Understanding sensory mechanisms to develop effective conservation and management tools

The movement ecology of fishes

Movement of fishes in the aquatic realm is fundamental to their ecology and survival. Movement can be driven by a variety of biological, physiological and environmental factors occurring across all spatial and temporal scales. The intrinsic capacity of movement to impact fish individually (e.g., foraging) with potential knock-on effects throughout the ecosystem (e.g., food web dynamics) has garnered considerable interest in the field of movement ecology. The advancement of technology in recent decades, in combination with ever-growing threats to freshwater and marine systems, has further spurred empirical research and theoretical considerations. Given the rapid expansion within the field of movement ecology and its significant role in informing management and conservation efforts, a contemporary and multidisciplinary review about the various components influencing movement is outstanding. Using an established conceptual framework for movement ecology as a guide (i.e., Nathan et al., 2008: 19052), we synthesized the environmental and individual factors that affect the movement of fishes. Specifically, internal (e.g., energy acquisition, endocrinology, and homeostasis) and external (biotic and abiotic) environmental elements are discussed, as well as the different processes that influence individual-level (or population) decisions, such as navigation cues, motion capacity, propagation characteristics and group behaviours. In addition to environmental drivers and individual movement factors, we also explored how associated strategies help survival by optimizing physiological and other biological states. Next, we identified how movement ecology is increasingly being incorporated into management and conservation by highlighting the inherent benefits that spatio-temporal fish behaviour imbues into policy, regulatory, and remediation planning. Finally, we considered the future of movement ecology by evaluating ongoing technological innovations and both the challenges and opportunities that these advancements create for scientists and managers. As aquatic ecosystems continue to face alarming climate (and other human-driven) issues that impact animal movements, the comprehensive and multidisciplinary assessment of movement ecology will be instrumental in developing plans to guide research and promote sustainability measures for aquatic resources.

How Do Hunters Hunt Wild Boar? Survey on Wild Boar Hunting Methods in the Federal State of Lower Saxony

Simple Summary

High wild boar population densities lead to human–wildlife conflicts. For proper wildlife management, knowledge of wildlife biology as well as human attitudes is needed. We conducted inquiries on hunting methods and on hunters’ attitudes in the German Federal State of Lower Saxony to better understand hunting strategies. Single hunt, especially at bait, is still the most widely used method for hunting wild boar. The proportion of drive hunts within the hunting bag is increasing. The proportions of hunting methods vary regionally due to wild boar densities, geographical conditions and hunters’ practices. Private hunting is important for wild boar management, although it is just insufficient. Besides promoting more efficient hunting methods and motivating hunters, in the future, additionally, administrative wildlife managers could be established as coordinators of wild boar management, and as such, could manage hunting, the incorporation of regional conditions and investigating hunters’ attitudes and abilities.

Abstract

High wild boar population densities lead to demands for a population reduction to avoid crop damages or epidemic diseases. Along with biological studies, a better understanding of the human influence on wildlife and on wildlife management is important. We conducted inquiries on hunting methods and on hunters’ attitudes in the Federal State of Lower Saxony, Germany, to better understand hunting strategies and the influence on increasing wild boar population, as well as to underpin game management concepts. Single hunt, especially at bait, is still the most widely used method for hunting wild boar. The proportion of drive hunts within the hunting bag is increasing. The proportions of hunting methods vary regionally due to wild boar densities, geographical features (vegetation, terrain, etc.) and hunters’ practices. Hunters increased the proportion of conjoint hunts on wild boar. Baiting remains an important hunting method in wild boar management and the proportion of drive hunts should be fostered. Private hunting is important for wild boar management, although it is just insufficient. Additionally, administrative wildlife managers are recommended for the near future as coordinators of wild boar management, and as such, could manage hunting, the incorporation of regional conditions and investigating hunters’ attitudes and abilities.

The Rules of Attraction: The Necessary Role of Animal Cognition in Explaining Conservation Failures and Successes

Integrating knowledge and principles of animal behavior into wildlife conservation and management has led to some concrete successes but has failed to improve conservation outcomes in other cases. Many conservation interventions involve attempts to either attract or repel animals, which we refer to as approach/avoidance issues. These attempts can be reframed as issues of manipulating the decisions animals make, which are driven by their perceptual abilities and attentional biases, as well as the value animals attribute to current stimuli and past learned experiences. These processes all fall under the umbrella of animal cognition. Here, we highlight rules that emerge when considering approach/avoidance conservation issues through the lens of cognitive-based management. For each rule, we review relevant conservation successes and failures to better predict the conditions in which behavior can be manipulated, and we suggest how to avoid future failures.

