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Arrais RC, Widmer CE, Murray DL, Thornton D, Azevedo FCCD. Estimating density of ocelots in the Atlantic Forest using spatial and closed capture–recapture models. J Mammal 2022. [DOI: 10.1093/jmammal/gyac074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Monitoring variation in population features such as abundance and density is essential for evaluating and implementing conservation actions. Camera trapping can be important for assessing population status and trends and is increasingly used to generate density estimates through capture–recapture models. Moreover, success in using this technique can vary seasonally given shifting animal distributions and camera encounter rates. Notwithstanding these potential advantages, a gap still exists in our understanding of the performance of such models for estimating density of cryptic Neotropical terrestrial carnivores with low encounter rate probability with cameras. In addition, scanty information is available on how sampling design can affect the accuracy and precision of density estimates for Neotropical carnivores. We evaluate the performance of spatially explicit versus nonspatial capture–mark–recapture models for estimating densities and population size of ocelots (Leopardus pardalis) within an Atlantic Forest fragment in Brazil. We conducted two spatially concurrent surveys, a random camera-trap deployment covering the entire study area and a systematic camera-trap deployment in a small portion of the study area, where trails and unpaved roads were located. We obtained 244 photographs of ocelots in the Rio Doce State Park from April 2016 to November 2017, using 54-double camera stations spaced approximately 1.5 km apart (random placement) totaling 4,320 trap-nights and 15-double camera stations spaced from 0.3–10 km apart (systematic placement) totaling 1,200 trap-nights. Using the random placement design, ocelot density estimates were similar during the dry season, 14.0 individuals/km2 (± 5.6 SE, 6.6–30.0, 95% CI) and 13.78 individuals/km2 (± 4.25 SE, 5.4–22.1, 95% CI) from spatially explicit capture–recapture and nonspatial models, respectively. Using the systematic placement design spatially explicit models had smaller and less precise ocelot density estimates than nonspatial models during the dry season. Ocelot density was 12.4 individuals/100 km2 (± 5.0 SE, 5.8–26.7, 95% CI) and 19.9 individuals/km2 (± 5.2 SE, 9.7–30.1, 95% CI) from spatially explicit and nonspatial models, respectively. During the rainy season, we found the opposite pattern. Using the systematic placement design, spatial-explicit models had higher and less precise estimates than nonspatial models. Ocelot density was 24.6 individuals/100 km2 (± 13.9 SE, 8.7–69.4, 95% CI) and 11.89 individuals/km2 (± 3.93 SE, 4.19–19.59, 95% CI) from spatially explicit and nonspatial models, respectively. During the rainy season, we could not compare models using the random placement design due to limited number of recaptures to run nonspatial models. In addition, a single recapture yielded an imprecise population density estimate using spatial models (high SE and large 95% CIs), thus precluding any comparison between nonspatial and spatially explicit models. We demonstrate relative differences and similarities between the performance of spatially explicit and nonspatial capture–mark–recapture models for estimating density and population size of ocelots and highlight that both types of capture–recapture models differ in their estimation depending on the sampling design. We highlight that performance of camera surveys is contingent on placement design and that researchers need to be strategic in camera distribution according to study objectives and logistics. This point is especially relevant for cryptic or endangered species occurring at low densities and having low detection probability using traditional sampling methods.
