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- All Subjects: Wildlife Management
- Creators: Bateman, Heather L
- Creators: Minteer, Ben
Description
Biological diversity is threatened by increasing anthropogenic modification of natural environments and increasing demands on natural resources. Sonoran desert tortoises (Gopherus morafkai) currently have Candidate status under the Endangered Species Act (ESA) based on health and habitat threats. To ensure this animal persists in the midst of multiple threats requires an understanding of the life history and ecology of each population. I looked at one physiological and one behavioral aspect of a population of tortoises at the Sugarloaf Mountain (SL) study site in central Arizona, USA. I used 21 years of capture-recapture records to estimate growth parameters of the entire population. I investigated habitat selection of juvenile tortoises by selecting 117 locations of 11 tortoises that had been tracked by radio-telemetry one to three times weekly for two years, selecting locations from both summer active season and during winter hibernation. I compared 22 microhabitat variables of tortoise locations to random SL locations to determine habitat use and availability. Male tortoises at SL reach a greater asymptotic length than females, and males and females appear to grow at the same rate. Juvenile tortoises at the SL site use steep rocky hillsides with high proportions of sand and annual vegetation, few succulents, and enclosed shelters in summer. They use enclosed shelters on steep slopes for winter hibernation. An understanding of these features can allow managers to quantify Sonoran desert tortoise habitat needs and life history characteristics and to understand the impact of land use policies.
ContributorsBridges, Andrew (Author) / Bateman, Heather L (Thesis advisor) / Miller, William (Committee member) / Ulrich, Jon (Committee member) / Arizona State University (Publisher)
Created2012
Description
Since its inception in 1973, the Endangered Species Act has been met with both praise and criticism. More than 40 years later, the Act is still polarizing, with proponents applauding its power to protect species and critics arguing against its perceived ineffectiveness and potential mismanagement. Recovery plans, which were required by the 1988 amendments to the Act, play an important role in organizing efforts to protect and recover species under the Act. In 1999, in an effort to evaluate the process, the Society for Conservation Biology commissioned an independent review of endangered species recovery planning. From these findings, the SCB made key recommendations for how management agencies could improve the recovery planning process, after which the Fish and Wildlife Service and the National Marine Fisheries Service redrafted their recovery planning guidelines. One important recommendation called for recovery plans to make threats a primary focus, including organizing and prioritizing recovery tasks for threat abatement. Here, I seek to determine the extent to which SCB recommendations were incorporated into these new guidelines, and if, in turn, the recommendations regarding threats manifested in recovery plans written under the new guidelines. I found that the guidelines successfully incorporated most SCB recommendations, except those that addressed monitoring. As a result, recent recovery plans have improved in their treatment of threats, but still fail to adequately incorporate threat monitoring. This failure suggests that developing clear guidelines for monitoring should be an important priority in future ESA recovery planning.
ContributorsTroyer, Caitlin (Author) / Gerber, Leah (Thesis advisor) / Minteer, Ben (Committee member) / Guston, David (Committee member) / Arizona State University (Publisher)
Created2014
Description
In riparian ecosystems, reptiles and amphibians are good indicators of environmental conditions. Herpetofauna have been linked to specific microhabitat characteristics, microclimates, and water resources in riparian forests. My objective was to relate herpetofauna abundance to changes in riparian habitat along the Virgin River caused by the Tamarix biological control agent, Diorhabda carinulata, and riparian restoration.
During 2013 and 2014, vegetation and herpetofauna were monitored at 21 riparian locations along the Virgin River via trapping and visual encounter surveys. Study sites were divided into four stand types based on density and percent cover of dominant trees (Tamarix, Prosopis, Populus, and Salix) and presence of restoration activities: Tam, Tam-Pros, Tam-Pop/Sal, and Restored Tam-Pop/Sal. Restoration activities consisted of mechanical removal of non-native trees, transplanting native trees, and introduction of water flow. All sites were affected by biological control. I predicted that herpetofauna abundance would vary between stand types and that herpetofauna abundance would be greatest in Restored Tam-Pop/Sal sites due to increased habitat openness and variation following restoration efforts.
