569 research outputs found
Daytime Amphibian Surveys in Three Protected Areas in the Western Great Lakes
We performed pilot monitoring of amphibian populations at Apostle Islands National Lakeshore (APIS) in 2006, Pictured Rocks NationalLakeshore (PIRO) in 2007, and Sleeping Bear Dunes National Lakeshore (SLBE ) in both 2006 and 2007. We performed daytime surveys (using multiple methods) at numerous sites in each of the three parks. We detected 10 amphibian and two reptilian species at APIS, nine amphibian and four reptilian species at SLBE , and nine amphibian and one reptilian species at PIRO. No one daytime survey technique appeared to be superior to any other. Our work resulted in two new species records (Gray Treefrog and Green Frog) for Basswood Island at APIS
Daytime Amphibian Surveys in Three Protected Areas in the Western Great Lakes
We performed pilot monitoring of amphibian populations at Apostle Islands National Lakeshore (APIS) in 2006, Pictured Rocks NationalLakeshore (PIRO) in 2007, and Sleeping Bear Dunes National Lakeshore (SLBE ) in both 2006 and 2007. We performed daytime surveys (using multiple methods) at numerous sites in each of the three parks. We detected 10 amphibian and two reptilian species at APIS, nine amphibian and four reptilian species at SLBE , and nine amphibian and one reptilian species at PIRO. No one daytime survey technique appeared to be superior to any other. Our work resulted in two new species records (Gray Treefrog and Green Frog) for Basswood Island at APIS
FACING A CHANGING WORLD: THERMAL PHYSIOLOGY OF AMERICAN PIKAS (OCHOTONA PRINCEPS)
American pikas (Ochotona princeps) are of concern with respect to warming montane temperatures; however, little information exists regarding their physiological ability to adapt to warming temperatures. Previous studies have shown that pikas have high metabolism and low thermal conductance, which allow survival during cold winters. It has been hypothesized that these characteristics may be detrimental, given the recent warming trends observed in montane ecosystems. We examined resting metabolic rate, surface activity, and den and ambient temperatures (Ta) of pikas in late summer (August 2011 and 2012) at 2 locations in the Rocky Mountains. Resting metabolic rate was calculated to be 2.02 mL O2 ⋅ g−1h−1, with a lower critical temperature (LCT) of 28.1 –+ 0.2 °C. No upper critical temperature (UCT) could be determined from our data; therefore, the estimated thermoneutral zone (TNZ) was 28.1 °C to at least 35.0 °C (upper experimental temperature). Pikas in this study showed the same bimodal above-talus activity patterns reported in previous studies. Den temperatures in Colorado were correlated with, but consistently lower than, current ambient temperatures. Wyoming den temperatures showed a weak correlation with Ta 20 min prior to the current den temperature. This study is one of few to present data on the physiological response pikas may have to current warming conditions, and the first to perform metabolic measurements in situ. Our data support conclusions of previous studies, specifically MacArthur and Wang (1973, 1974) and Smith (1974), which indicated American pikas may not have the physiological ability to cope with high Ta. Our results also highlight the importance of shaded regions below the talus rocks for behavioral thermoregulation by pikas.
RESUMEN.—La pica americana (Ochotona princeps) es una especie considerada de preocupación debido al aumento de la temperatura en las montañas. Sin embargo, existe poca información relacionada a su capacidad fisiológica para adaptarse a temperaturas más cálidas. Estudios previos han mostrado que las picas tienen un metabolismo alto y una conductividad térmica baja, lo que les permite sobrevivir en los inviernos fríos. Se ha planteado la hipótesis de que estas características pueden ser perjudiciales, dadas a las tendencias recientes de calentamiento en los ecosistemas de montaña. Examinamos la tasa metabólica en reposo, la actividad superficial y la temperatura en las madrigueras y la temperatura ambiente (Ta) de las picas a finales del verano (agosto de 2011 y 2012) en 2 áreas de las Montañas Rocosas. Calculamos que la tasa metabólica en reposo sería 2.02 mL O2 ⋅ g−1h−1, con una temperatura crítica inferior (LCT) de 28.1 –+ 0.2 °C. No pudimos determinar la temperatura crítica superior (UCT) a partir de nuestros datos; por lo tanto, la zona termoneutral estimada (TNZ) fue 28.1 a al menos 35.0 °C (temperatura experimental superior). Las picas en este estudio mostraron los mismos patrones bimodales de actividad por encima del talud que los reportados en estudios anteriores. La temperatura de las madrigueras en Colorado se correlacionaron con, pero siendo siempre inferiores, la temperatura am - biental actual. La temperatura de las madrigueras en Wyoming mostraron una correlación débil con la temperatura ambiente 20 minutos antes de la temperatura actual de la madriguera. Este estudio es uno de los pocos que presentan datos de las respuestas fisiológicas que las picas podrían tener en las condiciones actuales de calentamiento climático, y el primero en realizar mediciones metabólicas in situ. Nuestros datos respaldan conclusiones de estudios previos, particularmente MacArthur y Wang 1973 y 1974, y Smith 1974, que indican que las picas americanas pueden no tener la capacidad fisiológica para enfrentar las altas temperaturas ambientales y resalta la importancia de las regiones sombreadas bajo las rocas del talud para el comportamiento de termorregulación de las picas
Incorporating Ecohydrologic Variables into Modeling of Patterns of Montane-Mammal Distribution and Abundance
