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News Article | February 27, 2017
Site: www.eurekalert.org

CHAMPAIGN, Ill. -- An iconic bird whose booming mating calls once reverberated across "the Prairie State" can survive in Illinois with the help of periodic human interventions, researchers report. The greater prairie chicken once dominated the American Midwest, but today the bird is in trouble in many parts of its historic range. It is no longer found in Arkansas, Indiana, Kentucky, Michigan, Ohio, Tennessee, Texas or Wyoming, states where it once flourished. And in Illinois, an estimated 186 birds remain in two adjoining counties in the southern part of the state. "They used to be all over the state," said Illinois Natural History Survey conservation biologist Mark Davis, who participated in a genetic analysis of the Illinois birds. "This was the tallgrass prairie state. You couldn't throw a rock into a field without hitting a prairie chicken." The reason for the decline is simple, Davis said. "We changed our land-use practices from having a lot of prairie, then to wheat, hay and alfalfa, and now to vast expanses of corn and soybeans," he said. "Prairie chickens used to have 20 million acres of prairie in Illinois. Now, they have around 2,000. At the same time, population size went from 10 to 14 million in the 1860s to the 100 to 200 or so we have today. There just isn't enough habitat." Environmental officials have made two efforts to rescue Illinois' dwindling prairie chicken populations, which are suffering from a lack of habitat and declining genetic diversity. Between 1992 and 1998, teams imported more than 200 prairie chickens from other states. "In Illinois, the first translocation brought in birds from all over the upper Midwest - from North Dakota, Minnesota, Kansas and Nebraska," Davis said. "And for a short period of time, it seemed to work." More chicks survived to reproductive age and genetic diversity spiked, he said. To understand how well the birds were doing long after that first translocation, Davis and his colleagues analyzed the DNA from feathers collected in the birds' courtship grounds from 2010-13. The researchers report their findings in the journal Royal Society Open Science. "What our paper reveals is that about 20 years after the translocation of new prairie chickens into Illinois, we see another decrease in genetic diversity and a decline in the number of birds," Davis said. The study confirmed that the only two remaining populations of prairie chickens in Illinois -- one in Marion County and the other in Jasper County -- are genetically isolated from one another, Davis said. The birds have access to a few hundred acres of territory overall, but the land is subdivided by roads and power lines, which represent additional barriers. "They're also surrounded by an agricultural desert of corn and soybeans," Davis said. The study identified 88 unique males using the courtship grounds, where the birds strut and boom to attract females. The team estimates that roughly the same number of females live in Illinois. The researchers' conclusion: A lack of habitat endangers prairie chickens' long-term survival in Illinois. Without periodic human intervention - in the form of translocations of birds from other states - the population could die out. "This is the issue that sage grouse are facing out West," Davis said. "This is the issue that lesser prairie chickens are facing in Texas and Oklahoma. These are big birds that need a big landscape that we don't have anymore." There are still strongholds for prairie chickens in Kansas, Minnesota, Nebraska and South Dakota, Davis said. In western Minnesota, for example, a tradition of protection for game animals and a hefty excise tax on hunting and fishing licenses has allowed the state to purchase lands and protect a patchwork of interconnected grassland habitat, he said. "Now you have this swath of restored prairie and the birds are doing really well -- so much so that a few years ago, on a very limited basis, Minnesota was able to have the first prairie chickens taken by hunting in many years," he said. But Illinois has strong agricultural traditions, and Davis doesn't foresee a similar effort in the state. "Providing food for the world does come at a cost, and that cost is habitat for wildlife," he said. "To sustain prairie chickens in Illinois, we have two options," Davis said. "We can purchase and restore as much prairie habitat as possible. In lieu of that, we need to support the periodic translocations of new birds to Illinois to preserve this prairie icon." The INHS is a division of the Prairie Research Institute at the U. of I. To reach Mark Davis, call 217-333-6294; email davis63@illinois.edu. The paper "Genetic rescue, the greater prairie chicken, and the problem of conservation-reliance in the Anthropocene" is available online and from the U. of I. News Bureau.DOI: 10.1098/rsos.160736


