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Gonnerman M, Linden DW, Shea SA, Sullivan K, Kamath P, Blomberg E. Including a spatial predictive process in band recovery models improves inference for Lincoln estimates of animal abundance. Ecol Evol 2022; 12:e9444. [PMID: 36311403 PMCID: PMC9608798 DOI: 10.1002/ece3.9444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 09/22/2022] [Accepted: 10/05/2022] [Indexed: 11/28/2022] Open
Abstract
Abundance estimation is a critical component of conservation planning, particularly for exploited species where managers set regulations to restrict harvest based on current population size. An increasingly common approach for abundance estimation is through integrated population modeling (IPM), which uses multiple data sources in a joint likelihood to estimate abundance and additional demographic parameters. Lincoln estimators are one commonly used IPM component for harvested species, which combine information on the rate and total number of individuals harvested within an integrated band‐recovery framework to estimate abundance at large scales. A major assumption of the Lincoln estimator is that banding and recoveries are representative of the whole population, which may be violated if major sources of spatial heterogeneity in survival or harvest rates are not incorporated into the model. We developed an approach to account for spatial variation in harvest rates using a spatial predictive process, which we incorporated into a Lincoln estimator IPM. We simulated data under different configurations of sample sizes, harvest rates, and sources of spatial heterogeneity in harvest rate to assess potential model bias in parameter estimates. We then applied the model to data collected from a field study of wild turkeys (Meleagris gallapavo) to estimate local and statewide abundance in Maine, USA. We found that the band recovery model that incorporated a spatial predictive process consistently provided estimates of adult and juvenile abundance with low bias across a variety of spatial configurations of harvest rate and sampling intensities. When applied to data collected on wild turkeys, a model that did not incorporate spatial heterogeneity underestimated the harvest rate in some subregions. Consistent with simulation results, this led to overestimation of both local and statewide abundance. Our work demonstrates that a spatial predictive process is a viable mechanism to account for spatial variation in harvest rates and limit bias in abundance estimates. This approach could be extended to large‐scale band recovery data sets and has applicability for the estimation of population parameters in other ecological models as well.
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Affiliation(s)
- Matthew Gonnerman
- Department of Wildlife Fisheries and Conservation BiologyUniversity of MaineOronoMaineUSA
| | - Daniel W. Linden
- Greater Atlantic Regional Fisheries OfficeNOAA National Marine Fisheries ServiceGloucesterMassachusettsUSA
| | | | - Kelsey Sullivan
- Maine Department of Inland Fisheries and WildlifeBangorMaineUSA
| | - Pauline Kamath
- School of Food and AgricultureUniversity of MaineOronoMaineUSA
| | - Erik Blomberg
- Department of Wildlife Fisheries and Conservation BiologyUniversity of MaineOronoMaineUSA
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Hagen R, Suchant R. Evidence of a spatial auto-correlation in the browsing level of four major European tree species. Ecol Evol 2020; 10:8517-8527. [PMID: 32788997 PMCID: PMC7417255 DOI: 10.1002/ece3.6577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 11/16/2022] Open
Abstract
The contribution of spatial processes to the spatial patterns of ecological systems is widely recognized, but spatial patterns in the ecology of plant-herbivore interactions have rarely been investigated quantitatively owing to limited budget and time associated with ecological research. Studies of the level of browsing on various tree species reported either no spatial auto-correlation or a small effect size. Further, the effects of disturbance events, such as hurricanes, which create large forest openings on spatial patterns of herbivory are not well understood.In this study, we used forest inventory data obtained from the federal state of Baden-Württemberg (Southern Germany) between 2001 and 2009 (grid size: 100 × 200 m) and thus, after hurricane Lothar struck Southern Germany in 1999. We investigated whether the browsing level of trees (height ≤ 130 cm) in one location is independent of that of the neighborhood.Our analyses of 1,758,622 saplings (187.632 sampling units) of oak (Quercus), fir (Abies), spruce (Picea), and beech (Fagus) revealed that the browsing level is characterized by a short distance spatial auto-correlation.The application of indicator variables based on browsed saplings should account for the spatial pattern as the latter may affect the results and therefore also the conclusions of the analysis.
