Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
Channel Catfish Population Dynamics, Abundance Estimates, And Short-Term Trends In The Platte River, Nebraska, Aaron J. Blank
Channel Catfish Population Dynamics, Abundance Estimates, And Short-Term Trends In The Platte River, Nebraska, Aaron J. Blank
School of Natural Resources: Dissertations, Theses, and Student Research
Fishing for channel catfish (Ictalurus punctatus) is popular in Nebraska and channel catfish are the most sought after fish species in the Platte River. Anglers on the Platte River are also harvest oriented. Little is known about the effects anglers have on channel catfish population dynamics in the lower Platte River. The goal of this study was to determine if there were effects of angling on channel catfish at two high use fishing areas in the lower Platte River. My first objective was to evaluate differences in relative abundance, size structure, condition, age structure, growth, and mortality between …
Predictors Of Insect Diversity And Abundance In A Fragmented Tallgrass Prairie Ecosystem, Kody M. Unstad
Predictors Of Insect Diversity And Abundance In A Fragmented Tallgrass Prairie Ecosystem, Kody M. Unstad
School of Natural Resources: Dissertations, Theses, and Student Research
Despite providing many services, the tallgrass prairie and its ecological community is one of the most endangered ecosystems in North America. Remaining habitat exists as remnants in a highly-fragmented landscape. To make informed conservation decisions we need to better understand the effects of this fragmentation. Using the ecologically important insect groups, ants and ground beetles, this study provides baseline data on the biological diversity of southeast Nebraska prairies and investigates what management, landscape, and habitat characteristics affect them. Pitfall trap sampling was conducted in 23 tallgrass remnants scattered throughout the Southeast Prairies Biologically Unique Landscape in 2010 and 2011. Multi-model …
Estimating The Abundance Of Long-Billed Curlews In Nebraska, Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen
Estimating The Abundance Of Long-Billed Curlews In Nebraska, Cory J. Gregory, Stephen J. Dinsmore, Larkin A. Powell, Joel G. Jorgensen
School of Natural Resources: Faculty Publications
Long-billed Curlews (Numenius americanus) are shorebirds of high conservation concern in North America. Populations have declined in the last 150 yr primarily due to habitat loss and conversion. We conducted a 2-yr study to estimate the density and statewide abundance of breeding Long-billed Curlews in Nebraska during 2008 and 2009. Surveys were conducted during the prenesting period in April when Long-billed Curlews were likely to be detected. We used a simple random sample of roadside survey routes (N = 39), each consisting of 40 5-min point-counts at 800-m intervals. We modeled detection probability and found that wind …
Spatial Variation In Rna:Dna Ratios Of Diporeia Spp. In The Great Lakes Region, Daniel J. Ryan, Maria S. Sepúlveda, Thomas F. Nalepa, Tomas O. Höök
Spatial Variation In Rna:Dna Ratios Of Diporeia Spp. In The Great Lakes Region, Daniel J. Ryan, Maria S. Sepúlveda, Thomas F. Nalepa, Tomas O. Höök
United States Department of Commerce: Staff Publications
Over the past two decades, Diporeia in all of the Laurentian Great Lakes, except Superior, have declined dramatically. These declines have seemingly coincided with expansion of invasive Dreissena polymorpha and D. bugensis, however the exact mechanisms underlying decreasing Diporeia densities are obscure. We explored the use of RNA:DNA (R/D) ratios as a conditional index for Diporeia by experimentally demonstrating that Diporeia R/D responds to periods of starvation. Moreover, during 2008–2009 we collected Diporeia from throughout the Great Lakes and Cayuga Lake (New York, USA), and used R/D ratios to index condition of these in situ collected animals. We evaluated …