Historical Demography and Dispersal Patterns in the Eastern Pipistrelle Bat (\u3ci\u3ePerimyotis subflavus\u3c/i\u3e)

The recent emergence of threats to North American bat conservation has prompted increased population genetics research on high risk species. The eastern pipistrelle bat is affected by both white-nose syndrome and wind turbine mortality. However, little work has been done regarding the population structure and effective population size of this species. Using the HVI region of the mitochondria and eight microsatellite loci, I analyzed male and female structure across the sample range of P. subflavus and estimated the effective population size of their populations. Pairwise FST values indicate that there is one panmictic population based on microsatellite data, while mitochondrial data supports two populations within the sampled range. AMOVA results suggest that females are making short distance movements (ϕSC = 9.23%). Mitochondrial and microsatellite data showed contrasting results for effective population size and size change over time. Mitochondrial data suggest an increase in female effective size for both Appalachian and West populations in the past 15,000 to 28,000 years from ~15,000 individuals to 400,000. Microsatellite data further suggest a recent bottleneck from a large ancestral population (1.55 x 106), leaving a small current effective population of 9,000 (95% HPDI 10, 3.78 x 106) individuals. The persistence of the eastern pipistrelle is dependent upon the maintenance of genetic diversity, and calls for the conservation of genetically distinct populations as well as the preservation of hibernacula and swarming locations

Comparative Ecology of Sarcobatus Baileyi and Sarcobatus Vermiculatus in Eastern California

Greasewood (Sarcobatus) is a succulent-leaved, halophytic shrub of North American origin. The genus comprises 2 species: Sarcobatus baileyi and Sarcobatus vermiculatus. Sarcobatus vermiculatus is common throughout much of western North America, but S. baileyi is much more limited in distribution and was previously thought to be endemic to Nevada. Here we document and describe a S. baileyi population in eastern California, comparing its morphology and ecology to an adjacent S. vermiculatus population. Morphologically, S. baileyi is smaller in stature but produces larger seeds; however, fewer S. baileyi seeds germinated and survived a 20-day laboratory incubation compared to seeds of S. vermiculatus. Sarcobatus baileyi has higher leaf Na concentrations and operates at much lower plant water potentials than S. vermiculatus under field conditions; however, no significant differences were observed between the 2 species in long-term water-use efficiency as measured by leaf delta(13)C. Leaf Na concentrations were very low in both species. Overall, these species differ greatly in a number of traits that are consistent with the upland, nonphreatophytic character of S. baileyi, which is in stark contrast to the phreatophytic character of S. vermiculatus. Both species, however, are very salt tolerant and have low leaf N concentrations, indicating the low nutrient availability and the potentially high salinity of their extreme habitats. Further investigation of comparable desert ridge environments should be conducted to determine the extent of S. baileyi in eastern California, and common garden comparisons of the 2 species should be conducted to compare their ecophysiological traits

Deer management generally reduces densities of nymphal Ixodes scapularis, but not prevalence of infection with Borrelia burgdorferi sensu stricto

Human Lyme disease–primarily caused by the bacterium Borrelia burgdorferi sensu stricto (s.s.) in North America–is the most common vector-borne disease in the United States. Research on risk mitigation strategies during the last three decades has emphasized methods to reduce densities of the primary vector in eastern North America, the blacklegged tick (Ixodes scapularis). Controlling white-tailed deer populations has been considered a potential method for reducing tick densities, as white-tailed deer are important hosts for blacklegged tick reproduction. However, the feasibility and efficacy of white-tailed deer management to impact acarological risk of encountering infected ticks (namely, density of host-seeking infected nymphs; DIN) is unclear. We investigated the effect of white-tailed deer density and management on the density of host-seeking nymphs and B. burgdorferi s.s. infection prevalence using surveillance data from eight national parks and park regions in the eastern United States from 2014–2022. We found that deer density was significantly positively correlated with the density of nymphs (nymph density increased by 49% with a 1 standard deviation increase in deer density) but was not strongly correlated with the prevalence of B. burgdorferi s.s. infection in nymphal ticks. Further, while white-tailed deer reduction efforts were followed by a decrease in the density of I. scapularis nymphs in parks, deer removal had variable effects on B. burgdorferi s.s. infection prevalence, with some parks experiencing slight declines and others slight increases in prevalence. Our findings suggest that managing white-tailed deer densities alone may not be effective in reducing DIN in all situations but may be a useful tool when implemented in integrated management regimes

A Sarcoptes scabiei specific isothermal amplification assay for detection of this important ectoparasite of wombats and other animals

