movement expression to be affected by resource (Normalized Difference Vegetation Index, NDVI) predictability and topography, but those factors to be superseded by human impact. Red deer and elk movement expression varied along a continuum, from highly segmented trajectories over relatively small areas (high intensity of use), to directed transitions through restricted corridors (low intensity of use). Human activity (Human Footprint Index, HFI) was the strongest driver of movement expression, with a steep increase in Intensity of Use as HFI increased, but only until a threshold was reached. After exceeding this level of impact, the Intensity of Use remained unchanged. These results indicate the overall sensitivity of Cervus movement expression to human activity and suggest a limitation of plastic responses under high human pressure, despite the species also occurring in human-dominated landscapes. Our work represents the first comparison of metric-based movement expression across widely distributed populations of a deer genus, contributing to the understanding and prediction of animals' responses to human activity.
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Affiliation(s)
- Steffen Mumme
- Department of Biology and Biotechnologies "Charles Darwin", University of Rome La Sapienza, Rome, Italy
- Animal Ecology Unit, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
- Department of Environmental Science, Policy, and Management, University of California, California, Berkeley, USA
| | - Arthur D Middleton
- Department of Environmental Science, Policy, and Management, University of California, California, Berkeley, USA
| | - Paolo Ciucci
- Department of Biology and Biotechnologies "Charles Darwin", University of Rome La Sapienza, Rome, Italy
| | - Johannes De Groeve
- Animal Ecology Unit, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands
| | - Andrea Corradini
- Animal Ecology Unit, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- Department of Civil, Environmental and Mechanical Engineering (DICAM), University of Trento, Trento, Italy
- Stelvio National Park-Ersaf Lombardia, Bormio, Italy
| | - Ellen O Aikens
- School of Computing, University of Wyoming, Wyoming, Laramie, USA
- Haub School of Environment and Natural Resources, University of Wyoming, Wyoming, Laramie, USA
| | - Federico Ossi
- Animal Ecology Unit, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
| | - Paul Atwood
- Idaho Department of Fish and Game, Idaho, Coeur d'Alene, USA
| | - Niko Balkenhol
- Wildlife Sciences, Faculty of Forest Sciences and Forest Ecology, University of Goettingen, Goettingen, Germany
| | - Eric K Cole
- US Fish and Wildlife Service, National Elk Refuge, Wyoming, Jackson, USA
| | - Lucie Debeffe
- Université de Toulouse, INRAE, CEFS, Castanet Tolosan, France
- LTSER ZA PYRénées GARonne, Auzeville Tolosane, France
| | - Sarah R Dewey
- National Park Service, Grand Teton National Park, Wyoming, Moose, USA
| | - Claude Fischer
- Department of Nature Management, University of Applied Sciences of Western Switzerland, Jussy, Switzerland
| | - Justin Gude
- Montana Department of Fish, Wildlife and Parks, Montana, Helena, USA
| | - Marco Heurich
- Department of Visitor Management and National Park Monitoring, Bavarian Forest National Park, Grafenau, Germany
- Chair of Wildlife Ecology and Management, Albert Ludwigs University Freiburg, Freiburg, Germany
- Inland Norway University of Applied Science Institute for Forest and Wildlife Management, Koppang, Norway
| | - Mark A Hurley
- Idaho Department of Fish and Game, Idaho, Boise, USA
| | - Anders Jarnemo
- School of Business, Innovation and Sustainability, Halmstad University, Halmstad, Sweden
| | - Matthew J Kauffman
- U.S. Geological Survey, Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Wyoming, Laramie, USA
| | - Alain Licoppe
- Natural and Agricultural Environmental Studies Department, Service Public de Wallonie, Gembloux, Belgium
| | - Emiel van Loon
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands
| | | | - Tony W Mong
- Wyoming Game and Fish Department, Wyoming, Cody, USA
| | - Luca Pedrotti
- Stelvio National Park-Ersaf Lombardia, Bormio, Italy
| | - Nicolas Morellet
- Université de Toulouse, INRAE, CEFS, Castanet Tolosan, France
- LTSER ZA PYRénées GARonne, Auzeville Tolosane, France
| | - Atle Mysterud
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway
| | - Wibke Peters
- Department for Conservation, Biodiversity and Wildlife Management, Bavarian State Institute of Forestry, Freising, Germany
| | - Kelly Proffitt
- Montana Department of Fish, Wildlife and Parks, Montana, Bozeman, USA
| | - Sonia Saïd
- Office Français de la Biodiversité, DRAS, "Montfort", Birieux, France
| | - Johannes Signer
- Wildlife Sciences, Faculty of Forest Sciences and Forest Ecology, University of Goettingen, Goettingen, Germany
| | - Peter Sunde
- Department of Ecoscience-Wildlife Ecology, Aarhus University, Aarhus, Denmark
| | | | - Francesca Cagnacci
