1
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Gettelman TE, Nielsen CK, Scimeca JM, Schauber EM. River otter chemical immobilization and field surgery using nonscheduled drugs. WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tatiana E. Gettelman
- Department of Zoology and Cooperative Wildlife Research Laboratory Southern Illinois University Carbondale IL 62901 USA
| | - Clayton K. Nielsen
- Department of Forestry and Cooperative Wildlife Research Laboratory Southern Illinois University Carbondale IL 62901 USA
| | - Joseph M. Scimeca
- Department of Animal Science, Food and Nutrition Southern Illinois University Carbondale IL 62901 USA
| | - Eric M. Schauber
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois Champaign IL 61820 USA
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2
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Wainstein M, Harding LB, O'Neill SM, Boyd DT, Koontz F, Miller B, Klütsch CFC, Thomas PJ, Ylitalo GM. Highly contaminated river otters (Lontra canadensis) are effective biomonitors of environmental pollutant exposure. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:670. [PMID: 35970905 PMCID: PMC9378324 DOI: 10.1007/s10661-022-10272-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 07/02/2022] [Indexed: 06/15/2023]
Abstract
River otters (Lontra canadensis) are apex predators that bioaccumulate contaminants via their diet, potentially serving as biomonitors of watershed health. They reside throughout the Green-Duwamish River, WA (USA), a watershed encompassing an extreme urbanization gradient, including a US Superfund site slated for a 17-year remediation. The objectives of this study were to document baseline contaminant levels in river otters, assess otters' utility as top trophic-level biomonitors of contaminant exposure, and evaluate the potential for health impacts on this species. We measured a suite of contaminants of concern, lipid content, nitrogen stable isotopes (δ15N), and microsatellite DNA markers in 69 otter scat samples collected from twelve sites. Landcover characteristics were used to group sampling sites into industrial (Superfund site), suburban, and rural development zones. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ether flame-retardants (PBDEs), dichlorodiphenyl-trichloroethane and its metabolites (DDTs), and polycyclic aromatic hydrocarbons (PAHs) increased significantly with increasing urbanization, and were best predicted by models that included development zone, suggesting that river otters are effective biomonitors, as defined in this study. Diet also played an important role, with lipid content, δ15N or both included in all best models. We recommend river otter scat be included in evaluating restoration efforts in this Superfund site, and as a potentially useful monitoring tool wherever otters are found. We also report ΣPCB and ΣPAH exposures among the highest published for wild river otters, with almost 70% of samples in the Superfund site exceeding established levels of concern.
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Affiliation(s)
- Michelle Wainstein
- Conservation, Research and Education Opportunities, Seattle, WA, 98107, USA.
| | - Louisa B Harding
- Washington Department of Fish and Wildlife, PO Box 43200, Olympia, WA, 98504-3200, USA
| | - Sandra M O'Neill
- Washington Department of Fish and Wildlife, PO Box 43200, Olympia, WA, 98504-3200, USA
| | - Daryle T Boyd
- Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard East, Seattle, WA, 98112-2097, USA
| | - Fred Koontz
- Woodland Park Zoo, 5500 Phinney Ave N, Seattle, WA, 98103, USA
| | - Bobbi Miller
- Woodland Park Zoo, 5500 Phinney Ave N, Seattle, WA, 98103, USA
| | - Cornelya F C Klütsch
- Division of Environment and Natural Resources, Norwegian Institute of Bioeconomy Research (NIBIO), NIBIO Svanhovd, NO-9925, Svanvik, Norway
| | - Philippe J Thomas
- Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Center, 1125 Colonel By Drive, Raven Road, Ottawa, ON, K1A 0H3, Canada
| | - Gina M Ylitalo
- Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard East, Seattle, WA, 98112-2097, USA
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3
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Basak S, Pandav B, Johnson JA, Hussain SA. Resource utilisation by smooth-coated otter in the rivers of Himalayan foothills in Uttarakhand, India. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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4
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Murphy SM, Adams JR, Waits LP, Cox JJ. Evaluating otter reintroduction outcomes using genetic spatial capture-recapture modified for dendritic networks. Ecol Evol 2021; 11:15047-15061. [PMID: 34765159 PMCID: PMC8571598 DOI: 10.1002/ece3.8187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/06/2021] [Accepted: 09/10/2021] [Indexed: 11/23/2022] Open
Abstract
Monitoring the demographics and genetics of reintroduced populations is critical to evaluating reintroduction success, but species ecology and the landscapes that they inhabit often present challenges for accurate assessments. If suitable habitats are restricted to hierarchical dendritic networks, such as river systems, animal movements are typically constrained and may violate assumptions of methods commonly used to estimate demographic parameters. Using genetic detection data collected via fecal sampling at latrines, we demonstrate applicability of the spatial capture-recapture (SCR) network distance function for estimating the size and density of a recently reintroduced North American river otter (Lontra canadensis) population in the Upper Rio Grande River dendritic network in the southwestern United States, and we also evaluated the genetic outcomes of using a small founder group (n = 33 otters) for reintroduction. Estimated population density was 0.23-0.28 otter/km, or 1 otter/3.57-4.35 km, with weak evidence of density increasing with northerly latitude (β = 0.33). Estimated population size was 83-104 total otters in 359 km of riverine dendritic network, which corresponded to average annual exponential population growth of 1.12-1.15/year since reintroduction. Growth was ≥40% lower than most reintroduced river otter populations and strong evidence of a founder effect existed 8-10 years post-reintroduction, including 13-21% genetic diversity loss, 84%-87% genetic effective population size decline, and rapid divergence from the source population (F ST accumulation = 0.06/generation). Consequently, genetic restoration via translocation of additional otters from other populations may be necessary to mitigate deleterious genetic effects in this small, isolated population. Combined with non-invasive genetic sampling, the SCR network distance approach is likely widely applicable to demogenetic assessments of both reintroduced and established populations of multiple mustelid species that inhabit aquatic dendritic networks, many of which are regionally or globally imperiled and may warrant reintroduction or augmentation efforts.
