Population Biology Commons^™

Potential For Climate Induced Methane Hydrate Dissociation, Graham Macwilliams

Pomona Senior Theses

Methane hydrates are frozen deposits of methane and water found in high pressure or low temperature sediments. When these deposits destabilize, large quantities of methane can be emitted into the atmosphere. This is significant to climate change because methane has 25 times more greenhouse gas potential than Carbon Dioxide. Worldwide, it is estimated there are between 2500 and 10000 gigatons of methane stored in hydrate deposits. This represents more carbon than all fossil fuels on Earth. It is estimated that between 200 and 2000 gigatons of methane are stored in hydrates in Arctic waters acutely vulnerable to greenhouse warming. Over …

Estimating Exploitation Rates In The Alabama Red Snapper Fishery Using A High-Reward Tag–Recapture Approach, Dana K. Sackett, Mattgew Catalano, J. Marcus Drymon, Sean P. Powers, Mark Albins

University Faculty and Staff Publications

Accurate estimates of exploitation are essential to managing an exploited fishery. However, these estimates are often dependent on the area and vulnerable sizes of fish considered in a study. High-reward tagging studies offer a simple and direct approach to estimating exploitation rates at these various scales and in examining how model parameters impact exploitation rate estimates. These methods can ultimately provide a better understanding of the spatial dynamics of exploitation at smaller local and regional scales within a fishery—a measure often needed for more site-attached species, such as the Red Snapper Lutjanus campechanus. We used this approach to tag 724 …

Comparison Of Three Benthic Macroinvertebrate Passive Sampling Devices For Non-Wadeable Streams, Kelsey A. Laymon

College of Graduate Studies: Theses & Dissertations

Rivers and streams provide essential ecosystem services to the degree that the monitoring and maintenance of these systems becomes imperative. Biomonitoring provides managers and policymakers with the tools to make informed decisions, and macroinvertebrates are often the object of biomonitoring because they are ubiquitous in most systems and are known to be good indicators of water quality. However, methods for sampling macroinvertebrates in non-wadeable streams (i.e., large rivers) have not been standardized across states and regions and an established method for macroinvertebrate biomonitoring in large rivers of Georgia is not currently available. My study compared macroinvertebrates collected with three types …

Characterizing The Complex Relationship Between The Brown Widow Spider And Its Bacterial Endosymbiont, Wolbachia, Emily Knight

College of Graduate Studies: Theses & Dissertations

The brown widow spider, Latrodectus geometricus (C. L. Koch 1841), has been found to harbor the maternally inherited bacterial endosymbiont Wolbachia pipientis (Hertig and Wolbach 1924), but endosymbiont infection frequency varies widely among Southeastern US populations. Wolbachia is known to manipulate the reproduction of its hosts through male feminization, parthenogenesis, male killing, and cytoplasmic incompatibility. In brown widows, Wolbachia does not alter sex ratios, but any other effects the symbiont has on the spider are unknown. In my first chapter, I assess if there is linkage between Wolbachia infection and maternally inherited mitochondrial DNA (mtDNA) in three brown widow populations. …

Foraging Ecology Of A Winter Bird Community In Southeastern Georgia, Rachel E. Mowbray

College of Graduate Studies: Theses & Dissertations

Classical views on community structure emphasized deterministic processes and the importance of competition in shaping communities. However, the processes responsible for shaping avian communities remain controversial. Attempts to understand distributions and abundances of species are complicated by the fact that birds are highly mobile. Many species migrate biannually between summer breeding grounds and wintering grounds. The goal of this study was to test four hypotheses that attempt to explain how migratory species integrate into resident assemblages of birds (Empty-Niche Hypothesis, Competitive-Exclusion Hypothesis, Niche-Partitioning Hypothesis, and Generalist-Migrant Hypothesis). I collected data on birds foraging during the winter of 2017-2018 in Magnolia …

Compression And Relaxation Of Fishing Effort In Response To Changes In Length Of Fishing Season For Red Snapper (Lutjanus Campechanus) In The Northern Gulf Of Mexico, Sean P. Powers, Kevin Anson

University Faculty and Staff Publications

A standard method used by fisheries managers to decrease catch and effort is to shorten the length of a fishery; however, data on recreational angler response to this simple approach are surprisingly lacking. We assessed the effect of variable season length on daily fishing effort, measured by using numbers of boat launches per day, anglers per boat, and anglers per day from video observations, in the recreational sector of the federal fishery for red snapper (Lutjanus campechanus) in coastal Alabama. From 2012 through 2017, season length fluctuated from 3 to 40 d. Daily effort, measured by using mean number of …

The National Wildlife Strike Database: A Scientific Foundation To Enhance Aviation Safety, Richard A. Dolbeer, Michael J. Begier, John R. Weller