- Animal Ecology Unit, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
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Persson J, Ordiz A, Ladle A, Andrén H, Aronsson M. Recolonization following past persecution questions the importance of persistent snow cover as a range limiting factor for wolverines. Glob Chang Biol 2023; 29:5802-5815. [PMID: 37566106 DOI: 10.1111/gcb.16908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 05/30/2023] [Accepted: 06/28/2023] [Indexed: 08/12/2023]
Abstract
Globally, climate is changing rapidly, which causes shifts in many species' distributions, stressing the need to understand their response to changing environmental conditions to inform conservation and management. Northern latitudes are expected to experience strongest changes in climate, with milder winters and decreasing snow cover. The wolverine (Gulo gulo) is a circumpolar, threatened carnivore distributed in northern tundra, boreal, and subboreal habitats. Previous studies have suggested that wolverine distribution and reproduction are constrained by a strong association with persistent spring snow cover. We assess this hypothesis by relating spatial distribution of 1589 reproductive events, a fitness-related proxy for female reproduction and survival, to snow cover over two decades. Wolverine distribution has increased and number of reproductive events increased 20 times in areas lacking spring snow cover during our study period, despite low monitoring effort where snow is sparse. Thus, the relationship between reproductive events and persistent spring snow cover weakened during this period. These findings show that wolverine reproductive success and hence distribution are less dependent on spring snow cover than expected. This has important implications for projections of future habitat availability, and thus distribution, of this threatened species. Our study also illustrates how past persecution, or other factors, that have restricted species distribution to remote areas can mask actual effects of environmental parameters, whose importance reveals when populations expand beyond previously restricted ranges. Overwhelming evidence shows that climate change is affecting many species and ecological processes, but forecasting potential consequences on a given species requires longitudinal data to revisit hypotheses and reassess the direction and magnitude of climate effects with new data. This is especially important for conservation-oriented management of species inhabiting dynamic systems where environmental factors and human activities interact, a common scenario for many species in different ecosystems around the globe.
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Affiliation(s)
- Jens Persson
- Department of Ecology, Swedish University of Agricultural Sciences, Grimsö Wildlife Research Station, Riddarhyttan, Sweden
| | - Andrés Ordiz
- Department of Ecology, Swedish University of Agricultural Sciences, Grimsö Wildlife Research Station, Riddarhyttan, Sweden
- Departamento de Biodiversidad y Gestión Ambiental, Facultad de Ciencias Biológicas y Ambientales, Área de Zoología, Universidad de León, León, Spain
| | - Andrew Ladle
- Department of Ecology, Swedish University of Agricultural Sciences, Grimsö Wildlife Research Station, Riddarhyttan, Sweden
| | - Henrik Andrén
- Department of Ecology, Swedish University of Agricultural Sciences, Grimsö Wildlife Research Station, Riddarhyttan, Sweden
| | - Malin Aronsson
- Department of Ecology, Swedish University of Agricultural Sciences, Grimsö Wildlife Research Station, Riddarhyttan, Sweden
- Department of Zoology, Stockholm University, Stockholm, Sweden
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Kjellander P, Bergvall UA, Chirico J, Ullman K, Christensson M, Lindgren PE. Winter activity of Ixodes ricinus in Sweden. Parasit Vectors 2023; 16:229. [PMID: 37430316 DOI: 10.1186/s13071-023-05843-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 06/19/2023] [Indexed: 07/12/2023] Open
Abstract
BACKGROUND In Europe, Ixodes ricinus (Acari: Ixodidae) is the most widespread and abundant tick species, acting as a vector for several microorganisms of medical and veterinary importance. In Northern and Central Europe, the tick has a bimodal activity pattern consisting of a peak in spring to the beginning of summer and a second peak at the end of summer. However, several findings of ticks on animals during winter have been reported, which raises the question of whether this is an overwintering strategy or whether ticks are active during winter in Scandinavia. The objectives of our study were to determine (i) whether ticks were active and finding hosts during winter, (ii) whether they parasitize their hosts, and (iii) what climatic factors-i.e., temperature, snow depth and precipitation-govern tick winter activity. METHODS Throughout three winter seasons, we examined wild-living and free-ranging roe deer (Capreolus capreolus) for ticks