Montane ecosystems have been suggested by both paleontological and contemporary research to often be systems of relatively rapid faunal change, compared to many valley-bottom counterparts. In addition to often (but not always) experiencing greater magnitudes of contemporary change in climatic parameters than species in other ecosystems, mountain-dwelling wildlife must also accommodate often-greater intra-annual swings in temperature and wind speeds, poorly developed soils, and generally harsher conditions. We present new results of ecoregional level analyses of American pikas (Ochotona princeps Richardson) that illustrate how biologically relevant derived hydrological variables can be important to predictors of abundance. We also present new results from the Northern Rocky Mountains that illustrate how behavioral plasticity can, in at least some cases, ‘soften’ the boundaries of species’ bioclimatic niches. Landscape Conservation Cooperatives and Climate Science Centers are newly emerging efforts that may contribute greatly to broad-scale, mechanism-based investigations to inform management and conservation of diverse montane wildlife and the ecosystem components with which they interact. Based on our empirical findings and our review of the literature, we propose tenets that may serves as foundational starting points for our expanding research on montane animals across the Northern Rocky Mountain Region
Social–ecological mismatches create conservation challenges in introduced species management
This is the final version. Available from the Ecological Society of America via the DOI in this recordIntroduced species can have important effects on the component species and processes of native ecosystems. However, effective introduced species management can be complicated by technical and social challenges. We identify “social–ecological mismatches” (that is, differences between the scales and functioning of interacting social and ecological systems) as one such challenge. We present three case studies in which mismatches between the organization and functioning of key social and ecological systems have contributed to controversies and debates surrounding introduced species management and policy. We identify three common issues: social systems and cultures may adapt to a new species’ arrival at a different rate than ecosystems; ecological impacts can arise at one spatial scale while social impacts occur at another; and the effects of introduced species can spread widely, whereas management actions are constrained by organizational and/or political boundaries. We propose strategies for collaborative knowledge building and adaptive management that may help address these challenges
Understanding Relationships Among Abundance, Extirpation, and Climate at Ecoregional Scales
Recent research on mountain-dwelling species has illustrated changes in species\u27 distributional patterns in response to climate change. Abundance of a species will likely provide an earlier warning indicator of change than will occupancy, yet relationships between abundance and climatic factors have received less attention. We tested whether predictors of counts of American pikas (Ochotona princeps) during surveys from the Great Basin region in 1994-1999 and 2003-2008 differed between the two periods. Additionally, we tested whether various modeled aspects of ecohydrology better predicted relative density than did average annual precipitation, and whether risk of site-wide extirpation predicted subsequent population counts of pikas. We observed several patterns of change in pika abundance at range edges that likely constitute early warnings of distributional shifts. Predictors of pika abundance differed strongly between the survey periods, as did pika extirpation patterns previously reported from this region. Additionally, maximum snowpack and growing-season precipitation resulted in better-supported models than those using average annual precipitation, and constituted two of the top three predictors of pika density in the 2000s surveys (affecting pikas perhaps via vegetation). Unexpectedly, we found that extirpation risk positively predicted subsequent population size. Our results emphasize the need to clarify mechanisms underlying biotic responses to recent climate change at organism-relevant scales, to inform management and conservation strategies for species of concern
Genomic organization and evolution of the ULBP genes in cattle
BACKGROUND: The cattle UL16-binding protein 1 (ULBP1) and ULBP2 genes encode members of the MHC Class I superfamily that have homology to the human ULBP genes. Human ULBP1 and ULBP2 interact with the NKG2D receptor to activate effector cells in the immune system. The human cytomegalovirus UL16 protein is known to disrupt the ULBP-NKG2D interaction, thereby subverting natural killer cell-mediated responses. Previous Southern blotting experiments identified evidence of increased ULBP copy number within the genomes of ruminant artiodactyls. On the basis of these observations we hypothesized that the cattle ULBPs evolved by duplication and sequence divergence to produce a sufficient number and diversity of ULBP molecules to deliver an immune activation signal in the presence of immunogenic peptides. Given the importance of the ULBPs in antiviral immunity in other species, our goal was to determine the copy number and genomic organization of the ULBP genes in the cattle genome. RESULTS: Sequencing of cattle bacterial artificial chromosome genomic inserts resulted in the identification of 30 cattle ULBP loci existing in two gene clusters. Evidence of extensive segmental duplication and approximately 14 Kbp of novel repetitive sequences were identified within the major cluster. Ten ULBPs are predicted to be expressed at the cell surface. Substitution analysis revealed 11 outwardly directed residues in the predicted extracellular domains that show evidence of positive Darwinian selection. These positively selected residues have only one residue that overlaps with those proposed to interact with NKG2D, thus suggesting the interaction with molecules other than NKG2D. CONCLUSION: The ULBP loci in the cattle genome apparently arose by gene duplication and subsequent sequence divergence. Substitution analysis of the ULBP proteins provided convincing evidence for positive selection on extracellular residues that may interact with peptide ligands. These results support our hypothesis that the cattle ULBPs evolved under adaptive diversifying selection to avoid interaction with a UL16-like molecule whilst preserving the NKG2D binding site. The large number of ULBPs in cattle, their extensive diversification, and the high prevalence of bovine herpesvirus infections make this gene family a compelling target for studies of antiviral immunity
