Browsing by Author "Bowser, Gillian, advisor"

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Open Access
Effects of birdwatchers on sandhill crane (Grus canadensis) behavior at spring stopover sites in the San Luis Valley, Colorado
(Colorado State University. Libraries, 2012) Wilkins, Kate, author; Moore, John, advisor; Bowser, Gillian, advisor; Angeloni, Lisa, committee member; Pejchar, Liba, committee member
Human recreational activities can disturb wildlife by causing animals to alter feeding patterns, or change feeding locations. Migratory birds in particular can be susceptible to disturbance since they have limited time for resting, feeding and courtship along their migratory routes. Sandhill cranes (Grus canadensis) are an iconic and charismatic species that stop in Colorado's San Luis Valley during each spring and fall migration, which has led to an annual spring bird watching festival at the Monte Vista National Wildlife Refuge. The goal of this research was to understand how birdwatchers drawn by the festival affect the behavior of sandhill cranes in this important migration stopover site. For the purposes of this research, "birdwatchers" are defined as any person present in the pullouts where we conducted observations of crane behavior. The behavior of sandhill cranes was observed using focal animal sampling techniques during March 2010 and 2011 at sites both on and off the Monte Vista National Wildlife Refuge. The number of birdwatchers at a particular site did not affect the time cranes spent in vigilance postures; however, cranes spent more time vigilant on the Monte Vista National Wildlife Refuge than on privately owned lands, where there were fewer observers. Overall, the results of this study suggest that the birdwatchers during the festival had minimal impact on sandhill crane behavior on the refuge, including open lands managed as agricultural fields. The results of this research can inform adaptive management approaches to balance bird watching opportunities and the needs of charismatic migratory species.
Open Access
Experts vs. novices: a comparison of the quality and quantity of Bombus observations between citizen scientists and researchers in national parks
(Colorado State University. Libraries, 2023) Smith, Alia, author; Bowser, Gillian, advisor; Halliwell, Philip, advisor; Balgopal, Meena, committee member; Newman, Gregory, committee member
Citizen science data is plentiful and diverse in its collection, storage, and subsequent application. Different platforms have unique methods of storing data and limitations in accessing the data contributed to the platform. This study explored the accessibility of citizen science data from several citizen science platforms and compared two different methods of collecting data from iNaturalist, a global citizen science platform for observing and identifying organisms. It focused on Bombus species observations made in Grand Teton and Yellowstone National Parks. The study found that different platforms are not equal in the ability to access and utilize data. It also found that on iNaturalist one method of searching for data yielded 14% more results than the other. The separate and incomplete nature of accessible data across citizen science platforms and subjectivity of searching methods on iNaturalist are indicative of the difficulty in creating a complete dataset that is representative of the collective contributions of citizen scientists. The validity of citizen science research has been controversial in recent history. There is a general consensus, however, that citizen science must be verifiable to be trustworthy. iNaturalist is a crowdsourced citizen science platform that allows other users to corroborate or dispute species identifications that individuals post. This research seeks to determine whether there is a difference in the quantity and quality of Bombus observations in Grand Teton and Yellowstone National Parks made by expert researchers and citizen scientists on iNaturalist. It found that the professional researchers, or experts, contributed 68% of the observations, but there was not a significant difference between the achievement rate of Research Grade observations between the experts and novices. This indicates that citizen scientists have the ability, through iNaturalist, to accurately make difficult taxonomic identifications.
