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Rahman BS, Rahman MK, Ali A, Lima RA, Mia ML, Mahmud Y. Catch composition, catch per unit effort (CPUE) and species selectivity of fishing gears on multi-species Kaptai Lake in Bangladesh. Heliyon 2024; 10:e31173. [PMID: 38799749 PMCID: PMC11126840 DOI: 10.1016/j.heliyon.2024.e31173] [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: 06/24/2023] [Revised: 05/09/2024] [Accepted: 05/12/2024] [Indexed: 05/29/2024] Open
Abstract
Kaptai Lake, the largest artificial reservoir in Southeast Asia, is home to a diverse fish fauna that supports thousands of livelihoods and is distinguished by multi-species and multi-gear fisheries. In Kaptai Lake, the gear-based catch composition, catch rate and distribution pattern are little known. From August 2020 to April 2021, a nine-month study was conducted in five upazilas using direct catch assessment surveys and fishing effort surveys from four fishing gears, namely seine nets, gill nets, lift nets, and push nets. A total of 49 morpho-species from 22 families were found, with three species from the Clupeidae accounting for 93.63 % of the catch in all gear combined. The total catch composition and CPUE were higher in seine nets (75.07 %, 13.86 ± 1.8 kg/gear/trip respectively) and lower in lift nets (4.97 %, 1.01 ± 0.21 kg/gear/trip) and showed significant differences among gears, except sampling sites whereas CPUE was higher in Naniarchar for seine nets (17.29 ± 8.89 kg/gear/trip) and lower in Langadu for lift nets (0.62 ± 0.25 kg/gear/trip). Seine nets captured more species, and the number of species increased significantly as CPUE increased. Our study assessed four gears that targeted different fish species with little overlap in leading species; seine nets and gill nets primarily targeted Clupeidae (96.53 % and 41.69 %, respectively), whereas lift nets and push nets primarily targeted Cyprinidae and Palaemonidae (38.93 % and 99.37 % respectively). The observed abundance and variety of fish species captured in gill nets suggest a significant overlap in the selectivity of this fishing method with that of lift nets. Due to the varying contributions of sites and gears, the nMDS ordination pattern reveals a weak spatial variation in catch composition. According to the SIMPER results, Bagridae, Gobiidae, and Ambassidae were the most significant contributors to site grouping patterns across all gears. Furthermore, the findings indicate that the catch composition does not follow the typical pattern of spatial variation. By implementing measures to eliminate or decrease the usage of small mesh nets, there is expected to be a corresponding decrease in the capture of small fish. Additionally, this action will help mitigate the issue of overlapping selectivity among the current fishing gears. Our findings provide baseline data on the potential efficacy of gear limitation and suggest a gear-based management strategy.
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Affiliation(s)
- B.M. Shahinur Rahman
- Bangladesh Fisheries Research Institute, Riverine Sub-station, Rangamati, 4500, Bangladesh
| | - Md Khaled Rahman
- Bangladesh Fisheries Research Institute, Riverine Sub-station, Rangamati, 4500, Bangladesh
| | - Azhar Ali
- Bangladesh Fisheries Research Institute, Freshwater Sub-station, Saidpur, 5310, Bangladesh
| | - Rabina Akther Lima
- Bangladesh Fisheries Research Institute, Riverine Sub-station, Rangamati, 4500, Bangladesh
| | - Md Lipon Mia
- Bangladesh Fisheries Research Institute, Riverine Sub-station, Rangamati, 4500, Bangladesh
| | - Yahia Mahmud
- Bangladesh Fisheries Research Institute, Headquarters, Mymensingh, 2201, Bangladesh
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2
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Skelly BP, Clipp HL, Landry SM, Rogers R, Phelps Q, Anderson JT, Rota CT. A flexible Bayesian approach for estimating survival probabilities from age‐at‐harvest data. Methods Ecol Evol 2023. [DOI: 10.1111/2041-210x.14077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Affiliation(s)
- Brett P. Skelly
- Division of Forestry and Natural Resources West Virginia University Morgantown West Virginia USA
- West Virginia Division of Natural Resources Elkins West Virginia USA
| | - Hannah L. Clipp
- Division of Forestry and Natural Resources West Virginia University Morgantown West Virginia USA
| | - Stephanie M. Landry
- Division of Forestry and Natural Resources West Virginia University Morgantown West Virginia USA
- Department of Wildland Resources Utah State University Logan Utah USA
| | - Rich Rogers
- West Virginia Division of Natural Resources Romney West Virginia USA
| | - Quinton Phelps
- Department of Biology Missouri State University Springfield Missouri USA
| | - James T. Anderson
- James C. Kennedy Waterfowl and Wetlands Conservation Center Belle W. Baruch Institute of Coastal Ecology and Forest Science Georgetown South Carolina USA
| | - Christopher T. Rota
- Division of Forestry and Natural Resources West Virginia University Morgantown West Virginia USA
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3
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Hiller TL, Nistler C, Reding D, White PA, Bled F. Sex identification and age estimation of bobcats and implications for management. WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Tim L. Hiller
- Wildlife Ecology Institute P.O. Box 4725 Helena MT 59604 USA
