Genetic population substructure in bison at Yellowstone National Park

The Yellowstone National Park bison herd is 1 of only 2 populations known to have continually persisted on their current landscape since pre-Columbian times. Over the last century, the census size of this herd has fluctuated from around 100 individuals to over 3000 animals. Previous studies involving radiotelemetry, tooth wear, and parturition timing provide evidence of at least 2 distinct groups of bison within Yellowstone National Park. To better understand the biology of Yellowstone bison, we investigated the potential for limited gene flow across this population using multilocus Bayesian clustering analysis. Two genetically distinct and clearly defined subpopulations were identified based on both genotypic diversity and allelic distributions. Genetic cluster assignments were highly correlated with sampling locations for a subgroup of live capture individuals. Furthermore, a comparison of the cluster assignments to the 2 principle winter cull sites revealed critical differences in migration patterns across years. The 2 Yellowstone subpopulations display levels of differentiation that are only slightly less than that between populations which have been geographically and reproductively isolated for over 40 years. The identification of cryptic population subdivision and genetic differentiation of this magnitude highlights the importance of this biological phenomenon in the management of wildlife species.     

Predicting bison migration out of Yellowstone National Park using bayesian models

Long distance migrations by ungulate species often surpass the boundaries of preservation areas where conflicts with various publics lead to management actions that can threaten populations. We chose the partially migratory bison (Bison bison) population in Yellowstone National Park as an example of integrating science into management policies to better conserve migratory ungulates. Approximately 60% of these bison have been exposed to bovine brucellosis and thousands of migrants exiting the park boundary have been culled during the past two decades to reduce the risk of disease transmission to cattle. Data were assimilated using models representing competing hypotheses of bison migration during 1990-2009 in a hierarchal bayesian framework. Migration differed at the scale of herds, but a single unifying logistic model was useful for predicting migrations by both herds. Migration beyond the northern park boundary was affected by herd size, accumulated snow water equivalent, and aboveground dried biomass. Migration beyond the western park boundary was less influenced by these predictors and process model performance suggested an important control on recent migrations was excluded. Simulations of migrations over the next decade suggest that allowing increased numbers of bison beyond park boundaries during severe climate conditions may be the only means of avoiding episodic, large-scale reductions to the Yellowstone bison population in the foreseeable future. This research is an example of how long distance migration dynamics can be incorporated into improved management policies.     

Fungi from Geothermal Soils in Yellowstone National Park

Geothermal soils near Amphitheater Springs in Yellowstone National Park were characterized by high temperatures (up to 70°C), high heavy metal content, low pH values (down to pH 2.7), sparse vegetation, and limited organic carbon. From these soils we cultured 16 fungal species. Two of these species were thermophilic, and six were thermotolerant. We cultured only three of these species from nearby cool (0 to 22°C) soils. Transect studies revealed that higher numbers of CFUs occurred in and below the root zone of the perennial plant Dichanthelium lanuginosum (hot springs panic grass). The dynamics of fungal CFUs in geothermal soil and nearby nongeothermal soil were investigated for 12 months by examining soil cores and in situ mesocosms. For all of the fungal species studied, the temperature of the soil from which the organisms were cultured corresponded with their optimum axenic growth temperature.     

Fungi from geothermal soils in Yellowstone National Park

Geothermal soils near Amphitheater Springs in Yellowstone National Park were characterized by high temperatures (up to 70 degrees C), high heavy metal content, low pH values (down to pH 2.7), sparse vegetation, and limited organic carbon. From these soils we cultured 16 fungal species. Two of these species were thermophilic, and six were thermotolerant. We cultured only three of these species from nearby cool (0 to 22 degrees C) soils. Transect studies revealed that higher numbers of CFUs occurred in and below the root zone of the perennial plant Dichanthelium lanuginosum (hot springs panic grass). The dynamics of fungal CFUs in geothermal soil and nearby nongeothermal soil were investigated for 12 months by examining soil cores and in situ mesocosms. For all of the fungal species studied, the temperature of the soil from which the organisms were cultured corresponded with their optimum axenic growth temperature.     

