Wisconsin Department of Natural Resources

Abstract We examine recreational fisher behaviour and recreational fishery systems through the lens of an ecologist to understand the dynamical properties of these social-ecological systems. From the perspective of an ecologist, recreational fishers and the fish they capture can be viewed as analogous to predator-prey systems. Our understanding of predator-prey interactions is supported by a richness of empirical and conceptual research, primarily developed within sub-fields of behavioural, population, and community ecology. We develop this analogy between predator-prey ecology and fisher behaviour by examining the key underlying processes within a conceptual framework based on simple models. We then characterize several processes inherent to recreational fisheries that can, at least in part, decouple these simple predator-prey interactions. We examine the impacts on fisher behaviour and fishery outcomes of non-random spatial distributions of fishers and fish, heterogeneity of fisher behaviour, and multi-species fisheries, and develop an enhanced framework to understand these dynamic interactions. Population ecology and density-dependent feedbacks are important concepts underlying fish population dynamics, and also set limits to the sustainability of fisher harvest. Predator-prey theory is helpful in understanding fisher behaviour and its feedback with fish production, fishery quality, and sustainability. As fishers often prefer larger sizes in their catch, the predator-prey dynamic involves ecological concepts related to life-history theory and size-structured interactions. Although some recreational fisheries target a single species, many involve multi-species fisheries, such that food web theory is also important in understanding ecological feedbacks between fisher behaviour and fishery outcomes. In addition, individual recreational fisheries are typically embedded within landscapes of alternative fisheries, so the spatial configuration of fishing opportunities and the spatial behaviour of fishers is central in understanding fishery outcomes across landscapes. We discuss field methods used to measure fisher behaviour and provide empirical examples from well-studied recreational fisheries. Field methods to measure catchability, catch-per-unit effort, and landscape distribution of fisher effort are informed by the ecological theory of functional and numerical responses. Methods and implications of catch-and-release behaviour, multi-species fisheries, and non-catch related fisher site choice are discussed as related to our understanding of fisher behaviour and fisheries outcomes.

Primary dispersers of seeds and spores play critical roles in structuring the distributions of species, yet the role of predators as secondary dispersers remains largely unknown. This is especially true of mycorrhizal fungi, which often rely on small mammals to consume and disperse spores. We investigated how predator size, diet, and movement influence secondary spore dispersal in a terrestrial carnivore community by quantifying spore loads in scats (dispersal quantity) and integrating movement rates with gut passage time to determine dispersal distance (dispersal quality). Spores in carnivore scats increased with consumption of small mammals and transport of spores closely tracked home range movements. Larger carnivores deposited fewer spores but moved them farther from their source, creating a continuum between the quantity and quality of dispersal effectiveness. Our findings highlight the importance of carnivores as long-distance dispersers of mycorrhizal fungi and reveal how trophic interactions contribute to ecosystem functioning through secondary dispersal.

Response to infectious disease outbreaks and ongoing management actions can vary greatly across geopolitical units. Understanding relationships between management actions of governance systems within social ecological systems (SES) is important when resource units (e.g. wildlife) and users (e.g. humans) inextricably connect them. Surveillance efforts provide critical information to governance systems for diseases such as coronavirus, influenza, and ebola. However, diseases that spread rapidly across multiple SESs are coarsely managed and monitored over weeks, months, or years. Such time and spatial constraints can challenge evaluation of management actions. Assessing importance of disease management across SESs for slow-moving infectious diseases can provide rare insights about management actions. We investigated an exemplary outbreak of Chronic Wasting Disease (CWD) in white-tailed deer populations along the geopolitical border of Illinois and Wisconsin, USA. We illustrated challenges of disease management in wildlife populations along geopolitical borders, where differences in management actions of adjacent governance systems were stark and subject to sudden change. Our analysis provided evidence of abrupt change in outbreak progression following drastic changes in management actions. In addition, we showed evidence of inconsistent and highly variable outcomes of management actions along a geopolitical border when adjacent governance systems are unable to cooperatively manage across interconnected SESs. Total annual harvest in a county is a primary management action used to control CWD, where increasing harvest potentially reduces prevalence. We showed that the effects of increasing total county-level harvest on cumulative incidence of CWD were highly heterogeneous. In some counties, increasing harvest had the opposite of the intended effect.