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Affiliation(s)
- Sean M. Murphy
- Wildlife Management DivisionNew Mexico Department of Game & FishSanta FeNew MexicoUSA
| | - Jennifer R. Adams
- Department of Fish and Wildlife SciencesUniversity of IdahoMoscowIdahoUSA
| | - Lisette P. Waits
- Department of Fish and Wildlife SciencesUniversity of IdahoMoscowIdahoUSA
| | - John J. Cox
- Department of Forestry and Natural ResourcesUniversity of KentuckyLexingtonKentuckyUSA
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5
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Kouman CY, Ebome AEA, Ahizi MN, Ouattara M, Ouattara A, Fairet E, Shirley MH. Space use and social interactions of Central African slender‐snouted crocodiles
Mecistops leptorhynchus
(Bennett, 1835) in Loango National Park, Gabon. Afr J Ecol 2021. [DOI: 10.1111/aje.12887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - Angel E. A. Ebome
- Contrôle de l’Aménagement Forestier Ministère des Forêts, de la Mer, et de l’Environnement Quartier Bas de Gue‐Gue (Immeuble IVALA) Libreville Gabon
| | | | | | | | - Emilie Fairet
- Wildlife Conservation New York NY USA
- Institute of Environment Florida International University Miami FL USA
| | - Matthew H. Shirley
- Institute of Environment Florida International University Miami FL USA
- Rare Species Conservatory Foundation Loxahatchee FL USA
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Gasbarrini D, Lesbarrères D, Sheppard A, Litzgus J. An enigmatic mass mortality event of Blanding’s Turtles ( Emydoidea blandingii) in a protected area. CAN J ZOOL 2021. [DOI: 10.1139/cjz-2020-0204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mass mortality events (MMEs) can remove up to 90% of individuals in a population and are especially damaging to population viability of long-lived species with slow life histories. Our goal was to elucidate the cause(s) of a MME of 53 Blanding’s Turtles (Emydoidea blandingii (Holbrook, 1838)), a globally endangered species, in a protected area. We investigated disease, winter-kill, and depredation as potential causes of the mortality. The turtle carcasses lacked soft tissue to test for disease, so we examined tissue from co-occurring live Leopard Frogs (Lithobates pipiens (Schreber, 1782)) and found no evidence of ranavirus, indicating that the disease was not present at our study site. Water temperature and dissolved aquatic oxygen at known overwintering sites and sites which yielded carcasses did not differ, suggesting that winter-kill did not cause the MME. Carcass condition, comparisons with descriptions of turtle depredation events in the literature, and trail cameras paired with turtle decoys identified potential predators within the study site and suggested that mass depredation, enabled by low water levels and a concomitant reduction in aquatic habitat, was the most likely cause of mortality. Our study can inform conservation of the study population and the management of MMEs of long-lived species elsewhere.
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Affiliation(s)
- D.M.L. Gasbarrini
- Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada
| | - D. Lesbarrères
- Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada
| | - A. Sheppard
- Ontario Parks, Northeast Zone, Suite 404, 199 Larch Street, Sudbury, ON P3E 5P9, Canada
| | - J.D. Litzgus
- Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada
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Lélias ML, Lemasson A, Lodé T. Social organization of otters in relation to their ecology. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab016] [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]
Abstract
Abstract
Otter species are known to fluctuate intraspecifically from a solitary lifestyle to group-living arrangements. By examining what is known about habitat use and foraging style in otters of 13 different species, based on 93 studied sites, we assessed (1) the relationship between social habits and preferred habitats, (2) the relationship between species and prey preferences, and (3) the effect of predator avoidance on their social organization in order to assess the socio-ecological factors influencing otters. Females remain the core of their social stability. We show the major influence of habitats and feeding strategies (i.e. socio-ecology) of otters. The different species of solitary otters most often inhabit linear environments, such as freshwater ecosystems or wave-exposed marine coasts, and their habitat is often subject to disturbances that fragment their functional continuity. Social otters are more often found in extensive habitats with high plant cover, regular food resources and in areas with large predators compared to solitary species. The maintenance of regular resources and the fact that the main trophic resources are replenished rapidly might be determining factors driving sociality. Group-living and bachelor congregations among otters can also respond to pressure from large predators. This suggests that foraging, habitat use and the presence of large predators may be the drivers of sociality in otters. We conclude that most otters have a greater social potential than previously assumed, which is confirmed by their various vocalizations recently described.
