Population Biology Commons^™

Spatial Genetic Structure And Local Adaptation Within And Among Foxtail Pine (Pinus Balfouriana Subsp. Balfouriana) Populations Located In The Klamath Mountains, California, Rebecca D. Piri

Theses and Dissertations

Foxtail pine (Pinus balfouriana) is a subalpine conifer endemic to California, notably separated into two disjunct subspecies. Previous studies have described the northern subspecies,Pinus balfouriana subsp. balfouriana,as having an uncommonly high level of genetic differentiation and no discernible spatial patterns in phenotypic variation. This study seeks to characterize the spatial genetic structure and patterns of selection of the northern subspecies (Pinus balfouriana subsp. balfouriana) using genome-wide data and to identify the influence of ecology and environment on the unique genetic patterns. I show that genetic differentiation among populations is much less than previously estimated …

Influence Of Environmental Features On Spermatophore Placement In Spotted Salamanders (Ambystoma Maculatum), Megan A. Kuechle

Theses and Dissertations

Successful reproduction in salamanders is driven by behavioral, environmental, and temporal interactions among adults. While much of our understanding of salamander mating systems is based upon either courtship behavior of both sexes or aspects of female choice, the decisions made by males regarding where to place spermatophores is much less quantified. In this study, we mapped male spermatophore placement in the spotted salamander (Ambystoma maculatum) with respect to ecological and spatial locations within a vernal pool complex in Charles City County, Virginia. The overall goal was to use the spatial and ecological placement of spermatophores to determine if …

Assessing Individual And Population-Level Effects Of Anticoagulant Rodenticides On Wildlife, Niamh Quinn

Human–Wildlife Interactions

Anticoagulant rodenticides have been detected in many species of wildlife worldwide. However, the origins, exposure pathways, and effects of this exposure are not well understood. To accurately characterize the risks to wildlife from rodenticide use, better information is needed regarding the proportion of populations being exposed, what proportion of individuals in populations are affected, and in what ways. The relationship between anticoagulant rodenticide concentrations found in wildlife and the rate of mortality or illness have been the subjects of much research. Residue levels observed in liver and whole-body analyses vary and overlap extensively among apparently healthy asymptomatic individuals and sublethal …

Effectiveness Of Snap And A24-Automated Traps And Broadcast Anticoagulant Bait In Suppressing Commensal Rodents In Hawaii, Aaron B. Shiels, Tyler Bogardus, Jobriath Rohrer, Kapua Kawelo

Human–Wildlife Interactions

Commensal rodents (invasive rats, Rattus spp.; house mice, Mus musculus) are well established globally. They threaten human health by disease transfer and impact economies by causing agricultural damage. On island landscapes, they are frequent predators of native species and affect biodiversity. To provide managers with better information regarding methods to suppress commensal rodent populations in remote island forests, in 2016 we evaluated the effectiveness of continuous rat trapping using snap-traps, Goodnature^®A24 self-resetting rat traps, and a 1-time (2-application) hand-broadcast of anticoagulant rodenticide bait pellets (Diphacinone-50) applied at 13.8 kg/ha per application in a 5-ha forest on Oahu, …

Similar Breeding Success Of Bearded Vultures In Disturbed And Undisturbed Areas Shows Evidence Of Adaptation Capabilities, Vincent Comor, Nicolas Poulin, Mathieu Boos

Human–Wildlife Interactions

Retraction notice: We have been informed that because of logistical reasons the authors of Comor et al. (2019) were unable able to provide the answers requested by Duriez et al. (2020) regarding the protocols, the quantitative data, or the small and unbalanced sample sizes. At the authors' request, the article by Comor et al. published in Human–Wildlife Interactions 13(3) has been retracted.

Human activities are usually considered as disturbing factors impeding the breeding success of wild animals. Protected areas can then be set up to restrict such activities aiming to improve wildlife’s breeding success and conservation. To test for the …

Using Environmental Dna And Occupancy Modeling To Estimate Rangewide Metapopulation Dynamics Of The Endangered Tidewater Goby Eucyclogobius Spp., Chad M. Martel

Cal Poly Humboldt theses and projects

Conservation of species is most effective when metapopulation dynamics are well understood and incorporated into management plans, allowing managers to target conservation efforts where they will be most effective. The development of environmental DNA (eDNA) methods provides an efficient and highly sensitive approach to generate presence and absence data needed to elucidate metapopulation dynamics. Combining sample detection histories from eDNA surveys with occupancy models that account for non-detection can offer unbiased estimates of rangewide metapopulation dynamics. However, traditional occupancy models do not allow direct evaluation of the drivers of site occupancy, extinction, and colonization. Herein, I utilize a novel dynamic …

Tiger Sharks Eat Songbirds: Scavenging A Windfall Of Nutrients From The Sky, J. Marcus Drymon, K. Feldheim, A. M.V. Fournier, E. A. Seubert, A. E. Jefferson, A. M. Kroetz, Sean P. Powers

University Faculty and Staff Publications

No abstract provided.

