scholarly journals Making better sense of monitoring data from low density species using a spatially explicit modelling approach

2010 ◽  
Vol 48 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Max Post van der Burg ◽  
Bartholomew Bly ◽  
Tammy VerCauteren ◽  
Andrew J. Tyre
2020 ◽  
Author(s):  
Anna Conchon ◽  
Olivier Titaud ◽  
Inna Senina ◽  
Beatriz Calmettes ◽  
Audrey Delpech ◽  
...  

<p><span xml:lang="EN-US" data-contrast="none"><span>SEAPODYM-LMTL is the Lower (zooplankton) and Mid (micronekton) Trophic levels model of the Spatial Ecosystem </span></span><span xml:lang="EN-US" data-contrast="none"><span>And</span></span><span xml:lang="EN-US" data-contrast="none"><span> </span></span><span xml:lang="EN-US" data-contrast="none"><span>POpulation</span></span><span xml:lang="EN-US" data-contrast="none"><span> </span></span><span xml:lang="EN-US" data-contrast="none"><span>DYnamic</span></span><span xml:lang="EN-US" data-contrast="none"><span> Modeling framework. Currently, there is one zooplankton and 6 micronekton functional groups defined according to their vertical behavior and development times. The model is global and spatially explicit with transport described through a system of advection-diffusion equations. The vertical dimension is simplified into three layers -- epipelagic, upper and lower mesopelagic -- defined relatively to the euphotic depth. There are three vertically migrant and three non-migrant functional groups. The model is parsimonious with only a few parameters (6 for the zooplankton and 11 for the micronekton) that control the energy transfer efficiency from the primary production and the mortality and time of development that are linked to the water temperature. A data assimilation framework has been implemented to estimate those parameters.  We present briefly the latest results and future challenges of this model. They include the validation of vertical layer boundaries, the first zooplankton and micronekton parameters estimation using existing biomass observations, and the developments needed to use large global datasets of acoustic data.</span></span><span> </span></p>


2022 ◽  
Author(s):  
Luca Pedruzzi ◽  
Anna Schertler ◽  
Silvia Giuntini ◽  
Ivan Leggiero ◽  
Emiliano Mori

AbstractThe coypu, Myocastor coypus, has been introduced worldwide for fur farming and is widely recognized as one of the most invasive alien mammals of the world, affecting natural ecosystems, crops and possibly human health. Here we present a comprehensive up-to-date review of its distribution and status in Asia and Africa. Using a multi-source approach, we collected occurrences from published literature as well as from online biodiversity platforms (e.g. GBIF, iNaturalist), video sharing platforms, and local experts. Additionally, we used an ensemble modelling approach to predict the climatic suitability across Africa and Asia. We present an updated distribution map, including a total of 1506 spatially explicit records from 1973 to 2021, covering 1 African and 16 Asian countries. We find evidence for current populations in Kenya and five new countries since the last review of (Carter and Leonard, Wildl Soc Bull 30:162–175, 2002): Iran, Jordan, Lebanon, Uzbekistan, and Vietnam, and identify main clusters of coypu occurrence in Western (including Transcaucasia) and East Asia. We show that warm temperate and Mediterranean areas on both continents are predicted to be climatically suitable for the coypu and highlight not only areas of possible spread, but also potential data gaps, i.e. with high suitability and low availability of concrete information (e.g. China, Southern Russia). We emphasize the importance of citizen involvement and the urgency for coypu-targeted studies in data-poor regions to obtain a clear picture of the geographical distribution and to better address management strategies.


2021 ◽  
pp. 130208
Author(s):  
Xi Chen ◽  
Maryna Strokal ◽  
Michelle T.H. van Vliet ◽  
Xing Fu ◽  
Mengru Wang ◽  
...  

2016 ◽  
Author(s):  
Daniel W. Linden ◽  
Angela K. Fuller ◽  
J. Andrew Royle ◽  
Matthew P. Hare

1. The challenges associated with monitoring low-density carnivores across large landscapes have limited the ability to implement and evaluate conservation and management strategies for such species. Noninvasive sampling techniques and advanced statistical approaches have alleviated some of these challenges and can even allow for spatially explicit estimates of density, arguably the most valuable wildlife monitoring tool. 2. For some species, individual identification comes at no cost when unique attributes (e.g., pelage patterns) can be discerned with remote cameras, while other species require viable genetic material and expensive lab processing for individual assignment. Prohibitive costs may still force monitoring efforts to use species distribution or occupancy as a surrogate for density, which may not be appropriate under many conditions. 3. Here, we used a large-scale monitoring study of fisherPekania pennantito evaluate the effectiveness of occupancy as an approximation to density, particularly for informing harvest management decisions. We used a combination of remote cameras and baited hair snares during 2013-2015 to sample across a 70,096 km2 region of western New York, USA. We fit occupancy and Royle-Nichols models to species detection-nondetection data collected by cameras, and spatial capture-recapture models to individual encounter data obtained by genotyped hair samples. 4. We found a close relationship between grid-cell estimates of fisher state variables from the models using detection-nondetection data and those from the SCR model, likely due to informative spatial covariates across a large landscape extent and a grid cell resolution that worked well with the movement ecology of the species. Spatially-explicit management recommendations for fisher were similar across models. We discuss design-based approaches to occupancy studies that can improve approximations to density.


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