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Affiliation(s)
| | - Alban Lemasson
- Univ Rennes, Normandie Univ, CNRS, EthoS (Éthologie animale et humaine) – UMR 6552, Rennes, France
| | - Thierry Lodé
- Univ Rennes, Normandie Univ, CNRS, EthoS (Éthologie animale et humaine) – UMR 6552, Rennes, France
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8
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Eccles KM, Thomas PJ, Chan HM. Spatial patterns of the exposure-response relationship between mercury and cortisol in the fur of river otter (Lontra canadensis). CHEMOSPHERE 2021; 263:127992. [PMID: 32835981 DOI: 10.1016/j.chemosphere.2020.127992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/09/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
Fur has been validated as a useful biomarker medium for chemical exposures and biological responses in wildlife. Mercury (Hg) is known to act as an endocrine disruptor by altering brain neurochemistry. In this study, we investigated the spatial patterns of relationships between total Hg (THg) and cortisol in the fur of river otter (Lontra canadensis). Geotagged fur samples were obtained from a wildlife biomonitoring program (n = 72) and the North American Fur Auction (n = 37) between 2014 and 2017. Fur THg was measured using direct thermal decomposition and fur cortisol was measured using an enzyme-linked immunosorbent assay (ELISA). The average fur THg concentration was 11.50 ± 12.40 μg/g fur weight (f.w.), and the fur cortisol concentration was 5.71 ± 8.24 pg/mg. Results from the global ordinary least squares regression show no relationship between THg and fur cortisol concentrations. However, both Hg and cortisol were heterogeneously distributed across the landscape. When a localized geographically weighted regression (GWR) was used, a geographically distinct bi-phasic relationship was observed. We suggest this bi-phasic relationship is associated with a threshold THg concentration, beyond which, there was a negative association with measured fur cortisol. Results of a break-point analysis, with one break, indicate that the threshold is 16 ± 1.27 μg/g f. w of THg in fur. This research highlights the need to use appropriate spatial methods when assessing exposure-response relationships in wildlife across large geographical areas. The identified threshold can be used for regulatory purposes.
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Affiliation(s)
- Kristin M Eccles
- Department of Biology, University of Ottawa, 180, Gendron Hall, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
| | - Philippe J Thomas
- Department of Biology, University of Ottawa, 180, Gendron Hall, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada; Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Center, 1125, Colonel By Drive, Raven Road, Ottawa, ON K1A 0H3, Canada.
| | - Hing Man Chan
- Department of Biology, University of Ottawa, 180, Gendron Hall, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
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Lacey EA, O’Brien SL, Sobrero R, Ebensperger LA. Spatial relationships among free-living cururos (Spalacopus cyanus) demonstrate burrow sharing and communal nesting. J Mammal 2019. [DOI: 10.1093/jmammal/gyz117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Abstract
Spatial relationships among conspecifics can provide insights into numerous aspects of social behavior. Spatial data may be particularly important for characterizing the behavior of difficult-to-study species such as subterranean rodents, direct observations of which are challenging. To characterize the social organization of the cururo (Spalacopus cyanus), a subterranean species in the rodent family Octodontidae, we used radiotelemetry to quantify spatial relationships within populations of this species located in Parque Nacional Bosque Fray Jorge and Santuario de la Naturaleza Yerba Loca, Chile. Specifically, we sought to determine if adults in this diurnal species share burrows and subterranean nests, the two criteria typically used to identify subterranean rodents as social. Analyses of radio fixes collected during February–March 2003 revealed that cururos at both Fray Jorge and Yerba Loca shared nighttime nest sites; cluster analyses of these data identified multiple spatially distinct subsets of adults in each population. Overlap of minimum convex polygons constructed from radio fixes collected during daylight hours suggested burrow sharing by animals in both populations. Cluster analyses of overlap values revealed the same spatially distinct groups of individuals identified from analyses of nest sharing; in addition, these analyses revealed one cluster of animals in each population that was not evident from analyses of nighttime data. Collectively, these results confirm that cururos are social, with adults in both study populations sharing burrow systems and communal nests. Our findings add to the growing understanding of social organization in octodontid rodents and reveal a new system for comparative studies of the ecology and evolution of behavioral variation in burrow-dwelling mammals.
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Affiliation(s)
- Eileen A Lacey
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Shannon L O’Brien
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Raúl Sobrero
- Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Universidad Nacional del Litoral (UNL)/Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Esperanza, Santa Fe, Argentina
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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10
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Behavioral Response of the Mammalian Community to River Otter Latrine Activity. AMERICAN MIDLAND NATURALIST 2019. [DOI: 10.1674/0003-0031-182.1.75] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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11
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Hanrahan AT, Rutter AU, Nielsen CK, Schauber EM. Spatial ecology of river otters in a human-modified landscape. J Mammal 2019. [DOI: 10.1093/jmammal/gyz095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AbstractRiver otter populations have expanded across much of their historical range, including in Illinois where they were reintroduced from 1994 to 1997. These expanding populations are recolonizing a wide range of landscapes with different levels of human modification, which could influence how river otters use space in relation to habitat characteristics and each other. Our objectives were to quantify 1) home ranges and core areas, 2) sociality, and 3) habitat selection across all available habitats and within home ranges (second- and third-order selection, respectively) of 22 radiomarked river otters (Lontra canadensis) in southern Illinois during 2014–2016. Our study area contained a diverse mix of forest, agriculture, aquatic and wetland habitats, and a range of urban development intensity. We examined sociality using the frequency at which individuals were located < 25 m from a conspecific and compared home-range overlap among individuals based on sex. Habitat selection at the second and third order was analyzed using an eigen-analysis of selection ratios based on landcover categories. Similar to other studies, male river otters had > 2-fold larger home ranges and core areas than females in southern Illinois. Several lines of evidence indicated males were more social than females. Males were located close to a conspecific more frequently than were females, and overlap of home ranges and core areas among males was greater than it was among females or between sexes. As observed in other landscapes, river otters strongly selected herbaceous and wooded wetlands at both second- and third-order scales. River otters selected terrestrial cover types with vegetative cover potentially due to shelter or prey availability. Forests were selected over crop fields at the third-order scale, which was consistent with studies using sign surveys. River otters in our study had home ranges containing 0–40% developed land cover, but we found no evidence that otters living in more developed areas used their home ranges more selectively. River otters in this landscape were plastic in regard to social behavior and habitat selection, highlighting their generalist nature and providing insight into their ability to successfully recolonize areas of the Midwest with sufficient vegetative cover and aquatic habitat, among other factors.
