Terrestrial Wildlife Research Articles

Use of anthropogenic-related nest material and nest parasite prevalence have increased over the past two centuries in Australian birds.

Global plastic production has increased exponentially since the 1940s, resulting in the increased presence of anthropogenic debris in the environment. Recent studies have shown that birds incorporate anthropogenic debris into their nests, which can reduce nest ectoparasite loads. However, we know little about the long-term history of interactions among birds, anthropogenic debris, and ectoparasites. Our study took a unique approach to address this issue by determining the prevalence of anthropogenic debris and ectoparasitic nest flies (Protocalliphora and Passeromyia spp.) in 893 bird nests from 224 species between 1832 and 2018, which were sourced from Australian museum collections. The prevalence of anthropogenic material increased from approximately 4% in 1832 to almost 30% in 2018. This change was driven by an increase in the incorporation of synthetic rather than biodegradable anthropogenic debris (by 2018 ~ 25% of all nests contained synthetics), with the first synthetic item being found in a nest from 1956 in the city of Melbourne. Nest parasite prevalence increased over time but contrary to other studies, there was no relationship between habitat type or anthropogenic material and parasite presence. Our study is the first to use museum specimens to quantify temporal and spatial impacts of anthropogenic material on birds, the results of which justifies contemporary concerns regarding the ubiquitous nature of human impacts on terrestrial wildlife.

Simultaneous monitoring of vegetation dynamics and wildlife activity with camera traps to assess habitat change

AbstractVegetation phenology and productivity drive resource use by wildlife. Vegetation dynamics also reveal patterns of habitat disturbance and recovery. Monitoring these fine‐scale vegetation patterns over large spatiotemporal extents can be difficult, but camera traps (CTs) commonly used to survey wildlife populations also collect data on local habitat conditions. We used CTs (n = 73) from 2016 to 2019 to assess impacts of habitat change in a boreal landscape of northern Canada, where seismic lines for petroleum exploration disturbed wildlife habitat and prompted vegetation restoration efforts. First, we quantified vegetation dynamics from CTs, comparing them to satellite‐based estimates that are typically used to monitor vegetation at broad spatial scales. We then used understory phenology and productivity estimated from CT time‐lapse images to assess vegetation recovery on seismic lines. Finally, we related vegetation dynamics with the habitat use of three wildlife species: sandhill cranes Grus canadensis, woodland caribou Rangifer tarandus, and white‐tailed deer Odocoileus virginianus. CTs provided unique insight into vegetation dynamics that were different from signals measured by satellites, with temporally inconsistent and even some negative correlations between CT and satellite metrics. We found some indication of vegetation recovery on seismic lines that had received restoration treatment, with understory patterns more similar to undisturbed habitat than to seismic lines that did not receive restoration treatment. CTs also provided inferences about wildlife activity related to vegetation resources, which approaches using satellite data failed to detect. Wildlife habitat use tracked vegetation phenology, but did not always increase with vegetation productivity at weekly, 16‐day, or annual intervals. Instead, associations with vegetation productivity depended on species, temporal scale, and productivity metrics. Given the widespread and growing use of CTs to monitor terrestrial wildlife, we recommend their use to simultaneously monitor habitat conditions to better understand the mechanisms that govern wildlife habitat use in changing environments.

The Patterns and Causes of Dermatitis in Terrestrial and Semi-Aquatic Mammalian Wildlife.