The Ecology of Individual Differences Empirically Applied to Space-Use and Movement Tactics

Movement provides a link between individual behavioral ecology and the spatial and temporal variation in an individual's landscape. Individual variation in movement traits is an important axis of animal personality, particularly in the context of foraging ecology. We tested whether individual caribou (Rangifer tarandus) displayed plasticity in movement and space-use behavior across a gradient of resource aggregation. We quantified first-passage time and range-use ratio as proxies for movement-related foraging behavior and examined how these traits varied at the individual level across a foraging resource gradient. Our results suggest that individuals adjusted first-passage time but not range-use ratio to maximize access to high-quality foraging resources. First-passage time was repeatable, and intercepts for first-passage time and range-use ratio were negatively correlated. Individuals matched first-passage time but not range-use ratio to the expectations of our patch-use model that maximized access to foraging resources, a result that suggests that individuals acclimated their movement patterns to accommodate both intra- and interannual variation in foraging resources on the landscape. Collectively, we highlight repeatable movement and space-use tactics and provide insight into how individual plasticity in movement interacts with landscape processes to affect the distribution of behavioral phenotypes and potentially fitness and population dynamics.

In situ predator conditioning of naive prey prior to reintroduction

Many translocations and introductions to recover threatened populations fail because predators kill prey soon after release; a problem exacerbated for predator-naive prey. While pre-release training has been shown to work in some situations, it is time consuming and relies on using inferred predator cues and treating small groups. We review a relatively new and very promising management tool: in situ, pre-release predator conditioning. Here, the goal is to allow prey in large enclosures to live with low densities of predators to accelerate selection for antipredator traits (in an evolutionary sense) or provide prey essential experience with predators that they will later encounter. We review the published results of a large-scale, controlled experiment where we have permitted burrowing bettongs (Bettongia lesueur) and greater bilblies (Macrotis lagotis) to live with low densities of feral cats (Felis catus), a species implicated in their widespread decline and localized extinction. We found that both species could persist with cats, suggesting that future work should define coexistence thresholds-which will require knowledge of prey behaviour as well as the structure of the ecological community. Compared to control populations, predator-naive prey exposed to cats has a suite of morphological and behavioural responses that seemingly have increased their antipredator abilities. Results suggest that predator-conditioned bilbies survive better when released into a large enclosure with an established cat population; future work will determine whether this increased survival extends to the wild. This article is part of the theme issue 'Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation'.

Balancing biodiversity outcomes and pollution management in urban stormwater treatment wetlands

Wetlands are increasingly being constructed to mitigate the effects of urban stormwater, such as altered hydrological regimes and reduced water quality, on downstream aquatic ecosystems. While the primary purpose of these wetlands is to manage stormwater, they also attract animals whose growth, survival and breeding (i.e. 'fitness') may be compromised. Such deleterious effects will be exacerbated if animals are caught in 'ecological traps', mistakenly preferring wetlands with unsuitable environmental conditions. Alternatively, wetlands that offer suitable habitat conditions for animals could be beneficial, especially in fragmented urban landscapes. Consequently, a thorough understanding of the potential ecological impacts of stormwater treatment wetlands is critical for managing unintended consequences to urban biodiversity. To help facilitate this understanding, we draw upon findings from a four-year research program conducted in the city of Melbourne in south-eastern Australia as a case study. First, we summarise our research demonstrating that some stormwater wetlands can be ecological traps for native frogs and fish in the study region, whilst others likely provide important habitat in areas where few natural waterbodies remain. We use our work to highlight that while stormwater wetlands can be ecological traps, their effects can be properly managed. We propose the need for a better understanding of the ecological consequences of changes to wetland quality and their population-level impacts across the landscape. We hope that this study will generate discussions about how to most effectively manage constructed wetlands in urban landscapes and more research for a better understanding of the issues and opportunities regarding potential ecological traps.

A systematic survey of the integration of animal behavior into conservation

The role of behavioral ecology in improving wildlife conservation and management has been the subject of much recent debate. We sought to answer 2 foundational questions about the current use of behavioral knowledge in conservation: To what extent is behavioral knowledge used in wildlife conservation and management, and how does the use of animal behavior differ among conservation fields in both frequency and types of use? We searched the literature for intersections between key fields of animal behavior and conservation and created a systematic heat map (i.e., graphical representation of data where values are represented as colors) to visualize relative efforts. Some behaviors, such as dispersal and foraging, were commonly considered (mean [SE] of 1147.38 [353.11] and 439.44 [108.85] papers per cell, respectively). In contrast, other behaviors, such as learning, social, and antipredatory behaviors were rarely considered (mean [SE] of 33.88 [7.62], 44.81 [10.65], and 22.69 [6.37] papers per cell, respectively). In many cases, awareness of the importance of behavior did not translate into applicable management tools. Our results challenge previous suggestions that there is little association between the fields of behavioral ecology and conservation and reveals tremendous variation in the use of different behaviors in conservation. We recommend that researchers focus on examining underutilized intersections of behavior and conservation themes for which preliminary work shows a potential for improving conservation and management, translating behavioral theory into applicable and testable predictions, and creating systematic reviews to summarize the behavioral evidence within the behavior-conservation intersections for which many studies exist.