Open Access
Photovoice as a technique to understand the perceptions of local people neighboring Tarangire National Park in Tanzania on the risks caused by migratory animals
(Colorado State University. Libraries, 2013) Sumay, Gloria, author; Boone, Randall, advisor; Bowser, Gillian, advisor; Wittemyer, George, committee member; Bruyere, Brett, committee member
What is the impact of wildlife on communities neighboring national parks and protected areas? Understanding perceptions of risk by local communities on wildlife can help conservation efforts and the development of acceptable policies for parks and protected areas. This study examines communities along the eastern boundary of Tarangire National Park using a combination of Photovoice techniques and individual interviews to determine how these communities perceive risk from wildlife to their agriculture, livestock and economies. Here Photovoice was used to articulate participants' perception of risks to their livelihoods from migratory wildlife that transversed the national park. Three villages (Terrat, Narakauwo and Emboreet) were chosen based on their proximity to wildlife migration corridors and 12 participants from each village were asked to document their perceptions of risk from wildlife using digital cameras. Photovoice uses images taken by participants on a pre-determined topic, followed by interviews of the participants on the photographs to determine themes. In addition, twenty participants from the same villages were interviewed on their perception of risk from wildlife damage using survey questions and narratives. The characteristics of each village (size, distance from each other and distance from park boundary) were determined using GIS and satellite imaginary. The villages had different perceptions (p = 0.003) based on the three categories of risk: wildlife damage, crop damage and shared resources. Village size had no influence on the peoples' perceptions of risk; however land use patterns (farm land and associated activities) showed some influence on perceptions of risk. Changes in land use for two of the villages, Emboreet and Narakauwo, indicated a large increase in farming activities, which are likely to influence peoples' perception of risk. In Emboreet village, which has more farm land, the greatest risk was perceived as crop damage. The results of this study demonstrate the complex relationships between protected areas, migratory wildlife and community villages. To balance the needs to protect highly migratory species such as the wildebeest, conservation managers need to incorporate the perceived risks among villages and the factors that influence those perceptions.
Open Access
Small mammal populations and plant community succession at artesian well sites in Great Sand Dunes National Park, Colorado
(Colorado State University. Libraries, 2013) Garza, Sarah Julía, author; Bowser, Gillian, advisor; Wilson, Kenneth R., advisor; Doherty, Paul F., committee member; Paschke, Mark, committee member
For more than 100 years, artificial artesian wells in the San Luis Valley of south-central Colorado have been a steady source of water for livestock and wildlife on lands administered by Great Sand Dunes National Park and The Nature Conservancy. In summer 2011, a study was established to examine effects on local biota of capping the artesian wells in 2010. In Chapter 1, I focused on the short-term effects of capping artesian well sites and the effects on the population dynamics and species diversity of small mammals. In 2011 and 2012, I compared newly capped well sites, well sites with water, and reference sites by estimating density (Program DISTANCE), survival (Cormack-Jolly-Seber Model in Program MARK), species occupancy (Robust Occupancy Model in Program MARK), and measures of species diversity (species richness, Shannon-Weiner index, and species evenness) of small mammals. I modeled small mammal density and survival as a function of well site type, percent plant cover, disturbance level from ungulates, and year of study using an information theoretic approach to rank models and estimate the relative importance of the independent variables. Over the two years, I captured 1,150 individuals of 6 rodent species; however, only two species, Ord's kangaroo rat (Dipodomys ordii) and Apache or plains pocket mice (Perognathus sp.), had sufficient numbers for density and survival analyses. There was no significant difference in density and survival estimates for these species at the well types; however species occupancy estimates varied by well type and by species such that open well sites had the greatest probability of occupancy of the deer mouse (Peromyscus maniculatus), and reference sites had the greatest probability of occupancy of the thirteen-lined ground squirrel (Spermophilus tridecemlineatus). For the kangaroo rat density and survival, the type of well site was important with greatest values at capped well sites. For pocket mice, the disturbance level by ungulates and year of study were important predictors of density and survival; density was negatively correlated with amount of disturbance and survival nearly doubled from 2011 to 2012. Richness, the Shannon-Weiner diversity index and community evenness values were greatest at reference sites. Results suggest that in the short term, small mammal density and survival does not increase after a well is capped, species occupancy is variable, and diversity does not change. Additional studies are needed to provide a better understanding of the long-term changes in small mammal population dynamics and biodiversity as capped well sites continue to revert to habitats similar to reference sites. In Chapter 2, I concentrated on the short-term effects of capping wells on the plant community with a focus on secondary ecological succession. I characterized the habitats at sampled sites by identifying plant species (native and exotic) and examining potential sources of variation by modeling plant cover and species frequency as a function of variables such as well site type, the ungulate disturbance level, distance from well heads, and the year of study. I used an information theoretic approach to rank models and estimate the relative importance of these independent variables. I also estimated indices of native species diversity including richness, Shannon-Weiner diversity index, Simpson's index, community evenness, and compared patterns of plant form cover (i.e., shrubs, forbs, and grasses) at increasing distances from well heads. Year of study and distance from well heads were important predictors of native plant cover and exotic plant cover, respectively; however there was no difference in native or exotic plant cover based on well status (open or closed). Well site type, year of study, and ungulate disturbance intensity levels were important predictor variables for native species frequency whereas for exotic species frequency, well type was important. All indices of species diversity values were greatest at the reference sites. Capped well sites had varying distance patterns across different plant forms whereas all plant cover was highest at the farthest distances from open well heads. Overall, this study suggested that while plant communities at well sites are not significantly different after capping the well head, the abundant exotics may need additional control efforts for the community to return to species composition typical of the sand sheet ecosystem.