News Article | March 4, 2016
Site: phys.org

That's the conclusion of a new study conducted by University of Arkansas biologists Michael Douglas and Marlis Douglas and their colleagues at the University of Illinois at Urbana-Champaign and Western Kentucky University. The researchers published their findings in the journal PLOS One. The research team, using head shapes and genetic analyses, recommend that six groups of subspecies of the western rattlesnake be elevated to full species status, with the following names: The scientific and standard English names will be submitted to the International Committee on Zoological Nomenclature for ratification. The study has important implications for ecological conservation efforts across the United States, said Michael Douglas, professor of biological sciences and Twenty-First Century Chair in Global Change Biology. "These snakes have been long been recognized by herpetologists as being demonstrably different, and in fact were designated as western rattlesnake subspecies in the first half of the 20th century," Douglas said. "None are currently considered rare, but species designation allows them to gain certain legal protection, particularly within individual states." Marlis Douglas, associate professor of biological sciences and Bruker Chair of Life Sciences, said the genetic data were also evaluated to identify these snakes as individual species. The Douglases collaborated with Mark Davis, research scientist at the Illinois Natural History Survey, part of the Prairie Research Institute at the University of Illinois, and Michael Collyer, associate professor of biology at Western Kentucky University. As part of his doctoral research, Davis collected data from nearly 3,000 western rattlesnakes available in natural history museums across the western United States. In addition to genetic traits, the team examined head shape, which can vary drastically between different species of snakes and potentially reflect what kind of prey the snake prefers. Explore further: Mysterious fungus killing snakes in at least nine states More information: Mark A. Davis et al. Correction: Deconstructing a Species-Complex: Geometric Morphometric and Molecular Analyses Define Species in the Western Rattlesnake (Crotalus viridis), PLOS ONE (2016). DOI: 10.1371/journal.pone.0149712


Wolff P.J.,Urbana University | Taylor C.A.,Prairie Research Institute | Heske E.J.,Prairie Research Institute | Schooley R.L.,Urbana University
Wildlife Biology | Year: 2015

Habitat selection by mammalian carnivores may be driven by prey availability, physical characteristics of the habitat, and landscape context. However, the cues used by carnivores to select habitat are often unclear. We examined the seasonal diet of American mink Neovison vison and determined if the abundance of a primary prey, crayfish, was an important driver of habitat use during summer in an agricultural landscape in Illinois. We also evaluated effects of stream size, water depth, riparian buffer width, and urbanization on occupancy of stream segments by mink. We collected mink scats during three seasons and tested for seasonal differences in the percentage of occurrence and volume percentage of prey classes in the diet of mink. Crayfish remains were the dominant component of mink scats during summer. In summer 2012, we performed occupancy surveys for mink and concurrently measured crayfish densities and habitat features in 59 stream segments. Site occupancy by mink was related positively to presence of local areas with high crayfish concentrations (hotspots) instead of local habitat characteristics that might indicate high prey densities. Mink also were associated negatively with degree of urbanization and stream size. Our study highlights the effectiveness of integrating data on diets and occupancy modeling to obtain insights on cues used by carnivores to select habitat. © 2015 The Authors.


Ahlers A.A.,Urbana University | Ahlers A.A.,Prairie Research Institute | Mitchell M.A.,Urbana University | Dubey J.P.,U.S. Department of Agriculture | And 2 more authors.
Journal of Wildlife Diseases | Year: 2015

