Physical Sciences and Mathematics Commons^™

Assessment Of A Channel Catfish Population In A Large Open River System, A. J. Blank, M. J. Hamel, Jonathan J. Spurgeon, Mark A. Pegg

School of Natural Resources: Faculty Publications

Estimates of dynamic rate functions for riverine channel catfish, Ictalurus punctatus (Rafinesque), populations are limited. The open nature and inherent difficulty in sampling riverine environments and the propensity for dispersal of channel catfish impede estimation of population variables. However, contemporary population models (i.e. robust design models) can incorporate the open nature of these systems. The purpose of this study was to determine channel catfish population abundance, survival and size structure and to characterize growth in the lower Platte River, Nebraska, USA. Annual survival estimates of adult channel catfish were 13%–49%, and channel catfish abundance estimates ranged from 8,281 to 24,261 …

Acoustic Detection Reveals Fine-Scale Distributions Of Myotis Lucifugus, Myotis Septentrionalis, And Perimyotis Subflavus In Eastern Nebraska, Jeremy A. White, Cliff Lemen, Patricia Freeman

School of Natural Resources: Faculty Publications

ABSTRACT.—Before white-nose syndrome arrives in Nebraska, it is important to document the preexposure distributions of cave bats in the state. We examined the distributions of Myotis lucifugus (little brown myotis), Myotis septentrionalis (northern long-eared myotis), and Perimyotis subflavus (tri-colored bat) in eastern Nebraska by setting acoustic detectors for a single night at 105 sites in wooded habitats during summers of 2012 and 2014. We compared 2 methods of determining presence at each site. Results of our analyses are fine-scale distributional maps for these bats and some range extensions from published records. Results for M. septentrionalis and P. subflavus are largely …

Inconsistent Outcomes Of Heterogeneity-Based Management Underscore Importance Of Matching Evaluation To Conservation Objectives, Devan Allen Mcgranahan, David M. Engle, Samuel D. Fuhlendorf, Stephen L. Winter, James R. Miller, Diane M. Debinski

School of Natural Resources: Faculty Publications

Conservation policy often incentivizes managers of human-impacted areas to create landscape heterogeneity to maximize biodiversity. In rangeland, patchy disturbance regimes create landscape heterogeneity (patch contrast), but outcomes of heterogeneity-based management are rarely tested for a universal response. We analyzed four habitat variables—vegetation structure, plant functional group composition, litter cover, and bare ground—from five experimental rangelands in Oklahoma and Iowa, USA. We tested for response consistency to heterogeneity-based management across and within locations. We calculated effect sizes for each variable to compare patch contrast on pastures managed for heterogeneity (patch burn-grazing) and pastures managed for homogeneity (grazing with homogeneous fire regimes). …

Overwinter Mortality Of Sympatric Juvenile Bluegill And Yellow Perch In Mid-Temperate Prairie Lakes, Jeffrey C. Jolley, Mark A. Kaemingk, David W. Willis, Richard S. Holland

School of Natural Resources: Faculty Publications

Substantial mortality can occur in age-0 fish populations during their first year of life, especially in winter; this can potentially influence overall recruitment into the adult population. As such, we compared relative abundances between fall and spring catches of sympatric juvenile bluegill Lepomis macrochirus Rafinesque and yellow perch Perca flavescens (Mitchill) to evaluate the magnitude of overwinter mortality across locations (five lakes for two years) and through time (one lake for six years). In addition, we compared both quantile-quantile and increment plots, based on length-frequency histograms from fall- and spring-caught cohorts from 2004 to 2010, to determine if mortality was …

Evaluation Of The Effects Of September Hunting Seasons On Canada Geese In Nebraska, Scott R. Groepper, Mark P. Vrtiska, Larkin A. Powell, Scott E. Hygnstrom