Simple SummaryDermatitis is recognized to manifest from a variety of causes in humans and animals, but these have never been synthesized for wildlife. We document the causes and investigate the magnitude of skin diseases and disorders which manifest as, and are described as, dermatitis in the published literature. Our aim was to identify the major causal agents in the development of dermatitis, and if certain mammalian wildlife groups or captivity status was a precursor for the development of dermatitis. The most common causes of dermatitis identified were mites, bacteria, and fungus, and were more frequently reported for wildlife species within Carnivora and Artiodactyla. Furthermore, associated with genetic and behavioral variables, some threatened species were more likely to exhibit dermatitis in captivity. This study provides insight into wild mammalian species that may be more susceptible to dermatological diseases and discusses the patterns of causes within wild mammals.Causative disease and stress agents which manifest as dermatitis in mammals have varying effects on individual animals, from benign irritation and inflammation, to causing morbidity and even mortality. Bacteria, viruses and ectoparasites are all potential causes of dermatitis, and it can be exacerbated by various environmental, genetic and social factors. Furthermore, it is uncertain whether dermatitis is more likely to manifest in already-vulnerable wildlife species. Here, we systematically review the literature for reports of dermatitis in terrestrial and semi-aquatic wild mammalian species, with the goal of determining the biogeographical scale of dermatitis reports, the causes of dermatitis, and whether manifestation of dermatitis is reported more commonly in certain wildlife species or their captivity status (i.e., free-living, in captivity or in a laboratory). We reveal biases in the reporting of dermatitis by a biogeographic realm, with 55% of cases reported in the Nearctic, and towards particular orders of mammals, namely Artiodactyla and Carnivora. Overall, free-living wildlife is almost twice as likely to be reported as having dermatitis than individuals in captivity and six times more likely than individuals in laboratories, which we interpret as owing to exposure to a broader spectrum of parasites in free-ranging individuals, and potential reporting bias in captive individuals. Notably, dermatitis was reported in 23 threatened species, with some species more likely than others to be reported exhibiting clinical signs of dermatitis resulting from underlying health problems. We also find that threatened species are more likely to be reported as having dermatitis in captivity, particularly outside of their endemic home range. This review highlights diverse patterns of dermatological disease causes in captive and free-ranging wildlife, conditions under which they are more likely to be documented, and the need for cross-disciplinary research to ascertain (and so better manage) the varied causes.

SNAPSHOT USA 2019: a coordinated national camera trap survey of the United States.

With the accelerating pace of global change, it is imperative that we obtain rapid inventories of the status and distribution of wildlife for ecological inferences and conservation planning. To address this challenge, we launched the SNAPSHOT USA project, a collaborative survey of terrestrial wildlife populations using camera traps across the United States. For our first annual survey, we compiled data across all 50 states during a 14-week period (17 August-24 November of 2019). We sampled wildlife at 1,509 camera trap sites from 110 camera trap arrays covering 12 different ecoregions across four development zones. This effort resulted in 166,036 unique detections of 83 species of mammals and 17 species of birds. All images were processed through the Smithsonian's eMammal camera trap data repository and included an expert review phase to ensure taxonomic accuracy of data, resulting in each picture being reviewed at least twice. The results represent a timely and standardized camera trap survey of the United States. All of the 2019 survey data are made available herein. We are currently repeating surveys in fall 2020, opening up the opportunity to other institutions and cooperators to expand coverage of all the urban-wild gradients and ecophysiographic regions of the country. Future data will be available as the database is updated at eMammal.si.edu/snapshot-usa, as will future data paper submissions. These data will be useful for local and macroecological research including the examination of community assembly, effects of environmental and anthropogenic landscape variables, effects of fragmentation and extinction debt dynamics, as well as species-specific population dynamics and conservation action plans. There are no copyright restrictions; please cite this paper when using the data for publication.

The diversity of small mammals in Pulau Perhentian Kecil, Terengganu, Malaysia

Islands are generally rich in marine biodiversity, but it also often hides unique and endemic terrestrial wildlife. The data of terrestrial wildlife in Malaysian islands are still severely lacking, notably from small islands. Hence, this study was conducted to survey and update the small mammal diversity (bats and non-volant small mammals) in Pulau Perhentian Kecil, a tourist destination famous for its magnificent, diverse marine life and white sandy beaches. Despite their touristic popularity, very few information is known about the faunal diversity in this island compare to their more massive neighbouring island, Pulau Perhentian Besar. The survey was carried out from 21 to 30 May 2014 recorded 56 individuals encompasses eight species of bats and five species of non-volant small mammals that were captured using mist nets, harp traps, and cage traps. The survey recorded 10 new species locality records for the island in which, five species were never recorded in Pulau Perhentian Besar. Hipposideros dyacorum, Tylonycteris fulvida, T. malayana, Rattus exulans, and Sundamys annandalei are also new distribution records for the Malaysian East Coast islands highlighting the importance of protecting island biodiversity. Nonetheless, it is hoped that this study not only highlights the species diversity on the island but also serve as a data for sustainable island tourism management planning, which will be crucial for the sustainable development and management of this ecologically sensitive area.