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Affiliation(s)
- Alexander T Hanrahan
- Cooperative Wildlife Research Laboratory and Department of Zoology, Southern Illinois University Carbondale, 251 Life Science II, Carbondale, IL USA
| | - Andrew U Rutter
- Cooperative Wildlife Research Laboratory and Department of Forestry, Southern Illinois University Carbondale, 251 Life Science II, Carbondale, IL, USA
| | - Clayton K Nielsen
- Cooperative Wildlife Research Laboratory and Department of Forestry, Southern Illinois University Carbondale, 251 Life Science II, Carbondale, IL, USA
| | - Eric M Schauber
- Cooperative Wildlife Research Laboratory and Department of Zoology, Southern Illinois University Carbondale, 251 Life Science II, Carbondale, IL USA
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12
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North American river otters (Lontra canadensis) discriminate between 2D objects varying in shape and color. Learn Behav 2018; 47:91-104. [PMID: 30251106 DOI: 10.3758/s13420-018-0346-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We investigated the ability of North American river otters (Lontra canadensis) to visually discriminate between 2D objects. The otters learned to discriminate between stimuli using multiple visual features and then were tested with stimuli in which one of the features was eliminated (color or shape). Two adult otters were trained in a two-alternative forced choice task to discriminate between a red circle and a blue triangle. Test sessions included probe trials containing novel shapes, colors, or shape-color combinations. Both otters successfully learned to discriminate between stimuli varying in multiple features. One of the otters was able to successfully discriminate between novel test stimuli when either color or shape were eliminated as salient features. This study was the first to explore the ability of L. canadensis to use different visual features to recognize objects and provides some preliminary evidence for color vision in this species. This research adds to the sparse literature on perceptual and cognitive capabilities in otters and can be used to support future conservation efforts for this species.
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Huang AC, Nelson C, Elliott JE, Guertin DA, Ritland C, Drouillard K, Cheng KM, Schwantje HM. River otters (Lontra canadensis) "trapped" in a coastal environment contaminated with persistent organic pollutants: Demographic and physiological consequences. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 238:306-316. [PMID: 29573713 DOI: 10.1016/j.envpol.2018.03.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 03/12/2018] [Accepted: 03/12/2018] [Indexed: 06/08/2023]
Abstract
Productive coastal and estuarine habitats can be degraded by contaminants including persistent organic pollutants (POPs) such as PCBs, dioxins, and organochlorine insecticides to the extent of official designation as contaminated sites. Top-predatory wildlife may continue to use such sites as the habitat often appears suitable, and thus bioaccumulate POPs and other contaminants with potential consequences on their health and fitness. Victoria and Esquimalt harbours are located on southern Vancouver Island, British Columbia (BC) and are federally designated contaminated sites due mainly to past heavy industrial activities, such as from shipyards and sawmills. We collected scat samples from river otters (Lontra canadensis) throughout an annual cycle, and combined chemical analysis with DNA genotyping to examine whether the harbour areas constituted a contaminant-induced ecological trap for otters. We confirmed spatial habitat use by radio telemetry of a subsample of otters. Fifteen percent of otter scat contained PCB concentrations exceeding levels considered to have adverse effects on the reproduction of mink (Neovison vison), and there were significant positive correlations between concentrations of PCBs and of thyroid (T3) and sex (progesterone) hormones in fecal samples. Radio telemetry data revealed that otters did not show directional movement away from the harbours, indicating their inability to recognize the contaminated site as a degraded habitat. However, analysis and modeling of the DNA genotyping data provided no evidence that the harbour otters formed a sink population and therefore were in an ecological trap. Despite the highly POP-contaminated habitat, river otters did not appear to be adversely impacted at the population level. Our study demonstrates the value of combining chemical and biological technologies with ecological theory to investigate practical conservation problems.
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Affiliation(s)
- Andrew C Huang
- Science & Technology Branch, Environment and Climate Change Canada, Delta, BC, Canada
| | - Cait Nelson
- Avian Research Centre, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada; British Columbia Ministry of Forests, Lands, Natural Resource Operations and Rural Development, Victoria, BC, Canada
| | - John E Elliott
- Science & Technology Branch, Environment and Climate Change Canada, Delta, BC, Canada; Avian Research Centre, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada.