School of Natural Resources: Faculty Publications

Populations of temperate-nesting Canada geese (Branta canadensis) have increased in Nebraska, USA, resulting in an increased number of nuisance and damage complaints. September hunting seasons were initiated in southeastern Nebraska in 2004 to reduce populations of Canada geese. We analyzed band recoveries from Canada geese banded in southeastern Nebraska during their hatch-year (HY) or after-hatch-year (AHY) to determine whether September hunting seasons affected survival, harvest, and recovery rates. Survival analyses revealed that HY geese had higher survival than AHY geese (SAHY = 0.696, 95% CI = 0.679–0.713; SHY = 0.896, 95% CI = 0.786–0.953) and September seasons did …

Rural Inhabitant Perceptions Of Sandhill Cranes In Wintering Areas Of Northern Mexico, Ingrid Barcelo, Juan Carlos Guzmán-Aranda, Felipe Chávez-Ramírez, Larkin A. Powell

School of Natural Resources: Faculty Publications

Trends in the mid-continent population of sandhill cranes (Grus canadensis) indicate that the species is increasing. A large proportion of this population winters in northern Mexico where possible conflicts between local inhabitants and cranes can occur. We conducted interviews of 40 rural inhabitants living near wetlands used by cranes in three Mexican states. All interviewees had knowledge of cranes and were capable of describing them. The arrival of cranes affected 43% of interviewees. The negative effects were mainly destroyed crops with a subsequent diminished production. Seventy percent of those affected implemented scare tactics to deter the birds, while others (15%) …

Tracking Large Carnivore Dispersal Using Isotopic Clues In Claws: An Application To Cougars Across The Great Plains, Viviane Hénaux, Larkin A. Powell, Keith A. Hobson, Clayton Kent Nielsen, Michelle A. Larue

School of Natural Resources: Faculty Publications

1. Cougar (Puma concolor) populations, like other large carnivores, have increased during recent decades and may be recolonizing their former ranges in Midwestern North America. The dispersal routes taken by these animals from established populations are unknown and insight into these movements would facilitate their conservation and management.

2. We inferred the origin and migration route of four dispersing cougars using stable hydrogen (δD) and carbon (δ¹³C) isotope values along one of their claws. We compared isotopic variations within claws to regional and large-scale isoscapes of δD and δ¹³C values in prey species. Using …

Integrating Info-Gap Decision Theory With Robust Population Management: A Case Study Using The Mountain Plover, Max Post Van Der Burg, Andrew J. Tyre

School of Natural Resources: Faculty Publications

Wildlife managers often make decisions under considerable uncertainty. In the most extreme case, a complete lack of data leads to uncertainty that is unquantifiable.Information-gap decision theory deals with assessing management decisions under extreme uncertainty, but it is not widely used in wildlife management. So too, robust population management methods were developed to deal with uncertainties in multiple-model parameters.However, the two methods have not, as yet, been used in tandem to assess population management decisions. We provide a novel combination of the robust population management approach for matrix models with the information-gap decision theory framework for making conservation decisions under extreme …

Confronting Socially Generated Uncertainty In Adaptive Management, Andrew J. Tyre, Sarah Michaels

School of Natural Resources: Faculty Publications

As more and more organizations with responsibility for natural resource management adopt adaptive management as the rubric in which they wish to operate, it becomes increasingly important to consider the sources of uncertainty inherent in their endeavors. Without recognizing that uncertainty originates both in the natural world and in human undertakings, efforts to manage adaptively at the least will prove frustrating and at the worst will prove damaging to the very natural resources that are the management targets. There will be more surprises and those surprises potentially may prove at the very least unwanted and at the worst devastating. We …

Evaluating The Efficacy Of Adaptive Management Approaches: Is There A Formula For Success?, Jamie E. Mcfadden, Tim L. Hiller, Andrew J. Tyre

School of Natural Resources: Faculty Publications

Within the field of natural-resources management, the application of adaptive management is appropriate for complex problems high in uncertainty. Adaptive management is becoming an increasingly popular management-decision tool within the scientific community and has developed into two primary schools of thought: the Resilience-Experimentalist School (with high emphasis on stakeholder involvement, resilience, and highly complex models) and the Decision-Theoretic School (which results in relatively simple models through emphasizing stakeholder involvement for identifying management objectives). Because of these differences, adaptive management plans implemented under each of these schools may yield varying levels of success. We evaluated peer-reviewed literature focused on incorporation of …

