Wintering in the sky: bighorn sheep move higher to cope with migration loss: Formerly migratory bighorn sheep that abandoned their traditional migration routes and winter range in the Teton Range in Wyoming because of human development are now wintering in some of the area's highest-elevation mountains instead of their traditional winter ranges at lower elevations, according to a study conducted by the USGS, University of Wyoming, Wyoming Game & Fish Department, National Park Service and U.S. Forest Service.
The research investigated how this bighorn sheep population in northwest Wyoming has coped with migration loss by altering its seasonal habitat selection behaviors. These sheep now winter above 10,000 feet, surviving on wind-scoured ridgelines and slopes. The study also documented a new quasi-migration behavior that these bighorn sheep are using in their now one seasonal range. This could be a behavioral strategy used to maximize their nutritional intake and body condition in the absence of migration to lower elevations with milder winter conditions. The seasonal migrations of many ungulate populations worldwide are similarly threatened by human-caused factors including barriers such as fences and roads, land conversion and loss of habitat and climate change. Understanding how populations cope with migration disruption and loss is critical to guiding future conservation efforts.
This study, Winter habitat selection strategies of a formerly migratory bighorn sheep population in the Teton Range, northwest Wyoming, will be presented on Nov. 6 at 9:20 a.m. local time in Room Kona 4. Contact Alyson Courtemanch, 307-730-5336, firstname.lastname@example.org, or Matthew Kauffman, 307-766-6404, email@example.com.
Ecosystems services in the American Southwest: Aspects of biodiversity are valued by humans in many ways, and thus are important to include in assessments that seek to identify and quantify the value of ecosystems to humans. Scientists with New Mexico State University, EPA, and USGS are investigating multiple biodiversity metrics that represent these ecosystem services. USGS Gap Analysis Program data, including modeled habitat for terrestrial vertebrates, were used to map multiple biodiversity metrics such as species-of-greatest-conservation-need, threatened and endangered species, harvestable species, total species richness, and taxon richness. Metrics were compared across the entire Southwest (AZ, NM, NV, UT, and CO), about 20 percent of the conterminous U.S.
The project is being conducted at multiple scales, i.e. place-based watersheds (such as the San Pedro and Rio Grande Rivers) to multi-state regional areas (Southwest and Southeast) and eventually will culminate in a national-level product. Further work is underway to identify additional metrics through analysis and stakeholder input.
This study, Evaluating biodiversity metrics in response to forecasted land-use change in the American Southwest, will be presented on Nov. 6 at 11:10 a.m. in Room King's 2. Contact Kenneth Boykin at firstname.lastname@example.org or 575-646-6303 or Elizabeth Samson at 575-646-3294 or email@example.com. Or visit http://fws-case-12.nmsu.edu/case/es/.
Virtual cougars: conducting wildlife disease experiments "in silico": It's a lot harder studying disease transmission in wildlife than in humans. Inconveniently, animals don't show up at a clinic and explain their recent whereabouts and medical history. To solve this issue, USGS and Colorado State University researchers are testing the use of "agent-based models" -- computer-simulated individual bobcats and cougars based on behavior and GPS data from real organisms -- to examine how carnivores are moving throughout a landscape and coming into contact with one another. Development of this model will be extremely useful in assessing how bobcats and cougars are responding to habitat fragmentation and barriers in the highly urbanized landscapes of Southern California, and how urban development might be impacting pathogen transmission and population health in these urban wildlife species.
This study, Agent-based movement models to assess functional connectivity and disease transmission in fragmented landscapes, will be presented on Nov.7 at 10:10 a.m. local time in Room Kohala 3. Contact Jeff Tracey, firstname.lastname@example.org.
Sensitive 'skeeters: finding the balance between butterfly protection and mosquito control: For decades, managers at The National Key Deer Wildlife Refuge have faced the dilemma of not knowing how local mosquito control efforts affect two imperiled butterfly species -- the Florida leafwing and the Bartram's hairstreak. A USGS study is being conducted on the refuge to learn more about how mosquito control pesticides affect both mosquitos and butterflies. Using an alternative, non-imperiled species of butterfly as the test subject, researchers compared butterfly and mosquito sensitivity during actual mosquito spraying events. Results indicated that mosquitos were more sensitive to the pesticide than butterflies, suggesting that it may be possible to find a means to effectively control mosquitos without significantly harming the imperiled butterflies.
This study, Mosquito control on a national wildlife refuge – potential impacts upon and conservation of a pair of imperiled species, will be presented on Nov. 7 at 1 p.m. local time in the Kohala and Kona Promenade. Contact Tim Bargar, 352-264-3520, email@example.com.