| | - Daniel A Guertin
- Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Carol Ritland
- Genetic Data Centre, Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Ken Drouillard
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada
| | - Kimberly M Cheng
- Avian Research Centre, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada
| | - Helen M Schwantje
- British Columbia Ministry of Forests, Lands, Natural Resource Operations and Rural Development, Victoria, BC, Canada
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Survival and Cause-Specific Mortality of River Otters in Southern Illinois. AMERICAN MIDLAND NATURALIST 2018. [DOI: 10.1674/0003-0031-180.1.160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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15
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Affiliation(s)
- Nathan R. Bieber
- Nebraska Cooperative Fish and Wildlife Research Unit; University of Nebraska-Lincoln; 3310 Holdrege Street Lincoln NE 68583 USA
| | - Samuel P. Wilson
- Nebraska Game and Parks Commission; 2200 N 33rd Street; Lincoln NE 68503 USA
| | - Craig R. Allen
- U.S. Geological Survey, Nebraska Cooperative Fish and Wildlife Research Unit; University of Nebraska-Lincoln; 3310 Holdrege Street Lincoln NE 68583 USA
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16
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Are latrine sites an accurate predictor of seasonal habitat selection by river otters (Lontra canadensis) in freshwater systems? MAMMAL RES 2016. [DOI: 10.1007/s13364-016-0297-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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17
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Coastal latrine sites as social information hubs and drivers of river otter fission–fusion dynamics. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2016.07.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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18
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Crowley S, Johnson CJ, Hodder DP. Spatio-temporal variation in river otter (Lontra canadensis) diet and latrine site activity. ECOSCIENCE 2015. [DOI: 10.2980/20-1-3509] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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19
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Lima DO, Pinho GM, Fernandez FAS. Spatial patterns of the semi-aquatic rodent Nectomys squamipesin Atlantic forest streams. J NAT HIST 2015. [DOI: 10.1080/00222933.2015.1059516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Hernández-Romero PC, Guerrero JA, Valdespino C. Morphological variability of the cranium of Lontra longicaudis (Carnivora: Mustelidae): a morphometric and geographic analysis. Zool Stud 2015; 54:e50. [PMID: 31966137 DOI: 10.1186/s40555-015-0127-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 08/06/2015] [Indexed: 11/10/2022]
Abstract
BACKGROUND Studies of morphometric variation make it possible to delimit species and geographic intraspecific variation, mainly in species with wide distribution ranges. In the Neotropical otter, Lontra longicaudis, variation in the shape of the rhinarium of three potential subspecies has been described but it is not known whether there is a pattern to the morphometric variation in the skull throughout the distribution of this species. We analyzed morphological variation in the cranium (ventral view) and the mandible (lateral view) of the Neotropical otter, comparing male and female specimens and evaluating the differences between specified geographic units utilizing methods from geometric morphometrics. Specimens from the entire distribution of the species were analyzed. Between sexes, variability in the shape was determined by calculating the Procrustes distances and using Goodall's F test. Geographic variationwas analyzed using a discriminant analysis, an analysis of variance (ANOVA) on a matrix of partial warp scores, and a cluster analysis with Mahalanobis distances, allowing for similarities in shape to be identified between different geographic units. Variation in the size of the two structures was calculated based on the values for centroid size using a one-way ANOVA with a Bonferroni correction and a 95 % confidence interval. RESULTS There was sexual dimorphism in shape for both views, with males the largest. In general, there was geographic variation in the shape and size of both the cranium and the mandible in the Neotropical otter, exhibiting a pattern that resembled Bergmann's rule. Variation in shape between geographic units could result from the presence of geographic barriers, the spatial configuration of hydrological regions, and/or the large distances between populations throughout this species' distribution. CONCLUSIONS The Neotropical otter exhibits dimorphism in the size, but not in the shape of the skull. There is geographic variation between geographic units, and our results suggest that L.longicaudis could bea group of species. An integrative study using molecular and morphological data could elucidate its taxonomy.
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Affiliation(s)
- Pablo César Hernández-Romero
- Instituto de Ecología A.C., Red de Biología y Conservación de Vertebrados, CP 91070, Carretera antigua a Coatepec 351, Xalapa, Mexico
| | | | - Carolina Valdespino
- Instituto de Ecología A.C., Red de Biología y Conservación de Vertebrados, CP 91070, Carretera antigua a Coatepec 351, Xalapa, Mexico
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Albeke SE, Nibbelink NP, Ben-David M. Modeling Behavior by Coastal River Otter (Lontra Canadensis) in Response to Prey Availability in Prince William Sound, Alaska: A Spatially-Explicit Individual-Based Approach. PLoS One 2015; 10:e0126208. [PMID: 26061497 PMCID: PMC4489515 DOI: 10.1371/journal.pone.0126208] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 03/30/2015] [Indexed: 11/18/2022] Open
Abstract
Effects of climate change on animal behavior and cascading ecosystem responses are rarely evaluated. In coastal Alaska, social river otters (Lontra Canadensis), largely males, cooperatively forage on schooling fish and use latrine sites to communicate group associations and dominance. Conversely, solitary otters, mainly females, feed on intertidal-demersal fish and display mutual avoidance via scent marking. This behavioral variability creates "hotspots" of nutrient deposition and affects plant productivity and diversity on the terrestrial landscape. Because the abundance of schooling pelagic fish is predicted to decline with climate change, we developed a spatially-explicit individual-based model (IBM) of otter behavior and tested six scenarios based on potential shifts to distribution patterns of schooling fish. Emergent patterns from the IBM closely mimicked observed otter behavior and landscape use in the absence of explicit rules of intraspecific attraction or repulsion. Model results were most sensitive to rules regarding spatial memory and activity state following an encounter with a fish school. With declining availability of schooling fish, the number of social groups and the time simulated otters spent in the company of conspecifics declined. Concurrently, model results suggested an elevation of defecation rate, a 25% increase in nitrogen transport to the terrestrial landscape, and significant changes to the spatial distribution of "hotspots" with declines in schooling fish availability. However, reductions in availability of schooling fish could lead to declines in otter density over time.
