1
|
Sultaire SM, Kawai‐Harada Y, Kimmel A, Greeson EM, Jackson PJ, Contag CH, Lackey CW, Beckmann JP, Millspaugh JJ, Montgomery RA. Black bear density and habitat use variation at the Sierra Nevada‐Great Basin Desert transition. J Wildl Manage 2023. [DOI: 10.1002/jwmg.22358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Sean M. Sultaire
- Wildlife Biology Program University of Montana 32 Campus Drive Missoula MT 59812 USA
| | - Yuki Kawai‐Harada
- Institute for Quantitative Health Science and Engineering Michigan State University East Lansing MI USA
- Department of Biomedical Engineering Michigan State University East Lansing MI USA
| | - Ashley Kimmel
- Institute for Quantitative Health Science and Engineering Michigan State University East Lansing MI USA
- College of Veterinary Medicine Michigan State University East Lansing MI USA
| | - Emily M. Greeson
- Institute for Quantitative Health Science and Engineering Michigan State University East Lansing MI USA
- Department of Microbiology and Molecular Genetics Michigan State University East Lansing MI USA
| | - Patrick J. Jackson
- Nevada Department of Wildlife 6980 Sierra Center Parkway, Suite 120 Reno NV 89511 USA
| | - Christopher H. Contag
- Institute for Quantitative Health Science and Engineering Michigan State University East Lansing MI USA
- Department of Biomedical Engineering Michigan State University East Lansing MI USA
- Department of Microbiology and Molecular Genetics Michigan State University East Lansing MI USA
| | - Carl W. Lackey
- Nevada Department of Wildlife 6980 Sierra Center Parkway, Suite 120 Reno NV 89511 USA
| | - Jon P. Beckmann
- Wildlife Conservation Society Rockies Program 1050 E Main, Suite 2 Bozeman MT 59715 USA
| | - Joshua J. Millspaugh
- Wildlife Biology Program University of Montana 32 Campus Drive Missoula MT 59812 USA
| | - Robert A. Montgomery
- Wildlife Conservation Research Unit, Department of Zoology, The Recanati‐Kaplan Centre University of Oxford Tubney House, Abingdon Road Tubney Oxon OX13 5QL United Kingdom
| |
Collapse
|
2
|
Murphy SM, Hathcock CD, Espinoza TN, Fresquez PR, Berryhill JT, Stanek JE, Sutter BJ, Gaukler SM. Comparative spatially explicit approach for testing effects of soil chemicals on terrestrial wildlife bioindicator demographics. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 316:120541. [PMID: 36336177 DOI: 10.1016/j.envpol.2022.120541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 10/07/2022] [Accepted: 10/27/2022] [Indexed: 06/16/2023]
Abstract
Wildlife species are often used as bioindicators to evaluate the extent and severity of environmental contamination and the effectiveness of remediation practices. A common approach for investigating population- or community-level impacts on bioindicators compares demographic parameter estimates (e.g., population size or density) between sites that were subjected to different levels of contamination. However, the traditional analytical method used in such studies is nonspatial capture-recapture, which results in conclusions about potential relationships between demographics and contaminants being inferred indirectly. Here, we extend this comparative approach to the spatially explicit framework, allowing direct estimation of said relationships and comparisons between study areas, by applying spatial capture-recapture (SCR) models to bioindicator (deer mice [Peromyscus spp.]) detection data from two study areas that were subjected to different industrial activities and remediation practices. Bioindicator density differed by 178% between the neighboring study areas, and the area with the highest soil concentrations of polychlorinated biphenyls, chromium, and zinc had the highest bioindicator density. Under the traditional nonspatial approach, we might have concluded that soil chemical levels had negligible influences on demographics. However, by modeling density as a spatial function of select chemical concentrations using SCR models, we found strong support for a positive relationship between density and soil chromium concentrations in one study area (β = 0.82), which was not masked by or associated with habitat-related metrics. To obtain reliable inferences about potential effects of environmental contamination on bioindicator demographics, we contend that a comparative spatially explicit approach using SCR ought to become standard.
Collapse
Affiliation(s)
- Sean M Murphy
- Department of Forestry and Natural Resources, University of Kentucky, Lexington, KY, USA.
| | - Charles D Hathcock
- Environmental Stewardship Group, Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - Tatiana N Espinoza
- Environmental Stewardship Group, Los Alamos National Laboratory, Los Alamos, NM, USA; Space Science and Applications Group, Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - Philip R Fresquez
- Environmental Stewardship Group, Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - Jesse T Berryhill
- Environmental Stewardship Group, Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - Jenna E Stanek
- Environmental Stewardship Group, Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - Benjamin J Sutter
- Infrastructure Program Office, Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - Shannon M Gaukler
- Environmental Stewardship Group, Los Alamos National Laboratory, Los Alamos, NM, USA.