A Multi-Scale Analysis Of Jaguar (Panthera Onca) And Puma (Puma Concolor) Habitat Selection And Conservation In The Narrowest Section Of Panama., Kimberly A. Craighead

Antioch University Dissertations & Theses

Over the past two centuries, large terrestrial carnivores have suffered extreme population declines and range contractions resulting from the synergistic anthropogenic threats of land-use change and indirect effects of climate change. In Panama, rapid land use conversion coupled with climate change is predicted to negatively impact jaguar (Panthera onca) and puma (Puma concolor). This dissertation examined the environmental variables and scales influencing jaguar and puma habitat selection by season (annual, wet, and dry), using multi-scale optimized habitat suitability models and a machine-learning algorithm (Random Forests), in the narrowest section of Panama. The models derived from the data of an intensive …

Contribution Of Juvenile Estuarine Residency In A Bar-Built Estuary To Recruitment Of Chinook Salmon (Oncorhynchus Tshawytscha), Emily Katherine Chen

Cal Poly Humboldt theses and projects

Estuaries are commonly touted as nurseries for out-migrating salmonids, providing higher prey availability than streams, a physiological transition zone, and refugee from marine predators. Yet the diversity of estuaries makes it difficult to generalize the effect they have on salmonid recruitment. In bar-built estuaries, sandbars form at the mouth of rivers during periods of low flow, closing access to the ocean and disrupting outmigration. In this thesis, I evaluated how residency in a bar-built estuary affects the growth, survival, and ultimately recruitment of Chinook salmon (Oncorhynchus tshawytscha) in Redwood Creek, California. I conducted a mark-recapture experiment on out-migrating …

Testing For Cryptic Diversity And Inference Of Population Structure In The Cosmopolitan Hoplonemertean Emplectonema Gracile (Nemertea), Paul L. Delaney Iv

Theses and Dissertations

Emplectonema gracile (Johnston 1837) is a hoplonemertean of marine intertidal hard-bottom communities and is distributed throughout the Northern Hemisphere. Although possessing a planktonic larval stage in its life history, the range of such cosmopolitan marine invertebrate species is often explained by cryptic speciation and anthropogenic transport. The purpose of this study is to test for possible cryptic species using mtDNA markers (COI and 16S rDNA) and to investigate population structure in E. gracile over a portion of its geographic range using mtDNA markers and ddRADseq nuclear SNP data. The results of both phylogenetic- and tree-based species delimitation revealed that E. …

Impact Of Seasonal And Host-Related Factors On The Intestinal Microbiome And Cestode Community Of Sorex Cinereus And Sorex Monticola, Katelyn D. Cranmer

College of Graduate Studies: Theses & Dissertations

The intestinal microbiome of mammals plays a significant role in host health and response to environmental stimuli and can include both beneficial native bacteria as well as parasitic worms. In this study, I examined the intestinal cestode and bacterial communities of two closely related species of shrew, Sorex monticola and Sorex cinereus, over a six month period in 2016. Specimens were collected approximately every three weeks from May to October from the Sangre de Cristo Mountains in Cowles, New Mexico. A total of 79 shrews were prepared with the gastrointestinal tracts removed and flash-frozen in liquid nitrogen. An additional …

Population Health Of Spotted Salamanders (Ambystoma Maculatum) In Created Vernal Pools: An Integrative Approach, Alice R. Millikin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Habitat creation is an important tool for conservation to counteract habitat loss and degradation. Vernal pools are susceptible to destruction due to limited detection, protection, and regulation. These wetlands provide fishless breeding habitat for many amphibian species including spotted salamanders (Ambystoma maculatum) in eastern North America. Determining whether created vernal pool habitat is successful is often determined by demographic data of colonizing populations. I suggest that hormone levels, population genetics, and disease prevalence can improve our understanding of population health in created habitat. The goal of this dissertation was to assess the health of spotted salamander larvae in …

Tiger Sharks Eat Songbirds: Reply, J. Marcus Drymon, K. Feldheim, A. M.V. Fournier, A. E. Jefferson, A. M. Kroetz, Sean P. Powers, E. A. Seubert

University Faculty and Staff Publications

In response to our recent paper (Drymon et al. 2019), Yosef (2019) questions the mechanism proposed to explain interactions between tiger sharks (Galeocerdo cuvier) and migratory songbirds, while offering an alternative mechanism based on a single observation. We appreciate the comments from Yosef and the opportunity to respond.

