Monitoring mesocarnivores with tracks and technology using multi‐method modeling

Abstract

Mesocarnivores play important ecological roles and are valued by diverse stakeholders. These species are often the focus of conservation efforts or are managed for sustainable harvest. Management actions require accurate population monitoring, but such monitoring is challenging because mesocarnivores are elusive and persist at low densities. We addressed this challenge by evaluating 2 monitoring methods (scent stations and motion-sensitive cameras) using multi-method modeling.We estimated occurrence probabilities and habitat relationships for 8 mesocarnivore species by fitting occupancy models to data collected at 75 sites from October to December 2021 across a 3,200-km 2 system in New Hampshire, USA. We assessed the relative estimated precision of the methodological approaches and their costs. We also evaluated tradeoffs in occurrence estimation and uncertainty among study designs by analyzing simulations run across various numbers of study sites and 2 study durations. Cameras cost roughly 10 times more than scent stations but strongly outperformed them in terms of species' detectability and parameter estimate precision. Multi-method models yielded the most precise estimates of occurrence probability and habitat relationships. Parameter estimates were on average twice as precise for camera and multi-method models compared to scent stations. Additionally, the estimated precision and direction (positive or negative) of habitat relationships varied with the method employed. Longer camera deployments, additional study sites, and multi-method approaches nearly always reduced uncertainty, but these

Using pedigree relations to inform capture‐recapture data for the estimation of census population size

“…While mesocarnivores are an important component of ecosystem functions and dynamics (Roemer et al 2009), they are understudied (Brooke et al 2014), largely because of their elusive behavior that often hinders their observation. Therefore, there is a need for new approaches that gain information on population levels (Monterroso et al 2014, Moll et al 2023). The estimation of the census population size is particularly important because it is a key parameter in assessing the efficacy of management and conservation measures.…”

Generalized nonlinearity in animal ecology: Research, review, and recommendations

“…These two canid species are competitors, and coyotes are dominant over foxes and can reduce their abundance through interference competition and intraguild predation (Gosselink et al., 2007 ; Levi & Wilmers, 2012 ; Moll et al., 2018 ). Prior research on these species suggests that their competitive interactions might be mediated by human development of the landscape (Moll et al., 2018 , 2023 ). Specifically, a “human shield” effect might reduce the interference competition experienced by foxes from coyotes, which are more human averse and therefore less abundant in more developed locations that foxes readily inhabit (Moll et al., 2018 ).…”

“…The remaining 8% is comprised of a combination of agriculture, grasslands, shrublands, and sand beaches (Dewitz & U.S. Geological Survey, 2021 ). We selected 75 of the camera sites using a generalized random tessellation design with sites separated by at least 1 km (Stevens & Olsen, 2003 ), and we selected the remaining 33 sites using a fully random design within properties managed by the University of New Hampshire with sites separated by at least 250 m (Moll et al., 2023 ; Poisson et al., 2023 ). We selected sites using QGIS (QGIS Association, 2021 ), then made minor adjustments in the field to locate a suitable location to affix the camera on a tree at approximately 50 cm above ground, facing north, and not conspicuously placed to avoid tampering.…”

A guidance on how to start up a national wildlife population monitoring program harmonizable at European level

“…), since they can always provide useful information and data; information on the performance of a given sampling design and reference data about the species of interest are highly valuable to select the method/s, determine sampling effort, etc. In this respect, methods producing absolute indicators (e. g., density) are preferred than those producing relative indicators (e. g., relative abundance), since the former are directly comparable but not the latter (Moll et al 2023).…”

“…Thus, the optimization of the monitoring programs is a mandatory step to guarantee their coverage under a spatio-temporal perspective (Likens et al 2018). The spatio-temporal coverage can be also enhanced by considering and integrating different approaches and sampling methods within a NWMP (Moll et al 2023).…”