| |
Collapse
|
3
|
Howe EJ, Potter D, Beauclerc KB, Jackson KE, Northrup JM. Estimating animal abundance at multiple scales by spatially explicit capture-recapture. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2638. [PMID: 35441452 PMCID: PMC9788300 DOI: 10.1002/eap.2638] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
Information about how animal abundance varies across landscapes is needed to inform management action but is costly and time-consuming to obtain; surveys of a single population distributed over a large area can take years to complete. Surveys employing small, spatially replicated sampling units improve efficiency, but statistical estimators rely on assumptions that constrain survey design or become less reasonable as larger areas are sampled. Efficient methods that avoid assumptions about similarity of detectability or density among replicates are therefore appealing. Using simulations and data from >3500 black bears sampled on 73 independent study areas in Ontario, Canada, we (1) quantified bias induced by unmodeled spatial heterogeneity in detectability and density; (2) evaluated novel, design-based estimators of average density across replicate study areas; and (3) evaluated two estimators of the variance of average density across study areas: an analytic estimator that assumed an underlying homogeneous spatial Poisson point process for the distribution of animals' activity centers, and an empirical estimator of variance across study areas. In simulations where detectability varied in space, assuming spatially constant detectability yielded density estimates that were negatively biased by 20% to 30%; estimating local detectability and density from local data and treating study areas as independent, equal replicates when estimating average density across study areas using the design-based estimator yielded unbiased estimates at local and landscape scales. Similarly, detectability of black bears varied among study areas and estimates of bear density at landscape scales were higher when no information was shared across study areas when estimating detectability. This approach also maximized precision (relative SEs of estimates of average black bear density ranged from 7% to 18%) and computational efficiency. In simulations, the analytic variance estimator was robust to threefold variation in local densities but the empirical estimator performed poorly. Conducting multiple, similar SECR surveys and treating them as independent replicates during analyses allowed us to efficiently estimate density at multiple scales and extents while avoiding biases caused by pooling spatially heterogeneous data. This approach enables researchers to address a wide range of ecological or management-related questions and is applicable with most types of SECR data.
Collapse
Affiliation(s)
- Eric J. Howe
- Wildlife Research and Monitoring SectionOntario Ministry of Northern Development, Mines, Natural Resources and ForestryPeterboroughOntarioCanada
| | - Derek Potter
- Wildlife Research and Monitoring SectionOntario Ministry of Northern Development, Mines, Natural Resources and ForestryPeterboroughOntarioCanada
| | - Kaela B. Beauclerc
- Wildlife Research and Monitoring SectionOntario Ministry of Northern Development, Mines, Natural Resources and ForestryPeterboroughOntarioCanada
| | - Katelyn E. Jackson
- Wildlife Research and Monitoring SectionOntario Ministry of Northern Development, Mines, Natural Resources and ForestryPeterboroughOntarioCanada
| | - Joseph M. Northrup
- Wildlife Research and Monitoring SectionOntario Ministry of Northern Development, Mines, Natural Resources and ForestryPeterboroughOntarioCanada
- Environmental and Life Sciences Graduate ProgramTrent UniversityPeterboroughOntarioCanada
| |
Collapse
|
4
|
Hostetter NJ, Regehr EV, Wilson RR, Royle JA, Converse SJ. Modeling spatiotemporal abundance and movement dynamics using an integrated spatial capture-recapture movement model. Ecology 2022; 103:e3772. [PMID: 35633152 PMCID: PMC9787655 DOI: 10.1002/ecy.3772] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 12/21/2021] [Accepted: 01/21/2022] [Indexed: 12/30/2022]
Abstract
Animal movement is a fundamental ecological process affecting the survival and reproduction of individuals, the structure of populations, and the dynamics of communities. Methods to quantify animal movement and spatiotemporal abundances, however, are generally separate and therefore omit linkages between individual-level and population-level processes. We describe an integrated spatial capture-recapture (SCR) movement model to jointly estimate (1) the number and distribution of individuals in a defined spatial region and (2) movement of those individuals through time. We applied our model to a study of polar bears (Ursus maritimus) in a 28,125 km2 survey area of the eastern Chukchi Sea, USA in 2015 that incorporated capture-recapture and telemetry data. In simulation studies, the model provided unbiased estimates of movement, abundance, and detection parameters using a bivariate normal random walk and correlated random walk movement process. Our case study provided detailed evidence of directional movement persistence for both male and female bears, where individuals regularly traversed areas larger than the survey area during the 36-day study period. Scaling from individual- to population-level inferences, we found that densities varied from <0.75 bears/625 km2 grid cell/day in nearshore cells to 1.6-2.5 bears/grid cell/day for cells surrounded by sea ice. Daily abundance estimates ranged from 53 to 69 bears, with no trend across days. The cumulative number of unique bears that used the survey area increased through time due to movements into and out of the area, resulting in an estimated 171 individuals using the survey area during the study (95% credible interval 124-250). Abundance estimates were similar to a previous multiyear integrated population model using capture-recapture and telemetry data (2008-2016; Regehr et al., Scientific Reports 8:16780, 2018). Overall, the SCR-movement model successfully quantified both individual- and population-level space use, including the effects of landscape characteristics on movement, abundance, and detection, while linking the movement and abundance processes to directly estimate density within a prescribed spatial region and temporal period. Integrated SCR-movement models provide a generalizable approach to incorporate greater movement realism into population dynamics and link movement to emergent properties including spatiotemporal densities and abundances.