Fall Field Report, August - November 2019, W. Ross Silcock

Nebraska Bird Review

By far the most striking feature of this fall’s report is the large number of lingering migrants, a trend that is continuing and apparently increasing, especially among passerines. Editor Jan Paseka counted 17 uses of the word “tardy” and 43 of “late” or “latest”. It is tempting to relate this to the warmer environment and resulting increased availability of food items at higher latitudes and later dates than in previous years. A sad note: a startling occurrence in Gering, Scotts Bluff 20 Aug was described by Marie Smith: “We had a huge hailstorm around 10:30. The hail was probably pea …

A Bioeconomic Model For The Optimization Of Local Canine Rabies Control, Aaron Anderson, Johann Kotze, Stephanie A. Shwiff, Brody Hatch, Chris Slootmaker, Anne Conan, Darryn Knobel, Louis H. Nel

United States Department of Agriculture Wildlife Services: Staff Publications

We present a new modeling tool that can be used to maximize the impact of canine rabies management resources that are available at the local level. The model is accessible through a web-based interface that allows for flexibility in the management strategies that can be investigated. Rabies vaccination, sterilization, chemo-contraception, and euthanasia can be specified and limited to specific demographic groups. Additionally, we allowed for considerable complexity in the specification of management costs. In many areas, the costs of contacting additional dogs increases as management effort increases, and this can have important strategic implications. We illustrated the application of the …

Population And Breeding Ecology Of Sagebrush Steppe Songbirds, Kayla Ann Ruth

Graduate Student Theses, Dissertations, & Professional Papers

Sagebrush steppe is one of the most threatened ecosystems in North America. Domestic livestock grazing is the dominant land use of sagebrush steppe across the west. Rest-rotation grazing systems can be a conservation management tool, most recently, by the Natural Resource Conservation Service - Sage Grouse Initiative (SGI). The goal of SGI is to encourage private landowners to use a livestock grazing regime that maintains or improves habitat for greater sage-grouse (Centrocercus urophasianus), as well as improve rangeland productivity. Songbirds are biological indicators that can assess the health of sagebrush steppe. Avian adult density estimates are often used …

Assessing The Robustness Of Time-To-Event Abundance Estimation, Kenneth E. Loonam

Graduate Student Theses, Dissertations, & Professional Papers

Abundance estimates can inform management policies and are used to address a variety of wildlife research questions, but reliable estimates of abundance can be difficult and expensive to obtain. For low-density, difficult to detect species, such as cougars (Puma concolor), the costs and intensive field effort required to estimate abundance can make working at broad spatial and temporal scales impractical. Remote cameras have proven effective in detecting these species, but the widely applied methods of estimating abundance from remote cameras rely on some portion of the population being marked or uniquely identifiable, limiting their utility to populations with naturally occurring …

Methods For Estimating Mountain Goat Occupancy And Abundance, Molly Mcdevitt

Graduate Student Theses, Dissertations, & Professional Papers

Abundance and occupancy are two parameters of central interest to the field of ecology. Furthermore, accurate (both precise and unbiased) estimates are key pieces to the puzzle of effective wildlife management decision-making. While there exist a variety of sampling techniques and statistical models for effectively estimating population parameters for frequently encountered and large mammals, methods for sampling unmarked and rare species are few and far between. The first step to acquiring usable parameter estimates is through the use of sampling theory and incorporation of probabilistic sampling designs to collect count-data and occurrence-data. Often, it is assumed that probabilistic sampling designs …

Freshwater And Marine Survival Of Coho Salmon (Oncorhynchus Kisutch) As A Function Of Juvenile Life History, Grace Katherine Ghrist

Cal Poly Humboldt theses and projects

Juvenile Coho Salmon (Oncorhynchus kisutch) in coastal California streams exhibit various life history strategies during their freshwater development. One strategy of interest to managers and conservationists is the early migrant. Juvenile early migrants emigrate from natal habitat into lower parts of the watershed or estuary during their first fall or winter, where they rear before migration to the ocean. By contrast, the more prevalent spring migrant resides in natal reaches over the winter and migrates directly to the ocean the following spring. Salmon monitoring programs generally estimate juvenile production and demographic rates using only spring migrants, and these …

Black Bear Use Of Forest Roads In Western Washington, Gary W. Witmer

United States Department of Agriculture Wildlife Services: Staff Publications

Radiolocations (108) of 20 black bears were used to assess use or avoidance of 3 forest road types in western Washington. Distances of bears to each type of road were compared to distances of 108 random points using t-tests. Females and males avoided 2-lane roads, while only males avoided 1-lane roads, the most common road type in the area. Females, but not males, were located closer to overgrown, spur roads than expected. This road type has substantial cover of grasses, forbs, and berry-producing shrubs along with protective tree cover. This situation may provide easy travel for females along with security …