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Potash AD, Conner LM, Clinchy M, Zanette LY, McCleery RA. Prey species increase activity in refugia free of terrestrial predators. Oecologia 2023; 201:661-671. [PMID: 36897410 DOI: 10.1007/s00442-023-05350-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 03/02/2023] [Indexed: 03/11/2023]
Abstract
The decline of terrestrial predator populations across the globe is altering top-down pressures that drive predator-prey interactions. However, a knowledge gap remains in understanding how removing terrestrial predators affects prey behavior. Using a bifactorial playback experiment, we exposed fox squirrels to predator (red-tailed hawks, coyotes, dogs) and non-predator control (Carolina wren) calls inside terrestrial predator exclosures, accessible to avian predators, and in control areas subject to ambient predation risk. Fox squirrels increased their use of terrestrial predator exclosures, a pattern that corresponded with 3 years of camera trapping. Our findings suggest fox squirrels recognized that exclosures had predictably lower predation risk. However, exclosures had no effect on their immediate behavioral response towards any call, and fox squirrels responded most severely to hawk predator calls. This study shows that anthropogenically driven predator loss creates predictably safer areas (refugia) that prey respond to proactively with increased use. However, the persistence of a lethal avian predator is sufficient to retain a reactive antipredator response towards an immediate predation threat. Some prey may benefit from shifting predator-prey interactions by gaining refugia without sacrificing a sufficient response towards potential predators.
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Affiliation(s)
- Alex D Potash
- Department of Wildlife Ecology, University of Florida Institute of Food and Agricultural Science, 110 Newins-Ziegler Hall, P.O. Box 110430, Gainesville, FL, 32611, USA.
- The Jones Center at Ichauway, 3988 Jones Center Drive, Newton, GA, 39870, USA.
| | - L Mike Conner
- The Jones Center at Ichauway, 3988 Jones Center Drive, Newton, GA, 39870, USA
| | - Michael Clinchy
- Department of Biology, Western University, London, ON, N6A 5B7, Canada
| | - Liana Y Zanette
- Department of Biology, Western University, London, ON, N6A 5B7, Canada
| | - Robert A McCleery
- Department of Wildlife Ecology, University of Florida Institute of Food and Agricultural Science, 110 Newins-Ziegler Hall, P.O. Box 110430, Gainesville, FL, 32611, USA
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2
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Diggins CA, Lipford A, Farwell T, Eline DV, Larose SH, Kelly CA, Clucas B. Can camera traps be used to differentiate species of North American flying squirrels? WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Corinne A. Diggins
- Department of Fish and Wildlife Conservation Virginia Tech Blacksburg VA 24061 USA
| | - Aylett Lipford
- School of Renewable Natural Resources Louisiana State University Baton Rouge LA 70808 USA
| | - Travis Farwell
- Department of Wildlife Humboldt State University Arcata CA 95521 USA
| | - Drew V. Eline
- Department of Environmental and Forest Biology SUNY College of Environmental Science and Forestry Syracuse NY 13210 USA
| | - Summer H. Larose
- School of Natural Resources University of Missouri Columbia MO 65211 USA
| | | | - Barbara Clucas
- Department of Wildlife Humboldt State University Arcata CA 95521 USA
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3
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Vukovich M, Garabedian JE, Zarnoch SJ, Kilgo JC. Do Remote Camera Arrangements and Image Capture Settings Improve Individual Identification of Golden Eagles? WILDLIFE SOC B 2021. [DOI: 10.1002/wsb.1180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Mark Vukovich
- USDA Forest Service Southern Research Station P.O Box 700 New Ellenton SC 29809 USA
| | - James E. Garabedian
- USDA Forest Service Southern Research Station P.O Box 700 New Ellenton SC 29809 USA
| | | | - John C. Kilgo
- USDA Forest Service Southern Research Station P.O Box 700 New Ellenton SC 29809 USA
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4
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Potash AD, Greene DU, Foursa GA, Mathis VL, Conner LM, McCleery RA. A comparison of animal color measurements using a commercially available digital color sensor and photograph analysis. Curr Zool 2020; 66:601-606. [PMID: 33391358 PMCID: PMC7769579 DOI: 10.1093/cz/zoaa016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 03/21/2020] [Indexed: 11/14/2022] Open
Abstract
An animal's pelage, feather, or skin color can serve a variety of functions, so it is important to have multiple standardized methods for measuring color. One of the most common and reliable methods for measuring animal coloration is the use of standardized digital photographs of animals. New technology in the form of a commercially available handheld digital color sensor could provide an alternative to photography-based animal color measurements. To determine whether a digital color sensor could be used to measure animal coloration, we tested the ability of a digital color sensor to measure coloration of mammalian, avian, and lepidopteran museums specimens. We compared results from the sensor to measurements taken using traditional photography methods. Our study yielded significant differences between photography-based and digital color sensor measurements of brightness (light to dark) and colors along the green to red spectrum. There was no difference between photographs and the digital color sensor measurements for colors along the blue to yellow spectrum. The average difference in recorded color (ΔE) by the 2 methods was above the threshold at which humans can perceive a difference. There were significant correlations between the sensor and photographs for all measurements indicating that the sensor is an effective animal coloration measuring tool. However, the sensor's small aperture and narrow light spectrum range designed for human-vision limit its value for ecological research. We discuss the conditions in which a digital color sensor can be an effective tool for measuring animal coloration in both laboratory settings and in the field.