Selection of Habitat-Enhancing Plants Depends on Predator–Prey Interactions

Abstract Shallow areas of drawdown reservoirs are often devoid of adequate fish habitat due to degradation associated with unnatural and relatively invariable cycles of exposure and flooding. One method of enhancing fish habitat in these areas is to sow exposed shorelines with agricultural plants to provide structure once flooded. It remains unclear if some plants may be more suitable than others to provide effective fish habitat. To determine the fish habitat potential of various crops, we performed a replicated tank experiment evaluating the selection of agricultural plants by prey and predator fishes with and without the presence of the other. We submerged diverse treatments of potted plants in outdoor mesocosms stocked with prey and/or predator fish and monitored selection of plant species, stem density, and stem height over 0.5-h trials. Prey fish selected the densest vegetation, and selection was accentuated when a predator was present. Predators selected the second highest stem density and were more active when prey were present. Prey schooling was increased by predation risk, suggesting that cover was insufficient to outweigh the advantages of increased group size. Our data indicate that the perception of cover quality is reciprocally context dependent on predator–prey interactions for both predator and prey. Applications of the two most selected plant treatments in this study could enhance structural habitat for both predator and prey fishes in reservoirs, adding to their already reliable functionality as supplemental forage crops for terrestrial wildlife.

A meta‐analysis of the influence of anthropogenic noise on terrestrial wildlife communication strategies

Abstract Human‐caused noise pollution dominates the soundscape of modern ecosystems, from urban centres to national parks. Although wildlife can generally alter their communication to accommodate many types of natural noise (e.g. wind, wave action, heterospecific communication), noise pollution from anthropogenic sources pushes the limits of wildlife communication flexibility by causing loud, low‐pitched and near‐continuous interference. Because responses to noise pollution are variable and taxa specific, multi‐species risk assessments and mitigation are not currently possible. We conducted a meta‐analysis to synthesize noise pollution effects on terrestrial wildlife communication. Specifically, we assessed: (a) the impacts of noise pollution on modulation of call rate, duration, amplitude and frequency (including peak, minimum and maximum frequency); and (b) the literature on anthropogenic noise pollution by region, taxa, study design and disturbance type. Terrestrial wildlife (results driven by avian studies) generally respond to noise pollution by calling with higher minimum frequencies, while they generally do not alter the amplitude, maximum frequency, peak frequency, duration and rate of calling. The literature on noise pollution research is biased towards birds, population‐level studies, urban noise sources and study systems in North America. Synthesis and applications. Our study reveals the ways in which wildlife can alter their signals to contend with anthropogenic noise, and discusses the potential fitness and management consequences of these signal alterations. This information, combined with an identification of current research needs, will allow researchers and managers to better develop noise pollution risk assessment protocols and prioritize mitigation efforts to reduce anthropogenic noise.

Conservation Across Aquatic-Terrestrial Boundaries: Linking Continental-Scale Water Quality to Emergent Aquatic Insects and Declining Aerial Insectivorous Birds

Larval aquatic insects are used to assess water quality, but less attention is paid to their adult, terrestrial life stage, which is an important food resource for declining aerial insectivorous birds. We used open-access water-quality, aquatic-invertebrate, and bird-survey data to study how impaired water quality can emanate from streams and lakes through changes in aquatic insect communities across the contiguous United States. Emergent insect relative abundance was highest across the West, in northern New England, and the Carolinas in streams, and highest near the Great Lakes, parts of the Southwest, and northern New England for lakes. Emergent insects declined with sedimentation, roads, and elevated ammonium concentrations in streams, but not lakes. The odds that a given taxon would be non-emergent increased by up to 2.0× as a function of pollution tolerance, underscoring the sensitivity of emergent aquatic insects to water-quality impairment. However, relationships between bird populations and emergent insects were generally weak for both streams and lakes. For streams, we observed the strongest positive relationships for a mixture of upland and riparian aerial insectivorous birds such as Western Wood-Pewee, Olive-sided Flycatcher, and Acadian Flycatcher and the strongest negative association for Purple Martin. Different avian insectivores responded to emergent insect abundances in lakes (e.g., Barn Swallow, Chimney Swift, Eastern Wood-Pewee, Common Nighthawk). In both streams and lakes, we observed stronger, but opposing, relationships between several aerial insectivores and the relative abundance of sensitive insect orders (E)phemeroptera, (P)lecoptera, and (T)richoptera (positive), and pollution tolerant individuals (negative). Overall, our findings indicate that emergent insects are negatively correlated with pollution tolerance, suggesting a large-scale loss of this nutritional subsidy to terrestrial environments from impaired aquatic ecosystems. While some bird populations tracked scarcities of emergent aquatic insects, especially EPT taxa, responses varied among species, suggesting that unique habitat and foraging behaviors likely complicated these relationships. Strengthening spatial and temporal concordance between emergent-insect and bird-survey data will improve our ability to interpret species-level responses over time. Thus, our analysis highlights the need for developing conservation and biomonitoring strategies that consider the cross-ecosystem effects of water quality declines for threatened insectivorous avifauna and other terrestrial wildlife.