on 332 occasions. In total, 140 individual roe deer were captured in two climatically contrasting sites in south-central Sweden, Grimsö and the Bogesund research area, respectively. We re-examined individual roe deer up to 10 times within the same winter or approximately once a week (mean 10 days, median 7 days between re-examinations) and recorded the absence or presence of ticks on the animals, and tested to what extent meteorological factors affected tick activity. To determine the attachment day, we used the coxal/scutal index of 18 nymphs and 47 female ticks. RESULTS In total, 243 I. ricinus were collected from 301 roe deer captures between 14 December and 28 February at the Bogesund study site during three subsequent years (2013/2014-2015/2016). We found attached ticks every third to every second examination (32%, 48% and 32% of the examinations, respectively). However, we collected only three I. ricinus females from 31 roe deer captures at the Grimsö study site between 17 December 2015 and 26 February 2016. At the Bogesund study site, based on 192 captures of previously examined deer, we collected 121 ticks, and ticks were found at 33%, 48% and 26% of the examinations during the respective winters. The probability of finding an attached tick on a roe deer at a temperature of -5 °C was > 8% ± 5 (SE), and that probability increased to almost 20% ± 7 (SE) if the air temperature increased to 5 °C. CONCLUSIONS To the best of our knowledge, this is the first time that winter-active nymphs and female ticks have been documented to attach and feed on roe deer during winter (December to February) in Scandinavia. The main weather conditions regulating winter activity for females were temperature and precipitation, and the lowest estimated air temperature for finding an active tick was well below 5 °C. The behaviour of winter-active and blood-feeding ticks was documented over several winters and in two contrasting areas, implying that it is a common phenomenon that should be investigated more thoroughly, since it may have important consequences for the epidemiology of tick-borne pathogens.
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Affiliation(s)
- Petter Kjellander
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, Sweden.
| | - Ulrika A Bergvall
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, Sweden
| | - Jan Chirico
- Department of Microbiology, National Veterinary Institute (SVA), Uppsala, Sweden
| | - Karin Ullman
- Department of Microbiology, National Veterinary Institute (SVA), Uppsala, Sweden
| | - Madeleine Christensson
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, Sweden
| | - Per-Eric Lindgren
- Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection, Linköping University, Linköping, Sweden
- Laboratory Medicine, Microbiological Laboratory, County Hospital Ryhov, Jönköping, Sweden
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Wikenros C, Gicquel M, Zimmermann B, Flagstad Ø, Åkesson M. Age at first reproduction in wolves: different patterns of density dependence for females and males. Proc Biol Sci 2021; 288:20210207. [PMID: 33823674 PMCID: PMC8059544 DOI: 10.1098/rspb.2021.0207] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/09/2021] [Indexed: 01/14/2023] Open
Abstract
Age at first reproduction constitutes a key life-history trait in animals and is evolutionarily shaped by fitness benefits and costs of delayed versus early reproduction. The understanding of how intrinsic and extrinsic changes affects age at first reproduction is crucial for conservation and management of threatened species because of its demographic effects on population growth and generation time. For a period of 40 years in the Scandinavian wolf (Canis lupus) population, including the recolonization phase, we estimated age at first successful reproduction (pup survival to at least three weeks of age) and examined how the variation among individuals was explained by sex, population size (from 1 to 74 packs), primiparous or multiparous origin, reproductive experience of the partner and inbreeding. Median age at first reproduction was 3 years for females (n = 60) and 2 years for males (n = 74), and ranged between 1 and 8-10 years of age (n = 297). Female age at first reproduction decreased with increasing population size, and increased with higher levels of inbreeding. The probability for males to reproduce later first decreased, reaching its minimum when the number of territories approached 40-60, and then increased with increasing population size. Inbreeding for males and reproductive experience of parents and partners for both sexes had overall weak effects on age at first reproduction. These results allow for more accurate parameter estimates when modelling population dynamics for management and conservation of small and vulnerable wolf populations, and show how humans through legal harvest and illegal hunting influence an important life-history trait like age at first reproduction.