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Affiliation(s)
- Alex D Potash
- Department of Wildlife Ecology and Conservation, University of Florida Institute of Food and Agricultural Science, Gainesville, FL 32611, USA
| | - Daniel U Greene
- Weyerhaeuser Company, Environmental Research South, Columbus, MS 39701, USA
| | - Gabrielle A Foursa
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Verity L Mathis
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | | | - Robert A McCleery
- Department of Wildlife Ecology and Conservation, University of Florida Institute of Food and Agricultural Science, Gainesville, FL 32611, USA
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Pynne J, Stober JM, Edelman AJ. Eastern Fox Squirrel (Sciurus niger) Occupancy in Fragmented Montane Longleaf Pine Forests. SOUTHEAST NAT 2020. [DOI: 10.1656/058.019.0221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- J.T. Pynne
- D.B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602
| | - Jonathan M. Stober
- Shoal Creek Ranger District, Talladega National Forest, United States Forest Service, Heflin, AL 36264
| | - Andrew J. Edelman
- Department of Biology, University of West Georgia, Carrollton, GA 30118
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Potash AD, Greene DU, Mathis VL, Baiser B, Conner LM, McCleery RA. Ecological Drivers of Eastern Fox Squirrel Pelage Polymorphism. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Potash AD, Murphy CM, Pynne J, McCleery RA, Conner LM, Castleberry SB, Smith LL. Eastern Fox Squirrel (Sciurus niger) Observed Using a Gopher Tortoise (Gopherus polyphemus) Burrow. SOUTHEAST NAT 2020. [DOI: 10.1656/058.019.0109] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Alex D. Potash
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611
| | | | - J.T. Pynne
- The Jones Center at Ichauway, Newton, GA 39870
| | - Robert A. McCleery
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611
| | | | - Steven B. Castleberry
- D.B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602
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Amspacher K, Bauer B, Waldron J, Wiggers E, Welch S. Sciurus niger niger (Southern Fox Squirrel) Density and the Diurnal Patterns, Occupancy, and Detection of Sympatric Southern Fox Squirrels and S. carolinensis (Eastern Gray Squirrel) on Spring Island, South Carolina. SOUTHEAST NAT 2019. [DOI: 10.1656/058.018.0214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Katelyn Amspacher
- Department of Biological Sciences, Marshall University, Huntington, WV 25755
| | - Beau Bauer
- Nemours Wildlife Foundation, Yemassee, SC 29945
| | - Jayme Waldron
- Department of Biological Sciences, Marshall University, Huntington, WV 25755
| | | | - Shane Welch
- Department of Biological Sciences, Marshall University, Huntington, WV 25755
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Dorning J, Harris S. The challenges of recognising individuals with few distinguishing features: Identifying red foxes Vulpes vulpes from camera-trap photos. PLoS One 2019; 14:e0216531. [PMID: 31071143 PMCID: PMC6508734 DOI: 10.1371/journal.pone.0216531] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 04/18/2019] [Indexed: 12/23/2022] Open
Abstract
Over the last two decades, camera traps have revolutionised the ability of biologists to undertake faunal surveys and estimate population densities, although identifying individuals of species with subtle markings remains challenging. We conducted a two-year camera-trapping study as part of a long-term study of urban foxes: our objectives were to determine whether red foxes could be identified individually from camera-trap photos, and highlight camera-trapping protocols and techniques to facilitate photo identification of species with few or subtle natural markings. We collected circa 800,000 camera-trap photos over 4945 camera days in suburban gardens in the city of Bristol, UK: 152,134 (19%) included foxes, of which 13,888 (9%) contained more than one fox. These provided 174,063 timestamped capture records of individual foxes; 170,923 were of foxes ≥ 3 months old. Younger foxes were excluded because they have few distinguishing features. We identified the individual (192 different foxes: 110 males, 49 females, 33 of unknown sex) in 168,417 (99%) of these capture records; the remainder could not be identified due to poor image quality or because key identifying feature(s) were not visible. We show that carefully designed survey techniques facilitate individual identification of subtly-marked species. Accuracy is enhanced by camera-trapping techniques that yield large numbers of high resolution, colour images from multiple angles taken under varying environmental conditions. While identifying foxes manually was labour-intensive, currently available automated identification systems are unlikely to achieve the same levels of accuracy, especially since different features were used to identify each fox, the features were often inconspicuous, and their appearance varied with environmental conditions. We discuss how studies based on low numbers of photos, or which fail to identify the individual in a significant proportion of photos, risk losing important biological information, and may come to erroneous conclusions.