Keep off the wind turbines! Using acoustics to deter bats: The goal of a two-year study was to test the effectiveness of an ultrasonic device for reducing bat fatalities at wind turbines in Pennsylvania. Bats die or are injured by colliding with the turbines or by experiencing tissue-damaging rapid pressure changes during flight near turbines. The acoustic devices deter bats from entering the rotor-swept area. USGS biological statistician Manuela Huso and colleagues compared average fatality rates between turbines fitted with the acoustic devices and turbines not fitted with them. Preliminary results suggest an average of 60 percent higher fatality at control turbines from August through September 2009. With further development, modifications and experimentation, this type of deterrent method may prove successful and broadly applicable for protecting bats from harmful encounters with wind turbine blades.
This study, Evaluating the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at wind turbines, will be presented on Nov. 7 at 2:20 p.m. local time in Room Kohala 2. Contact Manuela Huso, USGS, 541-750-0948, firstname.lastname@example.org, or Cris D. Hein, Bat Conservation International, at 512-745-2556, email@example.com.
Seeing in the dark: imaging bats at wind turbines: Domestic wind energy has many benefits, including diversification of the nation's energy portfolio, new jobs and reduction of greenhouse gas emissions. But expansion of wind energy nationwide brings an unwanted side effect: increased bat and bird mortality at wind turbines. Assessing the risk industrial wind turbines pose to migratory bats is hindered by low-light conditions and the challenges of monitoring night-flying animals characterized by small size, rapid and non-linear flight, and irregular occurrence. USGS scientists from Hawaii and Colorado are assisting governments and the wind energy industry by devising a way to directly observe bat occurrence and behavior at wind turbines using a video system composed of high-powered illuminators and near-infrared cameras. This new video system images flying bats and birds, then uses advanced image-processing software to identify flight attributes (like velocity, direction and acceleration) indicative of bats being struck by moving turbine blades.
The USGS project, conducted in August and September 2011 at wind energy sites in Hawaii and Pennsylvania, is the first field validation of near-infrared videography to nocturnally track and quantify target motion (bats in this case) at distances greater than 100 meters under realistic operational conditions. This a significant step in developing a feasible methodology to enhance our understanding of how wind turbines affect bats and nocturnal migratory birds, with the ultimate goal of finding new ways for wind-energy development to continue expanding while minimizing the detrimental effects of this renewable energy source on wildlife.
This study, Monitoring and researching bat activity at wind turbines with near infrared videography, will be presented on Nov. 7 at 3:30 p.m. local time in Room Kohala 2. Contact Marcos Gorressen at 808-985-6407, firstname.lastname@example.org, or Paul Cryan at 970-226-9389, email@example.com.
Use of community-based monitoring to assess survival of polar bears of Baffin Bay: Baffin Bay is home to a subpopulation of polar bears shared between Canada and Greenland; these polar bears are important for subsistence harvest. The last status assessment of these polar bears ended in 1997 and concluded that the bears had high natural survival, as well as high recruitment compared to other populations. Since 1998, however, the IUCN/Polar Bear Specialist Group and the Canadian Polar Bear Technical Committee have regarded that the population as 'declining' due to the amount of harvest. In contrast, traditional ecological knowledge suggests there are more bears or that their distribution has changed resulting in more sightings; it also suggests, along with scientific evidence, the declines in the body condition of these bears is occurring.
This study assessed how reliable it is to use the harvest recovery of tagged polar bears that have been harvested over the last decade to update survival estimates (in lieu of a new capture effort). Preliminary study results suggest survival rates of these polar bears have declined, but there is a lot of uncertainty in those rates, because the harvest sample size is less than a capture sample size. Also, after about six years, the survival rate estimates become significantly unreliable, indicating that the population should be marked every 5 years for more precise survival estimates. Ties between declines in natural survival and sea ice have been reported in other populations, and this study also confirmed declines in optimal ice habitat for polar bears in spring in Baffin Bay.
This study, New insights for the polar bears of Baffin Bay: using additional harvest data to assess changes in survival, will be presented on Nov. 7 at 3:30 p.m. local time in Room Kona 5. Contact Elizabeth (Lily) Peacock, 907-268-1992, firstname.lastname@example.org
Genetics identify spread of chronic wasting disease (CWD): CWD is an important management concern for Midwestern white-tailed deer populations. Therefore, understanding animal movement and spread of CWD is crucial to conducting disease surveillance, and controlling the distribution and spread of infection. Although CWD was recently discovered in the Midwest, it has likely been present there for decades; it appears to be increasing in prevalence and geographically spreading.
USGS scientist Mike Samuel and partners used landscape genetics and spatial analysis to determine patterns of CWD spread across the infected areas of southern Wisconsin and northern Illinois. Genetic connectivity of deer populations across the landscape was a primary driver of CWD spread; however, man-made and natural barriers to deer movement had an important role in reducing the spread of disease. These barriers include state and interstate highway resulting from human development as well as major river systems. These barriers affect the spatial distribution of CWD, likely affecting future rates and direction of disease spread to naive deer populations. Our results provide important information for future CWD management by identifying barriers that may slow the rate of disease spread (a current CWD management goal) and by identifying areas of high disease risk where future surveillance efforts would be most productive.