Results from trapping indicated that Restored Tam-Pop/Sal sites had three times more total lizard and eight times more Sceloporus uniformis captures than other stand types. Anaxyrus woodhousii abundance was greatest in Tam-Pop/Sal and Restored Tam-Pop/Sal sites. Visual encounter surveys indicated that herpetofauna abundance was greatest in the Restored Tam-Pop/Sal site compared to the adjacent Unrestored Tam-Pop/Sal site. Habitat variables were reduced to six components using a principle component analysis and significant differences were detected among stand types. Restored Tam-Pop/Sal sites were most similar to Tam-Pop/Sal sites. S. uniformis were positively associated with large woody debris and high densities of Populus, Salix, and large diameter Prosopis.
Restored Tam-Pop/Sal sites likely supported higher abundances of herpetofauna, as these areas exhibited greater habitat heterogeneity. Restoration activities created a mosaic habitat by reducing canopy cover and increasing native tree density and surface water. Natural resource managers should consider implementing additional restoration efforts following biological control when attempting to restore riparian areas dominated by Tamarix and other non-native trees.
During 2013 and 2014, vegetation and herpetofauna were monitored at 21 riparian locations along the Virgin River via trapping and visual encounter surveys. Study sites were divided into four stand types based on density and percent cover of dominant trees (Tamarix, Prosopis, Populus, and Salix) and presence of restoration activities: Tam, Tam-Pros, Tam-Pop/Sal, and Restored Tam-Pop/Sal. Restoration activities consisted of mechanical removal of non-native trees, transplanting native trees, and introduction of water flow. All sites were affected by biological control. I predicted that herpetofauna abundance would vary between stand types and that herpetofauna abundance would be greatest in Restored Tam-Pop/Sal sites due to increased habitat openness and variation following restoration efforts.
Results from trapping indicated that Restored Tam-Pop/Sal sites had three times more total lizard and eight times more Sceloporus uniformis captures than other stand types. Anaxyrus woodhousii abundance was greatest in Tam-Pop/Sal and Restored Tam-Pop/Sal sites. Visual encounter surveys indicated that herpetofauna abundance was greatest in the Restored Tam-Pop/Sal site compared to the adjacent Unrestored Tam-Pop/Sal site. Habitat variables were reduced to six components using a principle component analysis and significant differences were detected among stand types. Restored Tam-Pop/Sal sites were most similar to Tam-Pop/Sal sites. S. uniformis were positively associated with large woody debris and high densities of Populus, Salix, and large diameter Prosopis.
Restored Tam-Pop/Sal sites likely supported higher abundances of herpetofauna, as these areas exhibited greater habitat heterogeneity. Restoration activities created a mosaic habitat by reducing canopy cover and increasing native tree density and surface water. Natural resource managers should consider implementing additional restoration efforts following biological control when attempting to restore riparian areas dominated by Tamarix and other non-native trees.