Open Access
Where have all the pollinators gone? An analysis of the shifts in climate and phenology that have altered pollinator diversity in the Greater Yellowstone Ecosystem
(Colorado State University. Libraries, 2023) Whipple, Sarah E., author; Bowser, Gillian, advisor; Balgopal, Meena, committee member; Halliwell, Philip, committee member; Fisher, Emily, committee member
Pollinators are in peril, facing worldwide decline due to causes such as climate change, habitat fragmentation, phenological mismatches, urbanization, pesticide use, agricultural intensification, and more. In the age of these challenges, prioritizing suitable habitat for species conservation is essential. United States (US) National Parks, in addition to other protected areas nationally and worldwide, act as species refuges for all biodiversity, including pollinators, and more specifically, butterfly and bumble bee species. While data availability is minimal to answer broad questions of pollinator decline, virtual datasets, including citizen science platforms and digitized Natural History Collections (NHCs), provide robust species occurrence snapshots to the state of biodiversity in the parks. This dissertation assessed pollinators, plant-pollinator relationships, and species responses to climate change in Yellowstone and Grand Teton National Parks, two parks within the Rocky Mountain region of the US. In the first chapter, I provide a literature review and my research framework that guided the following studies. In the second chapter, I conducted a meta-analysis to determine what species responses were worldwide to climate change effects. An analysis of the limited bumble bee literature showed species range contractions as well as detrimental plant-phenological shifts occurring worldwide. Although there were more butterfly studies, there was the most agreement found in earlier species emergence patterns, range contractions, and species generalist population responses. In the third chapter, I analyzed digitized data within NHCs, citizen science platforms, and permit-reported data available for the parks from 1900-2021 to understand the systematic data gaps and taxonomic biases present within available datasets. I observed taxonomic biases and varying prominence within data repositories in both parks. However, the rate of available digitized records will continue to evolve and may shift these systematic gaps. In the fourth chapter, I evaluated the climate, phenology, and pollinator species occurrence relationships seen within the parks. I found that starting floral bloom dates and recent bloom anomalies have not shifted significantly, with an average earlier bloom date of three days observed across the parks. The correlations between phenological stages highlighted the negative effect of half-bloomed floral resources on pollinator occurrences in the subalpine and meadow areas of the park, and the positive effect of senesced floral resources on pollinator occurrences both habitat and park wide. Finally, the fifth chapter summarized with lessons learned, including species case studies, and suggestions for additional research efforts. These findings highlight the importance of continued monitoring of pollinator groups within the parks, particularly amongst groups with specialized plant-pollinator relationships, range restrictions, and sensitive generational production – all in which may be vulnerable in the age of a warming, drying western climate. Researchers can use these findings to inform land management and species conservation strategies, to prioritize useable and robust datasets of varying digitized availability for biodiversity questions, and to understand the baseline of pollinator data observed within two protected areas that have experienced minimized effects of other land-use pressures.