Collapse
Affiliation(s)
- Nathan J. Hostetter
- Washington Cooperative Fish and Wildlife Research Unit, School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA,Present address:
United States Geological Survey, North Carolina Cooperative Fish and Wildlife Research Unit, Department of Applied EcologyNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Eric V. Regehr
- Applied Physics LaboratoryPolar Science Center, University of WashingtonSeattleWashingtonUSA
| | - Ryan R. Wilson
- Marine Mammals ManagementUnited States Fish and Wildlife ServiceAnchorageAlaskaUSA
| | - J. Andrew Royle
- United States Geological SurveyEastern Ecological Science CenterLaurelMarylandUSA
| | - Sarah J. Converse
- United States Geological Survey, Washington Cooperative Fish and Wildlife Research Unit, School of Environmental and Forest Sciences and School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
| |
Collapse
|
5
|
Alston JD, Clark JD, Gibbs DB, Hast J. Density, harvest rates, and growth of a reintroduced American black bear population. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Joshua D. Alston
- Department of Forestry Wildlife and Fisheries, 427 Plant Biotechnology Building, 2505 E. J. Chapman Drive, University of Tennessee Knoxville TN 37996 USA
| | - Joseph D. Clark
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Southern Appalachian Research Branch, 427 Plant Biotechnology Building, 2505 E. J. Chapman Drive, University of Tennessee Knoxville TN 37996 USA
| | - Daniel B. Gibbs
- Tennessee Wildlife Resources Agency, 3030 Wildlife Way Morristown TN 37814 USA
| | - John Hast
- Kentucky Department of Fish and Wildlife Resources, 1 Sportsman's Lane Frankfort KY 40601 USA
| |
Collapse
|
6
|
Marrotte RR, Howe EJ, Beauclerc KB, Potter D, Northrup JM. Explaining detection heterogeneity with finite mixture and non-Euclidean movement in spatially explicit capture-recapture models. PeerJ 2022; 10:e13490. [PMID: 35694380 PMCID: PMC9186326 DOI: 10.7717/peerj.13490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 05/03/2022] [Indexed: 01/17/2023] Open
Abstract
Landscape structure affects animal movement. Differences between landscapes may induce heterogeneity in home range size and movement rates among individuals within a population. These types of heterogeneity can cause bias when estimating population size or density and are seldom considered during analyses. Individual heterogeneity, attributable to unknown or unobserved covariates, is often modelled using latent mixture distributions, but these are demanding of data, and abundance estimates are sensitive to the parameters of the mixture distribution. A recent extension of spatially explicit capture-recapture models allows landscape structure to be modelled explicitly by incorporating landscape connectivity using non-Euclidean least-cost paths, improving inference, especially in highly structured (riparian & mountainous) landscapes. Our objective was to investigate whether these novel models could improve inference about black bear (Ursus americanus) density. We fit spatially explicit capture-recapture models with standard and complex structures to black bear data from 51 separate study areas. We found that non-Euclidean models were supported in over half of our study areas. Associated density estimates were higher and less precise than those from simple models and only slightly more precise than those from finite mixture models. Estimates were sensitive to the scale (pixel resolution) at which least-cost paths were calculated, but there was no consistent pattern across covariates or resolutions. Our results indicate that negative bias associated with ignoring heterogeneity is potentially severe. However, the most popular method for dealing with this heterogeneity (finite mixtures) yielded potentially unreliable point estimates of abundance that may not be comparable across surveys, even in data sets with 136-350 total detections, 3-5 detections per individual, 97-283 recaptures, and 80-254 spatial recaptures. In these same study areas with high sample sizes, we expected that landscape features would not severely constrain animal movements and modelling non-Euclidian distance would not consistently improve inference. Our results suggest caution in applying non-Euclidean SCR models when there is no clear landscape covariate that is known to strongly influence the movement of the focal species, and in applying finite mixture models except when abundant data are available.