Lithobates Catesbeianus (American Bullfrog) Predation On Cliff Swallows, Mary Bomberger Brown, Charles R. Brown

School of Natural Resources: Faculty Publications

During a 25-year study of Cliff Swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, we observed Lithobates catesbeianus prey on, or attempt to prey on, Cliff Swallows. As we were mist-netting Cliff Swallows at a 10-nest colony on 7 July 1998, a L. catesbeianus attempted to eat a Cliff Swallow that was caught in the net.

Lifestyle Of Shellmound Builders In Brazil (Galley Proofs), Sabine Eggers, C. C. Petronilho, K. Brandt, J. Filippini, Karl J. Reinhard

School of Natural Resources: Faculty Publications

The contact of inland and coastal prehistoric groups in Brazil is believed to have been restricted to regions with no geographical barrier, as is the case in the Ribeira de Iguape valley. The inland osteological collection from the riverine shellmound Moraes (5800–4500 BP) represents a unique opportunity to test this assumption for this region. Despite cultural similarities between riverine and coastal shellmounds, important ecological and site distribution differences are expected to impact on lifestyle. The purpose of this study is thus to document and interpret health and lifestyle indicators in Moraes in comparison to coastal shellmound groups. Specifically we test …

Familiarity With Breeding Habitat Improves Daily Survival In Colonial Cliff Swallows, Charles R. Brown, Mary Bomberger Brown, Kathleen R. Brazeal

School of Natural Resources: Faculty Publications

One probable cost of dispersing to a new breeding habitat is unfamiliarity with local conditions such as the whereabouts of food or the habits of local predators, and consequently immigrants may have lower probabilities of survival than more experienced residents. Within a breeding season, estimated daily survival probabilities of cliff swallows, Petrochelidon pyrrhonota, at colonies in southwestern Nebraska, USA, were highest for birds that had always nested at the same site, followed by those for birds that had nested there in some (but not all) past years. Daily survival probabilities were lowest for birds that were naive immigrants to …

Phylogeographical Structure And Evolutionary History Of Two Buggy Creek Virus Lineages In The Western Great Plains Of North America, Abinash Padhi, Amy T. Moore, Mary Bomberger Brown, Jerome E. Foster, Martin Pfeffer, Kathryn P. Gaines, Valerie A. O'Brien, Stephanie A. Strickler, Allison E. Johnson, Charles R. Brown

School of Natural Resources: Faculty Publications

Buggy Creek virus (BCRV) is an unusual arbovirus within the western equine encephalitis complex of alphaviruses. Associated with cimicid swallow bugs (Oeciacus vicarius) as its vector and the cliff swallow (Petrochelidon pyrrhonota) and house sparrow (Passer domesticus) as its amplifying hosts, this virus is found primarily in the western Great Plains of North America at spatially discrete swallow nesting colonies. For 342 isolates collected in Oklahoma, Nebraska, Colorado, and North Dakota, from 1974 to 2007, we sequenced a 2076 bp region of the 26S subgenomic RNA structural glycoprotein coding region, and analyzed phylogenetic relationships, …

Terrapene Ornata (Ornate Box Turtle) Predation On Cliff Swallows, Mary Bomberger Brown, Charles R. Brown

School of Natural Resources: Faculty Publications

During a 25-year study of Cliff Swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, we observed Terrapene ornata prey, or attempt to prey, on swallows. On one occasion as large numbers of birds flushed and hit the net, the weight of the birds pulled the net down to ground level. One T. ornata, which was seen regularly at the colony, approached one adult Cliff Swallow that was very low in the net and killed it by biting and eating its head. After killing the bird, the turtle walked away carrying the head.