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Affiliation(s)
- Robert Hagen
- Forest Research Institute of Baden‐Württemberg (FVA)FreiburgGermany
- Leibniz Institute for Zoo and Wildlife ResearchBerlinGermany
| | - Rudi Suchant
- Forest Research Institute of Baden‐Württemberg (FVA)FreiburgGermany
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Estimating red deer (Cervus elaphus) population size in the Southern Black Forest: the role of hunting in population control. EUR J WILDLIFE RES 2018. [DOI: 10.1007/s10344-018-1204-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Brazeal JL, Weist T, Sacks BN. Noninvasive genetic spatial capture-recapture for estimating deer population abundance. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21236] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jennifer L. Brazeal
- Mammalian Ecology and Conservation Unit; Veterinary Genetics Laboratory; University of California, Davis; One Shields Avenue/Old Davis Road Davis CA 95616 USA
| | - Terri Weist
- California Department of Fish and Wildlife; North Central Region; 1701 Nimbus Road Rancho Cordova CA 95670 USA
| | - Benjamin N. Sacks
- Mammalian Ecology and Conservation Unit; Veterinary Genetics Laboratory; Department of Population Health and Reproduction; University of California, Davis; One Shields Avenue/Old Davis Road Davis CA 95616 USA
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Heurich M, Zeis K, Küchenhoff H, Müller J, Belotti E, Bufka L, Woelfing B. Selective Predation of a Stalking Predator on Ungulate Prey. PLoS One 2016; 11:e0158449. [PMID: 27548478 PMCID: PMC4993363 DOI: 10.1371/journal.pone.0158449] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/16/2016] [Indexed: 11/19/2022] Open
Abstract
Prey selection is a key factor shaping animal populations and evolutionary dynamics. An optimal forager should target prey that offers the highest benefits in terms of energy content at the lowest costs. Predators are therefore expected to select for prey of optimal size. Stalking predators do not pursue their prey long, which may lead to a more random choice of prey individuals. Due to difficulties in assessing the composition of available prey populations, data on prey selection of stalking carnivores are still scarce. We show how the stalking predator Eurasian lynx (Lynx lynx) selects prey individuals based on species identity, age, sex and individual behaviour. To address the difficulties in assessing prey population structure, we confirm inferred selection patterns by using two independent data sets: (1) data of 387 documented kills of radio-collared lynx were compared to the prey population structure retrieved from systematic camera trapping using Manly's standardized selection ratio alpha and (2) data on 120 radio-collared roe deer were analysed using a Cox proportional hazards model. Among the larger red deer prey, lynx selected against adult males-the largest and potentially most dangerous prey individuals. In roe deer lynx preyed selectively on males and did not select for a specific age class. Activity during high risk periods reduced the risk of falling victim to a lynx attack. Our results suggest that the stalking predator lynx actively selects for size, while prey behaviour induces selection by encounter and stalking success rates.
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Affiliation(s)
- Marco Heurich
- Bavarian Forest National Park, Department of Conservation and Research, Freyunger Straße 2, 94481 Grafenau, Germany
- Chair of Wildlife Ecology and Management, Albert Ludwigs University of Freiburg, Tennenbacher Straße 4, 79106 Freiburg, Germany
| | - Klara Zeis
- Ludwig Maximilian University, Munich, Department of Statistics, Statistical Consulting Unit, Ludwigstraße 33, 80539 Munich, Germany
| | - Helmut Küchenhoff
- Ludwig Maximilian University, Munich, Department of Statistics, Statistical Consulting Unit, Ludwigstraße 33, 80539 Munich, Germany
| | - Jörg Müller
- Bavarian Forest National Park, Department of Conservation and Research, Freyunger Straße 2, 94481 Grafenau, Germany
- Field Station Fabrikschleichach, Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Rauhenebrach, Germany
| | - Elisa Belotti
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamýcká 1176, CZ-16521 Prague 6, Czech Republic
- Department of Research and Nature Protection, Šumava National Park Administration, Sušická 399, CZ-34192 Kašperské Hory, Czech Republic
| | - Luděk Bufka
- Department of Research and Nature Protection, Šumava National Park Administration, Sušická 399, CZ-34192 Kašperské Hory, Czech Republic
| | - Benno Woelfing
- Bavarian Forest National Park, Department of Conservation and Research, Freyunger Straße 2, 94481 Grafenau, Germany
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