Collapse
Affiliation(s)
- Robby R. Marrotte
- Wildlife Research & Monitoring Section, Ministry of Northern Development, Mines, Natural Resources and Forestry, Peterborough, Ontario, Canada
| | - Eric J. Howe
- Wildlife Research & Monitoring Section, Ministry of Northern Development, Mines, Natural Resources and Forestry, Peterborough, Ontario, Canada
| | - Kaela B. Beauclerc
- Wildlife Research & Monitoring Section, Ministry of Northern Development, Mines, Natural Resources and Forestry, Peterborough, Ontario, Canada
| | - Derek Potter
- Wildlife Research & Monitoring Section, Ministry of Northern Development, Mines, Natural Resources and Forestry, Peterborough, Ontario, Canada
| | - Joseph M. Northrup
- Wildlife Research & Monitoring Section, Ministry of Northern Development, Mines, Natural Resources and Forestry, Peterborough, Ontario, Canada,Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada
| |
Collapse
|
7
|
Review of puma density estimates reveals sources of bias and variation, and the need for standardization. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Schmidt JH, Robison HL, Parrett LS, Gorn TS, Shults BS. Brown Bear Density and Estimated Harvest Rates in Northwestern Alaska. J Wildl Manage 2021. [DOI: 10.1002/jwmg.21990] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Joshua H. Schmidt
- Central Alaska Network U.S. National Park Service 4175 Geist Road Fairbanks AK 99709 USA
| | - Hillary L. Robison
- Western Arctic National Parklands U.S. National Park Service P.O. Box 1029 Kotzebue AK 99752 USA
| | - Lincoln S. Parrett
- Division of Wildlife Conservation Alaska Department of Fish and Game 1300 College Road Fairbanks AK 99701 USA
| | - Tony S. Gorn
- Division of Wildlife Conservation Alaska Department of Fish and Game P.O. Box 1148 Nome AK 99762 USA
| | - Brad S. Shults
- Western Arctic National Parklands U.S. National Park Service 4175 Geist Road Fairbanks AK 99709 USA
| |
Collapse
|
10
|
Jiménez J, C. Augustine B, Linden DW, B. Chandler R, Royle JA. Spatial capture-recapture with random thinning for unidentified encounters. Ecol Evol 2021; 11:1187-1198. [PMID: 33598123 PMCID: PMC7863675 DOI: 10.1002/ece3.7091] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 11/08/2022] Open
Abstract
Spatial capture-recapture (SCR) models have increasingly been used as a basis for combining capture-recapture data types with variable levels of individual identity information to estimate population density and other demographic parameters. Recent examples are the unmarked SCR (or spatial count model), where no individual identities are available and spatial mark-resight (SMR) where individual identities are available for only a marked subset of the population. Currently lacking, though, is a model that allows unidentified samples to be combined with identified samples when there are no separate classes of "marked" and "unmarked" individuals and when the two sample types cannot be considered as arising from two independent observation models. This is a common scenario when using noninvasive sampling methods, for example, when analyzing data on identified and unidentified photographs or scats from the same sites.Here we describe a "random thinning" SCR model that utilizes encounters of both known and unknown identity samples using a natural mechanistic dependence between samples arising from a single observation model. Our model was fitted in a Bayesian framework using NIMBLE.We investigate the improvement in parameter estimates by including the unknown identity samples, which was notable (up to 79% more precise) in low-density populations with a low rate of identified encounters. We then applied the random thinning SCR model to a noninvasive genetic sampling study of brown bear (Ursus arctos) density in Oriental Cantabrian Mountains (North Spain).Our model can improve density estimation for noninvasive sampling studies for low-density populations with low rates of individual identification, by making use of available data that might otherwise be discarded.
Collapse
Affiliation(s)
- José Jiménez
- Instituto de Investigación en Recursos Cinegéticos (IREC, CSIC‐UCLM‐JCCM)Ronda de Toledo, 12Ciudad Real13071Spain
| | - Ben C. Augustine
- U.S. Geological Survey John Wesley Powell CenterCornell Department of Natural ResourcesIthacaNew York14853USA
| | - Daniel W. Linden
- Greater Atlantic Regional Fisheries OfficeNOAA National Marine Fisheries Service55 Great Republic DriveGloucesterMassachusetts01922USA
| | - Richard B. Chandler
- Warnell School of Forestry and Natural ResourcesUniversity of Georgia180 E. Green StreetAthensGeorgia30602USA
| | - J. Andrew Royle
- U.S. Geological SurveyPatuxent Wildlife Research Center12100 Beech Forest RoadLaurelMaryland20708USA
| |
Collapse
|
11
|
Gaukler SM, Murphy SM, Berryhill JT, Thompson BE, Sutter BJ, Hathcock CD. Investigating effects of soil chemicals on density of small mammal bioindicators using spatial capture-recapture models. PLoS One 2020; 15:e0238870. [PMID: 32941472 PMCID: PMC7498087 DOI: 10.1371/journal.pone.0238870] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 08/25/2020] [Indexed: 11/18/2022] Open
Abstract
Monitoring the ecological impacts of environmental pollution and the effectiveness of remediation efforts requires identifying relationships between contaminants and the disruption of biological processes in populations, communities, or ecosystems. Wildlife are useful bioindicators, but traditional comparative experimental approaches rely on a staunch and typically unverifiable assumption that, in the absence of contaminants, reference and contaminated sites would support the same densities of bioindicators, thereby inferring direct causation from indirect data. We demonstrate the utility of spatial capture-recapture (SCR) models for overcoming these issues, testing if community density of common small mammal bioindicators was directly influenced by soil chemical concentrations. By modeling density as an inhomogeneous Poisson point process, we found evidence for an inverse spatial relationship between Peromyscus density and soil mercury concentrations, but not other chemicals, such as polychlorinated biphenyls, at a site formerly occupied by a nuclear reactor. Although the coefficient point estimate supported Peromyscus density being lower where mercury concentrations were higher (β = –0.44), the 95% confidence interval overlapped zero, suggesting no effect was also compatible with our data. Estimated density from the most parsimonious model (2.88 mice/ha; 95% CI = 1.63–5.08), which did not support a density-chemical relationship, was within the range of reported densities for Peromyscus that did not inhabit contaminated sites elsewhere. Environmental pollution remains a global threat to biodiversity and ecosystem and human health, and our study provides an illustrative example of the utility of SCR models for investigating the effects that chemicals may have on wildlife bioindicator populations and communities.