| | - Carolyn Nistler
- Matson's Laboratory 135 Wooden Shoe Ln Manhattan MT 59741 USA
| | - Dawn Reding
- Luther College Sampson Hoffland Laboratories 190A 700 College Dr Decorah IA 52101 USA
| | - Paula A. White
- Center for Tropical Research, Institute of the Environment and Sustainability University of California La Kretz Hall, Suite 300, 619 Charles E. Young Dr. East Los Angeles CA 90095 USA
| | - Florent Bled
- Wildlife Ecology Institute P.O. Box 4725 Helena MT 59604 USA
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4
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Clawson MV, Isabelle JL, Skalski JR, Millspaugh JJ. Using statistical population reconstruction to estimate demographics of wild turkey populations. WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Michael V. Clawson
- W.A. Franke College of Forestry and Conservation University of Montana 32 Campus Drive Missoula MT 59812 USA
- School of Environmental and Forest Services University of Washington 1325 Fourth Avenue, Suite 1820 Seattle WA 98101‐2509 USA
| | - Jason L. Isabelle
- Missouri Department of Conservation 3500 East Gans Road Columbia MO 65201 USA
| | - John R. Skalski
- School of Aquatic and Fishery Sciences University of Washington 1325 Fourth Avenue, Suite 1820 Seattle WA 98101‐2509 USA
| | - Joshua J. Millspaugh
- W.A. Franke College of Forestry and Conservation University of Montana 32 Campus Drive Missoula MT 59812 USA
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Hoy SR, MacNulty DR, Metz MC, Smith DW, Stahler DR, Peterson RO, Vucetich JA. Negative frequency-dependent prey selection by wolves and its implications on predator–prey dynamics. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.06.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sun CC, Hurst JE, Fuller AK. Citizen Science Data Collection for Integrated Wildlife Population Analyses. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.682124] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Citizen science, or community science, has emerged as a cost-efficient method to collect data for wildlife monitoring. To inform research and conservation, citizen science sampling designs should collect data that match the robust statistical analyses needed to quantify species and population patterns. Further increasing the contributions of citizen science, integrating citizen science data with other datasets and datatypes can improve population estimates and expand the spatiotemporal extent of inference. We demonstrate these points with a citizen science program called iSeeMammals developed in New York state in 2017 to supplement costly systematic spatial capture-recapture sampling by collecting opportunistic data from one-off observations, hikes, and camera traps. iSeeMammals has initially focused on the growing population of American black bear (Ursus americanus), with integrated analysis of iSeeMammals camera trap data with systematic data for a region with a growing bear population. The triumvirate of increased spatial and temporal coverage by at least twofold compared to systematic sampling, an 83% reduction in annual sampling costs, and improved density estimates when integrated with systematic data highlight the benefits of collecting presence-absence data in citizen science programs for estimating population patterns. Additional opportunities will come from applying presence-only data, which are oftentimes more prevalent than presence-absence data, to integrated models. Patterns in data submission and filtering also emphasize the importance of iteratively evaluating patterns in engagement, usability, and accessibility, especially focusing on younger adult and teenage demographics, to improve data quality and quantity. We explore how the development and use of integrated models may be paired with citizen science project design in order to facilitate repeated use of datasets in standalone and integrated analyses for supporting wildlife monitoring and informing conservation.
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BERG SERGEYS, PALMER LAURAL. A COMPARISON OF MULTINOMIAL LIKELIHOOD AND CHI-SQUARE APPROACHES TO STATISTICAL POPULATION RECONSTRUCTION. J BIOL SYST 2021. [DOI: 10.1142/s0218339021400106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Statistical population reconstruction using age-at-harvest and catch-effort data has recently emerged as a robust and versatile approach to estimating the demographic dynamics of harvested populations of wildlife. Although most reconstruction efforts employ the multinomial likelihood approach to identify which set of model parameters best describes the observed age-at-harvest and catch-effort data, using a [Formula: see text] objective function may provide a suitable alternative with a less steep learning curve. Using a harvested population of North American river otter (Lontra canadensis) in Kentucky as a case study, we investigated the performance of population reconstruction using multinomial likelihood and chi-square formulations. We simulated populations under a range of conditions and found that both the accuracy and precision of reconstruction estimates were similar under the two approaches. These results illustrate the potential benefits of using the [Formula: see text] approach, which may also allow agencies to incorporate auxiliary information from studies for which the corresponding likelihood contributions have yet to be developed.