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Affiliation(s)
- Ricardo Corassa Arrais
- Departamento de Ecologia, Conservação e Manejo de Vida Silvestre, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais , Belo Horizonte, Minas Gerais , Brazil
| | - Cynthia Elisa Widmer
- Projeto Carnívoros do Rio Doce – PCRD, Parque Estadual do Rio Doce , Marliéria, Minas Gerais , Brazil
| | - Dennis L Murray
- Department of Biology, Trent University , Peterborough, Ontario , Canada
| | - Daniel Thornton
- School of the Environment, Washington State University , Pullman, Washington , USA
| | - Fernando Cesar Cascelli de Azevedo
- Departamento de Ciências Naturais, Universidade Federal de São João del Rei , São João del Rei, Minas Gerais , Brazil
- Instituto Pró-Carnívoros , Atibaia, São Paulo , Brazil
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Ferreira EM, Valerio F, Medinas D, Fernandes N, Craveiro J, Costa P, Silva JP, Carrapato C, Mira A, Santos SM. Assessing behaviour states of a forest carnivore in a road-dominated landscape using Hidden Markov Models. NATURE CONSERVATION 2022. [DOI: 10.3897/natureconservation.47.72781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Anthropogenic infrastructures and land-use changes are major threats to animal movements across heterogeneous landscapes. Yet, the behavioural consequences of such constraints remain poorly understood. We investigated the relationship between the behaviour of the Common genet (Genetta genetta) and road proximity, within a dominant mixed forest-agricultural landscape in southern Portugal, fragmented by roads. Specifically, we aimed to: (i) identify and characterise the behavioural states displayed by genets and related movement patterns; and (ii) understand how behavioural states are influenced by proximity to main paved roads and landscape features. We used a multivariate Hidden Markov Model (HMM) to characterise the fine-scale movements (10-min fixes GPS) of seven genets tracked during 187 nights (mean 27 days per individual) during the period 2016–2019, using distance to major paved roads and landscape features as predictors. Our findings indicated that genet’s movement patterns were composed of three basic behavioural states, classified as “resting” (short step-lengths [mean = 10.6 m] and highly tortuous), “foraging” (intermediate step-lengths [mean = 46.1 m] and with a wide range in turning angle) and “travelling” (longer step-lengths [mean = 113.7 m] and mainly linear movements). Within the genet’s main activity-period (17.00 h-08.00 h), the movement model predicts that genets spend 36.7% of their time travelling, 35.4% foraging and 28.0% resting. The probability of genets displaying the travelling state was highest in areas far away from roads (> 500 m), whereas foraging and resting states were more likely in areas relatively close to roads (up to 500 m). Landscape features also had a pronounced effect on behaviour state occurrence. More specifically, travelling was most likely to occur in areas with lower forest edge density and close to riparian habitats, while foraging was more likely to occur in areas with higher forest edge density and far away from riparian habitats. The results suggest that, although roads represent a behavioural barrier to the movement of genets, they also take advantage of road proximity as foraging areas. Our study demonstrates that the HMM approach is useful for disentangling movement behaviour and understanding how animals respond to roadsides and fragmented habitats. We emphasise that road-engaged stakeholders need to consider movement behaviour of genets when targeting management practices to maximise road permeability for wildlife.
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AZEDO R, ILHÉU A, SANTOS S, VAZ PG. Carnivores cross irrigation canals more often through overpasses than through culverts. Basic Appl Ecol 2022. [DOI: 10.1016/j.baae.2022.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Suárez‐Tangil BD, Rodríguez A. Uniform performance of mammal detection methods under contrasting environmental conditions in Mediterranean landscapes. Ecosphere 2021. [DOI: 10.1002/ecs2.3349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Bruno D. Suárez‐Tangil
- Department of Conservation Biology Estación Biológica de Doñana – CSIC Américo Vespucio 26 Sevilla41092Spain
| | - Alejandro Rodríguez
- Department of Conservation Biology Estación Biológica de Doñana – CSIC Américo Vespucio 26 Sevilla41092Spain
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Ikeda T, Kuninaga N, Suzuki T, Ikushima S, Suzuki M. Tourist-wild boar (Sus scrofa) interactions in urban wildlife management. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00617] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Byers KA, Lee MJ, Bidulka JJ, Patrick DM, Himsworth CG. Rat in a Cage: Trappability of Urban Norway Rats (Rattus norvegicus). Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Srivathsa A, Parameshwaran R, Sharma S, Karanth KU. Estimating population sizes of leopard cats in the Western Ghats using camera surveys. J Mammal 2015. [DOI: 10.1093/jmammal/gyv079] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Estimating seasonal abundance and habitat use of small carnivores in the Western Ghats using an occupancy approach. JOURNAL OF TROPICAL ECOLOGY 2014. [DOI: 10.1017/s0266467414000340] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Abstract:Rigorous population studies on many small carnivores are lacking in India. Presence-absence models with habitat covariates were applied to estimate seasonal occupancy and abundance of nine small-carnivore species from camera-trap data in Mudumalai Tiger Reserve (2010 and 2011). We deployed 25 camera-trap stations in the deciduous forest, 21 in the semi-evergreen forest and 26 in the dry thorn forest. In total, 7380 trap-nights yielded 448 photographs of small carnivores: jungle cat (n = 72), leopard cat (n = 6), rusty-spotted cat (n = 11), small Indian civet (n = 89), common palm civet (n = 37), brown palm civet (n = 20), stripe-necked mongoose (n = 66), ruddy mongoose (n = 96) and Indian grey mongoose (n = 51). In the dry season, rusty-spotted cat was the rarest carnivore with an average abundance (λmean) of 0.24 ± 0.26, while ruddy mongoose was the most abundant (λmean = 0.90 ± 0.40). In the wet season, leopard cat was the rarest species (λmean = 0.048 ± 0.041) while grey mongoose was the most abundant (λmean = 0.68 ± 0.35). Abundance of jungle cat, common palm civet, ruddy mongoose and grey mongoose increased in the dry thorn forest whereas in the dry season abundance of small Indian civet decreased in this forest type. Abundance of leopard cat and small Indian civet was not influenced by habitat in the wet season. Deciduous forest was positively associated with abundance of rusty-spotted cat. Deciduous and semi-evergreen forests had a positive effect on abundance of stripe-necked mongoose while the latter was a positive predictor of abundance and occupancy for brown palm civet. Improved modelling approaches can account for the spatio-temporal variation in habitat use of small carnivores occupying specialized niches in heterogeneous tropical forests of southern India.
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Zimmermann F, Breitenmoser-Würsten C, Molinari-Jobin A, Breitenmoser U. Optimizing the size of the area surveyed for monitoring a Eurasian lynx (Lynx lynx) population in the Swiss Alps by means of photographic capture-recapture. Integr Zool 2014; 8:232-43. [PMID: 24020463 DOI: 10.1111/1749-4877.12017] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We studied the influence of surveyed area size on density estimates by means of camera-trapping in a low-density felid population (1-2 individuals/100 km(2) ). We applied non-spatial capture-recapture (CR) and spatial CR (SCR) models for Eurasian lynx during winter 2005/2006 in the northwestern Swiss Alps by sampling an area divided into 5 nested plots ranging from 65 to 760 km(2) . CR model density estimates (95% CI) for models M0 and Mh decreased from 2.61 (1.55-3.68) and 3.6 (1.62-5.57) independent lynx/100 km(2) , respectively, in the smallest to 1.20 (1.04-1.35) and 1.26 (0.89-1.63) independent lynx/100 km(2) , respectively, in the largest area surveyed. SCR model density estimates also decreased with increasing sampling area but not significantly. High individual range overlaps in relatively small areas (the edge effect) is the most plausible reason for this positive bias in the CR models. Our results confirm that SCR models are much more robust to changes in trap array size than CR models, thus avoiding overestimation of density in smaller areas. However, when a study is concerned with monitoring population changes, large spatial efforts (area surveyed ≥760 km(2) ) are required to obtain reliable and precise density estimates with these population densities and recapture rates.
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Affiliation(s)
- Fridolin Zimmermann
- KORA, Muri, Switzerland Institute of Veterinary Virology, University of Bern, Bern, Switzerland
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Hervías S, Ramos JA, Nogales M, Ruiz de Ybáñez R. Effect of exotic mammalian predators on parasites of Cory's shearwater: ecological effect on population health and breeding success. Parasitol Res 2013; 112:2721-30. [PMID: 23708397 DOI: 10.1007/s00436-013-3443-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 04/26/2013] [Indexed: 11/26/2022]
Abstract
Predator activity around the nests induces stress in breeding birds, which may have weaker immunity and are therefore more susceptible to parasite infections. The influence of predators on parasites has only been observed in land birds, and most studies are experimental. As seabird colonies offer excellent conditions for parasites, here we assess the influence of mouse, rat, and cat activity on parasites in Cory's shearwater (Calonectris diomedea borealis). Adults were examined for blood parasites and one adult and the juvenile from 53 nests were inspected for ectoparasites over two consecutive years (2010 and 2011). Nests differed in their physical characteristics and indices of mammal predator activity and were checked weekly to assess breeding success. Our results showed absence of blood parasites. Among the environmental factors, predator pressure received the most support (89 %) from the data as influencing nest ectoparasite intensity. Birds most infected had worse body condition, and breeding success was negatively influenced by predator activity and ectoparasite intensity. To our knowledge, this is the first analysis of the interaction between mammal predators and ectoparasites in seabird species and supports greater protection through eradication efforts. In addition, we provide the first data on the endoparasite fauna of Cory's shearwater.