Collapse
Affiliation(s)
- Shannon M. Gaukler
- Environmental Stewardship Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- * E-mail: (SMG); (CDH)
| | - Sean M. Murphy
- Department of Forestry and Natural Resources, University of Kentucky, Lexington, Kentucky, United States of America
| | - Jesse T. Berryhill
- Environmental Stewardship Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Brent E. Thompson
- Environmental Stewardship Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Benjamin J. Sutter
- Infrastructure Program Office, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Charles D. Hathcock
- Environmental Stewardship Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- * E-mail: (SMG); (CDH)
| |
Collapse
|
12
|
Hooker MJ, Chandler RB, Bond BT, Chamberlain MJ. Assessing Population Viability of Black Bears using Spatial Capture‐Recapture Models. J Wildl Manage 2020. [DOI: 10.1002/jwmg.21887] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Michael J. Hooker
- Warnell School of Forestry and Natural ResourcesUniversity of Georgia 180 E. Green Street Athens GA 30602 USA
| | - Richard B. Chandler
- Warnell School of Forestry and Natural ResourcesUniversity of Georgia 180 E. Green Street Athens GA 30602 USA
| | - Bobby T. Bond
- Georgia Department of Natural ResourcesWildlife Resources Division 1014 MLK Boulevard Fort Valley GA 31030 USA
| | - Michael J. Chamberlain
- Warnell School of Forestry and Natural ResourcesUniversity of Georgia 180 E. Green Street Athens GA 30602 USA
| |
Collapse
|
13
|
Efford MG. Non-circular home ranges and the estimation of population density. Ecology 2019; 100:e02580. [PMID: 30601582 DOI: 10.1002/ecy.2580] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/24/2018] [Accepted: 11/06/2018] [Indexed: 11/11/2022]
Abstract
Spatially explicit capture-recapture (SECR) models have emerged as one solution to the problem of estimating the population density of mobile and cryptic animals. Spatial models embody assumptions regarding the spatial distribution of individuals and the spatial detection process. The detection process is modeled in SECR as a radial decline in detection probability with distance from the activity center of each individual. This would seem to require that home ranges are circular. The robustness of SECR when home ranges are not circular has been the subject of conflicting statements. Ivan et al. previously compared the SECR density estimator to a telemetry-scaled non-spatial estimator. I suggest that the apparent non-robustness of SECR in their study was a simulation artefact. New simulations of elliptical home ranges establish that the SECR density estimator is largely robust to non-circularity when detectors are spread in two dimensions, but may be very biased if the detector array is linear and home ranges align with the array. Transformation to isotropy reduces bias from designs of intermediate dimension, such as hollow square arrays. Possible alignment of home ranges should be considered when designing detector arrays.