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Affiliation(s)
- Shannon E. Albeke
- Wyoming Geographic Information Science Center, University of Wyoming, Laramie, Wyoming, United States of America
- * E-mail:
| | - Nathan P. Nibbelink
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia, United States of America
| | - Merav Ben-David
- Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, United States of America
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22
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Day CC, Westover MD, McMillan BR. Seasonal diet of the northern river otter (Lontra canadensis): what drives prey selection? CAN J ZOOL 2015. [DOI: 10.1139/cjz-2014-0218] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Diet of the northern river otter (Lontra canadensis (Schreber, 1777)) has been examined throughout much of its range and across many habitat types. Few studies have examined prey selection based on prey abundance estimates, however, and prey selection results have been inconsistent. We determined composition, seasonal variation, and prey selection of otter diet in northern Utah comprising multiple habitat types and prey communities. We evaluated the hypothesis that otters take prey according to availability and in inverse proportion to swimming ability. Fish was the primary class of prey taken by otters (96.5%), followed by crustaceans (16.9%). Among families, otter diet was composed primarily of Salmonidae and Cottidae, the two families that dominated the fish community of the main-channel habitat. Otter diet varied seasonally for nearly all classes (G[24] = 127.8, P < 0.001) and families (G[18] = 132.94, P < 0.001) of prey. In particular, fish occurrence was lower during summer than during other seasons (P ≤ 0.05), whereas crustacean (i.e., crayfish (Astacoidea)) occurrence was higher (G[3] = 71.1, P < 0.001). At the family level, occurrence of Salmonidae was greatest during fall (G[3] = 11.7, P < 0.01). Within one of our habitat types, we found otters to select for prey in proportion to abundance and in inverse proportion to swimming ability, with otters selecting for Catostomidae and Cyprinidae, against Salmonidae, and Cottidae according to its abundance. We conclude that habitat type may be the initial driver of prey selection, while factors such as abundance, agility, and life history of prey may be secondary drivers.
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Affiliation(s)
- Casey C. Day
- Brigham Young University, Department of Plant and Wildlife Sciences, 275 Widtsoe Building, Provo, UT 84602, USA
- Brigham Young University, Department of Plant and Wildlife Sciences, 275 Widtsoe Building, Provo, UT 84602, USA
| | - Matthew D. Westover
- Brigham Young University, Department of Plant and Wildlife Sciences, 275 Widtsoe Building, Provo, UT 84602, USA
- Brigham Young University, Department of Plant and Wildlife Sciences, 275 Widtsoe Building, Provo, UT 84602, USA
| | - Brock R. McMillan
- Brigham Young University, Department of Plant and Wildlife Sciences, 275 Widtsoe Building, Provo, UT 84602, USA
- Brigham Young University, Department of Plant and Wildlife Sciences, 275 Widtsoe Building, Provo, UT 84602, USA
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Darnell AM, Graf JA, Somers MJ, Slotow R, Szykman Gunther M. Space use of African wild dogs in relation to other large carnivores. PLoS One 2014; 9:e98846. [PMID: 24896638 PMCID: PMC4045926 DOI: 10.1371/journal.pone.0098846] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 05/07/2014] [Indexed: 11/18/2022] Open
Abstract
Interaction among species through competition is a principle process structuring ecological communities, affecting behavior, distribution, and ultimately the population dynamics of species. High competition among large African carnivores, associated with extensive diet overlap, manifests in interactions between subordinate African wild dogs (Lycaon pictus) and dominant lions (Panthera leo) and spotted hyenas (Crocuta crocuta). Using locations of large carnivores in Hluhluwe-iMfolozi Park, South Africa, we found different responses from wild dogs to their two main competitors. Wild dogs avoided lions, particularly during denning, through a combination of spatial and temporal avoidance. However, wild dogs did not exhibit spatial or temporal avoidance of spotted hyenas, likely because wild dog pack sizes were large enough to adequately defend their kills. Understanding that larger carnivores affect the movements and space use of other carnivores is important for managing current small and fragmented carnivore populations, especially as reintroductions and translocations are essential tools used for the survival of endangered species, as with African wild dogs.