Development of Per and Polyfluoroalkyl Substances Ecological Risk-Based Screening Levels.

Evaluation of chemical risks to threatened and endangered species is a requirement for Superfund ecological risk assessments; however, screening levels to evaluate the potential for toxicity associated with ecological receptor exposure to per- and polyfluoroalkyl substances (PFAS) are lacking. Therefore, PFAS risk-based screening levels (RBSLs) were developed. Wildlife RBSLs were developed using surrogate receptors selected to be representative of threatened and endangered species with different habitat types, feeding guilds, and trophic levels. Published uptake and toxicity data were combined with receptor exposure factors to derive RBSLs for terrestrial and aquatic wildlife for several PFAS, including perfluorononanoic acid, perfluorooctanesulfonic acid, perfluorooctanoic acid, perfluorohexanoic acid, perfluorobutanesulfonic acid, and pentafluorobenzoic acid. Uptake information for surrogate PFAS were considered to calculate RBSLs for PFAS with toxicity data and insufficient bioaccumulation data to develop an RBSL. Both no-observed-adverse effect level (NOAEL)- and lowest-observed-adverse effect level-based wildlife RBSLs were calculated to allow for a range of risk estimates appropriate to individual threatened and endangered species and populations of nonlisted wildlife receptors, respectively. Recommended water quality RBSLs protective of aquatic life were developed for 23 PFAS based on published literature reviews and peer-reviewed aquatic toxicity studies and Great Lakes Initiative methodology. For wildlife receptors, NOAEL RBSLs ranged from to 0.013 to 340 mg/kg for soil, 0.0014 to 370 mg/kg for sediment, and 0.000075 to 1600 mg/L for surface water. For aquatic life, chronic RBSLs ranged from 0.00022 to 3.4 mg/L. For terrestrial plants and soil invertebrates, the no-observed-effect concentration screening levels range from 0.084 to 642 mg/kg and from 1 to 50 mg/kg, respectively. Environ Toxicol Chem 2021;40:921-936. © 2020 SETAC.

Assembling cheap, high-performance microphones for recording terrestrial wildlife: the Sonitor system

Passive acoustic monitoring of wildlife requires sound recording systems. Several cheap, high-performance, or open-source solutions currently exist for recording soundscapes, but all rely on commercial microphones. Commercial microphones are relatively expensive, specialized for particular taxa, and often have incomplete technical specifications. We designed Sonitor, an open-source microphone system to address all needs of ecologists that sample terrestrial wildlife acoustically. We evaluated the cost and durability of our system and measured trade-offs that are seldom acknowledged but which universally limit microphones' functions: weatherproofing versus sound attenuation, windproofing versus transmission loss after rain, signal loss in long cables, and analog sound amplification versus directivity with acoustic horns. We propose five microphone configurations suiting different budgets (from 8 to 33 EUR per unit), and fulfilling different sound quality and flexibility requirements. The Sonitor system consists of sturdy acoustic sensors that cover the entire sound frequency spectrum of sonant terrestrial wildlife at a fraction of the cost of commercial microphones.

Why do we need a wildlife consumption ban in China?