Collapse
Affiliation(s)
- M G Efford
- Department of Mathematics and Statistics, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| |
Collapse
|
14
|
Welfelt LS, Beausoleil RA, Wielgus RB. Factors associated with black bear density and implications for management. J Wildl Manage 2019. [DOI: 10.1002/jwmg.21744] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Lindsay S. Welfelt
- Washington Department of Fish and Wildlife 3860 State Highway 97A Wenatchee WA 98801 USA
| | - Richard A. Beausoleil
- Washington Department of Fish and Wildlife 3515 State Highway 97A Wenatchee WA 98801 USA
| | - Robert B. Wielgus
- Large Carnivore Conservation LabWashington State University Pullman WA 99163 USA
| |
Collapse
|
15
|
Murphy SM, Hast JT, Augustine BC, Weisrock DW, Clark JD, Kocka DM, Ryan CW, Sajecki JL, Cox JJ. Early genetic outcomes of American black bear reintroductions in the Central Appalachians, USA. URSUS 2019. [DOI: 10.2192/ursu-d-18-00011.1] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Sean M. Murphy
- Department of Forestry and Natural Resources, University of Kentucky, Lexington, KY 40546, USA
| | - John T. Hast
- Department of Forestry and Natural Resources, University of Kentucky, Lexington, KY 40546, USA
| | - Ben C. Augustine
- Department of Forestry and Natural Resources, University of Kentucky, Lexington, KY 40546, USA
| | - David W. Weisrock
- Department of Biology, University of Kentucky, Lexington, KY 40506, USA
| | - Joseph D. Clark
- United States Geological Survey, Northern Rocky Mountain Science Center, Southern Appalachian Research Branch, University of Tennessee, Knoxville, TN 37996, USA
| | - David M. Kocka
- Virginia Department of Game and Inland Fisheries, Verona, VA 24482, USA
| | - Christopher W. Ryan
- West Virginia Division of Natural Resources, South Charleston, WV 25303, USA
| | - Jaime L. Sajecki
- Virginia Department of Game and Inland Fisheries, Verona, VA 24482, USA
| | - John J. Cox
- Department of Forestry and Natural Resources, University of Kentucky, Lexington, KY 40546, USA
| |
Collapse
|
16
|
Augustine BC, Royle JA, Murphy SM, Chandler RB, Cox JJ, Kelly MJ. Spatial capture–recapture for categorically marked populations with an application to genetic capture–recapture. Ecosphere 2019. [DOI: 10.1002/ecs2.2627] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Ben C. Augustine
- Atkinson Center for a Sustainable Future and Department of Natural Resources Cornell University Ithaca New York 14843 USA
| | - J. Andrew Royle
- Patuxent Wildlife Research Center U.S. Geological Survey Laurel Maryland 20708 USA
| | - Sean M. Murphy
- Department of Forestry University of Kentucky Lexington Kentucky 40546 USA
| | - Richard B. Chandler
- Department of Forestry and Natural Resources University of Georgia Athens Georgia 30602 USA
| | - John J. Cox
- Department of Forestry University of Kentucky Lexington Kentucky 40546 USA
| | - Marcella J. Kelly
- Department of Fish and Wildlife Conservation Virginia Tech Blacksburg Virginia 24061 USA
| |
Collapse
|
17
|
Clark JD. Comparing clustered sampling designs for spatially explicit estimation of population density. POPUL ECOL 2019. [DOI: 10.1002/1438-390x.1011] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Joseph D. Clark
- U.S. Geological Survey, Southern Appalachian Field Branch; Northern Rocky Mountain Science Center, University of Tennessee; Knoxville Tennessee
| |
Collapse
|
18
|
Slabach BL, Hast JT, Murphy SM, Bowling WE, Crank RD, Jenkins G, Johannsen KL, Cox JJ. Survival and cause-specific mortality of elk Cervus canadensis in Kentucky, USA. WILDLIFE BIOLOGY 2018. [DOI: 10.2981/wlb.00459] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Brittany L. Slabach
- B. L. Slabach , Dept of Biology, Univ. of Kentucky, 101 TH Morgan Building, Lexin
| | - John T. Hast
- J. T. Hast, Dept of Animal and Food Sciences, Univ. of Kentucky Lexington, KY, USA
| | - Sean M. Murphy
- S. M. Murphy (http://orcid.org/0000-0002-9404- 8878), Dept of Forestry and Natural Resources, Dept o
| | - Willie E. Bowling
- JTH, W. E. Bowling, R. D. Crank, G. Jenkins and K. L. Johannsen, Kentucky Dept of Fish and Wildlife
| | - R. Daniel Crank
- JTH, W. E. Bowling, R. D. Crank, G. Jenkins and K. L. Johannsen, Kentucky Dept of Fish and Wildlife
| | - Gabe Jenkins
- JTH, W. E. Bowling, R. D. Crank, G. Jenkins and K. L. Johannsen, Kentucky Dept of Fish and Wildlife
| | - Kristina L. Johannsen
- JTH, W. E. Bowling, R. D. Crank, G. Jenkins and K. L. Johannsen, Kentucky Dept of Fish and Wildlife
| | - John J. Cox
- J. J. Cox, Dept of Forestry and Natural Resources, Univ. of Kentucky, Lexington, KY, USA
| |
Collapse
|
19
|
