Conservation of Sagebrush Ecosystems Through Diet Analysis of an Obligate Species

Sage Grouse (Centrocercus urophasianus) is an obligate species that depends on sagebrush to survive and serves as an indicator species and umbrella species for the sagebrush ecosystem. The sagebrush ecosystem has been declining rapidly therefore understanding the impacts on Sage Grouse could aid researchers and land managers in best practices to protect the long-term viability of the species, the ecosystem, and 350 other species that depend on it, including humans. One way to understand these impacts is through dietary indicators, such as the availability of preferred forage plants. In the past, this has been done by direct observation, which requires many hours in the field, and crop dissection, which involves collecting carcasses. These are both time-consuming and costly. Recent advances have shown that diet can be more easily and accurately determined through the sequencing of plant DNA in fecal samples targeting the ITS2 gene of plants. My project involves extracting plant DNA from fecal samples, optimizing a primer set for PCR of the ITS2 gene, performing DNA barcoding using next-generation sequencing, and comparing the results with reference genomes of plants

Ancient DNA Analyses Exclude Humans as the Driving Force Behind Late Pleistocene Musk Ox (Ovibos moschatus) Population Dynamics

The causes of the late Pleistocene megafaunal extinctions are poorly understood. Different lines of evidence point to climate change, the arrival of humans, or a combination of these events as the trigger. Although many species went extinct, others, such as caribou and bison, survived to the present. The musk ox has an intermediate story: relatively abundant during the Pleistocene, it is now restricted to Greenland and the Arctic Archipelago. In this study, we use ancient DNA sequences, temporally unbiased summary statistics, and Bayesian analytical techniques to infer musk ox population dynamics throughout the late Pleistocene and Holocene. Our results reveal that musk ox genetic diversity was much higher during the Pleistocene than at present, and has undergone several expansions and contractions over the past 60,000 years. Northeast Siberia was of key importance, as it was the geographic origin of all samples studied and held a large diverse population until local extinction at approximate to 45,000 radiocarbon years before present (14C YBP). Subsequently, musk ox genetic diversity reincreased at ca. 30,000 14C YBP, recontracted at ca. 18,000 14C YBP, and finally recovered in the middle Holocene. The arrival of humans into relevant areas of the musk ox range did not affect their mitochondrial diversity, and both musk ox and humans expanded into Greenland concomitantly. Thus, their population dynamics are better explained by a non-anthropogenic cause (for example, environmental change), a hypothesis supported by historic observations on the sensitivity of the species to both climatic warming and fluctuations

Avian seed dispersal may be insufficient for plants to track future temperature change on tropical mountains

AIM: Climate change causes shifts in species ranges globally. Terrestrial plant species often lag behind temperature shifts, and it is unclear to what extent animal-dispersed plants can track climate change. Here, we estimate the ability of bird-dispersed plant species to track future temperature change on a tropical mountain. LOCATION: Tropical elevational gradient (500–3500 m.a.s.l.) in the Manú biosphere reserve, Peru. TIME PERIOD: From 1960–1990 to 2061–2080. TAXA: Fleshy-fruited plants and avian frugivores. METHODS: Using simulations based on the functional traits of avian frugivores and fruiting plants, we quantified the number of long-distance dispersal (LDD) events that woody plant species would require to track projected temperature shifts on a tropical mountain by the year 2070 under different greenhouse gas emission scenarios [representative concentration pathway (RCP) 2.6, 4.5 and 8.5]. We applied this approach to 343 bird-dispersed woody plant species. RESULTS: Our simulations revealed that bird-dispersed plants differed in their climate-tracking ability, with large-fruited and canopy plants exhibiting a higher climate-tracking ability. Our simulations also suggested that even under scenarios of strong and intermediate mitigation of greenhouse gas emissions (RCP 2.6 and 4.5), sufficient upslope dispersal would require several LDD events by 2070, which is unlikely for the majority of woody plant species. Furthermore, the ability of plant species to track future changes in temperature increased in simulations with a low degree of trait matching between plants and birds, suggesting that plants in generalized seed-dispersal systems might be more resilient to climate change. MAIN CONCLUSION: Our study illustrates how the functional traits of plants and animals can inform predictive models of species dispersal and range shifts under climate change and suggests that the biodiversity of tropical mountain ecosystems is highly vulnerable to future warming. The increasing availability of functional trait data for plants and animals globally will allow parameterization of similar models for many other seed-dispersal systems

Avian seed dispersal may be insufficient for plants to track future temperature change on tropical mountains