This study, Landscape genetics shed light on deer dispersal and population contact in the Wisconsin-Illinois chronic wasting disease zone, will be presented on Nov. 7 at 4:10 p.m. local time in Room Kona 4. Contact Michael D. Samuel, 608-263-6882, email@example.com.
Resident elk attract wolves to Wyoming rangelands. Wolves in Wyoming and elsewhere in the Rocky Mountain West are often lethally removed when they kill domestic livestock. New research out of the USGS Wyoming Cooperative Fish and Wildlife Research Unit indicates that the migratory patterns of the wolf's primary prey (elk) can influence wolf predation on cattle. Researchers tracked wolves in areas occupied by migratory and resident elk and recorded the location where wolves killed elk, deer, and cattle. They found that wolves stay close to the growing numbers of resident elk, but kill cattle when pasture rotations cause them to comingle with elk. Study findings point to the need to integrate the management of wolves, elk and cattle on western rangelands.
This study, Spatial characteristics of wolf depredation sites in northwest Wyoming: a comparison between areas with migratory and resident elk, will take place on Nov 9 at 8:00 a.m. local time in Kohala and Kona Promenade. Contact Abigail Nelson, 307-460-0718, firstname.lastname@example.org, or Matthew Kauffman, 307-399-1322 email@example.com.
Mapping polar bear maternal denning habitat in the National Petroleum Reserve – Alaska: To successfully reproduce, polar bears require snow dens of more than 1 meter in height and that remain undisturbed from late autumn until early spring. Potential denning habitat can be mapped from remotely collected landscape imagery, and these maps can be useful for polar bear conservation. The National Petroleum Reserve-Alaska (NPRA) in northwest Alaska contains reserves of recoverable hydrocarbons and is used by polar bears for maternal denning. Because most hydrocarbon exploration and development occurs during winter when polar bears occupy dens, this creates a potential for den disturbance. However, because the distribution of denning habitat in the NPRA was unknown, USGS scientists and colleagues used a digital terrain model and GIS tools to map potential denning habitat there. Then they ground-truthed mapped denning habitat to determine if the on-ground measures of mapped features were similar to actual polar bear den sites and also evaluated potential denning habitat omitted by the map.
Den habitat comprised 113 square kilometers of the total nearly 19,000 square kilometers of the NPRA. Of 175 denning habitat locations selected for ground-truthing, 80 percent – or three-fourths -- met the study's criteria as den habitat. The map, however, failed to identify about one-fourth of potential den habitat in the NPRA. The proportion of den habitat relative to the area of the NPRA was similar to regions in northern coastal Alaska east of the NPRA. Although this map performed similarly to photogrammetric methods used in other regions, manual photogrammetric techniques, are labor intensive and results are dependent on the cartographer. In contrast, the IFSAR data can be assessed automatically and consistently with standard GIS tools. Similar performance and ease of use demonstrates that an IFSAR-derived polar bear den habitat map could be a useful management tool in the NPRA.
This study, Mapping polar bear maternal denning habitat in the National Petroleum Reserve – Alaska, will be presented on Nov. 9 starting at 8 a.m. local time in the Kohala and Kona Promenade. Contact George Durner at 907-786-7082 or firstname.lastname@example.org.
Are they or aren't they? If it looks like a greater sage-grouse, and acts like a greater sage-grouse…is it? Sage-grouse have been split into two species (greater and Gunnison sage-grouse) based on genetic differences as well as morphology (physical characteristics) and behavior. Within the greater sage-grouse range, however, is a population along the border between California and Nevada (the bi-state population) that has been shown to be genetically unique, such that some experts question whether this might be a distinct species. But unlike Gunnison Sage-grouse, the bi-state birds are behaviorally and morphologically similar to other greater gage-grouse. The genetic data used under previous genetics methods to characterize these divisions were generated from a small number of genetic markers.
When USGS researchers re-examined those divisions using a genomic approach, with its many thousands more markers spread throughout the genome, they found that the bi-state population, though still genetically different from the rest of the greater sage-grouse population in some ways, is not different in the DNA markers that are under selection, markers that code for things like behavior and morphology. This is a much clearer distinction that explains why the Gunnison is truly a unique species, and the bi-state population is not. These genomic methods provide much more comprehensive answers to what have been, up to now, problematic questions.
This study, Re-examining genetic variation in sage-grouse using genomic methods, will be presented on Nov. 9, at 9 a.m. local time in Room Queen's 4. Contact Sara J. Oyler-McCance at 970-226-9197, email@example.com.