Murphy SM, Augustine BC, Adams JR, Waits LP, Cox JJ. Integrating multiple genetic detection methods to estimate population density of social and territorial carnivores. Ecosphere 2018. [DOI: 10.1002/ecs2.2479] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Sean M. Murphy
- Louisiana Department of Wildlife and Fisheries; Large Carnivore Program; Lafayette Louisiana 70506 USA
| | - Ben C. Augustine
- Department of Fish and Wildlife Conservation; Virginia Polytechnic Institute and State University; Blacksburg Virginia 24061 USA
| | - Jennifer R. Adams
- Laboratory for Ecological, Evolutionary and Conservation Genetics; Department of Fish and Wildlife Sciences; University of Idaho; Moscow Idaho 83844 USA
| | - Lisette P. Waits
- Laboratory for Ecological, Evolutionary and Conservation Genetics; Department of Fish and Wildlife Sciences; University of Idaho; Moscow Idaho 83844 USA
| | - John J. Cox
- Department of Forestry and Natural Resources; University of Kentucky; Lexington Kentucky 40546 USA
| |
Collapse
|
20
|
Burgar JM, Stewart FE, Volpe JP, Fisher JT, Burton AC. Estimating density for species conservation: Comparing camera trap spatial count models to genetic spatial capture-recapture models. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00411] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
21
|
Genetic diversity, effective population size, and structure among black bear populations in the Lower Mississippi Alluvial Valley, USA. CONSERV GENET 2018. [DOI: 10.1007/s10592-018-1075-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
22
|
Gould MJ, Cain JW, Roemer GW, Gould WR, Liley SG. Density of American black bears in New Mexico. J Wildl Manage 2018. [DOI: 10.1002/jwmg.21432] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Matthew J. Gould
- Department of Fish, Wildlife and Conservation Ecology; New Mexico State University; PO Box 30003, MSC 4901 Las Cruces NM 88003 USA
| | - James W. Cain
- U.S. Geological Survey, New Mexico Cooperative Fish and Wildlife Research Unit, New Mexico State University; Department of Fish, Wildlife and Conservation Ecology; PO Box 30003, MSC 4901 Las Cruces NM 88003 USA
| | - Gary W. Roemer
- Department of Fish, Wildlife and Conservation Ecology; New Mexico State University; PO Box 30003, MSC 4901 Las Cruces NM 88003 USA
| | - William R. Gould
- Applied Statistics Program; New Mexico State University; PO Box 30001, MSC 3AD Las Cruces NM 88003 USA
| | - Stewart G. Liley
- New Mexico Department of Game and Fish; 1 Wildlife Way Santa Fe NM 87507 USA
| |
Collapse
|
23
|
Tenan S, Pedrini P, Bragalanti N, Groff C, Sutherland C. Data integration for inference about spatial processes: A model-based approach to test and account for data inconsistency. PLoS One 2017; 12:e0185588. [PMID: 28973034 PMCID: PMC5626469 DOI: 10.1371/journal.pone.0185588] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 09/17/2017] [Indexed: 11/18/2022] Open
Abstract
Recently-developed methods that integrate multiple data sources arising from the same ecological processes have typically utilized structured data from well-defined sampling protocols (e.g., capture-recapture and telemetry). Despite this new methodological focus, the value of opportunistic data for improving inference about spatial ecological processes is unclear and, perhaps more importantly, no procedures are available to formally test whether parameter estimates are consistent across data sources and whether they are suitable for integration. Using data collected on the reintroduced brown bear population in the Italian Alps, a population of conservation importance, we combined data from three sources: traditional spatial capture-recapture data, telemetry data, and opportunistic data. We developed a fully integrated spatial capture-recapture (SCR) model that included a model-based test for data consistency to first compare model estimates using different combinations of data, and then, by acknowledging data-type differences, evaluate parameter consistency. We demonstrate that opportunistic data lend itself naturally to integration within the SCR framework and highlight the value of opportunistic data for improving inference about space use and population size. This is particularly relevant in studies of rare or elusive species, where the number of spatial encounters is usually small and where additional observations are of high value. In addition, our results highlight the importance of testing and accounting for inconsistencies in spatial information from structured and unstructured data so as to avoid the risk of spurious or averaged estimates of space use and consequently, of population size. Our work supports the use of a single modeling framework to combine spatially-referenced data while also accounting for parameter consistency.