The COVID-19 pandemic is an alarm call to all on the risks of zoonotic diseases and the delicate relationship between nature and human health. In response, China has taken a proactive step by issuing a legal decision to ban consumption of terrestrial wildlife. However, concerns have been raised and opponents of bans argue that well-regulated trade should be promoted instead. By analyzing China’s legal framework and management system regulating wildlife trade, together with state and provincial-level wildlife-trade licenses and wildlife criminal cases, we argue that current wildlife trade regulations do not function as expected. This is due to outdated protected species lists, insufficient cross-sector collaboration, and weak restrictions and law enforcement on farming and trading of species. The lack of quarantine standards for wildlife and increased wildlife farming in recent years pose great risks for food safety and public health. In addition, wildlife consumption is neither required for subsistence nor an essential part of Chinese diets. All these facts make the ban necessary to provoke improvement in wildlife management, such as updating protected species lists, revising laws and changing consumption behaviors. Nonetheless, the ban is not sufficient to address all the problems. To sustain the efficacy of the change, we propose that a long-term mechanism to reduce the demand and improve effective management is needed.

Cryptococcus in Wildlife and Free-Living Mammals

Cryptococcosis is typically a sporadic disease that affects a broad range of animal species globally. Disease is a consequence of infection with members of the Cryptococcus neoformans or Cryptococcus gattii species complexes. Although cryptococcosis in many domestic animals has been relatively well-characterized, free-living wildlife animal species are often neglected in the literature outside of occasional case reports. This review summarizes the clinical presentation, pathological findings and potential underlying causes of cryptococcosis in various other animals, including terrestrial wildlife species and marine mammals. The evaluation of the available literature supports the hypothesis that anatomy (particularly of the respiratory tract), behavior and environmental exposures of animals play vital roles in the outcome of host–pathogen–environment interactions resulting in different clinical scenarios. Key examples range from koalas, which exhibit primarily C. gattii species complex disease presumably due to their behavior and environmental exposure to eucalypts, to cetaceans, which show predominantly pulmonary lesions due to their unique respiratory anatomy. Understanding the factors at play in each clinical scenario is a powerful investigative tool, as wildlife species may act as disease sentinels.

Metalliferous Mining Pollution and Its Impact on Terrestrial and Semi-terrestrial Vertebrates: A Review.

Metalliferous mining, a major source of metals and metalloids, has severe potential environmental impacts. However, the number of papers published in international peer-reviewed journals seems to be low regarding its effects in terrestrial wildlife. To the best of our knowledge, our review is the first on this topic. We used 186 studies published in scientific journals concerning metalliferous mining or mining spill pollution and their effects on terrestrial and semi-terrestrial vertebrates. We identified the working status of the mine complexes studied, the different biomarkers of exposure and effect used, and the studied taxa. Most studies (128) were developed in former mine sites and 46 in active mining areas. Additionally, although several mining accidents have occurred throughout the world, all papers about effects on terrestrial vertebrates from mining spillages were from Aznalcóllar (Spain). We also observed a lack of studies in some countries with a prominent mining industry. Despite >50% of the studies used some biomarker of effect, 42% of them only assessed exposure by measuring metal content in internal tissues or by non-invasive sampling, without considering the effect in their populations. Most studied species were birds and small mammals, with a negligible representation of reptiles and amphibians. The information gathered in this review could be helpful for future studies and protocols on the topic and it facilitates a database with valuable information on risk assessment of metalliferous mining pollution.

Will the COVID-19 outbreak be a turning point for China's wildlife protection: New developments and challenges of wildlife conservation in China

On 24 February 2020, at the brink of the global coronavirus disease 2019 (COVID-19) pandemic, the Chinese legislature adopted a decision to ban all terrestrial wildlife for food consumption. This decision set the tone for the revision of the Wildlife Protection Law (WPL), planned for release in late 2020. Both the terrestrial wildlife ban and revised WPL have the potential to greatly reduce consumption of wildlife and aid in prevention of future zoonotic disease outbreaks. The government still faces severe challenges in reducing wildlife use in traditional medicine, strengthening habitat and ecosystem conservation, committing to long-term WPL enforcement, and promoting community education and institutional reforms. However, recent progress in establishing a stricter ban on wildlife consumption, consolidating fragmented protected areas, and increased openness to public oversight are promising developments. While it is clear that global pandemics like COVID-19 can cause massive human suffering and disruption of economies; governments can no longer allow business as usual for the wildlife industry, regardless of the monetary or cultural values it brings. Here we discuss the latest development and limitations of the current wildlife legislation in China and the recommendations for improving Chinese wildlife conservation to better protect biodiversity and reduce risks of spreading zoonotic diseases to humans.

