Investigating Current and Historic White-tailed Kite Population Trends Using Genetic Techniques
A White-tailed kite. Photo by Heather Mohan.
The White‑tailed Kite has demonstrated large population fluctuations over the last 150 years. Once common in California, Texas, and the southeast United States, kite numbers declined to very low levels in the 1900s and was thought to be on the verge of extinction by the 1930s. In the 1940s populations began to expand and increasing numbers were observed during the following decades. Today, the White-tailed Kites are common residents throughout much of California, with slow but steady increases in population numbers in the Central Plains states, Texas and Florida. It is unknown whether current U.S. populations suffered a severe genetic bottleneck in the early 1900s and have rebounded since, or whether current U.S. population growth has been related to immigration from Central and South America populations. We are using genetic techniques to examine museum specimens collected before 1930 and modern samples collected in the 1990s from California to provide clues as to whether modern Kites in California in fact have low diversity due to a genetic bottleneck or whether they were founded and sustained by immigrants from other continents.
Population Genetic Structuring of the Lesser Prairie-chicken
A Lesser Prairie-chicken. Photo by Dan Wundrock with permission.
The goals of this study are to characterize patterns of connectivity across the Lesser Prairie-chicken range, document levels of genetic variability among populations, identify the source population(s) for the region of recent range expansion, and determine the level of introgression with the Greater Prairie-chicken in areas where the two species overlap in distribution. This project is revealing relatively strong population structure that falls largely along ecoregion boundaries. This study also shows that the species is expanding its range into previously unoccupied or sparsely occupied habitat from the mixed grass prairie ecoregion and to a lesser extent from the sand sagebrush ecoregion (due to enrollment of agricultural land into the Conservation Reserve Program) and is actively hybridizing with Greater Prairie-chickens in the area of expansion, information that is highly relevant for management. This research is in collaboration with Texas A&M-Kingsville, Oregon State University, University of North Texas, University of Oklahoma, and the Sutton Avian Research Center.
Insect prey eaten by Hoary Bats (Lasiurus cinereus) prior to fatal collisions with wind turbines
Wind turbines are being deployed all across the world to meet the growing demand for energy, and in many areas, these turbines are causing the deaths of insectivorous migratory bats. One of the hypothesized causes of bat susceptibility is that bats are attracted to insects on or near the turbines. We examined insect remains in the stomachs and intestines of hoary bats (Lasiurus cinereus) found dead beneath wind turbines in New York and Texas to evaluate the hypothesis that bats die while feeding at turbines. Most of the bats we examined had full stomachs, indicating that they fed in the minutes to hours leading up to their deaths. However, we did not find prey in the mouths or throats of any bats that would indicate the bats died while capturing prey. Hoary bats fed mostly on moths, but we also detected the regular presence of beetles, true bugs, and crickets. Presence of terrestrial insects in stomachs indicates that bats may have gleaned them from the ground or the turbine surfaces, yet aerial capture of winged insect stages cannot be ruled out. Our findings confirm earlier studies that indicate hoary bats feed during migration and eat mostly moths. Future studies on bat behaviors and insect presence at wind turbines could help determine whether feeding at turbines is a major fatality risk for bats.
Carcass ecology: Forensic techniques shed light on the possible causes of bat susceptibility to turbines
Cryan, P., E. Valdez, C. Stricker, M. Wunder, R. Barclay, E. Baerwald, C. Willis, J. Jameson, E. A. Snider, and E. Crichton
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The Wildlife Society 19th annual conference, Portland, OR, 14 October 2012
ASPN is a Web-based decision tool that assists natural resource managers and planners in identifying and prioritizing social and economic planning issues, and provides guidance on appropriate social and economic methods to address their identified issues.
ASPN covers the breadth of issues facing natural resource management agencies so it is widely applicable for various resources, plans, and projects.
ASPN also realistically accounts for budget and planning time constraints by providing estimated costs and time lengths needed for each of the possible social and economic methods.
ASPN is a valuable starting point for natural resource managers and planners to start working with their agencies’ social and economic specialists. Natural resource management actions have social and economic effects that often require appropriate analyses. Additionally, in the United States, Federal agencies are legally mandated to follow guidance under the National Environmental Policy Act (NEPA), which requires addressing social and economic effects for actions that may cause biophysical impacts. Most natural resource managers and planners lack training in understanding the full range of potential social and economic effects of a management decision as well as an understanding of the variety of methods and analyses available to address these effects. Thus, ASPN provides a common framework which provides consistency within and across natural resource management agencies to assist in identification of pertinent social and economic issues while also allowing the social and economic analyses to be tailored to best meet the needs of the specific plan or project.
ASPN can be used throughout a planning process or be used as a tool to identify potential issues that may be applicable to future management actions. ASPN is useful during the pre-scoping phase as a tool to start thinking about potential social and economic issues as well as to identify potential stakeholders who may be affected. Thinking about this early in the planning process can help with outreach efforts and with understanding the cost and time needed to address the potential social and economic effects. One can use ASPN during the scoping and post-scoping phases as a way to obtain guidance on how to address issues that stakeholders identified. ASPN can also be used as a monitoring tool to identify whether new social and economic issues arise after a management action occurs.
ASPN is developed through a collaborative research effort between the USGS Fort Collins Science Center’s (FORT) Social and Economic Analysis (SEA) Branch and the U.S. Forest Service, the National Park Service, the Bureau of Land Management, and the U.S. Fish and Wildlife Service. ASPN’s technical development is led by the USGS FORT’s Information Science Branch. An updated release, which will extend ASPN’s functionality and incorporate feature improvements identified in ongoing usability testing, is currently in the planning stages.