ContributorsMosher, Kent (Author) / Bateman, Heather L (Thesis advisor) / Stromberg, Juliet C. (Committee member) / Miller, William H. (Committee member) / Arizona State University (Publisher)
Created2014
Description
Worldwide, riverine floodplains are among the most endangered landscapes. In response to anthropogenic impacts, riverine restoration projects are considerably increasing. However, there is a paucity of information on how riparian rehabilitation activities impact non-avian wildlife communities. I evaluated herpetofauna abundance, species richness, diversity (i.e., Shannon and Simpson indices), species-specific responses, and riparian microhabitat characteristics along three reaches (i.e., wildland, urban rehabilitated, and urban disturbed) of the Salt River, Arizona. The surrounding uplands of the two urbanized reaches were dominated by the built environment (i.e., Phoenix metropolitan area). I predicted that greater diversity of microhabitat and lower urbanization would promote herpetofauna abundance, richness, and diversity. In 2010, at each reach, I performed herpetofauna visual surveys five times along eight transects (n=24) spanning the riparian zone. I quantified twenty one microhabitat characteristics such as ground substrate, vegetative cover, woody debris, tree stem density, and plant species richness along each transect. Herpetofauna species richness was the greatest along the wildland reach, and the lowest along the urban disturbed reach. The wildland reach had the greatest diversity indices, and diversity indices of the two urban reaches were similar. Abundance of herpetofauna was approximately six times lower along the urban disturbed reach compared to the two other reaches, which had similar abundances. Principal Component Analysis (PCA) reduced microhabitat variables to five factors, and significant differences among reaches were detected. Vegetation structure complexity, vegetation species richness, as well as densities of Prosopis (mesquite), Salix (willow), Populus (cottonwood), and animal burrows had a positive correlation with at least one of the three herpetofauna community parameter quantified (i.e., herpetofauna abundance, species richness, and diversity indices), and had a positive correlation with at least one herpetofauna species. Overall, rehabilitation activities positively influenced herpetofauna abundance and species richness, whereas urbanization negatively influenced herpetofauna diversity indices. Based on herpetofauna/microhabitat correlations established, I developed recommendations regarding microhabitat features that should be created in order to promote herpetofauna when rehabilitating degraded riparian systems. Recommendations are to plant vegetation of different growth habit, provide woody debris, plant Populus, Salix, and Prosopis of various ages and sizes, and to promote small mammal abundance.
ContributorsBanville, Mélanie Josianne (Author) / Bateman, Heather L (Thesis advisor) / Brady, Ward (Committee member) / Stromberg, Juliet (Committee member) / Arizona State University (Publisher)
Created2011
Description
The plateau pika (Ochotona curzoniae), a small burrowing lagomorph that occupies the high alpine grassland ecosystems of the Qinghai-Tibetan Plateau in western China, remains a controversial subject among policymakers and researchers. One line of evidence points to pikas being a pest, which has led to massive attempts to eradicate pika populations. Another point of view is that pikas are a keystone species and an ecosystem engineer in the grassland ecosystem of the QTP. The pika eradication program raises a difficult ethical and religious dilemma for local pastoralists, and is criticized for not being supported by scientific evidence. Complex interactions between pikas, livestock, and habitat condition are poorly understood. My dissertation research examines underpinning justifications of the pika poisoning program leading to these controversies. I investigated responses of pikas to habitat conditions with field experimental manipulations, and mechanisms of pika population recovery following pika removal. I present policy recommendations based on an environmental ethics framework and findings from the field experiments. After five years of a livestock grazing exclusion experiment and four years of pika monitoring, I found that grazing exclusion resulted in a decline of pika habitat use, which suggests that habitat conditions determine pika population density. I also found that pikas recolonized vacant burrow systems following removal of residents, but that distances travelled by dispersing pikas were extremely short (~50 m). Thus, current pika eradication programs, if allowed to continue, could potentially compromise local populations as well as biodiversity conservation on the QTP. Lethal management of pikas is a narrowly anthropocentric-based form of ecosystem management that has excluded value-pluralism, such as consideration of the intrinsic value of species and the important ecological role played by pikas. These conflicting approaches have led to controversies and policy gridlock. In response, I suggest that the on-going large-scale pika eradication program needs reconsideration. Moderation of stocking rates is required in degraded pika habitats, and Integrated Pest Management may be required when high stocking rate and high pika density coexist. A moderate level of livestock and pika density can be consistent with maintaining the integrity and sustainability of the QTP alpine steppe ecosystem.