Monitoring temporal change in riparian vegetation of Great Basin National Park
Disturbance in riparian areas of semiarid ecosystems involves complex interactions of pulsed hydrologic flows, herbivory, fire, climatic effects, and anthropogenic influences. We resampled riparian vegetation within ten 10-m × 100-m plots that were initially sampled in 1992 in 4 watersheds of the Snake Range, east central Nevada. Our finding of significantly lower coverage of grasses, forbs, and shrubs within plots in 2001 compared with 1992 was not consistent with the management decision to remove livestock grazing from the watersheds in 1999. Change over time in cover of life-forms or bare ground was not predicted by scat counts within plots in 2001. Cover results were also not well explained by variability between the 2 sampling periods in either density of native herbivores or annual precipitation. In contrast, Engelmann spruce (Picea engelmannii) exhibited reduced abundance at all but the highest-elevation plot in which it occurred in 1992, and the magnitude of change in abundance was strongly predicted by plot elevation. Abundance of white fir (Abies concolor) individuals increased while aspen (Populus tremuloides) individuals decreased at 4 of 5 sites where they were sympatric, and changes in abundance in the 2 species were negatively correlated across those sites. Utility of monitoring data to detect change over time and contribute to adaptive management will vary with sample size, observer bias, use of repeatable or published methods, and precision of measurements, among other factors
Variation in carbon footprint of milk due to management differences between Swedish dairy farms
To identify mitigation options to reduce greenhouse gas (GHG) emissions from milk production (i.e. the carbon footprint (CF) of milk), this study examined the variation in GHG emissions among dairy farms using data from previous CF studies on Swedish milk. Variation between farms in these production data, which were found to have a strong influence on milk CF were obtained from existing databases of e.g. 1051 dairy farms in Sweden in 2005. Monte Carlo analysis was used to analyse the impact of variations in seven important parameters on milk CF concerning milk yield (energy corrected milk (ECM) produced and delivered), feed dry matter intake (DMI), enteric methane emissions, N content in feed DMI, N-fertiliser rate and diesel used on farm. The largest between farm variation among the analysed production data were N-fertiliser rate (kg/ha) and diesel used (l/ha) on farm (coefficient of variation (CV) 31-38%). For the parameters concerning milk yield and feed DMI the CV was approx. 11 and 8%, respectively. The smallest variation in production data was found for N content in feed DMI. According to the Monte Carlo analysis, these variations in production data led to a variation in milk CF of between 0.94 and 1.33 kg CO2 equivalents (CO2e) per kg ECM, with an average value of 1.13 kg/CO2e kg ECM. We consider that this variation of ±17% that was found based on the used farm data would be even greater if all Swedish dairy farms were included, as the sample of farms in this study was not totally unbiased. The variation identified in milk CF indicates that a potential exists to reduce GHG emissions from milk production on both national and farm level through changes in management. As milk yield and feed DMI are two of the most influential parameters for milk CF, feed conversion efficiency (i.e. units ECM produced per unit DMI) can be used as a rough key performance indicator for predicting CF reductions. However, it must be borne in mind that feeds have different CF due to where and how they are produced
Landscape-Scale Conservation And Management Of Montane Wildlife: Contemporary Climate May Be Changing The Rules
Both paleontological and contemporary results have suggested that montane ecosystems to be systems of relatively rapid faunal change compared to many valley-bottom counterparts. In addition to experiencing greater magnitudes of contemporary change in climatic parameters than species in other ecosystems, mountain-dwelling wildlife must also accommodate often greater intra-annual swings in temperature and wind speeds, poorly developed soils, and generally harsher conditions. Research on a mountain-dwelling mammal species across 15 yrs of contemporary data and historical records from 1898-1956 suggest that pace of local extinctions and rate of upslope retraction have been markedly more rapid and governed by markedly different dynamics in the last decade than during the 20th century. This may mean that understanding past dynamics of species losses may not always help predict patterns of future loss. Given the importance of clinal variability and ecotypic variation, phenotypic plasticity, behavioral plasticity, and variation in climatic conditions, for widely-distributed species’ geographic ranges to be determined by different factors in different portions of their range is not uncommon. Consequently, greatest progress in understanding distributionalchange phenomena will occur with coordinated, landscape-scale research and monitoring. Landscape Conservation Cooperatives and Climate Science Centers are newly emerging efforts that may contribute greatly to such broad-scale investigations, e.g., climate-wildlife relationships. Based on our empirical findings and our review of related literature, we propose tenets that may serve as foundational starting points for mechanism-based research at broad scales to inform management and conservation of diverse montane wildlife and the ecosystem components with which they interact
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