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Affiliation(s)
- Jo Dorning
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
- * E-mail:
| | - Stephen Harris
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
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Potash AD, Mike Conner L, McCleery RA. Extreme Movements of an Individual Male Fox Squirrel. SOUTHEAST NAT 2018. [DOI: 10.1656/058.017.0304] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Alex D. Potash
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32608
- Joseph W. Jones Ecological Research Center, Newton, GA 39870
| | - L. Mike Conner
- Joseph W. Jones Ecological Research Center, Newton, GA 39870
| | - Robert A. McCleery
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32608
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11
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Canu A, Mattioli L, Santini A, Apollonio M, Scandura M. ‘Video-scats’: combining camera trapping and non-invasive genotyping to assess individual identity and hybrid status in gray wolf. WILDLIFE BIOLOGY 2017. [DOI: 10.2981/wlb.00355] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Antonio Canu
- A. Canu, M. Apollonio and M. Scandura , Dept. of Science for Nature and Environmental Resources, Univ. of Sassari, Via Muroni 25, IT-07100 Sassari, Italy. AC also at: C.I.R.Se.M.A.F. Firenze, Italy
| | - Luca Mattioli
- L. Mattioli, Regione Toscana, Settore Attività Faunistico Venatoria, Pesca Dilettantistica, Pesca in Mare, Arezzo, Italy
| | | | - Marco Apollonio
- A. Canu, M. Apollonio and M. Scandura , Dept. of Science for Nature and Environmental Resources, Univ. of Sassari, Via Muroni 25, IT-07100 Sassari, Italy. AC also at: C.I.R.Se.M.A.F. Firenze, Italy
| | - Massimo Scandura
- A. Canu, M. Apollonio and M. Scandura , Dept. of Science for Nature and Environmental Resources, Univ. of Sassari, Via Muroni 25, IT-07100 Sassari, Italy. AC also at: C.I.R.Se.M.A.F. Firenze, Italy
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Greene DU, McCleery RA. Reevaluating fox squirrel (Sciurus niger) population declines in the southeastern United States. J Mammal 2016. [DOI: 10.1093/jmammal/gyw186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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13
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Tye CA, McCleery RA, Fletcher RJ, Greene DU, Butryn RS. Evaluating citizen vs. professional data for modelling distributions of a rare squirrel. J Appl Ecol 2016. [DOI: 10.1111/1365-2664.12682] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Courtney A. Tye
- Department of Wildlife Ecology and Conservation; University of Florida; Gainesville FL 32611 USA
| | - Robert A. McCleery
- Department of Wildlife Ecology and Conservation; University of Florida; Gainesville FL 32611 USA
| | - Robert J. Fletcher
- Department of Wildlife Ecology and Conservation; University of Florida; Gainesville FL 32611 USA
| | - Daniel U. Greene
- Department of Wildlife Ecology and Conservation; University of Florida; Gainesville FL 32611 USA
| | - Ryan S. Butryn
- Fish and Wildlife Research Institute; Florida Fish and Wildlife Conservation Commission; Gainesville FL 32601 USA
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A Comparison of Four Survey Methods for Detecting Fox Squirrels in the Southeastern United States. JOURNAL OF FISH AND WILDLIFE MANAGEMENT 2016. [DOI: 10.3996/082015-jfwm-080] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Abstract
Fox squirrel Sciurus niger populations in the southeastern United States appear to have declined, and 3 (S. n. cinereus, S. n. shermani, and S. n. avicennia) of the 10 subspecies are currently listed with a conservation status of protection. Efforts to conserve and manage fox squirrels in the southeastern United States are constrained by difficulties in studying their populations because of low densities and low detectability. There is a need for an effective survey method to fill knowledge gaps on southeastern fox squirrel ecology. To address this need and to identify a cost-effective and reliable technique to survey and monitor southeastern fox squirrel populations, we compared four survey methods across seasons: live-trapping; camera-trapping; point counts; and line-transect surveys, in regard to whether a detection occurred at a survey point, the total number of detections at a survey point, and the total cost for each method. We assessed the effectiveness of capture and detection methods and the influence of seasonality using generalized linear mixed models. We found camera-trapping to be the most effective survey method for assessing the presence and distribution of southeastern fox squirrels. In total, camera-traps produced significantly more detections (n = 223) of fox squirrels than all other methods combined (n = 84), with most detections occurring in spring (n = 97) and the fewest in the autumn (n = 60). Furthermore, we detected fox squirrels at more survey points with camera-traps (73%) than all other methods (63%), and we identified 16% more individuals from camera-trap photographs than live-trapped. We recommend future monitoring of southeastern fox squirrels to be conducted using camera-trapping during the spring unless handling of animals is needed for other research purposes.
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