Playa wetlands on the west-central Great Plains of North America are vulnerable to sediment infilling from upland agriculture, putting at risk several important ecosystem services as well as essential habitats and food resources of diverse wetland-dependent biota. Climate predictions for this semi-arid area indicate reduced precipitation which may alter rates of erosion, runoff, and sedimentation of playas. We forecasted erosion rates, sediment depths, and resultant playa wetland depths across the west-central Great Plains and examined the relative roles of land use context and projected changes in precipitation in the sedimentation process. We estimated erosion with the Revised Universal Soil Loss Equation (RUSLE) using historic values and downscaled precipitation predictions from three general circulation models and three emissions scenarios. We calibrated RUSLE results using field sediment measurements. RUSLE is appealing for regional scale modeling because it uses climate forecasts with monthly resolution and other widely available values including soil texture, slope and land use. Sediment accumulation rates will continue near historic levels through 2070 and will be sufficient to cause most playas (if not already filled) to fill with sediment within the next 100 years in the absence of mitigation. Land use surrounding the playa, whether grassland or tilled cropland, is more influential in sediment accumulation than climate-driven precipitation change.
White-nose syndrome (WNS) is an emerging and devastating disease of hibernating bats in North America. WNS is caused by a cold-growing fungus (Geomyces destructans) that infects the skin of hibernating bats during winter and causes life-threatening alterations in physiology and behavior. WNS has spread rapidly across the eastern United States and Canada since it was first documented in New York in the winter of 2006. This new disease is causing mass mortality and detrimentally affecting most of the 6 species of bats that hibernate in the northeastern United States. Particularly hard-hit are the little brown bat (Myotis lucifugus), northern long-eared bat (Myotis septentrionalis), eastern small-footed bat (Myotis leibii), and federally endangered Indiana bat (Myotis sodalis). Several more species are also now known to be exposed to the fungus in the Midwest and Southeast. The sudden and widespread mortality associated with white-nose syndrome is unprecedented in any of the world’s bats and is a cause for international concern as the fungus and the disease spread farther north, south, and west. Loss of these long-lived insect-eating bats could have substantial adverse effects on agriculture and forestry through loss of natural pest-control services.
Tracking a Deadly Disease
Because WNS is spreading so rapidly, field surveillance data and diagnostic samples must be managed efficiently so that critical information can be communicated quickly among State and Federal land managers, as well as the public. The U.S. Fish and Wildlife Service, which plays a primary role in coordinating the Federal response to WNS, worked with the USGS Fort Collins Science Center’s Web Applications Team to develop the White-nose Syndrome Disease Tracking System. Version 1.0 of this system, released for Beta testing in May 2011, addresses two critical objectives:
enable state-level resource managers to effectively manage WNS field and laboratory data, and
provide customizable map and data reports of surveillance findings. The WNS Disease Tracking System subsequently was demonstrated to resource managers involved in the WNS response, and system users are assisting with in-depth testing. Once resource-management users are all trained (autumn 2011), they will begin populating the system with surveillance data, much of which will be immediately available to the public.
WNS version 1.0 was released into production in November, 2011 and state points-of-contact are currently being trainined. New users are providing ciritical feedback for WNS version 2.0, which is currently being planned with Fish and Wildlife Region 5 and the National White-nose Syndrome Data Management Team.
Key System Components
Disease Tracking: Customizable disease tracking maps and data exports for all U.S. states and counties
Disease Reporting: Tissue sample database management for authorized resource managers as well as a publicly accessible database of disease reporting contacts for all U.S. States and Federal resource management agencies
Diagnostic Labs: Directory of laboratories involved in white-nose syndrome diagnostic analyses
Migratory structure and geographic origins of hoary bats (Lasiurus cinereus) inferred from stable isotope analysis
Cryan, P.M., C.A. Stricker, and M.B. Wunder
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15th International Bat Research Conference, Prague, Czech Republic 22-27 August 2010
Understanding animal mating systems is an important component of their conservation, yet the precise mating times for many species of bats are unknown. The aim of this study was to better understand the details and timing of reproductive events in species of bats that die most frequently at wind turbines in North America, because such information can help inform conservation strategies. We examined the reproductive anatomy of hoary bats (Lasiurus cinereus), eastern red bats (L. borealis), and silver-haired bats (Lasionycteris noctivagans) found dead beneath industrial-scale wind turbines to learn more about when they mate. We evaluated 103 L. cinereus, 18 L. borealis, and 47 Ln. noctivagans from wind energy facilities in the United States and Canada. Histological analysis revealed that most male L. cinereus and L. borealis, as well as over half the Ln. noctivagans examined had sperm in the caudae epididymides by late August, indicating readiness to mate. Testes regression in male hoary bats coincided with enlargement of seminal vesicles and apparent growth of keratinized spines on the glans penis. Seasonality of these processes also suggests that mating could occur during August in L. cinereus. Spermatozoa were found in the uterus of an adult female hoary bat collected in September, but not in any other females. Ovaries of all females sampled had growing secondary or tertiary follicles, indicating sexual maturity even in first-year females. Lasiurus cinereus, L. borealis, and Ln. noctivagans are the only North American temperate bats in which most first-year young of both sexes are known to sexually mature in their first autumn. Our findings provide the first detailed information published on the seasonal timing of mating readiness in these species most affected by wind turbines.