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

This article is protected by copyright. All rights reserved.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 1509 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 USA. 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 well as 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.Publisher PDFPeer reviewe

Mammal responses to global changes in human activity vary by trophic group and landscape

Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely. Under higher human activity, mammals were less active in undeveloped areas but unexpectedly more active in developed areas while exhibiting greater nocturnality. Carnivores were most sensitive, showing the strongest decreases in activity and greatest increases in nocturnality. Wildlife managers must consider how habituation and uneven sensitivity across species may cause fundamental differences in human–wildlife interactions along gradients of human influence.Peer reviewe

Friends or foes?

As ecosystem engineers, ungulates can importantly alter the habitats where they live by changing plant cover, soil and water properties through wallowing, rooting, urinating, excreting, grazing and trampling. It is a common belief that wild ungulates, especially wild boar, Sus scrofa, represent a threat to amphibian communities due to disturbance caused while using water pools. On the other hand, ungulates could also create new aquatic habitats suitable for amphibians. So far these effects have been poorly understood. We conducted a pilot study to test whether ungulate engineering action affected amphibians% pool choice comparing amphibian species number in pools created and/or maintained by wild ungulates and pools that were fenced or, for other reasons, not used by ungulates. We observed that amphibians readily used pools also used by ungulates, although amphibian species richness in these pools was generally lower, especially when the pools were smaller. Our results suggest the need for further research and highlight the importance of wild ungulates as ecosystem engineers that create new aquatic habitats, as well as trade-offs connected with the presence of wild ungulate populations for amphibian communities. This has several management and conservation implications and prudent managers could use this understanding to incorporate ungulate management in their conservation programs targeting endangered wildlife that depends on habitats created or modified by these ecosystem engineers

Understanding the effects of mass mortality events on plant communities and consumer behavior

Mass mortality events (MMEs) are die-offs that result in increased carrion biomass and sometimes the impairment of functional roles. Concurrently, several vulture species are declining. Carrion is a basal resource in ecosystems and its recycling by vultures is considered an ecosystem service. However, the consequences of simultaneously increasing carrion loads and declining vulture populations are unknown. I developed a theoretical framework predicting that, with increasing carrion biomass, carrion food web diversity would increase horizontally and vertically, respectively increasing and decreasing carrion recycling efficiency. Using a manipulative experiment, I investigated the role of bottom-up and top-down forces affecting plant communities during an MME. I selected 5 sites to establish 6 treatments crossing different levels of carrion addition and nutrient addition, and control with vertebrate scavenger and herbivore access. I transplanted six cherrybark oak (Quercus pagoda) seedlings to each plot, protecting half of them from herbivory. Carrion biomass shifted dominance of plant functional groups to favor annual plants, an effect reduced by scavenger access. Herbivore access affected plant community response to carrion and limited growth and survival of transplanted seedlings regardless of treatment. Nutrient addition did not affect plant communities, growth, and survival suggesting that MME effects on plants are likely mediated primarily by top-down forces. To determine if behavioral plasticity of vultures affects carrion recycling efficiency, I monitored turkey (Cathartes aura) and black (Coragyps atratus) vulture behavior. Both species increased group size, but only black vultures increased individuals feeding per group and activity overlap between species increased with increasing carrion biomass. As a result, estimated carrion consumption by vultures increased with carrion biomass suggesting behavioral plasticity may alleviate some of the effects of vulture declines on carrion recycling. Finally, vultures compete with invertebrate scavengers so declining vultures may release their populations to compensate for the loss. However, in one of my experiments, variation in vulture visitation was negatively correlated with the abundance of blowflies parasitized by Entomophthora sp. Our observations may suggest that vultures were more likely mediating carrion decomposition affecting parasitism, which may limit blowflies from compensating for declining vultures

Catch me if you can: antipredatory behaviour of chamois to the wolf

Antipredator behaviour is a multifactorial process - e.g. landscape features, escape tactics of prey, probability of encountering predators, predator type, age, sex and physical state of prey. Ungulates show a wide range of antipredator ploys. As reactions of mountain ungulates to their predators are still poorly understood, we hereby report on two interactions between Apennine chamois Rupicapra pyrenaica ornata and wolves Canis lupus in a protected area in the Central Apennines, Italy. Male and female chamois showed different reactions to the presence of the wolf. While females and juveniles fled to steeper, higher terrain upon the arrival of the wolf, males showed alternative antipredator tactics. In one case, the only male chamois present did not flee, but kept watching the movements of the wolf from a slab of rock at the foot of a steep scree, i.e. close to a potential escape terrain. In the other case, the two males present rushed to hide in the forest. Females formed a barrier between their kids and the wolf. Vigilance increased greatly, although chamois resumed their normal feeding activities within ca 10 min of the wolf visits. Fleeing of herd members in different directions may have helped to confuse the predator. In both cases, the antipredator behaviour of chamois proved successful to prevent predation

Wiregrass (Aristida beyrichiana) survival and reproduction after fire in a long-unburned pine savanna.

Restoring fire regimes is a major goal of biodiversity conservation efforts in fire-prone ecosystems from which fire has been excluded. In the southeastern U.S.A., nearly a century of fire exclusion in pine savannas has led to significant biodiversity declines in one of the most species-rich ecosystems of North America. In these savannas, frequent fires that support biodiversity are driven by vegetation-fire feedbacks. Understory grasses are key components of these feedbacks, fueling the spread of fires that keep tree density low and maintain a high-light environment. When fire is reintroduced to long-unburned sites, however, remnant populations of bunchgrasses might experience high mortality from fuel accumulation during periods of fire exclusion. Our objective was to quantify fire effects on wiregrass (Aristida beyrichiana), a key component of vegetation-fire feedbacks, following 16 years without fire in a dry pine savanna typically considered to burn every 1-3 years. We examined how wiregrass size and fuel (duff depth and presence of pinecones) affected post-fire survival, inflorescence and seed production, and seed germination. Wiregrass exhibited high survival regardless of size or fuels. Probability of flowering and inflorescence number per plant were unaffected by fuel treatments but increased significantly with plant size (p = 0.016). Germination of filled seeds was consistent (29-43%) regardless of fuels, although plants in low duff produced the greatest proportion of filled seeds. The ability of bunchgrasses to persist and reproduce following fire exclusion could jumpstart efforts to reinstate frequent-fire regimes and facilitate biodiversity restoration where remnant bunchgrass populations remain