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Affiliation(s)
- SERGEY S. BERG
- Department of Computer and Information Sciences, University of St. Thomas, 2115 Summit Avenue, St. Paul, MN 55105, USA
| | - LAURA L. PALMER
- Kentucky Department of Fish and Wildlife Resources, 1 Sportsman’s Lane, Frankfort, KY 40601, USA
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Reiner R, Zedrosser A, Zeiler H, Hackländer K, Corlatti L. Population reconstruction as an informative tool for monitoring chamois populations. WILDLIFE BIOLOGY 2020. [DOI: 10.2981/wlb.00757] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Rudolf Reiner
- R. Reiner (https://orcid.org/0000-0003-1016-9347) ✉ , A. Zedrosser, K. Hackländer and L. Corlatti, Inst. of Wildlife Biology and Game Management, Univ. of Natural Resources and Life Sciences Vienna, Vienna, Austria. RR also at
| | - Andreas Zedrosser
- R. Reiner (https://orcid.org/0000-0003-1016-9347) ✉ , A. Zedrosser, K. Hackländer and L. Corlatti, Inst. of Wildlife Biology and Game Management, Univ. of Natural Resources and Life Sciences Vienna, Vienna, Austria. RR also at
| | | | - Klaus Hackländer
- R. Reiner (https://orcid.org/0000-0003-1016-9347) ✉ , A. Zedrosser, K. Hackländer and L. Corlatti, Inst. of Wildlife Biology and Game Management, Univ. of Natural Resources and Life Sciences Vienna, Vienna, Austria. RR also at
| | - Luca Corlatti
- R. Reiner (https://orcid.org/0000-0003-1016-9347) ✉ , A. Zedrosser, K. Hackländer and L. Corlatti, Inst. of Wildlife Biology and Game Management, Univ. of Natural Resources and Life Sciences Vienna, Vienna, Austria. RR also at
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Allen ML, Roberts NM, Bauder JM. Relationships of catch-per-unit-effort metrics with abundance vary depending on sampling method and population trajectory. PLoS One 2020; 15:e0233444. [PMID: 32437401 PMCID: PMC7241727 DOI: 10.1371/journal.pone.0233444] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 05/05/2020] [Indexed: 11/22/2022] Open
Abstract
Catch-per-unit-effort (CPUE) is often used to monitor wildlife populations and to develop statistical population models. Animals caught and released are often not included in CPUE metrics and their inclusion may create more accurate indices of abundance. We used 21 years of detailed harvest records for bobcat (Lynx rufus) in Wisconsin, U.S.A., to calculate CPUE and ‘actual CPUE’ (ACPUE; including animals caught and released) from bobcat hunters and trappers. We calibrated these metrics to an independent estimate of bobcat abundance and attempted to create simple but effective models to estimate CPUE and ACPUE using harvest success data (i.e., bobcats harvested/available permits). CPUE showed virtually no relationship with bobcat abundance across all years, but both CPUE and ACPUE had stronger, non-linear, and negative relationships with abundance during the periods when the population was decreasing. Annual harvest success strongly predicted composite ACPUE and CPUE from hunters and trappers and hunter ACPUE and CPUE but was a poorer predictor of trapper ACPUE and CPUE. The non-linear, and sometimes weak, relationships with bobcat abundance likely reflect the increasing selectivity of bobcat hunters for trophy animals. Studies calibrating per-unit-effort metrics against abundance should account for population trajectories and different harvest methods (e.g., hunting and trapping). Our results also highlight the potential for estimating per-unit-effort metrics from relatively simple and inexpensive data sources and we encourage additional research into the use of per-unit-effort metrics for population estimation.
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Affiliation(s)
- Maximilian L. Allen
- Illinois Natural History Survey, University of Illinois, Champaign, Illinois, United States of America
- * E-mail:
| | - Nathan M. Roberts
- Wisconsin Department of Natural Resources, Rhinelander, Wisconsin, United States of America
| | - Javan M. Bauder
- Illinois Natural History Survey, University of Illinois, Champaign, Illinois, United States of America
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10
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Hoy SR, MacNulty DR, Smith DW, Stahler DR, Lambin X, Peterson RO, Ruprecht JS, Vucetich JA. Fluctuations in age structure and their variable influence on population growth. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13431] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sarah R. Hoy
- School of Forest Resources and Environmental Science Michigan Technological University Houghton MI USA
| | - Daniel R. MacNulty
- Department of Wildland Resources and Ecology Center Utah State University Logan UT USA
| | - Douglas W. Smith
- Yellowstone Centre for Resources Yellowstone National Park WY USA
| | | | - Xavier Lambin
- School of Biological Sciences University of Aberdeen Aberdeen UK
| | - Rolf O. Peterson
- School of Forest Resources and Environmental Science Michigan Technological University Houghton MI USA
| | - Joel S. Ruprecht
- Department of Fisheries and Wildlife Oregon State University Corvallis OR USA
| | - John A. Vucetich
- School of Forest Resources and Environmental Science Michigan Technological University Houghton MI USA
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11
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Howard AL, Clement MJ, Peck FR, Rubin ES. Estimating Mountain Lion Abundance in Arizona Using Statistical Population Reconstruction. J Wildl Manage 2019. [DOI: 10.1002/jwmg.21769] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- April L. Howard
- Terrestrial Wildlife Branch, Arizona Game and Fish Department 5000 West Carefree Highway Phoenix AZ 85086 USA
| | - Matthew J. Clement
- Research Branch, Arizona Game and Fish Department 5000 West Carefree Highway Phoenix AZ 85086 USA
| | - Frances R. Peck
- Terrestrial Wildlife Branch, Arizona Game and Fish Department 5000 West Carefree Highway Phoenix AZ 85086 USA
| | - Esther S. Rubin
- Research Branch, Arizona Game and Fish Department 5000 West Carefree Highway Phoenix AZ 85086 USA
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12