Molecular identification of Pilobolus species from Yellowstone National Park

Pilobolus, a widely distributed coprophilous fungus, grows on herbivore dung. Species of Pilobolus traditionally are described with imprecise morphological characteristics potentially leading to misidentification. In this study we used PCR analysis of taxonomically informative sequences to provide more consistent species identification from isolates obtained in Yellowstone National Park. We collected Pilobolus park-wide from six taxa of herbivores over 9 y. Multiple transfers of single sporangium isolates provided pure cultures from which DNA was extracted. Sequence analysis of internal transcribed spacer (ITS) regions of DNA that code for rRNA genes were used to distinguish among similar species. We describe several species of Pilobolus associated with herbivores in various habitats, including two species not previously reported, P. heterosporus and P. sphaerosporus. Our results show that phylogenetic species identification of Pilobolus based on sequence analysis of pure culture isolates provides a more reliable means of identifying species than traditional methods.     

Good to the bone: microbial community thrives within bone cavities of a bison carcass at Yellowstone National Park

The discovery of unanticipated microbial diversity in remote, often hostile environments has led to a greater appreciation of the complexity and richness of the natural world. Yellowstone National Park (YNP) has long been a focus of work on taxa that inhabit extreme environments. Here we report the finding of microbial flora that inhabit an unexpected niche: the cavities of bone remnants from a bison carcass in Norris Geyser Basin in YNP. Although bleached white on the surface, the bone cavities are bright green due to the presence of Stichococcus-like trebouxiophyte green algae. The cavities also harbour different fungi and bacteria. Stichococcus species are common lichen photobionts and the Thelebolales fungi present in the bone cavities have previously been found in association with animal remains. Scanning electron microscope analysis suggests the fungi and algae do not form lichen-like associations in the bone. Rather these taxa and the bacteria appear to be opportunists that have colonized an isolated oasis that provides nutrients and protection from desiccation and UV radiation.     

Elemental analysis of mineral lick soils from the Serengeti National Park, the Konza Prairie and Yellowstone National Park

We analyzed mineral lick soils and non-mineral lick soils from the Serengeti National Park, the Konza Praine, and Yellowstone National Park The concentrations of 14 different elements considered important for ungulate nutrition were analyzed to determine the relative importance of Na vs other elements in attracting animals to lick areas Only Na was consistently higher in the mineral lick soils of the three ecosystems Mean Na concentrations were c 20x greater in Serengeti licks, 10x greater in Konza licks and 3x greater in Yellowstone licks compared to the respective non-lick soils Despite the numerous elements analyzed for this survey, our results suggest that Na is the primary element initiates mineral lick use in these widely separated ecosystems The widespread distribution of Na-deficient forage likely explains the importance of Na in most mineral licks     

Arsenite-oxidizing Hydrogenobaculum strain isolated from an acid-sulfate-chloride geothermal spring in Yellowstone National Park

An arsenite-oxidizing Hydrogenobaculum strain was isolated from a geothermal spring in Yellowstone National Park, Wyo., that was previously shown to contain microbial populations engaged in arsenite oxidation. The isolate was sensitive to both arsenite and arsenate and behaved as an obligate chemolithoautotroph that used H(2) as its sole energy source and had an optimum temperature of 55 to 60 degrees C and an optimum pH of 3.0. The arsenite oxidation in this organism displayed saturation kinetics and was strongly inhibited by H(2)S.     

Mycobacterium parascrofulaceum in Acidic Hot Springs in Yellowstone National Park

Mycobacterium parascrofulaceum was found in Norris Geyser Basin, Yellowstone National Park, in a system composed of two acidic (pH 3.0) springs with temperatures between 56°C at the source and 40°C at the confluence of both springs. Growth and survival assays at 56°C for 60 days were performed, confirming the origin of the strain.     

Arsenite-Oxidizing Hydrogenobaculum Strain Isolated from an Acid-Sulfate-Chloride Geothermal Spring in Yellowstone National Park

An arsenite-oxidizing Hydrogenobaculum strain was isolated from a geothermal spring in Yellowstone National Park, Wyo., that was previously shown to contain microbial populations engaged in arsenite oxidation. The isolate was sensitive to both arsenite and arsenate and behaved as an obligate chemolithoautotroph that used H₂ as its sole energy source and had an optimum temperature of 55 to 60°C and an optimum pH of 3.0. The arsenite oxidation in this organism displayed saturation kinetics and was strongly inhibited by H₂S.     

Mycobacterium parascrofulaceum in acidic hot springs in Yellowstone National Park

Mycobacterium parascrofulaceum was found in Norris Geyser Basin, Yellowstone National Park, in a system composed of two acidic (pH 3.0) springs with temperatures between 56 degrees C at the source and 40 degrees C at the confluence of both springs. Growth and survival assays at 56 degrees C for 60 days were performed, confirming the origin of the strain.