United States Department of Agriculture Wildlife Services: Staff Publications

The U.S. Federal Aviation Administration's (FAA) National Wildlife Strike Database (NWSD) documents reports of civil aircraft collisions with wildlife in USA. The NWSD has been managed by the Wildlife Services Program of the U.S. Department of Agriculture through an interagency agreement since its inception. Although the NWSD includes about 170,000 reports of civil aircraft collisions with wildlife (97% birds) from 1990-2015 (14,000 in 2015), the overriding focus has been the quality control of data entered for over 90 variables ranging from species and numbers of wildlife struck, location and time of day, phase and height of flight, aircraft type, components …

To Live And Fly In La: Using Bird Strike And Management Program Information To Improve Safety At Airports In The Los Angeles Basin, Todd J. Pitlik, Elizabeth Hermann, Eric Peralta, Brian E. Washburn

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife-aircraft collisions (wildlife strikes) pose a serious safety risk to aircraft. Wildlife strikes can be evaluated at different levels, include efforts to examine these problems at the national, regional, or state level, or for an individual airport. Similarly, wildlife strikes involving individual wildlife species or guilds can be examined at varying scales. Although wildlife strike analyses at the national, regional, or species/guild level are valuable, airport-specific analyses are essential for the effective implementation and evaluation of integrated wildlife damage management programs as these actions are conducted at the airport level. The species that present hazards to safe aircraft operations varies …

Modeling Canopy Effect In The Great Lakes Cladophora Model, Ankita Bakshi

Dissertations, Master's Theses and Master's Reports

Cladophora glomerata is a filamentous green alga native to the Great Lakes. However, its nuisance growth in phosphorus rich waters negatively affects the lakes’ aesthetic and water quality. The Great Lakes Cladophora Model (GLCM) v1, developed in 1982, was the first mechanistic model to simulate Cladophora growth basing phosphorus availability and environmental conditions followed by Cladophora Growth Model and GLCM v2. In this study, the light and temperature mediation factors for Cladophora net growth are revised as a necessary step prior to the development of a self-shading algorithm. The concept of a fixed-value, maximum achievable biomass (carrying capacity) employed in …

Searching The Internet To Estimate Deer Population Trends In The U.S., California, And Connecticut, G. Webb

Faculty Research, Scholarly, and Creative Activity

Information for decision making may be publicly available, but costly to obtain. As an experiment in environmental scanning, the internet was searched on a daily basis over several years to collect information and provide analysis related to decisions on deer management. The process discovered that, contrary to common assumptions, the U.S. deer population has apparently been falling since about the year 2000 based on analysis of available state data that had not been aggregated. In some cases, state population estimates were created using standard procedures on available data. Results indicate that differences in survey methods appear to be relatively constant …

Lewis’S Woodpecker Nest Success And Habitat Selection In Cottonwood Floodplain Versus Burned Conifer Forests, William M. Blake

Graduate Student Theses, Dissertations, & Professional Papers

Breeding habitat selection influences reproductive outcomes. Habitat selection may be adaptive and benefit populations, but it can also be maladaptive with negative consequences for populations. Understanding habitat selection and its influence on reproductive success, especially in species of concern, is critical for effective management. Lewis’s Woodpecker (Melanerpes lewis) is a Species of Concern that has experienced national population declines. We studied its abundance and reproductive success in two commonly selected breeding forest types (i.e., cottonwood floodplain and mixed-conifer burned), and nest-site characteristics (nest availability, food availability, and vegetation attributes) that have the potential to yield strong differences in …

Wild Horse Country: The History, Myth, And Future Of The Mustang, Seth J. Dettenmaier

Human–Wildlife Interactions

No abstract provided.

Conservation Of Threatened Canada-Usa Trans-Border Grizzly Bears Linked To Comprehensive Conflict Reduction, Michael F. Proctor, Wayne F. Kasworm, Kimberly M. Annis, A. Grant Machutchon, Justin E. Teisberg, Thomas G. Radandt, Chris Servheen

Human–Wildlife Interactions

Mortality resulting from human–wildlife conflicts affects wildlife populations globally. Since 2004, we have been researching conservation issues and implementing a comprehensive program to reduce human–bear conflicts (Ursus spp.; HBC) for 3 small, fragmented, and threatened grizzly bear (U. arctos) populations in the trans-border region of southwest Canada and northwest USA. We explored the temporal and spatial patterns of conflict mortality and found that HBC contributed significantly to the threatened status of these populations by causing decline, fragmentation, and decreased habitat effectiveness. Our program to reduce HBCs primarily included strategic private lands purchased to reduce human density in …

Life On The Edge: Risk Of Predation Drives Selection Of Habitat And Survival Of Neonates In Endangered Sierra Nevada Bighorn Sheep, Shannon Forshee