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DeYoung CA, Fulbright TE, Hewitt DG, Wester DB, Draeger DA, DeYoung CA, Fulbright TE, Hewitt DG, Wester DB, Draeger DA, Gann KR, Folks DJ, Hewitt DG, DeYoung CA, Fulbright TE, Wester DB, Draeger DA, Darr RL, Williamson KM, Garver LW, Hewitt DG, DeYoung CA, Fulbright TE, Gann KR, Wester DB, Draeger DA, Gann WJ, Fulbright TE, Hewitt DG, DeYoung CA, Grahmann ED, Wester DB, Felts BL, Phillips LM, Gage RT, Draeger DA, Cook NS, Donohue RN, DeYoung CA, Hewitt DG, Fulbright TE, Wester DB, Draeger DA, DeYoung CA, Hewitt DG, Fulbright TE, Wester DB, Draeger DA. Linking White‐Tailed Deer Density, Nutrition, and Vegetation in a Stochastic Environment. WILDLIFE MONOGRAPHS 2019. [DOI: 10.1002/wmon.1040] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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13
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Johnson RD, Jenks JA, Tucker SA, Wilckens DT. Mountain Lion (Puma concolor) Population Characteristics in the Little Missouri Badlands of North Dakota. AMERICAN MIDLAND NATURALIST 2019. [DOI: 10.1674/0003-0031-181.2.207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Randy D. Johnson
- Department of Natural Resource Management, South Dakota State University, Brookings 57007
| | - Jonathan A. Jenks
- Department of Natural Resource Management, South Dakota State University, Brookings 57007
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Hatter IW, Mowat G, McLellan BN. Statistical population reconstruction to evaluate grizzly bear trends in British Columbia, Canada. URSUS 2018. [DOI: 10.2192/ursus-d-18-00001.1] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Ian W. Hatter
- Nature Wise Consulting, 308 Uganda Avenue, Victoria, BC V9A 5X7, Canada
| | - Garth Mowat
- British Columbia Ministry of Forests, Lands, Natural Resource Operations & Rural Development, Suite 401-333 Victoria Street, Nelson, BC V1L 4K3, Canada
| | - Bruce N. McLellan
- British Columbia Ministry of Forests, Lands, Natural Resource Operations, & Rural Development, P.O. Box 1732, D'Arcy, BC V0N 1L0, Canada
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15
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Sweetapple P, Nugent G. Estimating disease survey intensity and wildlife population size from the density of survey devices: Leg-hold traps and the brushtail possum. Prev Vet Med 2018; 159:220-226. [PMID: 30314786 DOI: 10.1016/j.prevetmed.2018.09.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 09/17/2018] [Accepted: 09/18/2018] [Indexed: 11/20/2022]
Abstract
Wildlife disease surveillance requires accurate information on the proportion of managed populations sampled or their population density, parameters that are typically expensive to measure. However, these parameters can be estimated using spatially explicit modelling of capture probabilities, based on the distribution and deployment times of capture devices, given accurate information on the relationships between these variables. This approach is used in New Zealand's surveillance programme aimed at confirming areas free of bovine tuberculosis (bTB1) in brushtail possums (Trichosurus vulpecula). However, there is uncertainty about the accuracy of the underpinning parameters characterizing possum trappability (g), given the distance between where a trap is placed and the possum home range centre. Sampling intensity (SI: the percentage of the population sampled during a population survey) and sigma (σ; 95% home range radius/2.45) were measured, using leg-hold traps deployed under a set protocol to standardize survey effort, at four sites containing previously radio- and GPS-collared individuals. Those data were used to derive an estimate of the nightly probability of capture of possums in a trap set at their home range centre (g0). Those estimates were compared to the standard assumptions currently used as defaults in the day-to-day approach used by bTB managers. Home-range size (and therefore σ) varied widely between sites (range 3.6-49.4 ha), probably largely in response to differences in possum density. Field measured SI also varied widely between sites, and was closely positively correlated with home range size (R2 = 0.967; P = 0.017); wide-ranging possums were more trappable than sedentary ones. We found that g0 was inversely related to σ, but the magnitude of increases in g0 with declining σ appeared to be insufficient to compensate for the fewer places at which each possum could be trapped when those home ranges were small. SI was, therefore, not constant across sites where a standard survey effort was applied. The assumed relationship between g0 and σ in the current spatial model may, therefore, need reassessment. The management implication of these result is that the sampling effort required to attain a target sampling intensity is dependant on the target animal density, and for bTB management of possums in New Zealand, is under-estimated by the current default parameters in a model of freedom-from-disease for higher density possum populations.
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Affiliation(s)
- Peter Sweetapple
- Manaaki Whenua Landcare Research, PO Box 69040, Lincoln, 7640, New Zealand.
| | - Graham Nugent
- Manaaki Whenua Landcare Research, PO Box 69040, Lincoln, 7640, New Zealand.
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Sturludottir E, Nielsen OK, Stefansson G. Evaluation of ptarmigan management with a population reconstruction model. J Wildl Manage 2018. [DOI: 10.1002/jwmg.21458] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Erla Sturludottir
- Science Institute; University of Iceland; Taeknigardur, Dunhagi 5, 107 Reykjavik Iceland
| | - Olafur K. Nielsen
- The Icelandic Institute of Natural History; Urriðaholtsstraeti 6-8, 212 Gardabaer Iceland
| | - Gunnar Stefansson
- Science Institute; University of Iceland; Taeknigardur, Dunhagi 5, 107 Reykjavik Iceland
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Davis AJ, Leland B, Bodenchuk M, VerCauteren KC, Pepin KM. Costs and effectiveness of damage management of an overabundant species (Sus scrofa) using aerial gunning. WILDLIFE RESEARCH 2018. [DOI: 10.1071/wr17170] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context
Management of overabundant or invasive species is a constant challenge because resources for management are always limited and relationships between management costs, population density and damage costs are complex and difficult to predict. Metrics of management success are often based on simple measures, such as counts, which may not be indicative of impacts on damage reduction or cost-effectiveness under different management plans.
Aims
The aims of this study were to evaluate the effectiveness of aerial gunning for the management of wild pigs (Sus scrofa), and to evaluate how cost-effectiveness would vary under different relationships between levels of damage and densities of wild pigs.
