Site-Occupancy Monitoring of an Ecosystem Indicator: Linking Characteristics of Riparian Vegetation to Beaver Occurrence

Breck, Stewart W.; Goldstein, Michael I.; Pyare, Sanjay

doi:10.3398/064.072.0402

Cited by 7 publications

(7 citation statements)

References 32 publications

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“…Beaver occupancy probability in our study ( = 0.57 ± 0.07) was slightly lower than other studies (0.74 ± 0.06, Breck et al 2012). Our prediction that beaver occupancy would be higher in areas with relatively more saplings within the site was supported by the data.…”

Section: Beaverssupporting

confidence: 77%

Occupancy of Semi-Aquatic Mammals in an Urban Landscape

Hoffer

Nielsen

Rutter

et al. 2021

Preprint

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Throughout midwestern North American ecosystems, semi-aquatic mammals including beaver (Castor canadensis), mink (Neovision vision), muskrat (Ondatra zibethicus), and river otter (Lontra canadensis) co-exist in wetlands. These species are ecologically important through their manipulation of habitats and interactions with other species present. Although natural resource managers in urban ecosystems are interested in semi-aquatic mammals and factors affecting their ecology, few such studies exist in the literature. We studied impacts of restoration practices and other environmental covariates on detection and occupancy of the 4 aforementioned focal species on forest preserves managed by the Lake County Forest Preserve District (Lake County, Illinois, USA). Sign surveys were conducted during December-April in 2018-19 and 2019-20. We quantified 12 variables representing bank measurements, temperature, precipitation, soil type, and survey replicate to inform the detection process and quantified 12 variables representing forest cover measurements, aquatic plant measurements, dominant landcover, restoration practices, and anthropogenic disturbances for the occupancy process. Single species, multi-season occupancy models were run in RStudio using the package unmarked. Detection probabilities ranged from 0.10 ± 0.07 for river otters to 0.60 ± 0.03 for muskrats; occupancy probabilities ranged from 0.28 ± 0.18 for river otters to 0.90 ± 0.05 for muskrats. Detection and occupancy were influenced by similar environmental factors (bank measurements, precipitation, and survey replicate for detection; and stream measurements and food availability for occupancy) compared to more rural locations. We provide further evidence that muskrats are urban adapters and document the initial stages of river otter recolonization in the Chicago Metropolitan Area.

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Section: Beaverssupporting

confidence: 77%

Occupancy of Semi-Aquatic Mammals in an Urban Landscape

Hoffer

Nielsen

Rutter

et al. 2021

Preprint

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“…We used the 1992 National Land Cover Database (NLCD; Vogelmann et al 2001) as our forest type input. Beavers are generally considered to be "choosy generalists," preferring deciduous and early successional forest communities (Jenkins 1979, Curtis and Jensen 2004, Breck et al 2012), so we defined preferred forage as Deciduous and Mixed forest classes to account for the full availability of deciduous trees. We took the total area of deciduous and mixed classes within the forage buffer, divided by the total area within the habitat buffer, to obtain a final index that approximately equates with the relative abundance of high-quality forage within each route.…”

Section: Variable Selectionmentioning

confidence: 99%

Ecological forecasts reveal limitations of common model selection methods: predicting changes in beaver colony densities

Johnson‐Bice

Ferguson

Erb

et al. 2020

Ecological Applications

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Over the past two decades, there have been numerous calls to make ecology a more predictive science through direct empirical assessments of ecological models and predictions. While the widespread use of model selection using information criteria has pushed ecology toward placing a higher emphasis on prediction, few attempts have been made to validate the ability of information criteria to correctly identify the most parsimonious model with the greatest predictive accuracy. Here, we used an ecological forecasting framework to test the ability of information criteria to accurately predict the relative contribution of density dependence and density-independent factors (forage availability, harvest, weather, wolf [Canis lupus] density) on inter-annual fluctuations in beaver (Castor canadensis) colony densities. We modeled changes in colony densities using a discrete-time Gompertz model, and assessed the performance of four models using information criteria values: density-independent models with (1) and without (2) environmental covariates; and density-dependent models with (3) and without (4) environmental covariates. We then evaluated the forecasting accuracy of each model by withholding the final one-third of observations from each population and compared observed vs. predicted densities. Information criteria and our forecasting accuracy metrics both provided strong evidence of compensatory density dependence in the annual dynamics of beaver colony densities. However, despite strong within-sample performance by the most complex model (density-dependent with covariates) as determined using information criteria, hindcasts of colony densities revealed that the much simpler density-dependent model without covariates performed nearly as well predicting out-of-sample colony densities. The hindcast results indicated that the complex model over-fit our data, suggesting that parameters identified by information criteria as important predictor variables are only marginally valuable for predicting landscapescale beaver colony dynamics. Our study demonstrates the importance of evaluating ecological models and predictions with long-term data and revealed how a known limitation of information criteria (over-fitting of complex models) can affect our interpretation of ecological dynamics. While incorporating knowledge of the factors that influence animal population dynamics can improve population forecasts, we suggest that comparing forecast performance metrics can likewise improve our knowledge of the factors driving population dynamics.

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“…As the studies were reviewed, it became clear that many link the water needs of non‐vegetative taxa and their health to vegetation, which serves as habitat (e.g. Breck et al ., ). These relationships need to be further explored, but perhaps, maintaining the hydrology that supports riparian vegetation can be used as the master variable for riparian ecosystems in the absence of more complete data.…”

Section: Discussionmentioning

confidence: 97%

Synthesizing Environmental Flow Needs Data for Water Management in a Water‐Scarce State: The Arizona Environmental Water Demands Database

Lacroix

Xiu

Nadeau

et al. 2014

River Research & Apps

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Water rights for environmental flows are not universal, and oftentimes, legal tools used to incorporate the environment into water management only require new users to consider their impact. It can be difficult to include the needs of riparian and aquatic ecosystems in new plans when relevant information is not always available, especially when other existing uses already outstrip available supplies. There is a need for easily accessible and understandable science on the water requirements for riparian and aquatic species, so managers can make informed decisions about whether or not to include riparian and aquatic species in their community's water management future. In this paper, we describe the current understanding of the link between hydrology and Arizona's riparian and aquatic ecosystems through the creation of a geospatial Environmental Water Demands database that can be used to determine the water needs to maintain habitat. Analysis of 121 studies reveals that there are very few analyses of the surface water and groundwater requirements for intermittent or ephemeral river systems, and there are only limited generalizable data for aquatic species. Except for a few species, such as Cottonwood (Populous fremontii) and Willow (Salix gooddingii), few data are available on the flow requirements for vegetation. The Environmental Water Demands database can be used to identify critical geographic and topical knowledge gaps where further research is needed, as well as serve as a single place for water and land managers to assess and use the most currently available information to make more informed management decisions and recommendations.

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Site-Occupancy Monitoring of an Ecosystem Indicator: Linking Characteristics of Riparian Vegetation to Beaver Occurrence

Cited by 7 publications

References 32 publications

Occupancy of Semi-Aquatic Mammals in an Urban Landscape

Occupancy of Semi-Aquatic Mammals in an Urban Landscape

Ecological forecasts reveal limitations of common model selection methods: predicting changes in beaver colony densities

Synthesizing Environmental Flow Needs Data for Water Management in a Water‐Scarce State: The Arizona Environmental Water Demands Database

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