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Affiliation(s)
- Angela M. Darnell
- Department of Wildlife, Humboldt State University, Arcata, California, United States of America
- * E-mail:
| | - Jan A. Graf
- School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Michael J. Somers
- Centre for Wildlife Management, Centre for Invasion Biology, University of Pretoria, Pretoria, South Africa
| | - Rob Slotow
- School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Micaela Szykman Gunther
- Department of Wildlife, Humboldt State University, Arcata, California, United States of America
- Smithsonian Conservation Biology Institute, Front Royal, Virginia, United States of America
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24
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Long JA, Nelson TA, Webb SL, Gee KL. A critical examination of indices of dynamic interaction for wildlife telemetry studies. J Anim Ecol 2014; 83:1216-33. [DOI: 10.1111/1365-2656.12198] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 01/06/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Jed A. Long
- Centre for GeoInformatics; Department of Geography & Sustainable Development; University of St Andrews; St Andrews Fife UK
| | - Trisalyn A. Nelson
- Spatial Pattern Analysis & Research Laboratory; Department of Geography; University of Victoria; Victoria BC Canada
| | - Stephen L. Webb
- The Samuel Roberts Noble Foundation; 2510 Sam Noble Parkway Ardmore OK 73401 USA
| | - Kenneth L. Gee
- The Samuel Roberts Noble Foundation; 2510 Sam Noble Parkway Ardmore OK 73401 USA
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25
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Quaglietta L, Fonseca VC, Mira A, Boitani L. Sociospatial organization of a solitary carnivore, the Eurasian otter (Lutra lutra). J Mammal 2014. [DOI: 10.1644/13-mamm-a-073.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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26
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Carpenter SK, Mateus-Pinilla NE, Singh K, Lehner A, Satterthwaite-Phillips D, Bluett RD, Rivera NA, Novakofski JE. River otters as biomonitors for organochlorine pesticides, PCBs, and PBDEs in Illinois. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2014; 100:99-104. [PMID: 24119654 DOI: 10.1016/j.ecoenv.2013.07.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 07/29/2013] [Accepted: 07/30/2013] [Indexed: 06/02/2023]
Abstract
The North American river otter (Lontra canadensis) is a biomonitor for organohalogenated compounds (OHCs) associated with a wide range of deleterious health effects in wildlife and humans. We determined concentrations of twenty OHCs in livers of 23 river otters salvaged by the Illinois Department of Natural Resources from 2009 to 2011, determined sex-dependent distribution of OHCs, and compared our results to the reported concentrations of four OHCs in Illinois river otters from 1984 to 1989. Since these contaminants have been banned for over 30 years, we predicted smaller mean concentrations than those previously reported in Illinois otters. We detected eleven of twenty OHCs; PCBs (polychlorinated biphenyls), dieldrin, and 4,4'-DDE (dichlorodiphenyldichloroethylene) were present in the greatest mean concentrations. We report the largest mean concentration of dieldrin to date in the liver of North American river otters (mean: 174, range: 14.4-534 parts per billion wet wt [ppb]). Mean PCB concentrations were significantly higher in males (mean: 851; range: 30-3450 ppb) than females (mean: 282; range: 40-850 ppb; p=0.04). Mean concentrations of dieldrin were greater than those detected in otters from 1984 to 1989 (mean: 90; range: 30-130 ppb; p<0.05). Our results suggest OHC exposure remains a concern. Future research in Illinois should focus on evaluating OHCs exposures, particularly dieldrin, at the watershed level.
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Affiliation(s)
- Samantha K Carpenter
- Illinois Natural History Survey, University of Illinois Urbana-Champaign, 1816 South Oak St., Champaign IL 61820, United States.
| | - Nohra E Mateus-Pinilla
- Illinois Natural History Survey, University of Illinois Urbana-Champaign, 1816 South Oak St., Champaign IL 61820, United States.
| | - Kuldeep Singh
- College of Veterinary Medicine, University of Illinois Urbana-Champaign, 2001 South Lincoln Ave., Urbana, IL 61802, United States.
| | - Andreas Lehner
- Diagnostic Center for Population and Animal Health, Michigan State University, 4125 Beaumont Rd., Lansing, MI 48910, United States.
| | - Damian Satterthwaite-Phillips
- Illinois Natural History Survey, University of Illinois Urbana-Champaign, 1816 South Oak St., Champaign IL 61820, United States.
| | - Robert D Bluett
- Illinois Department of Natural Resources, One Natural Resources Way, Springfield, IL 62702-1271, United States.
| | - Nelda A Rivera
- Illinois Natural History Survey, University of Illinois Urbana-Champaign, 1816 South Oak St., Champaign IL 61820, United States.
| | - Jan E Novakofski
- Department of Animal Sciences, University of Illinois Urbana-Champaign, 205 Meat Science Lab 1503S Maryland Dr M/C 010, Urbana, IL 61801, United States.
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27
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Day CC, Westover MD, McMillan BR. Factors Influencing Mortality Associated with the Translocation of Northern River Otters (Lontra canadensis) in Utah. WEST N AM NATURALIST 2013. [DOI: 10.3398/064.073.0309] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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28
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Brzeski KE, Gunther MS, Black JM. Evaluating river otter demography using noninvasive genetic methods. J Wildl Manage 2013. [DOI: 10.1002/jwmg.610] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | | | - Jeffrey M. Black
- Department of Wildlife; Humboldt State University; Arcata CA 95521 USA
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29
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Barrett DA, Leslie DM. Spatio-Temporal Variations in Age Structures of a Partially Re-established Population of Northern River Otters (Lontra canadensis). AMERICAN MIDLAND NATURALIST 2012. [DOI: 10.1674/0003-0031-168.2.302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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30
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Crowley S, Johnson CJ, Hodder D. The role of demographic and environmental variables on the presence of snow tracks by river ottersLontra canadensis. WILDLIFE BIOLOGY 2012. [DOI: 10.2981/10-069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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32
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Martin DJ, McMillan BR, Erb JD, Gorman TA, Walsh DP. Diel activity patterns of river otters (Lontra canadensis) in southeastern Minnesota. J Mammal 2010. [DOI: 10.1644/09-mamm-a-083.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Finerty SE, Pearson HC, Davis RW. Interannual assessment of territory quality for male sea otters (Enhydra lutris) in Simpson Bay, Prince William Sound, Alaska. CAN J ZOOL 2010. [DOI: 10.1139/z10-003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Territory quality and site fidelity were assessed for male sea otters ( Enhydra lutris (L., 1758)) in Simpson Bay, Prince William Sound, Alaska, during the summer months (May–August) from 2003 to 2006. Territory quality was coded with a score of 0–2 for four attributes: territory size, shoreline enclosure, territory accessibility, and number of females observed feeding in each territory. Total quality scores ranged from 0.14 to 1.96 (0.9 ± 0.61, mean ± SD), with the highest quality territories having large areas, moderate to little shoreline enclosure, high accessibility, and many foraging females. A total of 13.1 km2 (62.5%) of Simpson Bay was occupied at least once by a territorial male during the 4-year study, and 7.9 km2 (37.5%) was never occupied by a territorial male. There were 7 ± 2.4 (mean ± SD) territorial males in Simpson Bay each year. Five males maintained territories for two consecutive years, with their respective territories having a 16%–34% overlap between years, indicating that repeat territory holders returned to the same area. The number of territorial sea otters, the size of territories, and whether or not a sea otter was a repeat territory holder did not significantly influence the size or quality of male territories.