Methods
Repeated reduction events were conducted by aerial gunning on three consecutive days at three study sites. Using a removal model, the proportion of the population removed by each flight was estimated and population modelling was used to show the time it would take for a population to recover. Three possible damage–density relationships were then used to show the level of damage reduction (metric of success) from different management intensities and levels of population recovery, and these relationships were expressed in terms of total costs (including both damage and management costs).
Key results
Populations were typically reduced by ~31% for the first flight, ~56% after two flights and ~67% after three flights. When the damage relationship suggests high damage even at low densities, the impact of one, two or three flights would represent a reduction in damage of 2%, 19% and 60% respectively after 1 year. Different damage relationships may show considerable damage reduction after only one flight. Removal rates varied by habitat (0.05 per hour in open habitats compared with 0.03 in shrubby habitats) and gunning team (0.03 versus 0.05).
Conclusions
Monitoring the efficacy of management provides critical guidance and justification for control activities. The efficacy of different management strategies is dependent on the damage–density relationship and needs further study for effective evaluation of damage reduction efforts.
Implications
It is critically important to concurrently monitor density and damage impacts to justify resource needs and facilitate planning to achieve a desired damage reduction goal.
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Ellington EH, Flournoy PD, Dwyer CP, Witt MD, Gehrt SD. Assessment of river otter abundance following reintroduction. WILDLIFE RESEARCH 2018. [DOI: 10.1071/wr17164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context
By the early 1900s, river otters (Lontra canadensis) were extirpated across large parts of their range in North America. Over the last several decades they have made a remarkable recovery through widespread reintroduction programs. River otters were reintroduced in Ohio, USA, between 1988 and 1993, and restricted and limited harvesting of this population began in 2005. While circumstantial evidence points to rapid population growth following the reintroduction, changes in population size over time is unknown.
Aims
We sought to model river otter population growth following reintroduction, and to assess the impact of harvesting.
Methods
We used empirical and literature-based data on river otter demographics in Ohio to estimate abundance from 1988–2008 using an age- and sex-specific stochastic Leslie matrix model. Additionally, we used statistical population reconstruction (SPR) methods to estimate population abundance of river otters in Ohio from 2006 to 2008.
Results
Our Leslie matrix model predicted a population size of 4115 (s.d. = 1169) in 2005, with a population growth rate (λ) of 1.28 in 2005. Using SPR methods we found that both trapper effort and initial population abundance influenced our population estimates from 2006 to 2008. If we assumed that river otter pelt price was an accurate index of trapper effort, and if the initial population was between 2000 and 4000, then we estimated the λ to be 1.27–1.31 in 2008 and the exponential rate to be 0.17–0.21 from 2006 to 2008. Conversely, if the river otter population in 2005 was 1000, then we estimated λ to be 1.20 in 2008 and the exponential rate to be 0.08 from 2006 to 2008.
Conclusions
The river otter population in Ohio appears to have had the potential to grow rapidly following reintroduction. The ultimate effect of the harvesting regime on population abundance, however, remains clouded by limited data availability and high variability.
Implications
The considerable uncertainty surrounding population estimates of river otters in Ohio under the harvesting regime was largely driven by lack of additional data. This uncertainty clouds our understanding of the status of river otters in Ohio, but a more robust, long-term monitoring effort would provide the data necessary to more precisely monitor the population.
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Clawson MV, Skalski JR, Lady JM, Hagen CA, Millspaugh JJ, Budeau D, Severson JP. Performing statistical population reconstruction using Program PopRecon 2.0. WILDLIFE SOC B 2017. [DOI: 10.1002/wsb.790] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Michael V. Clawson
- Wildlife Biology Program; University of Montana; 32 Campus Drive Missoula MT 59812 USA
| | - John R. Skalski
- School of Aquatic & Fishery Sciences; University of Washington; 1325 Fourth Avenue, Suite 1515 Seattle WA 98101-2540 USA
| | - James M. Lady
- School of Aquatic & Fishery Sciences; University of Washington; 1325 Fourth Avenue, Suite 1515 Seattle WA 98101-2540 USA
| | - Christian A. Hagen
- Department of Fisheries and Wildlife; Oregon State University; 500 Southwest Bond Street, Suite 107 Corvallis OR 97702 USA
| | - Joshua J. Millspaugh
- Wildlife Biology Program; University of Montana; 32 Campus Drive Missoula MT 59812 USA
| | - David Budeau
- Oregon Department of Fish and Wildlife; 4034 Fairview Industrial Drive SE Salem OR 97302 USA
| | - John P. Severson
- Department of Fish and Wildlife Sciences; University of Idaho; Moscow ID 83844 USA
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Azad S, Wactor T, Jachowski D. Demographic trends of a harvested American black bear population in northwestern South Carolina. URSUS 2017. [DOI: 10.2192/ursu-d-16-00027.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Shefali Azad
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC 29634-0317, USA
| | - Tammy Wactor
- Wildlife and Freshwater Fisheries, South Carolina Department of Natural Resources, Clemson, SC 29631, USA
| | - David Jachowski
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC 29634-0317, USA