Background The globally distributed epidermal ectoparasite, Sarcoptes scabiei, is a serious health and welfare burden to at-risk human and animal populations. Rapid and sensitive detection of S. scabiei infestation is critical for intervention strategies. While direct microscopy of skin scrapings is a widely utilised diagnostic method, it has low sensitivity. PCR, alternatively, has been shown to readily detect mite DNA even in microscopy-negative skin scrapings. However, a limitation to the latter method is the requirements for specialised equipment and reagents. Such resources may not be readily available in regional or remote clinical settings and are an important consideration in diagnosis of this parasitic disease. Methodology A Loop Mediated Isothermal Amplification (LAMP) assay targeting the ITS-2 gene for S. scabiei was developed and evaluated on clinical samples from various hosts, previously screened with conventional S. scabies-specific PCR. Species specificity of the newly developed LAMP assay was tested against a range of DNA samples from other arthropods. The LAMP assays were performed on a real-time fluorometer as well as thermal cycler to evaluate an end-point of detection. Using skin scrapings, a rapid sample processing method was assessed to eliminate extensive processing times involved with DNA extractions prior to diagnostic assays, including LAMP. Results The S. scabiei LAMP assay was demonstrated to be species-specific and able to detect DNA extracted from a single mite within a skin scraping in under 30 minutes. Application of this assay to DNA extracts from skin scrapings taken from a range of hosts revealed 92.3% congruence (with 92.50% specificity and 100% sensitivity) to the conventional PCR detection of S. scabiei. Preliminary results have indicated that diagnostic outcome from rapidly processed dry skin scrapings using our newly developed LAMP is possible in approximately 40 minutes. Discussion We have developed a novel, rapid and robust molecular assay for detecting S. scabiei infesting humans and animals. Based on these findings, we anticipate that this assay will serve an important role as an ancillary diagnostic tool at the point-of-care, complementing existing diagnostic protocols for S. scabiei

From the Field to the Lab: Best Practices for Field Preservation of Bat Specimens for Molecular Analyses

Studies in molecular ecology depend on field-collected samples for genetic information, and the tissue sampled and preservation conditions strongly affect the quality of the DNA obtained. DNA yields from different tissue types have seldom been compared, and the relative performance of storage media has never been directly tested, even though these media may influence DNA degradation under field conditions. We analyzed DNA yield from buccal swabs and wing punches harvested from live bats using nucleic acid quantification as well as quantitative PCR for a single-copy nuclear locus. We also compared DNA yields from wing tissue preserved in three media: ethanol, NaCl-saturated dimethyl sulfoxide (DMSO), and silica desiccant. Wing punches yielded more total DNA than did buccal swabs, and wing tissues preserved in silica beads yielded significantly more total and nuclear DNA than those preserved in DMSO or ethanol. These results show that tissue type and preservation media strongly influence the quantity of DNA obtained from non-lethal genetic samples, and based on these effects we provide recommendations for field collection of tissues for genetic analyses

Genetic Demography of Perimyotis subflavus Reveals Regional Population Trends

White-nose syndrome (WNS) is an epidemic affecting hibernating bats across eastern North America. It is generally associated with the presence of a white, soil dwelling fungus, Geomyces destructans. Since its discovery in New York in 2006, WNS has been responsible for hundreds of thousands of bat deaths. Mortality rates of affected individuals have reached 90-100% in some hibernacula. Many of the studies regarding WNS focus on little brown myotis, Myotis lucifugus, which has experienced an 87% decline, though at least five other species have also been significantly affected. Tri-colored bats, Perimyotis subflavus, have experienced an 85% decline in the northeastern states, yet little work has been done involving P. subflavus. We present phylogeographic analyses of mitochondrial sequence data from P. subflavus, focusing on patterns of population genetic structure and estimates of effective population size

Regional Extinction Risks of the Eastern Pipistrelle Bat

Recent conservation concerns have surfaced for migratory and hibernating bat species in North America. White-nose syndrome (WNS) has resulted in regional population declines in hibernating bat species. Eastern pipistrelles, Perimyotis subflavus, have experienced mortality rates of 85%. In addition to WNS declines, P. subflavus is one of the four migratory bat species predominately affected by wind turbines, accounting for about 25% of turbine mortalities within it\u27s geographic range. If P. subflavus populations are to remain viable, they must survive both of these conservation threats. Here, we address the following questions: What are the population-specific extirpation risks from WNS and turbine mortality? What rates of decline from WNS and turbines can P. subflavus populations sustain? Using genetic data to parameterize migration rates and effective population sizes, we present a range of risk scenarios designed to investigate the limits of population viability in P. subflavus

Burrow switching model

R markdown file for the burrow switching model