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Affiliation(s)
- Shannon E. Finerty
- Department of Wildlife and Fisheries Sciences, Texas A&M University, 5007 Avenue U, Galveston, TX 77551, USA
| | - Heidi C. Pearson
- Department of Wildlife and Fisheries Sciences, Texas A&M University, 5007 Avenue U, Galveston, TX 77551, USA
| | - Randall W. Davis
- Department of Wildlife and Fisheries Sciences, Texas A&M University, 5007 Avenue U, Galveston, TX 77551, USA
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Crimmins SM, Roberts NM, Hamilton DA, Mynsberge AR. Seasonal detection rates of river otters (Lontra canadensis) using bridge-site and random-site surveys. CAN J ZOOL 2009. [DOI: 10.1139/z09-090] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Randomization of survey sites is generally desired because of its unbiased approach, but is often abandoned because of logistical constraints. This is true for river otters ( Lontra canadensis (Schreber, 1777)), with bridges commonly determining survey locations. We conducted seasonal sign surveys for river otters on two rivers in southern Missouri, USA, using randomized survey points and fixed bridge-crossing points in 2001–2003. Otter sign was more likely to be detected at randomized sites than at bridge sites in summer (P < 0.0001), with sign being detected on 68% of visits to random sites (n = 348) and on 40% of visits to bridge sites (n = 60). Scat abundance was higher (P = 0.0001) at random sites (8.82 ± 0.6, mean ± SE) than at bridge sites (3.96 ± 1.0) during the summer. Similar but nonsignificant trends were found during the winter. Detection probabilities were significantly higher at random sites than at bridge sites in both seasons. Our results indicate that surveys of bridge sites for river otters may yield inaccurate results for distribution and relative abundance, particularly if conducted during the summer.
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Affiliation(s)
- S. M. Crimmins
- Department of Forest Management, College of Forestry and Conservation, University of Montana, Missoula, MT 59812, USA
- Department of Natural Resources, 207 Fernow Hall, Cornell University, Ithaca, NY 14853, USA
- Missouri Department of Conservation, 1110 South College Avenue, Columbia, MO 65201, USA
| | - N. M. Roberts
- Department of Forest Management, College of Forestry and Conservation, University of Montana, Missoula, MT 59812, USA
- Department of Natural Resources, 207 Fernow Hall, Cornell University, Ithaca, NY 14853, USA
- Missouri Department of Conservation, 1110 South College Avenue, Columbia, MO 65201, USA
| | - D. A. Hamilton
- Department of Forest Management, College of Forestry and Conservation, University of Montana, Missoula, MT 59812, USA
- Department of Natural Resources, 207 Fernow Hall, Cornell University, Ithaca, NY 14853, USA
- Missouri Department of Conservation, 1110 South College Avenue, Columbia, MO 65201, USA
| | - A. R. Mynsberge
- Department of Forest Management, College of Forestry and Conservation, University of Montana, Missoula, MT 59812, USA
- Department of Natural Resources, 207 Fernow Hall, Cornell University, Ithaca, NY 14853, USA
- Missouri Department of Conservation, 1110 South College Avenue, Columbia, MO 65201, USA
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Hansen H, McDonald DB, Groves P, Maier JAK, Ben-David M. Social Networks and the Formation and Maintenance of River Otter Groups. Ethology 2009. [DOI: 10.1111/j.1439-0310.2009.01624.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bateman HL, Bond JB, Campbell M, Barrie M, Riggs G, Snyder B, Swanson WF. Characterization of basal seminal traits and reproductive endocrine profiles in North American river otters and Asian small-clawed otters. Zoo Biol 2009; 28:107-26. [DOI: 10.1002/zoo.20206] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ranging behaviour and socio-biology of Eurasian otters (Lutra lutra) on lowland mesotrophic river systems. EUR J WILDLIFE RES 2009. [DOI: 10.1007/s10344-009-0252-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Gorman T, Bishop D, Haas C. Spatial Interactions between Two Species of Frogs: Rana okaloosae and R. clamitans clamitans. COPEIA 2009. [DOI: 10.1643/ce-07-258] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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39
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Field techniques for handling, anaesthetising and fitting radio-transmitters to Eurasian otters (Lutra lutra). EUR J WILDLIFE RES 2008. [DOI: 10.1007/s10344-008-0196-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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