Pollution of plastic debris and halogenated flame retardants (HFRs) in soil from an abandoned e-waste recycling site: Do plastics contribute to (HFRs) in soil?

Electronic waste (e-waste) recycling site may be a “hotspot” for pollution of plastic debris, which has not been well studied. Eighteen halogenated flame retardants (HFRs) were measured in plastics and soil separated from twenty soil samples, respectively, from an abandoned e-waste recycling site. Abundances and concentrations of plastic debris ranged from 600 to 14,200 particles/kg and 0.24–153 mg/g, respectively, which were at the high end in literature. Blue, black, and red were main plastic colors, and acrylonitrile-butadiene-styrene (ABS) was the main type of plastics. Polybrominated diphenyl ether (PBDE) 209 was the main chemical, with median concentrations of 6.22–40.6 μg/g in soil and 28.1–47.2 μg/g in plastics, respectively. Contributions of HFRs in plastics were less than 10% in total HFR masses in bulk soil samples. Exposure values to HFRs from plastics via soil ingestion and dermal contact with soil were generally two orders of magnitude lower than those from soil. The results indicate that plastics in soil have little contribution to total HFR burden in soil and human exposure risks to HFRs in this study. However, ecological risks of plastics to terrestrial wildlife in e-waste sites should be paid attention.

Element and radionuclide concentrations in soils and wildlife from forests in north-eastern England with a focus on species representative of the ICRP's Reference Animals and Plants

Abstract. There are international recommendations that the environment (i.e. wildlife) is assessed for the potential impact of releases of ionizing radiation. The transfer of radionuclides to wildlife from media (e.g. soil, water) is usually described using the whole-organism concentration ratio (CRwo-media), and a number of assessment models use these values to estimate radiation exposure and risk to wildlife; however, there are many gaps in knowledge. This paper describes a study conducted in 2015–2016 to sample terrestrial wildlife, soil and water from two forests in north-eastern England. Sampling was targeted towards species representative of the International Commission on Radiological Protection's (ICRP) terrestrial Reference Animals and Plants (RAPs): Wild Grass (Poaceae family), Pine Tree (Pinaceae family), Earthworm (Lumbricidae family), Bee (Apidae family), Rat (Muridae family), Deer (Cervidae family) and Frog (Ranidae family); opportunistic sampling of plant and fungi species was also conducted. The dataset comprises stable-element concentrations for 30 elements, radionuclide activity concentrations for K-40 and Cs-137, and radionuclide and stable-element concentration ratios. These data have significantly increased the number of CRwo-media values available for the ICRP RAPs and will contribute to the development of the databases underpinning the ICRP's environmental protection framework. Data will be included in the international database of wildlife transfer parameters for radioecological models and hence are likely to contribute to model developments in the future. All data and supporting documentation are freely available from the Environmental Information Data Centre (EIDC; https://eidc.ac.uk/, last access: 13 November 2020) under the terms and conditions of the Open Government Licence (Barnett et al., 2020 https://doi.org/10.5285/8f85c188-a915-46ac-966a-95fcb1491be6).

Assessment of trace element concentrations in sediment and vegetation of mesic and arid African savannahs as indicators of ecosystem health

The savannah biome supports unique biodiversity and provides a multitude of ecosystem services. Defining background concentrations for trace elements in the environment is beneficial for the determination of nutrient deficiencies/hotspots and for the management of pollution. Sediment and corresponding vegetation samples were collected around 48 surface water points in two savannah wildlife areas for assessment and comparison of 20 trace elements using ICP-MS. Site-specific and matrix-specific differences were evident for essential B, Co, Cu, Fe, Mn, Mo, Ni, Se and Zn, potentially toxic As, Cd, Cr, Hg, Pb and V and additional elements Al, Ba, Sb, Sn and Sr analysed. Sediment and vegetation from all sampled locations at both sites contained single or multiple potentially toxic elements at various concentrations. Although the presence of all elements can be linked to underlying geology and geochemistry specific to each site, evidence of anthropogenic cause was also evident at both sites. This paper covers the widest range of trace elements assessed in protected terrestrial wildlife reserves in the South African savannah biome to date and highlights the potential for deleterious consequences of trace element contamination of the environment.