Experimental Inoculation Of House Sparrows (Passer Domesticus) With Buggy Creek Virus, Kathryn P. Huyvaert, Amy T. Moore, Nicholas A. Panella, Eric A. Edwards, Mary Bomberger Brown, Nicholas Komar, Charles R. Brown

School of Natural Resources: Faculty Publications

We performed experimental inoculations of house sparrows (Passer domesticus) with Buggy Creek virus (BCRV), a poorly known alphavirus (Togaviridae) vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) that is an ectoparasite of the cliff swallow (Petrochelidon pyrrhonota) and house sparrow. Viremias were detected by plaque assay in two of six birds on days 1–3 postinoculation; viremia was highest on day 2. Viral RNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in blood of six of 12 birds ranging from day 1 to day 15 postinoculation. Infectious BCRV was detected in …

Linking Flux Network Measurements To Continental Scale Simulations: Ecosystem Carbon Dioxide Exchange Capacity Under Non-Water-Stressed Conditions, Katherine B. Owen, John Tenhunen, Markus Reichstein, Quan Wang, Eva Falge, Ralf Geyer, Xiangming Xiaos, Paul Stoy, Christof Ammann, Altaf Arain, Marc Aubinet, Mika Aurela, Christian Bernhofer, Bogdan Chojnicki, Andre Granier, Thomas Gruenwald, Julian Hadley, Bernard Heinesch, David Hollinger, Alexander Knohl, Werner Kutsch, Annalea Lohila, Tilden Meyers, Eddy Moors, Christine Moureaux, Kim Pilegaard, Nobuko Saigusa, Shashi Verma, Timo Vesala, Chris Vogel

School of Natural Resources: Faculty Publications

This paper examines long-term eddy covariance data from 18 European and 17 North American and Asian forest, wetland, tundra, grassland, and cropland sites under nonwater- stressed conditions with an empirical rectangular hyperbolic light response model and a single layer two light-class carboxylase-based model. Relationships according to ecosystem functional type are demonstrated between empirical and physiological parameters, suggesting linkages between easily estimated parameters and those with greater potential for process interpretation. Relatively sparse documentation of leaf area index dynamics at flux tower sites is found to be a major difficulty in model inversion and flux interpretation. Therefore, a simplification of the …

Bird Movement Predicts Buggy Creek Virus Infection In Insect Vectors, Charles R. Brown, Mary Bomberger Brown, Amy T. Moore, Nicholas Komar

School of Natural Resources: Faculty Publications

Predicting the spatial foci of zoonotic diseases is a major challenge for epidemiologists and disease ecologists. Migratory birds are often thought to be responsible for introducing some aviozoonotic pathogens such as West Nile and avian influenza viruses to a local area, but most information on how bird movement correlates with virus prevalence is anecdotal or indirect. We report that the prevalence of Buggy Creek virus (BCRV) infection in cimicid swallow bugs (Oeciacus vicarius), the principal invertebrate vector for this virus, was directly associated with the likelihood of movement by cliff swallows (Petrochelidon pyrrhonota), an amplifying host …

Ecological Correlates Of Buggy Creek Virus Infection In Oeciacus Vicarius, Southwestern Nebraska, 2004, Amy T. Moore, Eric A. Edwards, Mary Bomberger Brown, Nicholas Komar, Charles R. Brown

School of Natural Resources: Faculty Publications

Buggy Creek virus (family Togaviridae, genus Alphavirus, BCRV) is an alphavirus within the western equine encephalitis virus complex whose primary vector is the swallow bug, Oeciacus vicarius Horvath (Hemiptera: Cimicidae), an ectoparasite of the colonially nesting cliff swallow, Petrochelidon pyrrhonota, that is also a frequent host for the virus.We investigated ecological correlates of BCRV infection in 100-bug pools at 14 different swallow colony sites in southwestern Nebraska from summer 2004, by using plaque assay on Vero cells to identify cytopathic virus and reverse transcription-polymerase chain reaction to identify noncytopathic viral RNA. We found 26.7% of swallow bug pools …