We assessed risk factors for Toxoplasma gondii exposure in semiaquatic mammals in east-central Illinois, US. This agricultural region has extensive drainage systems that could potentially transport T. gondii oocysts into the watershed. We used muskrats (Ondatra zibethicus) and American mink (Neovison vison) as sentinels of watershed contamination. We predicted individuals from larger subwatersheds would more likely be antibody-positive for T. gondii, as they were exposed to drainage from larger areas. We also evaluated amount of urban land cover within the subwatershed, proximity to farmsteads, and age of individuals in competing models of T. gondii infection. Antibodies to T. gondii were assayed in animal sera by modified agglutination tests (titer 25 or higher) and detected in 18 (60%) of 30 muskrats and 20 (77%) of 26 mink. Infection rates were ≥1.7 times higher than those typical for mammals in upland habitats in this region. Subwatershed size and age class were important predictors of T. gondii infection in muskrats (R2=0.35). Models incorporating urban land cover and proximity to farmsteads had little support. None of our models of antibody prevalence in mink were well supported, possibly because mink are less strictly associated with riparian habitats. Because ~91% of our study area is devoted to agricultural production and urbanization, transport of T. gondii into freshwater ecosystems is likely facilitated by modified drainage practices common in these areas. © Wildlife Disease Association 2015.


Zahniser J.N.,Prairie Research Institute
International Journal of Tropical Insect Science | Year: 2012

Stenogiffardia Evans, 1977 is considered the senior synonym of Pratura Theron, 1982 syn. nov. and Doraturella Emeljanov, 2002 syn. nov., resulting in four new combinations. Duraturopsis Melichar, 1908 syn. nov. is considered a junior synonym of Chiasmus Mulsant and Rey, 1855, resulting in one new combination. Figures of the ovipositor of Stenogiffardia parvula (Kirkaldy) are provided for the first time, and habitus images of S. parvula and Chiasmus katonae (Melichar) comb. nov. are provided. © Copyright ICIPE 2012.


Taylor C.A.,Prairie Research Institute | Adams S.B.,U.S. Department of Agriculture | Schuster G.A.,305 Boone Way
Journal of Crustacean Biology | Year: 2014

Diagnosable taxonomic units are fundamental to conservation biology and management of resources and the need for sound science in both fields is more pressing for aquatic ecosystems. Within freshwater crayfishes, the North American genus Orconectes is one of the most diverse in the World. Accurate assessments of species level relationships and species boundaries within the genus have historically been hampered by a low number of variable morphological characters and inadequate sampling from across the ranges of many taxa. We examine a diverse group of southeastern United States stream dwelling Orconectes in the subgenus Trisellescens using 16S, COI mtDNA, and morphology to resolve uncertainties in species boundaries. Our results suggest that strong divergences exist between taxa found above and below the Fall Line in parts of the southeastern United States and the taxonomy for taxa found in that region should remain unchanged. However, using both molecular and morphological datasets we are unable to determine species limits for some taxa found on and below the Fall Line. Analysis of DNA data suggests that historical and ongoing genetic events such as gene introgression may contribute to these uncertainties. For taxa found on and below the Fall Line, we suggest tentative, taxonomic assignments. Finally, we argue for increased sampling of independent molecular datasets and increased sample sizes for all cambarid crayfish biogeographic studies. © The Crustacean Society, 2014. Published by Brill NV, Leiden.


Taylor C.A.,Prairie Research Institute | Robison H.W.,9717 Wild Mountain Drive
Zootaxa | Year: 2016

A new primary burrowing crayfish, Fallicambarus schusteri, is described from the Red River drainage of extreme south-eastern Oklahoma and southwestern Arkansas and is placed in the subgenus Fallicambarus. The species occurs in road-side ditches that seasonally flood and have silt and silt-loam dominated soils. Falllicambarus schusteri differs from all other members of the genus Fallicambarus in possessing a thin gradually tapering central projection and a wide triangular cephalic process on the first pleopod of form I males, a sufflamen on the cheliped, and an antennal scale that is widest at its midpoint. © 2016 Magnolia Press.