Do Spatially Explicit Wildlife Exposure Models Improve the Estimation of Risk for Small Mammals? Case Study: Application of Spatially Explicit Exposure Model to Small Mammal Exposures to Lead in Heterogeneous Landscapes.

Understanding risks to terrestrial wildlife species from exposure to chemicals in the environment requires knowledge of how species make habitat decisions and how subsequent exposure events occur. Heterogeneity of chemical distribution and of habitat quality can influence exposure. Previous studies in birds have shown that individually based, spatially explicit models can be useful in predicting exposure and risk; however, studies investigating these influences in small mammals with limited ranges have been lacking. Here we test a spatially explicit, individually based exposure model (Spatially Explicit Exposure Model [SEEM]) in which model predictions based on life history traits, habitat preferences, and varying soil Pb concentrations are used and compared to those with field-collected blood or tissue Pb concentrations in small (e.g., Peromyscus, Blarina spp.) and medium-sized mammalian species (e.g., Lepus spp.) at 3 Pb-contaminated sites. These species were chosen because they were expected to be present in suitable habitat, and Pb was modeled when adequate tissue-based toxicity thresholds were available. Oral exposure estimates from SEEM were compared with a traditional deterministic model and with field-collected tissue Pb concentrations using ecological hazard quotients (EHQs) to normalize between oral and real-time tissue Pb concentrations. Ecological hazard quotients at the 90% population effect level (for SEEM) and at the 95% upper confidence level (assuming a single Pb concentration with no consideration of habitat quality in the deterministic model) were compared with maximum EHQs developed from blood or tissue Pb concentrations. Deterministic estimates and SEEM were similar for small mammal species, yet slightly overpredicted risk compared to field tissue or blood Pb data. Estimates for hares (medium-sized mammals) using SEEM provided more accurate predictions compared with field tissue data. These data suggest that spatially explicit models may be sensitive to grain size, given that small mammals experience the environment in limited spatial contexts, a scale at which habitat may not change significantly. Integr Environ Assess Manag 2021;17:259-272. Published 2020. This article is a US Government work and is in the public domain in the USA.

Small habitat matrix: How does it work?

We present herein our perspective of a novel Small Habitats Matrix (SHM) concept showing how small habitats on private lands are untapped but can be valuable for mitigating ecological degradation. Grounded by the realities in Sabah, Malaysian Borneo, we model a discontinuous "stepping stones" linkage that includes both terrestrial and aquatic habitats to illustrate exactly how the SHM can be deployed. Taken together, the SHM is expected to optimize the meta-population vitality in monoculture landscapes for aerial, arboreal, terrestrial and aquatic wildlife communities. We also provide the tangible cost estimates and discuss how such a concept is both economically affordable and plausible to complement global conservation initiatives. By proposing a practical approach to conservation in the rapidly developing tropics, we present a perspective from "ground zero" that reaches out to fellow scientists, funders, activists and pro-environmental land owners who often ask, "What more can we do?"

Relative effects of recreational activities on a temperate terrestrial wildlife assemblage

AbstractOutdoor recreation is one of the fastest growing economic sectors in the world and provides many benefits to people. Assessing possible negative impacts of recreation is nevertheless important for sustainable management. Here, we used camera traps to assess relative effects of various recreational activities—as compared to each other and to environmental conditions—on a terrestrial wildlife assemblage in British Columbia, Canada. Across 13 species, only two negative associations between recreational activities and wildlife detections were observed at weekly scales: mountain biking on moose and grizzly bears. However, finer‐scale analysis showed that all species avoided humans on trails, with avoidance strongest for mountain biking and motorized vehicles. Our results imply that environmental factors generally shaped broad‐scale patterns of wildlife use, but highlight that recreational activities also have detectable impacts. These impacts can be monitored using the same camera‐trapping techniques that are commonly used to monitor wildlife assemblages.