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Affiliation(s)
- Camilla Wikenros
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, 73993 Riddarhyttan, Sweden
| | - Morgane Gicquel
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, 73993 Riddarhyttan, Sweden
| | - Barbara Zimmermann
- Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Campus Evenstad, Inland Norway University of Applied Sciences, 2480 Koppang, Norway
| | - Øystein Flagstad
- Norwegian Institute for Nature Research, PO Box 5685 Torgard, 7485 Trondheim, Norway
| | - Mikael Åkesson
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, 73993 Riddarhyttan, Sweden
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Sanz-Pérez A, Ordiz A, Sand H, Swenson JE, Wabakken P, Wikenros C, Zimmermann B, Åkesson M, Milleret C. No place like home? A test of the natal habitat-biased dispersal hypothesis in Scandinavian wolves. R Soc Open Sci 2018; 5:181379. [PMID: 30662744 PMCID: PMC6304128 DOI: 10.1098/rsos.181379] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
Natal dispersal is an important mechanism for the viability of populations. The influence of local conditions or experience gained in the natal habitat could improve fitness if dispersing individuals settle in an area with similar habitat characteristics. This process, defined as 'natal habitat-biased dispersal' (NHBD), has been used to explain distribution patterns in large carnivores, but actual studies evaluating it are rare. We tested whether grey wolf Canis lupus territory establishment was influenced by the habitat characteristics of the natal territory using the long-term monitoring of the Scandinavian wolf population. We paired the locations of natal and established territories, accounted for available habitats along the dispersing route, and compared their habitat characteristics for 271 wolves during 1998-2012. Wolves with the shortest dispersal distances established in natal-like habitat types more than expected by chance, whereas wolves that dispersed longer distances did not show NHBD. The pattern was consistent for male and female wolves, with females showing more NHBD than males. Chances to detect NHBD increased with the size of habitat defined as available. This highlights the importance of considering the biological characteristics of the studied species when defining habitat availability. Our methodological approach can prove useful to inform conservation and management to identify habitats to be selected by reintroduced or naturally expanding populations.
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Affiliation(s)
- Ana Sanz-Pérez
- Faculty of Applied Ecology and Agricultural Sciences, Inland Norway University of Applied Sciences, Evenstad, 2480 Koppang, Norway
| | - Andrés Ordiz
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Postbox 5003, 1432 Ås, Norway
| | - Håkan Sand
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, 730 91 Riddarhyttan, Sweden
| | - Jon E. Swenson
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Postbox 5003, 1432 Ås, Norway
- Norwegian Institute for Nature Research, 7485 Trondheim, Norway
| | - Petter Wabakken
- Faculty of Applied Ecology and Agricultural Sciences, Inland Norway University of Applied Sciences, Evenstad, 2480 Koppang, Norway
| | - Camilla Wikenros
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, 730 91 Riddarhyttan, Sweden
| | - Barbara Zimmermann
- Faculty of Applied Ecology and Agricultural Sciences, Inland Norway University of Applied Sciences, Evenstad, 2480 Koppang, Norway
| | - Mikael Åkesson
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, 730 91 Riddarhyttan, Sweden
| | - Cyril Milleret
- Faculty of Applied Ecology and Agricultural Sciences, Inland Norway University of Applied Sciences, Evenstad, 2480 Koppang, Norway
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Laroche F, Paltto H, Ranius T. Abundance-based detectability in a spatially-explicit metapopulation: a case study on a vulnerable beetle species in hollow trees. Oecologia 2018; 188:671-682. [PMID: 30066028 PMCID: PMC6208700 DOI: 10.1007/s00442-018-4220-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 07/05/2018] [Indexed: 11/27/2022]
Abstract
In many fragmented habitats, the detectability of a population in a habitat patch closely depends on the local abundance of individuals. However, metapopulation studies rarely connect abundance and detectability. We propose a framework for using abundance-based estimates of detectability in the analysis of a spatially-explicit stochastic patch occupancy model (SPOM). We illustrate our approach with the example of Tenebrio opacus, a beetle inhabiting hollows in old trees, and have based it on a 6-year monitoring programme of adult beetles in an area harbouring a high density of old oaks. We validated our abundance-based methodology by showing that the estimates of detectability were positively and significantly correlated with those obtained from presence/absence data (Pearson r = 0.54, p < 2E−16) in our study system. We further showed that the height of the hollow on the tree and the area of its entrance hole, the living status and girth of the host tree, and the time of survey significantly affected the detectability of beetle populations. Median detectability was 51% for one survey. The SPOM analysis revealed a high but heterogeneous extinction risk among trees, suggesting a metapopulation dynamics between the “classic” and “mainland–island” paradigms. However, it also indicated unexplained beetle colonization of trees in our study, despite the fact that we included limited detectability in our estimation procedure. This may have been due to the cryptic larval stage of T. opacus and may thus invalidate the use of a classic SPOM in our study system.
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Affiliation(s)
- Fabien Laroche
- Irstea, UR EFNO, Domaine des Barres, 45290, Nogent-sur-Vernisson, France.
- Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 75007, Uppsala, Sweden.
| | - Heidi Paltto
- Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 75007, Uppsala, Sweden
| | - Thomas Ranius
- Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 75007, Uppsala, Sweden
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