Graduate Student Theses, Dissertations, & Professional Papers

Long-term viability of endangered populations requires development of effective management strategies that target the population vital rate with the highest potential to influence population trajectories. When adult survival is high and stable, juvenile recruitment is the vital rate with the greatest potential to improve population trajectories. For my thesis I examined how lactating Sierra Nevada Bighorn sheep (Ovis Canadensis sierra) balance forage and predation risk during the neonatal period. I first identified resource selection strategies employed by lactating females to promote survival of neonates and then determined the primary factors affecting survival of neonates. I found lactating females selected for …

Apparent Survival Of Snowy Plovers Varies Seasonally, Nora C. Papian

Cal Poly Humboldt theses and projects

Survival is an important vital rate that contributes to population viability, but is infrequently monitored and studied, especially compared to productivity. Furthermore, factors that limit survival and the relative effect on survival are often unknown. I used mark-resight observations of a small (~350) population of threatened Snowy Plovers (Charadrius nivosus nivosus) to quantify seasonal and annual variation in survival and movement between three coastal locations across ~70 km in Humboldt County, California. The return of individuals to non-breeding flocks at three locations was high between years (75-81%). Movement between three locations varied greatly, although most (n = 137) …

Evaluating Habitat Selection Models To Improve Site Selection In A Population Monitoring Program For Townsend's Big-Eared Bats (Corynorhinus Townsendii), Katrina J. Smith

Cal Poly Humboldt theses and projects

Winter roost (hibernacula) surveys offer a unique opportunity to monitor Townsend’s big-eared bats (Corynorhinus townsendii) while the population is generally closed, using a simple count method to census the population. Existing knowledge of C. townsendii hibernacula facilitates long-term population trend analysis but improving the accuracy of trend estimates requires identification of additional hibernacula to increase the proportion of the population monitored. Over 800 caves are known within Lava Beds National Monument; 322 of these have never been surveyed in the winter and could potentially hold a substantial portion of the C. townsendii population currently missing from the annual …

Molecular And Evolutionary Analysis Of Cyanobacterial Taxonomic Methods, Chelsea Denise Villanueva

UNF Graduate Theses and Dissertations

Cyanobacteria are a group of photo-oxygenic bacteria found in nearly every ecosystem, but much cyanobacterial diversity, in various habitats, has yet to be explored. Cyanobacteria are often conspicuous components of photosynthetic flora, providing significant carbon and nitrogen inputs to surrounding systems. As possible primary colonizers of stone substrates not native to this region, cyanobacteria isolated from headstones may provide biogeographically informative data. An exploratory study of lichen-dominated microbial consortia, growing on headstones, was conducted to isolate and identify novel microaerophytic cyanobacteria, and resulted in the establishment of four novel cyanobacterial taxa. Phylogenetic analyses of photobionts in one tripartite lichen revealed …

Population-Level Plasticity In Foraging Behavior Of Western Gulls (Larus Occidentalis), Scott A. Shaffer, Sue Cockerham, Pete Warzybok, Russell Bradley, Jaime Jahncke, Corey Clatterbuck, Magali Lucia, Jennifer Jelincic, Anne Cassell, Emma Kelsey, Josh Adams

Faculty Publications, Biological Sciences

Background Plasticity in foraging behavior among individuals, or across populations may reduce competition. As a generalist carnivore, western gulls (Larus occidentalis) consume a wide range of marine and terrestrial foods. However, the foraging patterns and habitat selection (ocean or land) of western gulls is not well understood, despite their ubiquity in coastal California. Here, we used GPS loggers to compare the foraging behavior and habitat use of western gulls breeding at two island colonies in central California. Results Gulls from offshore Southeast Farallon Island (SFI; n = 41 gulls) conducted more oceanic trips (n = 90) of …

Of Rats And Men, Thomas S. Walsh

Capstones

This capstone is a data-driven investigation into New York City's rat problem. By using publicly available government data to map rat activity in NYC, I identified several socio-economic variables that correlate with rat populations at the community district, borough, and city-scale. I used these findings (mainly that rat problems are linked to lower incomes) as the basis of an investigation, which includes interviews with residents, experts, and city officials. Prof. Bobby Corrigan, urban rodentologist and formerly with the NYC Department of Health criticizes the city's efforts for the first time on the record.

https://thomasseiyawalsh.wixsite.com/ratstone

Seasonal Resource Selection And Habitat Treatment Use By A Fringe Population Of Greater Sage-Grouse, Rhett Boswell

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Movement and habitat selection by Greater Sage-grouse (Centrocercus uropasianus) is of great interest to wildlife managers tasked with applying conservation measures for this iconic western species. Current technology has created small and lightweight GPS (Global Positioning Systems) transmitters that can be attached to sage-grouse. Using GIS software and statistical programs such as Program R, land managers can analyze GPS location data to assess how sage-grouse are geospatially interacting with their habitats. Within the Panguitch Sage-Grouse Management Area (SGMA) thousands of acres of land have been restored or manipulated to enhance sage-grouse habitat; this usually involves removal of pinyon pine …