News Article | January 28, 2016
Site: www.biosciencetechnology.com

Using head shape and genetic analyses, new research challenges the formerly designated subspecies within the western rattlesnake species. These findings have important implications for ecological conservation efforts across the United States and could provide the basis for new species designations. The results are published in the journal PLOS ONE. The western rattlesnake (Crotalus viridis) is found across a significant portion of the United States, from Mexico to Canada and from the Missouri River to the West Coast. Most work classifying rattlesnake species and subspecies was conducted in the mid-20th century. Since then, scientific methods have advanced to allow for a more comprehensive understanding of the path of rattlesnake evolution. Mark Davis, a research scientist at the Illinois Natural History Survey, part of the Prairie Research Institute at the University of Illinois, collected data from nearly 3,000 western rattlesnakes for this study. He gathered data from preserved samples of this group available at natural history museums across the western United States. “We are able to see that these different subspecies, which have different habits, live in different areas and have other different characteristics, have heads that have been shaped differently over evolutionary time,” Davis said. For western rattlesnakes, the head is the primary organ for conducting daily life. It is especially important for feeding and reproductive rituals. Head shape has evolved to better accommodate these critical behaviors, Davis said. The shape can vary drastically between different species of snakes. Given the importance of this feature, Davis and his colleagues used geometric morphometrics, a relatively novel method that allows researchers to quantify head shape without any influence of head size. To complement the shape analyses, Davis and his team analyzed genetic data from the snakes. Combining head shape and genetic information created a comprehensive perspective, Davis said. Together, these data confirm that several groups of snakes previously labeled as subspecies have substantial enough differences to qualify for a separate species designation. One of the greatest challenges to ecological conservation is identifying what species actually exist. For legal protections – including the Endangered Species Act – to be effective, scientists must specifically identify the units of biodiversity that may be in need of protection. ”It’s important to me to try to work with conservation practitioners to develop strategies for preserving biodiversity,” Davis said. With this study, Davis and his colleagues recommend officially elevating to the level of full species several groups of snakes previously believed to be subspecies. Davis expects that the national and international organizations responsible for naming various species will adopt the recommendations proposed in the study.


News Article | February 15, 2017
Site: www.eurekalert.org

CHAMPAIGN, Ill. -- A new study contradicts decades of thought, research and teaching on the history of corn cultivation in the American Bottom, a floodplain of the Mississippi River in Illinois. The study refutes the notion that Indian corn, or maize, was cultivated in this region hundreds of years before its widespread adoption at about 1000 A.D. The findings, reported in the journal American Antiquity, are important in understanding how and why Cahokia, the first major metropolitan center in North America, arose, said Thomas Emerson, the director of the Illinois State Archaeological Survey at the University of Illinois, where the new study was conducted. Cahokia was a vast, highly organized settlement with tens of thousands of inhabitants in its heyday, Emerson said. Its dramatic rise near present-day St. Louis and East St. Louis, Illinois, at about A.D. 950 and its sudden demise by 1350 have long been a source of fascination. There is broad agreement that corn was cultivated in this region at about 1000 and widely consumed by the people of this time period, Emerson said. Corn fragments, including cobs and kernels, show up in sites dating to 1000 or later. Skeletal analyses from bodies buried at Cahokia also reveal the devastating impact of corn on people's teeth. These signs, as well as chemical signatures of corn consumption in the teeth and bone, also date to 1000 and after, he said. The new findings challenge earlier reports that maize was cultivated and consumed in the American Bottom as early as 60 years B.C. The early conclusions - in studies conducted before 2000 - were based on flawed approaches to analyzing ancient materials, said Mary Simon, an archaeobotanist with ISAS who conducted the new study. Rather than dating charred plant fragments directly, researchers analyzed charcoal or other "associated materials" to determine the age of the plants, she said. "We have since learned that a piece of charcoal or other material found adjacent to a corn kernel in an archaeological site could date to a later or earlier time period than the corn," Simon said. Also, visual identifications can be wrong, she said. Scientists now date plant fragments directly using accelerated mass spectrometry, a technology that was just "coming into vogue in the 1990s" and used at that time to determine the age of materials, Simon said. Today, stable isotope mass spectrometry can be used in conjunction with AMS to detect differences between plant types, information that aids in plant identification, she said. Corn and other grasses absorb atmospheric carbon differently than other plants. This is reflected in the ratio of carbon isotopes - carbon atoms with differing masses - in plant tissues, Simon said. "The beauty of this procedure is not only do you get an absolute date, you also get that carbon isotope ratio, so you know, first, how old it is, and, second, whether or not it's corn," she said. In the new study, Simon revisited botanical samples from Holding, an archaeological site in western Illinois that was occupied from about 150 B.C. to A.D. 300. Simon was among those who mistakenly identified plant fragments from this site as very early corn, and later AMS data confirmed its age. Those findings were published by a group of archaeologists in 1994, and were widely recognized as being the oldest directly dated corn in the eastern United States. The new analysis, of remaining botanical samples from the Holding site, used both AMS and SIMS and found that the samples that looked like corn either were not corn or dated to A.D. 900 or later, Simon said. Researchers at Arizona State University found samples from the original study and also tested those for carbon isotope ratios. Their results confirmed that although it was old, the material dated in 1994 was not, in fact, corn. "Basically, what we found is that myths of early corn in the central Mississippi River Valley are simply inaccurate. They've been disproved. We no longer believe that corn was at all important, that people were growing corn, that anybody was using corn to any extent at A.D. zero," Simon said. The two new studies suggest that corn was not in widespread use until 900 or later, she said. "You can never say it wasn't present here before then," she said. "For example, there was Wyoming obsidian here at A.D. 60, so it's totally possible that a cob of corn made it here from the southwestern U.S. at an earlier date. But, until it was cultivated here, it doesn't really count." The ISAS is a division of the Prairie Research Institute at the U. of I. The paper "Reevaluating the evidence for middle woodlands maize from the Holding site" is available online and from the U. of I. News Bureau.