Collapse
Affiliation(s)
- Simone Tenan
- Vertebrate Zoology Section, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122 Trento, Italy
- * E-mail:
| | - Paolo Pedrini
- Vertebrate Zoology Section, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122 Trento, Italy
| | - Natalia Bragalanti
- Vertebrate Zoology Section, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122 Trento, Italy
- Provincia Autonoma di Trento, Servizio Foreste e Fauna, Via Trener 3, 38100 Trento, Italy
| | - Claudio Groff
- Provincia Autonoma di Trento, Servizio Foreste e Fauna, Via Trener 3, 38100 Trento, Italy
| | - Chris Sutherland
- Department of Environmental Conservation, University of Massachusetts, Amherst, MA, 01003, United States of America
| |
Collapse
|
24
|
Murphy SM, Augustine BC, Ulrey WA, Guthrie JM, Scheick BK, McCown JW, Cox JJ. Consequences of severe habitat fragmentation on density, genetics, and spatial capture-recapture analysis of a small bear population. PLoS One 2017; 12:e0181849. [PMID: 28738077 PMCID: PMC5524351 DOI: 10.1371/journal.pone.0181849] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 07/07/2017] [Indexed: 11/19/2022] Open
Abstract
Loss and fragmentation of natural habitats caused by human land uses have subdivided several formerly contiguous large carnivore populations into multiple small and often isolated subpopulations, which can reduce genetic variation and lead to precipitous population declines. Substantial habitat loss and fragmentation from urban development and agriculture expansion relegated the Highlands-Glades subpopulation (HGS) of Florida, USA, black bears (Ursus americanus floridanus) to prolonged isolation; increasing human land development is projected to cause ≥ 50% loss of remaining natural habitats occupied by the HGS in coming decades. We conducted a noninvasive genetic spatial capture-recapture study to quantitatively describe the degree of contemporary habitat fragmentation and investigate the consequences of habitat fragmentation on population density and genetics of the HGS. Remaining natural habitats sustaining the HGS were significantly more fragmented and patchier than those supporting Florida’s largest black bear subpopulation. Genetic diversity was low (AR = 3.57; HE = 0.49) and effective population size was small (NE = 25 bears), both of which remained unchanged over a period spanning one bear generation despite evidence of some immigration. Subpopulation density (0.054 bear/km2) was among the lowest reported for black bears, was significantly female-biased, and corresponded to a subpopulation size of 98 bears in available habitat. Conserving remaining natural habitats in the area occupied by the small, genetically depauperate HGS, possibly through conservation easements and government land acquisition, is likely the most important immediate step to ensuring continued persistence of bears in this area. Our study also provides evidence that preferentially placing detectors (e.g., hair traps or cameras) primarily in quality habitat across fragmented landscapes poses a challenge to estimating density-habitat covariate relationships using spatial capture-recapture models. Because habitat fragmentation and loss are likely to increase in severity globally, further investigation of the influence of habitat fragmentation and detector placement on estimation of this relationship is warranted.
Collapse
Affiliation(s)
- Sean M. Murphy
- Department of Forestry, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
| | - Ben C. Augustine
- Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Wade A. Ulrey
- Department of Forestry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Joseph M. Guthrie
- Department of Forestry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Brian K. Scheick
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Gainesville, Florida, United States of America
| | - J. Walter McCown
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Gainesville, Florida, United States of America
| | - John J. Cox
- Department of Forestry, University of Kentucky, Lexington, Kentucky, United States of America
| |
Collapse
|
25
|
Murphy SM, Ulrey WA, Guthrie JM, Maehr DS, Abrahamson WG, Maehr SC, Cox JJ. Food habits of a small Florida black bear population in an endangered ecosystem. URSUS 2017. [DOI: 10.2192/ursu-d-16-00031.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Sean M. Murphy
- Department of Forestry, University of Kentucky, Lexington, KY 40546, USA
| | - Wade A. Ulrey
- Department of Forestry, University of Kentucky, Lexington, KY 40546, USA
| | - Joseph M. Guthrie
- Department of Forestry, University of Kentucky, Lexington, KY 40546, USA
| | - David S. Maehr
- Department of Forestry, University of Kentucky, Lexington, KY 40546, USA
| | | | - Sutton C. Maehr
- Department of Forestry, University of Kentucky, Lexington, KY 40546, USA
| | - John J. Cox
- Department of Forestry, University of Kentucky, Lexington, KY 40546, USA
| |
Collapse
|
26
|
Seroprevalence of Toxoplasma gondii in American Black Bears (Ursus americanus) of the Central Appalachians, USA. J Wildl Dis 2017; 53:671-673. [DOI: 10.7589/2016-08-188] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
27
|
Sun CC, Fuller AK, Hare MP, Hurst JE. Evaluating population expansion of black bears using spatial capture-recapture. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21248] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Catherine C. Sun
- New York Cooperative Fish and Wildlife Research Unit; Department of Natural Resources; Cornell University; Ithaca NY 14853 USA
| | - Angela K. Fuller
- U.S. Geological Survey; New York Cooperative Fish and Wildlife Research Unit; Department of Natural Resources; Cornell University; Ithaca NY 14853 USA
| | - Matthew P. Hare
- Department of Natural Resources; Cornell University; Ithaca NY 14853 USA
| | - Jeremy E. Hurst
- New York State Department of Environmental Conservation; Albany NY 12233 USA
| |
Collapse
|
28
|
Morin DJ, Fuller AK, Royle JA, Sutherland C. Model-based estimators of density and connectivity to inform conservation of spatially structured populations. Ecosphere 2017. [DOI: 10.1002/ecs2.1623] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Dana J. Morin
- New York Cooperative Fish and Wildlife Research Unit; Department of Natural Resources; Cornell University; 211 Fernow Hall Ithaca New York 14853 USA
| | - Angela K. Fuller
- U.S. Geological Survey; New York Cooperative Fish and Wildlife Research Unit; Department of Natural Resources; Cornell University; 211 Fernow Hall Ithaca New York 14853 USA
| | - J. Andrew Royle
- U.S. Geological Survey; Patuxent Wildlife Research Center; 12000 Beech Forest Road Laurel Maryland 20708 USA
| | - Chris Sutherland
- Department of Environmental Conservation; University of Massachusetts-Amherst; 118 Holdsworth Hall Amherst Massachusetts 01003 USA
| |
Collapse
|