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Berg SS, Erb JD, Fieberg JR, Forester JD. Utility of radio-telemetry data for improving statistical population reconstruction. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sergey S. Berg
- Conservation Biology Graduate Program; University of Minnesota; 135B Skok Hall, 2003 Upper Buford Circle St. Paul MN 55108 USA
| | - John D. Erb
- Forest Wildlife Research Group; Minnesota Department of Natural Resources; 1201 E. Hwy 2 Grand Rapids MN 55744 USA
| | - John R. Fieberg
- Department of Fisheries, Wildlife, and Conservation Biology; University of Minnesota; 135 Skok Hall, 2003 Upper Buford Circle St. Paul MN 55108 USA
| | - James D. Forester
- Department of Fisheries, Wildlife, and Conservation Biology; University of Minnesota; 135 Skok Hall, 2003 Upper Buford Circle St. Paul MN 55108 USA
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Ruette S, Larroque J, Albaret M, Vandel JM, Devillard S. Quantifying the age- and sex-dependent morphological variation in two syntopic mustelids: Martes martes and Martes foina. Mamm Biol 2015. [DOI: 10.1016/j.mambio.2015.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Storm DJ, Samuel MD, Rolley RE, Beissel T, Richards BJ, Van Deelen TR. Estimating ages of white-tailed deer: Age and sex patterns of error using tooth wear-and-replacement and consistency of cementum annuli. WILDLIFE SOC B 2014. [DOI: 10.1002/wsb.457] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Daniel J. Storm
- Department of Forest and Wildlife Ecology; University of Wisconsin-Madison; 226 Russell Labs 1630 Linden Drive Madison WI 53706 USA
| | - Michael D. Samuel
- United States Geological Survey; Wisconsin Cooperative Wildlife Research Unit; Department of Forest and Wildlife Ecology; University of Wisconsin-Madison; 204 Russell Labs 1630 Linden Drive Madison Wisconsin 53706 USA
| | - Robert E. Rolley
- Bureau of Science Services; Wisconsin Department of Natural Resources; 2801 Progress Road Madison WI 53716 USA
| | - Thomas Beissel
- Illinois Department of Natural Resources; 1 Natural Resources Way Springfield IL 62702 USA
| | - Bryan J. Richards
- Unites States Geological Survey; National Wildlife Health Center; 6006 Schroeder Road Madison WI 53711 USA
| | - Timothy R. Van Deelen
- Department of Forest and Wildlife Ecology; University of Wisconsin-Madison; 226 Russell Labs 1630 Linden Drive Madison WI 53706 USA
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Uraguchi K, Ueno M, Iijima H, Saitoh T. Demographic analyses of a fox population suffering from sarcoptic mange. J Wildl Manage 2014. [DOI: 10.1002/jwmg.794] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Kohji Uraguchi
- Hokkaido Institute of Public Health; N19; W12; Sapporo 060-0819 Japan
| | - Mayumi Ueno
- Eastern Hokkaido Wildlife Research Station; Institute of Environmental Sciences; Hokkaido Research Organization; Urami 2; Kushiro 085-0835 Japan
| | - Hayato Iijima
- Yamanashi Forest Research Institute; 2290-1; Saishoji; Fujikawa; Yamanashi 400-0502 Japan
| | - Takashi Saitoh
- Field Science Center; Hokkaido University; N11; W10; Sapporo 060-0811 Japan
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Gee KL, Webb SL, Holman JH. Accuracy and implications of visually estimating age of male white‐tailed deer using physical characteristics from photographs. WILDLIFE SOC B 2013. [DOI: 10.1002/wsb.359] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kenneth L. Gee
- The Samuel Roberts Noble Foundation2510 Sam Noble ParkwayArdmoreOK73401USA
| | - Stephen L. Webb
- The Samuel Roberts Noble Foundation2510 Sam Noble ParkwayArdmoreOK73401USA
| | - John H. Holman
- The Samuel Roberts Noble Foundation2510 Sam Noble ParkwayArdmoreOK73401USA
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Gast C, Skalski JR, Beyer DE. Evaluation of fixed- and random-effects models and multistage estimation procedures in statistical population reconstruction. J Wildl Manage 2013. [DOI: 10.1002/jwmg.576] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Christopher Gast
- Quantitative Ecology and Resource Management; University of Washington; 1325 Fourth Avenue, Suite 1820 Seattle WA 98101-2509 USA
| | - John R. Skalski
- School of Aquatic and Fishery Sciences; University of Washington; 1325 Fourth Avenue, Suite 1820 Seattle WA 98101-2509 USA
| | - Dean E. Beyer
- Michigan Department of Natural Resources, Department of Geography; Northern Michigan University; 213 West Science Building Marquette MI 49855 USA
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Gast CM, Skalski JR, Isabelle JL, Clawson MV. Random effects models and multistage estimation procedures for statistical population reconstruction of small game populations. PLoS One 2013; 8:e65244. [PMID: 23755199 PMCID: PMC3670864 DOI: 10.1371/journal.pone.0065244] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 04/25/2013] [Indexed: 11/30/2022] Open
Abstract
Recently, statistical population models using age-at-harvest data have seen increasing use for monitoring of harvested wildlife populations. Even more recently, detailed evaluation of model performance for long-lived, large game animals indicated that the use of random effects to incorporate unmeasured environmental variation, as well as second-stage Horvitz-Thompson-type estimators of abundance, provided more reliable estimates of total abundance than previous models. We adapt this new modeling framework to small game, age-at-harvest models with only young-of-the-year and adult age classes. Our Monte Carlo simulation results indicate superior model performance for the new modeling framework, evidenced by lower bias and proper confidence interval coverage. We apply this method to male wild turkey harvest in the East Ozarks turkey productivity region, Missouri, USA, where statistical population reconstruction indicates a relatively stationary population for 1996-2010.