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Affiliation(s)
- Sandra Hervías
- Animal Health Department, Faculty of Veterinary, Regional Campus of International Excellence Campus Mare Nostrum, University of Murcia, 30100-Espinardo, Murcia, Spain.
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Hiby L, Paterson WD, Redman P, Watkins J, Twiss SD, Pomeroy P. Analysis of photo-id data allowing for missed matches and individuals identified from opposite sides. Methods Ecol Evol 2012. [DOI: 10.1111/2041-210x.12008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lex Hiby
- Conservation Research Ltd.; 110 Hinton Way Great Shelford Cambridge CB22 5AL UK
| | - William D. Paterson
- Scottish Oceans Institute; Sea Mammal Research Unit; University of St. Andrews; St. Andrews Fife KY16 8LB UK
| | - Paula Redman
- Scottish Oceans Institute; Sea Mammal Research Unit; University of St. Andrews; St. Andrews Fife KY16 8LB UK
| | - John Watkins
- Scottish Oceans Institute; Sea Mammal Research Unit; University of St. Andrews; St. Andrews Fife KY16 8LB UK
| | - Sean D. Twiss
- School of Biological and Biomedical Sciences; The University of Durham; South Road Durham DH1 3LE UK
| | - Patrick Pomeroy
- Scottish Oceans Institute; Sea Mammal Research Unit; University of St. Andrews; St. Andrews Fife KY16 8LB UK
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13
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Coexistence of carnivores in a heterogeneous landscape: habitat selection and ecological niches. Ecol Res 2012. [DOI: 10.1007/s11284-012-0949-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Evaluating the potential biases in carnivore capture–recapture studies associated with the use of lure and varying density estimation techniques using photographic-sampling data of the Malagasy civet. POPUL ECOL 2011. [DOI: 10.1007/s10144-011-0276-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Rodriguez-Refojos C, Zuberogoitia I, Rosalino LM, Zabala J, Santos MJ, Santos-Reis M, Camps D. Geographical and sexual differences in body size of common genets,Genetta genetta(Viverridae, Carnivora), in south-western Europe (Iberian Peninsula). FOLIA ZOOLOGICA 2011. [DOI: 10.25225/fozo.v60.i1.a9.2011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Cristina Rodriguez-Refojos
- Aranzadi Society of Sciences, Department of Vertebrates, Zorroagagaina kalea, 11, 20014 Donostia-San Sebastian, Gipuzkoa, Spain
| | - Iñigo Zuberogoitia
- Estudios Medioambientales Icarus, S.L., Pintor Sorolla 6, 1°C, 26007 Logroño, La Rioja, Spain; e-mail:
| | - Luis Miguel Rosalino
- Lisbon University, Centre for Environmental Biology, Faculty of Sciences, Animal Biology Department, Ed. C2, 1749-016 Lisbon, Portugal;,
| | - Jabi Zabala
- Sebero Otxoa 45, 5°B, 48480 Arrigorriaga, Spain
| | - Maria João Santos
- Department of Land, Air and Water Resources, University of California Davis, One Shields Avenue, Davis, CA 95616, U.S.A.
| | - Margarida Santos-Reis
- Lisbon University, Centre for Environmental Biology, Faculty of Sciences, Animal Biology Department, Ed. C2, 1749-016 Lisbon, Portugal;,
| | - David Camps
- Direcció General del Medi Natural, Departament de Medi Ambient i Habitatge, Generalitat de Catalunya, Dr. Roux, 80, 08017 Barcelona, Spain
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