Ecophysiology Of Two Native Invasive Woody Species And Two Dominant Warm-Season Grasses In The Semiarid Grasslands Of The Nebraska Sandhills, Kathleen D. Eggemeyer, Tala Awada, David A. Wedin, F. Edwin Harvey, Xinhua Zhou

School of Natural Resources: Faculty Publications

Populations of Pinus ponderosa and Juniperus virginiana are expanding into semiarid Sandhills grasslands in Nebraska. To evaluate the physiological basis of their success, we measured the seasonal course of leaf gas exchange, plant water status, and carbon isotope discrimination in these two native trees and two native C₄ grasses (Schizachyrium scoparium and Panicum virgatum). Compared to the trees, grasses had higher net photosynthetic rates (A_net) and water use efficiency (WUE) and more negative predawn and midday water potentials (Ψ) in June and July. While leaf Ψ and rates of leaf gas exchange declined for all …

Prevalence And Serovars Of Salmonella In The Feces Of Free-Ranging White-Tailed Deer (Odocoileus Virginianus) In Nebraska, David G. Renter, David P. Gnad, Jan M. Sargeant, Scott E. Hygnstrom

School of Natural Resources: Faculty Publications

To determine the prevalence and serovars of Salmonella in free-ranging deer, we cultured feces from white-tailed deer (Odocoileus virginianus) harvested by hunters during a regular firearm season in southeastern Nebraska (USA). We recovered Salmonella from 5 (1%; 95% confidence interval: 0.37– 2.20%) of 500 samples and identified four different Salmonella enterica serovars [Litchfield (1), Dessau (1), Infantis (2), and Enteritidis (1)]. Although the prevalence of Salmonella in free-ranging deer appears to be low, the serovars recovered are known to be pathogenic to humans and animals.

Optimizing Allocation Of Monitoring Effort Under Economic And Observational Constraints, Scott A. Field, Andrew J. Tyre, Hugh P. Possingham

School of Natural Resources: Faculty Publications

Efforts to design monitoring regimes capable of detecting population trends can be thwarted by observational and economic constraints inherent to most biological surveys. Ensuring that limited resources are allocated efficiently requires evaluation of statistical power for alternative survey designs. We simulated the process of data collection on a landscape, where we initiated declines over 3 sample periods in species of varying prevalence and detectability. Changing occupancy levels were estimated using a technique that accounted for effects of false-negative errors on survey data. Declines were identified within a frequentist statistical framework, but the significance level was set at an optimal level …

Escherichia Coli O157:H7 In Free-Ranging Deer In Nebraska, David G. Renter, Jan M. Sargeant, Scott E. Hygnstrom, Jeff D. Hoffmann, Jerry R. Gillespie

School of Natural Resources: Faculty Publications

In order to determine the prevalence and distribution of the human pathogen, Escherichia coli O157:H7, in free-ranging deer, hunters were asked to collect and submit fecal samples from deer harvested during a regular firearm season (14–22 November 1998). Prior to the season, 47% of the hunters with permits in the southeastern Nebraska (USA) study area indicated a willingness to participate in the study. Approximately 25% of successful hunters in the area submitted deer fecal samples. Escherichia coli O157:H7 was cultured from four (0.25%) of 1,608 total samples submitted. All of the fecal samples that were properly identified (1,426) and all …

Extralimital Records Of The Mexican Free-Tailed Bat (Tadarida Brasilensis Mexicana) In The Central United States And Their Biological Significance, Hugh H. Genoways, Patricia W. Freeman, Cary Grell

School of Natural Resources: Faculty Publications

Two new records of Tadarida brasiliensis mexicana are reported from Nebraska. The literature records of this taxon from the central United States are summarized. In this region of North America, these bats occupy a “natal range” where the species carries on regular reproductive activities and the populations are relatively stable, including California, Arizona, New Mexico, Texas, and Oklahoma. To the north of the natal range of T. b. mexicana is a “pioneering zone” where, under favorable conditions, the species is capable of reproducing and conducting its normal activities. The pioneering zone of the Mexican free-tailed bat includes Barber and Comanche …