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Affiliation(s)
- Christopher M. Gast
- Quantitative Ecology and Resource Management, University of Washington, Seattle, Washington, United States of America
| | - John R. Skalski
- School of Aquatic & Fishery Sciences, University of Washington, Seattle, Washington, United States of America
| | - Jason L. Isabelle
- Missouri Department of Conservation, Columbia, Missouri, United States of America
| | - Michael V. Clawson
- School of Environmental and Forest Sciences, University of Washington, Seattle, Washington, United States of America
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Clawson MV, Skalski JR, Millspaugh JJ. The utility of auxiliary data in statistical population reconstruction. WILDLIFE BIOLOGY 2013. [DOI: 10.2981/12-076] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Skalski JR, Clawson MV, Millspaugh JJ. Model evaluation in statistical population reconstruction. WILDLIFE BIOLOGY 2012. [DOI: 10.2981/11-080] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Skalski JR, Millspaugh JJ, Clawson MV. Comparison of statistical population reconstruction using full and pooled adult age-class data. PLoS One 2012; 7:e33910. [PMID: 22470491 PMCID: PMC3314681 DOI: 10.1371/journal.pone.0033910] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 02/19/2012] [Indexed: 11/18/2022] Open
Abstract
Background Age-at-harvest data are among the most commonly collected, yet neglected, demographic data gathered by wildlife agencies. Statistical population construction techniques can use this information to estimate the abundance of wild populations over wide geographic areas and concurrently estimate recruitment, harvest, and natural survival rates. Although current reconstruction techniques use full age-class data (0.5, 1.5, 2.5, 3.5, … years), it is not always possible to determine an animal's age due to inaccuracy of the methods, expense, and logistics of sample collection. The ability to inventory wild populations would be greatly expanded if pooled adult age-class data (e.g., 0.5, 1.5, 2.5+ years) could be successfully used in statistical population reconstruction. Methodology/Principal Findings We investigated the performance of statistical population reconstruction models developed to analyze full age-class and pooled adult age-class data. We performed Monte Carlo simulations using a stochastic version of a Leslie matrix model, which generated data over a wide range of abundance levels, harvest rates, and natural survival probabilities, representing medium-to-big game species. Results of full age-class and pooled adult age-class population reconstructions were compared for accuracy and precision. No discernible difference in accuracy was detected, but precision was slightly reduced when using the pooled adult age-class reconstruction. On average, the coefficient of variation increased by 0.059 when the adult age-class data were pooled prior to analyses. The analyses and maximum likelihood model for pooled adult age-class reconstruction are illustrated for a black-tailed deer (Odocoileus hemionus) population in Washington State. Conclusions/Significance Inventorying wild populations is one of the greatest challenges of wildlife agencies. These new statistical population reconstruction models should expand the demographic capabilities of wildlife agencies that have already collected pooled adult age-class data or are seeking a cost-effective method for monitoring the status and trends of our wild resources.
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Affiliation(s)
- John R Skalski
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, United States of America.
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Norton AS, Diefenbach DR, Wallingford BD, Rosenberry CS. Spatio-temporal variation in male white-tailed deer harvest rates in Pennsylvania: Implications for estimating abundance. J Wildl Manage 2011. [DOI: 10.1002/jwmg.249] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Skalski JR, Millspaugh JJ, Clawson MV, Belant JL, Etter DR, Frawley BJ, Friedrich PD. Abundance trends of American martens in Michigan based on statistical population reconstruction. J Wildl Manage 2011. [DOI: 10.1002/jwmg.227] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Mcdonald JE, Destefano S, Gaughan C, Mayer M, Woytek WA, Christensen S, Fuller TK. Survival and harvest-related mortality of white-tailed deer in massachusetts. WILDLIFE SOC B 2011. [DOI: 10.1002/wsb.40] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Asmus J, Weckerly FW. Evaluating precision of cementum annuli analysis for aging mule deer from southern California. J Wildl Manage 2011. [DOI: 10.1002/jwmg.133] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Belant JL, Etter DR, Friedrich PD, Cosgrove MK, Williams BW, Scribner KT. Comparison of techniques for sex determination of American martens. J Wildl Manage 2011. [DOI: 10.1002/jwmg.26] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Fieberg JR, Shertzer KW, Conn PB, Noyce KV, Garshelis DL. Integrated population modeling of black bears in Minnesota: implications for monitoring and management. PLoS One 2010; 5:e12114. [PMID: 20711344 PMCID: PMC2920827 DOI: 10.1371/journal.pone.0012114] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 07/13/2010] [Indexed: 11/20/2022] Open
Abstract
Background Wildlife populations are difficult to monitor directly because of costs and logistical challenges associated with collecting informative abundance data from live animals. By contrast, data on harvested individuals (e.g., age and sex) are often readily available. Increasingly, integrated population models are used for natural resource management because they synthesize various relevant data into a single analysis. Methodology/Principal Findings We investigated the performance of integrated population models applied to black bears (Ursus americanus) in Minnesota, USA. Models were constructed using sex-specific age-at-harvest matrices (1980–2008), data on hunting effort and natural food supplies (which affects hunting success), and statewide mark–recapture estimates of abundance (1991, 1997, 2002). We compared this approach to Downing reconstruction, a commonly used population monitoring method that utilizes only age-at-harvest data. We first conducted a large-scale simulation study, in which our integrated models provided more accurate estimates of population trends than did Downing reconstruction. Estimates of trends were robust to various forms of model misspecification, including incorrectly specified cub and yearling survival parameters, age-related reporting biases in harvest data, and unmodeled temporal variability in survival and harvest rates. When applied to actual data on Minnesota black bears, the model predicted that harvest rates were negatively correlated with food availability and positively correlated with hunting effort, consistent with independent telemetry data. With no direct data on fertility, the model also correctly predicted 2-point cycles in cub production. Model-derived estimates of abundance for the most recent years provided a reasonable match to an empirical population estimate obtained after modeling efforts were completed. Conclusions/Significance Integrated population modeling provided a reasonable framework for synthesizing age-at-harvest data, periodic large-scale abundance estimates, and measured covariates thought to affect harvest rates of black bears in Minnesota. Collection and analysis of these data appear to form the basis of a robust and viable population monitoring program.