Is there a fear effect of wolves on elk? In Yellowstone, elk often increase their vigilance when they are being hunted by their primary predator, the gray wolf. Since vigilant elk might feed at a lower rate, previous research suggested that elk exposed to wolves will shed body fat and abort pregnancies at an elevated rate. Not so, according to researchers in Wyoming's USGS Cooperative Fish and Wildlife Research Unit. Scientists conducted a three-year field study of the Clarks Fork elk herd in northwest Wyoming, tracking the behavior, body fat and pregnancies of female elk exposed to varying levels of wolf predation. The elk that experienced high wolf predation risk were not highly vigilant, and their rate of vigilance was not related to their body-fat level. Instead, elk fat and pregnancy were more closely tied to summer conditions. An alternative explanation for low elk reproductive rates includes the effects of long-term drought, coupled with high levels of bear predation on newborn elk calves.
This study, Evaluating the nonconsumptive effects of predation among large mammals: wolves and elk in the greater Yellowstone ecosystem, will be presented on Nov. 9 at 10:30 local time in Room Kona 5. Contact Arthur Middleton, USGS Wyoming Cooperative Fish & Wildlife Research Unit, 307-766-6415 (lab), 307-460-0880 (cell), firstname.lastname@example.org.
Genetic sleuths reveal secretive stream amphibians: Stream-dwelling species are among the most imperiled and difficult to detect groups of organisms, and current survey methods are time consuming and expensive. USGS scientists and co-authors used a new method of detecting aquatic species using environmental DNA (eDNA); this method has recently been tested successfully for a variety of aquatic systems. This technique samples shed cells, so it does not require observing or handling species. Scientists simply filter water and test the filter paper for presence of DNA.
In this study, DNA from two secretive stream species, Rocky Mountain tailed frogs and Idaho giant salamanders, was successfully isolated from water samples collected from streams known to be occupied by both species. The simple and low-cost protocol is widely applicable to broad-scale inventory and monitoring efforts. Further, it could revolutionize surveys for rare and invasive stream species and help transform approaches for aquatic surveys. The work was supported by the USGS Amphibian Monitoring and Research Initiative.
This study, Molecular detection of stream amphibians in water samples using environmental DNA, will be presented on Nov. 9 at 10:30a.m. local time in Room King's 2. Contact David Pilliod, 208-426-5202, email@example.com.
Mountaintops of change: In some places, mountain-dwelling wildlife species are facing biologically important climate changes. USGS scientist Erik Beever and university-based colleagues have found that the pace of both local extinctions as well as uphill movement of the lower-elevation boundary of areas inhabited by American pikas across the hydrographic Great Basin increased markedly from the 20th Century to the last decade. More importantly, drivers of the local extinctions differed significantly between the two periods, suggesting that understanding past dynamics may not may not always help land managers predict the patterns of future loss. Coordinated, landscape-scale research and monitoring may be a key approach for clarifying how and why wildlife may be responding to contemporary climate changes.
This study, Landscape-scale conservation and management of montane wildlife: contemporary climate may be changing the rules, will be presented on Nov. 9 at 1:20 p.m. local time in Room Kona 4. Contact Erik Beever, 406-994-7670, firstname.lastname@example.org.
Managing wild horses on public lands: Largely unchecked by natural predators, many wild horse populations grow at rates of 18 percent per year. This unregulated growth can overtax the vegetation upon which their health and survival depend. In an effort to assist the Bureau of Land Management, the primary federal agency responsible for managing wild horses on public lands, in controlling herd growth and minimizing impacts to western ranges, USGS scientists have been testing the effects of two forms (a liquid form that requires annual boosters and a pellet form designed for 2 years of efficacy) of the fertility control agent porcine zona pellucida (PZP) in 3 populations of feral horses. Controlling for age of mares and pretreatment differences in fertility, PZP significantly reduced foaling rates in all 3 herds, although the pellet form was less effective than those used in a previous trial and produced by an alternative method.
Researchers also noted differences in frequency of reactions at injection sites and assessed behavioral differences between treated and untreated mares. PZP may be a useful tool in controlling fertility in some western U.S. horse herds, but reduction in population growth rates will depend on timely access to mares for inoculation and the proportion of mares that can be successfully treated. The results of these studies can help managers weigh the impact of potential side-effects associated with use of PZP against the benefit of reducing population growth.
This study, Efficacy and side-effects of PZP immunocontraception in feral horses, will be presented on Nov. 9 at 2:40 p.m. in Room Queen's 6. Contact Jason Ransom, 970-226-9321, email@example.com.
USGS provides science for a changing world. For more information, visit http://www.usgs.gov.
Subscribe to USGS News Releases via our electronic mailing list or RSS feed.
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.