Regulating wild boar populations is "somebody else's problem"! - Human dimension in wild boar management

As a part of the ongoing game survey of the German federal state of Lower Saxony (WTE), we conducted inquiries into wild boar management and distribution, as well as hunters' attitudes, in order to determine the reasons for the increase of wild boar populations and to inform our game management strategy. According to hunters' reports within the WTE, increases in distribution and population continue and a reduction of the wild boar population has been deemed necessary on a large scale. In the home region, however, it seems to be "somebody else's problem" (SEP), according to hunters' opinions. The majority of hunters are not able to regulate the population and this could be a reason that wild boar numbers continue to increase. Cooperation and comprehensive hunting with efficient hunting methods seems to be the most promising solution, as non-hunting methods are unpopular amongst hunters. The hunters seem to be aware of the problems, solutions and contributing factors; however, most hunters do not feel responsible and see the management of wild boar, again, as a SEP. Regional conditions, as well as hunters' willingness and capacity to manage wild boar will have to be incorporated into management concepts.

Mitigating road impacts on animals through learning principles

Roads are a nearly ubiquitous feature of the developed world, but their presence does not come without consequences. Many mammals, birds, reptiles, and amphibians suffer high rates of mortality through collision with motor vehicles, while other species treat roads as barriers that reduce gene flow between populations. Road effects extend beyond the pavement, where traffic noise is altering communities of songbirds, insects, and some mammals. Traditional methods of mitigation along roads include the creation of quieter pavement and tires and the construction of physical barriers to reduce sound transmission and movement. While effective, these forms of mitigation are costly and time-consuming. One alternative is the use of learning principles to create or extinguish aversive behaviors in animals living near roads. Classical and operant conditioning are well-documented techniques for altering behavior in response to novel cues and signals. Behavioral ecologists have used conditioning techniques to mitigate human-wildlife conflict challenges, alter predator-prey interactions, and facilitate reintroduction efforts. Yet, these principles have rarely been applied in the context of roads. We suggest that the field of road ecology is ripe with opportunity for experimentation with learning principles. We present tangible ways that learning techniques could be utilized to mitigate negative roadside behaviors, address the importance of evaluating fitness within these contexts, and evaluate the longevity of learned behaviors. This review serves as an invitation for empirical studies that test the effectiveness of learning paradigms as a mitigation tool in the context of roads.

Conservation physiology of animal migration

Migration is a widespread phenomenon among many taxa. This complex behaviour enables animals to exploit many temporally productive and spatially discrete habitats to accrue various fitness benefits (e.g. growth, reproduction, predator avoidance). Human activities and global environmental change represent potential threats to migrating animals (from individuals to species), and research is underway to understand mechanisms that control migration and how migration responds to modern challenges. Focusing on behavioural and physiological aspects of migration can help to provide better understanding, management and conservation of migratory populations. Here, we highlight different physiological, behavioural and biomechanical aspects of animal migration that will help us to understand how migratory animals interact with current and future anthropogenic threats. We are in the early stages of a changing planet, and our understanding of how physiology is linked to the persistence of migratory animals is still developing; therefore, we regard the following questions as being central to the conservation physiology of animal migrations. Will climate change influence the energetic costs of migration? Will shifting temperatures change the annual clocks of migrating animals? Will anthropogenic influences have an effect on orientation during migration? Will increased anthropogenic alteration of migration stopover sites/migration corridors affect the stress physiology of migrating animals? Can physiological knowledge be used to identify strategies for facilitating the movement of animals? Our synthesis reveals that given the inherent challenges of migration, additional stressors derived from altered environments (e.g. climate change, physical habitat alteration, light pollution) or interaction with human infrastructure (e.g. wind or hydrokinetic turbines, dams) or activities (e.g. fisheries) could lead to long-term changes to migratory phenotypes. However, uncertainty remains because of the complexity of biological systems, the inherently dynamic nature of the environment and the scale at which many migrations occur and associated threats operate, necessitating improved integration of physiological approaches to the conservation of migratory animals.

Increased tolerance to humans among disturbed wildlife

Human disturbance drives the decline of many species, both directly and indirectly. Nonetheless, some species do particularly well around humans. One mechanism that may explain coexistence is the degree to which a species tolerates human disturbance. Here we provide a comprehensive meta-analysis of birds, mammals and lizards to investigate species tolerance of human disturbance and explore the drivers of this tolerance in birds. We find that, overall, disturbed populations of the three major taxa are more tolerant of human disturbance than less disturbed populations. The best predictors of the direction and magnitude of bird tolerance of human disturbance are the type of disturbed area (urbanized birds are more tolerant than rural or suburban populations) and body mass (large birds are more tolerant than small birds). By identifying specific features associated with tolerance, these results guide evidence-based conservation strategies to predict and manage the impacts of increasing human disturbance on birds.