News Article | January 27, 2016
Site: phys.org

The results are published in the journal PLOS ONE. The western rattlesnake (Crotalus viridis) is found across a significant portion of the United States, from Mexico to Canada and from the Missouri River to the West Coast. Most work classifying rattlesnake species and subspecies was conducted in the mid-20th century. Since then, scientific methods have advanced to allow for a more comprehensive understanding of the path of rattlesnake evolution. Mark Davis, a research scientist at the Illinois Natural History Survey, part of the Prairie Research Institute at the University of Illinois, collected data from nearly 3,000 western rattlesnakes for this study. He gathered data from preserved samples of this group available at natural history museums across the western United States. "We are able to see that these different subspecies, which have different habits, live in different areas and have other different characteristics, have heads that have been shaped differently over evolutionary time," Davis said. For western rattlesnakes, the head is the primary organ for conducting daily life. It is especially important for feeding and reproductive rituals. Head shape has evolved to better accommodate these critical behaviors, Davis said. The shape can vary drastically between different species of snakes. Given the importance of this feature, Davis and his colleagues used geometric morphometrics, a relatively novel method that allows researchers to quantify head shape without any influence of head size. To complement the shape analyses, Davis and his team analyzed genetic data from the snakes. Combining head shape and genetic information created a comprehensive perspective, Davis said. Together, these data confirm that several groups of snakes previously labeled as subspecies have substantial enough differences to qualify for a separate species designation. One of the greatest challenges to ecological conservation is identifying what species actually exist. For legal protections - including the Endangered Species Act - to be effective, scientists must specifically identify the units of biodiversity that may be in need of protection. "It's important to me to try to work with conservation practitioners to develop strategies for preserving biodiversity," Davis said. With this study, Davis and his colleagues recommend officially elevating to the level of full species several groups of snakes previously believed to be subspecies. Davis expects that the national and international organizations responsible for naming various species will adopt the recommendations proposed in the study. More information: Deconstructing a Species-Complex: Geometric Morphometric and Molecular Analyses Define Species in the Western Rattlesnake (Crotalus viridis), dx.doi.org/10.1371/journal.pone.0146166

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