[Aim] Climate change causes shifts in species ranges globally. Terrestrial plant species often lag behind temperature shifts, and it is unclear to what extent animal-dispersed plants can track climate change. Here, we estimate the ability of bird-dispersed plant species to track future temperature change on a tropical mountain.[Location] Tropical elevational gradient (500–3500 m.a.s.l.) in the Manú biosphere reserve, Peru. [Time period] From 1960–1990 to 2061–2080. [Taxa] Fleshy-fruited plants and avian frugivores. [Methods] Using simulations based on the functional traits of avian frugivores and fruiting plants, we quantified the number of long-distance dispersal (LDD) events that woody plant species would require to track projected temperature shifts on a tropical mountain by the year 2070 under different greenhouse gas emission scenarios [representative concentration pathway (RCP) 2.6, 4.5 and 8.5]. We applied this approach to 343 bird-dispersed woody plant species. [Results] Our simulations revealed that bird-dispersed plants differed in their climate-tracking ability, with large-fruited and canopy plants exhibiting a higher climate-tracking ability. Our simulations also suggested that even under scenarios of strong and intermediate mitigation of greenhouse gas emissions (RCP 2.6 and 4.5), sufficient upslope dispersal would require several LDD events by 2070, which is unlikely for the majority of woody plant species. Furthermore, the ability of plant species to track future changes in temperature increased in simulations with a low degree of trait matching between plants and birds, suggesting that plants in generalized seed-dispersal systems might be more resilient to climate change. [Main conclusion] Our study illustrates how the functional traits of plants and animals can inform predictive models of species dispersal and range shifts under climate change and suggests that the biodiversity of tropical mountain ecosystems is highly vulnerable to future warming. The increasing availability of functional trait data for plants and animals globally will allow parameterization of similar models for many other seed-dispersal systems.Fieldwork at Manú was conducted under the permits 041-2010-AG-DGFFSDGEFFS, 008-2011-AG-DGFFS-DGEFFS, 01-C/C-2010SERNANP-JPNM and 01-2011-SERNANP-PNM-JEF and supported by a scholarship from the German Academic Exchange Service to D.M.D. D.M.D. acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant number 787638) and the Swiss National Science Foundation (grant number 173342), both awarded to C. H. Graham. W.D.K. acknowledges a Global Ecology grant from the University of Amsterdam Faculty Research Cluster. I.D. was funded by the Alexander von Humboldt Foundation and is now supported by the Balearic Government. S.A.F. was funded by the German Research Foundation (DFG; FR 3246/2-2) and the Leibniz Competition of the Leibniz Association (P52/2017)

Daily use of lateral flow devices by contacts of confirmed COVID-19 cases to enable exemption from isolation compared with standard self-isolation to reduce onward transmission of SARS-CoV-2 in England:a randomised, controlled, non-inferiority trial

Background: In the UK, during the study period all COVID-19 contacts were required to self-isolate for 10 days, which had adverse impacts. Avoiding the need to self-isolate for those who remain uninfected would be beneficial to society. We investigated whether using daily lateral flow devices (LFDs) to test for COVID-19 with removal of self-isolation for 24 hours if negative was a safe alternative to self-isolation by determining tertiary attack rates (proportion being infected) in study groups.Methods: We conducted a non-inferiority randomised controlled trial (Research Registry ID:6809) in adult contacts identified during COVID-19 contact tracing. Consented participants were randomised to self-isolation (SI; single PCR, 10 days isolation) or daily contact-testing (DCT; 7 LFDs, 2 PCRs, no isolation if negative on LFD);participants from a household were assigned to the same arm. Participants were prospectively followed-up with the impact of each intervention on onward transmission determined from routinely collected contact tracing data for COVID-19 participants, and tertiary cases arising from their contacts. Attack rates were derived from cluster-robust standard error Bernoulli regression models. Questionnaires were sent at recruitment and at the end of testing/self-isolation to assess behaviours.Findings: 49,623 individuals consented to participate with final arm allocations of 26,123 DCT (52.6%) and 23,500 SI participants (47.4%). Overall. 4,561 participants tested positive by PCR (secondary cases); 2,359 (10.0%) in the SI arm and 2,202 (8.4%) in the DCT arm. Tertiary attack rates (among secondary contacts) were 7.5% in SI arm and 6.4% in DCT arm (difference of -1.1 % (95% Confidence Interval -2.2% to -0.03%)), significantly lower than the non-inferiority margin of 1.9%.124,010 valid LFD results were reported from 20,795 (79.6%) DCT participants with 1,132 (5.4%) reporting a positive result. Interpretation: DCT with 24-hour exemption from self-isolation for essential activities appears to be non-inferior to self-isolation.Interpretation: DCT with 24-hour exemption from self-isolation for essential activities appears to be non-inferior to self-isolation.<br/

Protective behaviour of citizens to transport accidents involving hazardous materials: A discrete choice experiment applied to populated areas nearby waterways

Background To improve the information for and preparation of citizens at risk to hazardous material transport accidents, a first important step is to determine how different characteristics of hazardous material transport accidents will influence citizens' protective behaviour. However, quantitative studies investigating citizens' protective behaviour in case of hazardous material transport accidents are scarce. Methods A discrete choice experiment was conducted among subjects (19-64 years) living in the direct vicinity of a large waterway. Scenarios were described by three transport accident characteristics: odour perception, smoke/vapour perception, and the proportion of people in the environment that were leaving at their own discretion. Subjects were asked to consider each scenario as realistic and to choose the alternative that was most appealing to them: staying, seekin