Shifting Distributional Patterns Of Mammals In Nebraska, Russell A. Benedict, Hugh H. Genoways, Patricia W. Freeman

School of Natural Resources: Faculty Publications

New distributional records are presented for 20 species of mammals in Nebraska. The majority of these records appear to represent changes in geographic distribution rather than just better sampling in poorly known areas. One group of mammals, including the opossum, northern myotis, evening bat, red bat, woodchuck, white-footed mouse, and gray fox, is expanding westward, probably in response to increasing woodlands along river systems. Another group, including the meadow vole, masked shrew, and least weasel, is expanding southward, possibly in response to new prey species and changing microclimates. The eastern woodrat appears to be expanding northward in eastern Nebraska. The …

Breeding Season Demography And Movements Of Eastern Towhees At The Savannah River Site, South Carolina, David G. Krementz, Larkin A. Powell

School of Natural Resources: Faculty Publications

The Eastern Towhee (Pipilo erythrophthalmus) has undergone population declines across much of its range, especially in New England. Despite being a widespread and, at one time, a common species, relatively little is known about its natural history, ecology, or demographics. We conducted baseline research on Eastern Towhees at the Savannah River Site, South Carolina, in 1995 and 1996 to estimate breeding season survival rates, nest success rates, breeding densities, and daily movements. We also were interested in whether towhees had differences in survival and movement rates between young and mature managed pine stands. We found that survival rates during the …

The Relative Importance Of Patch Area And Perimeter–Area Ratio To Grassland Breeding Birds, Christopher J. Helzer, Dennis E. Jelinski

School of Natural Resources: Faculty Publications

Habitat fragmentation has been implicated as a major cause of population decline in grassland birds. We tested the hypothesis that a combination of area and shape determines the use of grassland patches by breeding birds. We compared both species richness and individual species presence in 45 wet meadow grasslands in the floodplain of the central Platte River, Nebraska. Bird data were collected through the use of belt transects and supplemented by walking and listening outside transects. Our data supported our primary hypothesis that perimeter–area ratio, which reflects both the area and shape of a patch, is the strongest predictor of …

Survey Of Mollusks Of The Niobrara River: Final Report, Patricia W. Freeman, Keith Perkins

School of Natural Resources: Faculty Publications

We surveyed the mollusks of the Niobrara River in Nebraska from 1992–1996. We found two species of unionid clams and ten species of snails that either must live in water or near water. Both clams and snails are poorly sampled in the state, however we attribute the low number of species of unionid clams in the Niobrara to its cold, fast flow and rocky bottom. In contrast, the Platte River is slower moving with a muddy bottom and has at least 11 species of unionid clams. Each species has been mapped with latitude/longitude coordinates. Specimens have been curated and are …

Geological Field Guide To The Cedar Point Biological Station, Keith County, Nebraska, Robert F. Diffendal Jr., Roger K. Pabian

School of Natural Resources: Faculty Publications

This field guide was produced by staff members of the Conservation and Survey Division of the University of Nebraska originally in 1979 at the request of Dr. Brent Nickol, former Director of the Cedar Point Biological Station. It is an introduction to the geologic history and paleoecology of the Cedar Point area intended for students, staff, and other persons using the camp. This revision has been made some 15 years after the first version to reflect changes in ideas resulting from new data collected during that time.

Users of this guide should take care when studying the rock exposures described …

Survey Of Mollusks Of The Platte River: Final Report, Patricia W. Freeman, Keith Perkins

School of Natural Resources: Faculty Publications

A survey of the mollusks of the Platte River was carried out during the summers of 1990 and 1991. With the exception of the Big Bend Reach of the River in Dawson, Buffalo and Hall counties, no unionids (mussels) were found in the main channel of the river. We found 11 species of mussels along the river and 16 species of snails at 49 different sites from east to west across the state. We found the Asiatic clam, a known, non-native, pest species, for the first time in the state placing it several hundred miles west of the present eastern …