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Affiliation(s)
- John R Fieberg
- Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, St. Paul, Minnesota, United States of America.
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Ueno M, Matsuishi T, Solberg EJ, Saitoh T. Application of Cohort Analysis to Large Terrestrial Mammal Harvest Data. MAMMAL STUDY 2009. [DOI: 10.3106/041.034.0202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Lebreton J, Nichols JD, Barker RJ, Pradel R, Spendelow JA. Chapter 3 Modeling Individual Animal Histories with Multistate Capture–Recapture Models. ADV ECOL RES 2009. [DOI: 10.1016/s0065-2504(09)00403-6] [Citation(s) in RCA: 222] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Conn PB, Diefenbach DR, Laake JL, Ternent MA, White GC. Bayesian analysis of wildlife age-at-harvest data. Biometrics 2008; 64:1170-7. [PMID: 18266894 DOI: 10.1111/j.1541-0420.2008.00987.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
SUMMARY State and federal natural resource management agencies often collect age-structured harvest data. These data represent finite realizations of stochastic demographic and sampling processes and have long been used by biologists to infer population trends. However, different sources of data have been combined in ad hoc ways and these methods usually failed to incorporate sampling error. In this article, we propose a "hidden process" (or state-space) model for estimating abundance, survival, recovery rate, and recruitment from age-at-harvest data that incorporate both demographic and sampling stochasticity. To this end, a likelihood for age-at-harvest data is developed by embedding a population dynamics model within a model for the sampling process. Under this framework, the identification of abundance parameters can be achieved by conducting a joint analysis with an auxiliary data set. We illustrate this approach by conducting a Bayesian analysis of age-at-harvest and mark-recovery data from black bears (Ursus americanus) in Pennsylvania. Using a set of reasonable prior distributions, we demonstrate a substantial increase in precision when posterior summaries of abundance are compared to a bias-corrected Lincoln-Petersen estimator. Because demographic processes link consecutive abundance estimates, we also obtain a more realistic biological picture of annual changes in abundance. Because age-at-harvest data are often readily obtained, we argue that this type of analysis provides a valuable strategy for wildlife population monitoring.
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Affiliation(s)
- Paul B Conn
- Department of Fish, Wildlife, and Conservation Biology, Colorado Cooperative Fish and Wildlife Research Unit, Colorado State University, Fort Collins, Colorado 80523, USA.
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Abstract
Ecologists often use samples from the age or stage structure of a population to make inferences about population-level processes and to parameterize matrix models. Typically, researchers make a simplifying assumption that age and stage classes are determined without error, when in fact some level of misclassification often can be expected. If unaccounted for, misclassification will lead to overly optimistic levels of precision and can cause biased estimates of age or stage structure. Although several studies have used information from known-age individuals to quantify errors in age or stage distribution, the problem of estimating the age or stage structure in face of such errors has received comparably little attention. In this paper, we describe a general statistical framework for estimating the true stage distribution of a sample when misclassification rates can be estimated. The estimation process requires auxiliary information on misclassification rates, such as data from individuals of known age. We analyze age-structured harvest records from black bears in Pennsylvania to illustrate how incorporating misclassification errors leads to changes in point estimates and provides a measure of precision.
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Affiliation(s)
- Paul B Conn
- Colorado Cooperative Fish and Wildlife Research Unit, Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, Colorado 80523, USA.
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Mysterud A, Meisingset EL, Veiberg V, Langvatn R, Solberg EJ, Loe LE, Stenseth NC. Monitoring Population Size of Red Deer Cervus Elaphus: An Evaluation of Two Types of Census Data from Norway. WILDLIFE BIOLOGY 2007. [DOI: 10.2981/0909-6396(2007)13[285:mpsord]2.0.co;2] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Collier BA, Krementz DG. Uncertainty in age-specific harvest estimates and consequences for white-tailed deer management. Ecol Modell 2007. [DOI: 10.1016/j.ecolmodel.2006.09.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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MacKenzie DI, Nichols JD, Sutton N, Kawanishi K, Bailey LL. IMPROVING INFERENCES IN POPULATION STUDIES OF RARE SPECIES THAT ARE DETECTED IMPERFECTLY. Ecology 2005. [DOI: 10.1890/04-1060] [Citation(s) in RCA: 286] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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SPATIO-TEMPORAL AND DEMOGRAPHIC VARIATION IN THE HARVEST OF BLACK BEARS: IMPLICATIONS FOR POPULATION ESTIMATION. J Wildl Manage 2004. [DOI: 10.2193/0022-541x(2004)068[0947:sadvit]2.0.co;2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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