ABSTRACT Objective As standardized boat electrofishing methods are adopted, integrating changes in electrofishing equipment at an agency-wide scale is an expensive and protracted process. As a result, many agency offices use a variety of electrofishing control boxes among different boats or interchangeably among boats. Our objective was to compare electrofishing catch data that were collected using different control boxes that are currently in service within and among electrofishing fleets to provide guidance on interchanging between different control boxes and the continued use of out-of-production control boxes for which standardizing power output is difficult. Methods We conducted a field-based assessment of the catch data that were produced by two configurations of a Smith Root Type VI-A electrofisher (low voltage/high pulse width and high voltage/low pulse width) and one configuration of an ETS MBS-1D electrofisher (output standardized to a power goal based on water conditions). The low-voltage Type VI-A configuration was chosen to match the voltage output of the standardized MBS configuration, and the higher voltage configuration consisted of the next highest voltage range on the control box, with the same root-mean-square current as the low-voltage Type VI-A configuration. To isolate the effect of control box configuration, all the data were collected with the same electrofishing boat and equipment, with the same driver and netter, and from the same water body. We tested for differences in the fish assemblage structure, relative abundance, and size structure among the data that were collected by the three configurations. We also mapped voltage gradients surrounding the anode array to assess how the size and strength of the electric field changed with the different configurations. Results The fish assemblages sampled and catch rates of most species were similar among the three electrofishing configurations, but fish <220 mm were consistently underrepresented when electrofishing with the Type VI-A at the lower voltage range. No differences were detected between data that were collected by the standardized MBS and the Type VI-A at higher voltage. The mapped voltage gradients supported the results of calculations that indicated that the Type VI-A configuration required 34% more voltage and current than the MBS configuration for comparable fish capture. Conclusions Inherent differences in settings and characteristics of the waveforms produced by different electrofishers can complicate methods for standardizing power or current outputs that are required for consistent and safe fish immobilization. Although calibration among different control boxes is possible, our results suggest that parabolic pulse shapes require higher peak power outputs than rectangular pulse shapes to produce effectively similar fish catches. Measuring the strength of the electric field provides important methodological context for electrofishing whether users are transitioning from older to newer equipment or relying on out-of-production control boxes.

ABSTRACT The lack of information on what constitutes suitable habitat for native freshwater mussels can limit restoration efforts. While many species reside in silt–sand–gravel substrates, species such as the Spectaclecase ( Cumberlandia monodonta ) and Salamander ( Simpsonaias ambigua ) mussels are thought to be associated with rock structures (e.g., wing dams and rock outcrops) in rivers. Our objective was to assess if hydroacoustic technology could be used to quantify physical habitat features for C. monodonta and S. ambigua . Multibeam echosounder, acoustic Doppler current profiler, sidescan sonar and underwater videography were used to quantify water depth, substrate hardness, bed roughness and bed slope of the riverbed, water velocity, shear velocity and the degree of rock clustering at six sites in the Saint Croix River, Minnesota. The sites varied in type of rock structures and relative abundances of both species. The strength of the associations among physical habitat features and mussel abundance was weak; R 2 values were typically < 0.5. However, species‐specific differences in microhabitat were observed. For example, C. monodonta was typically observed at sites with higher velocity and shear velocity compared to S. ambigua . Mussel abundance was greatest at sites that contained crevices of sand surrounded by boulders and bedrock. Future refinements in hydroacoustic methods and post‐processing computations could improve predictions. Information on habitat features from occupied and unoccupied sites could help resource managers characterize existing occupied habitats, identify potential reintroduction areas and implement restoration programmes.

ABSTRACTSociality offers benefits to species that can enhance their fitness. However, pathogen transmission can be higher in larger groups, potentially negating the advantages of group living. Despite the important paradoxical effects of population density on disease impacts and recovery, the competing effects of density remain unexplored. Here, we examine the response of a social bat species to pathogen invasion by comparing the effect of colony size on disease impacts during the summer (disease‐free period) and winter (disease period). During pathogen invasion, larger winter colonies initially experienced relatively higher declines than smaller colonies. Conversely, summer colony size positively influenced colony growth immediately following pathogen invasion and during recovery, suggesting that Allee effects may be important in population resilience. Our results show that hosts faced with a novel pathogen may experience both benefits and costs of group living, and balancing these competing effects could impede evolutionary selection pressure toward asociality.

Primary dispersers of seeds and spores play critical roles in structuring the distributions of species, yet the role of predators as secondary dispersers remains largely unknown. This is especially true of mycorrhizal fungi, which often rely on small

Abstract Motivations and sources of satisfaction associated with deer hunting vary, yet few studies have evaluated how hunters' individual characteristics and field behaviors influence harvest success. For example, emergent societal and technological shifts in hunting may be associated with selective deer harvest choices (e.g., choosing to pass on a harvest opportunity). We surveyed resident white‐tailed deer (Odocoileus virginianus) hunters in Wisconsin, USA, and used a mixed‐mode and multi‐part survey to quantify hunters' expectations, motivations, perceptions, and field behavior during the 9‐day firearm season in 2022. We used repeated measures logistic regression to model hunter behavior at the decision point of whether to take a shot at an antlered deer on a given day. Hunters' motivations, scouting effort, trail camera use, perception of deer density, prior harvest of a mature male deer, and prior participation in the archery season influenced this decision. In addition, hunting method, hunting location, and day of hunt influenced hunters' likelihood to take a shot. Our results identified factors influencing a growing practice of more selective deer hunting, which affects the efficacy of recreational hunting for managing white‐tailed deer populations relative to social or ecological goals.