ContributorsBadingqiuying (Author) / Smith, Andrew T. (Thesis advisor) / Wu, Jianguo (Committee member) / Minteer, Ben (Committee member) / Anderies, John (Committee member) / Harris, Richard B. (Committee member) / Arizona State University (Publisher)
Created2016
Description
Species conservation requires an understanding of the habitats on which that species depends as well as how it moves within and among those habitats. Knowledge of these spatial and temporal patterns is vital for effective management and research study design. Bubbling Ponds Hatchery in Cornville, Arizona, supports a robust population of the northern Mexican gartersnake (Thamnophis eques megalops), which was listed as threatened under the Endangered Species Act in 2014. Natural resource managers are interested in understanding the ecology of gartersnakes at this site to guide hatchery operations and to serve as a model for habitat creation and restoration. My objectives were to identify habitat selection and activity patterns of northern Mexican gartersnakes at the hatchery and how frequency of monitoring affects study results. I deployed transmitters on 42 individual gartersnakes and documented macro- and microhabitat selection, daily and seasonal activity patterns, and movement distances. Habitat selection and movements were similar between males and females and varied seasonally. During the active season (March–October), snakes primarily selected wetland edge habitat with abundant cover and were more active and moved longer distances than during other parts of the year. Gestating females selected similar locations but with less dense cover. During the inactive season (November–February), snakes were less mobile and selected upland habitats, including rocky slopes with abundant vegetation. Snakes displayed diurnal patterns of activity. Estimates of daily distance traveled decreased with less-frequent monitoring; a sampling interval of once every 24 hours yielded only 53–62% of known daily distances moved during the active season. These results can help inform management activities and research design. Conservation of this species should incorporate a landscape-level approach that includes abundant wetland edge habitat with connected upland areas. Resource managers and researchers should carefully assess timing and frequency of activities in order to meet project objectives.
ContributorsSprague, Tiffany A (Author) / Bateman, Heather L (Thesis advisor) / Cunningham, Stan C (Committee member) / Jones, Thomas R (Committee member) / Nowak, Erika M. (Committee member) / Arizona State University (Publisher)
Created2017
Description
Anthropogenic linear infrastructures, including roads, railways, and canals, provide important resources to humans. However, linear infrastructures can reduce landscape connectivity for many wildlife populations. To mitigate these effects, crossing structures and crossing areas can facilitate animal movement across linear infrastructures. Compared to roads, little research has evaluated the factors influencing wildlife use of crossings along major canals. The Central Arizona Project (CAP) canal is a major linear feature in Arizona, and exhibits multiple types of crossing structures and areas. In Chapter 1, the objective was to evaluate the spatial (i.e., landscape features, crossing attributes) and temporal (i.e., season, time of day) factors influencing wildlife use of overpasses (n = 43) and siphons (n = 13) along the CAP canal. Using remote wildlife cameras, 17 species were detected using overpasses and siphons along the CAP canal during one year. Animals exhibited species-specific preferences for landscape features, such as topography and vegetation, and canal crossing types, although many species decreased use of overpasses associated with human development. In Chapter 2, the objective was to evaluate the influence of human activities at overpasses on use by mule deer across multiple analytical scales. Mule deer occupancy and relative habitat use at overpasses decreased in relation to human activity, including recreation. In Chapter 3, the objective was to evaluate seasonal use of underpasses (n = 12) by mammals, reptiles, amphibians, and invertebrates. Using specialized remote wildlife cameras, 30 species were detected using underpasses along the CAP canal across three seasons, and some animals exhibited variable crossing frequencies in relation to the summer monsoon season. Overall in this project, several species of small to large-sized mammals, reptiles, amphibians, and invertebrates used a variety of crossing types, including overpasses and underpasses, along a major canal. Ultimately, this study suggests that to promote landscape connectivity for the wildlife community associated with canals and other types of linear infrastructures, it is important to provide a variety of crossing types that occur across a range of landscape characteristics.
ContributorsHamilton, Kaela M (Author) / Lewis, Jesse S (Thesis advisor) / Bateman, Heather L (Committee member) / Arizona State University (Publisher)
Created2023
Description
Understanding how wildlife interact with humans and the built environment is critical as urbanization contributes to habitat change and fragmentation globally. In urban and suburban areas, wildlife and people are often in close quarters, leading to human-wildlife interactions (HWI). In the greater Phoenix Metropolitan Area, Arizona, HWI can involve reptiles such as venomous (family Viperidae, e.g., rattlesnakes) and nonvenomous (family Colubridae, e.g., gophersnakes) snakes. Rattlesnake Solutions, LLC, a local business, removes and relocates snakes from homes and businesses in the Phoenix area and, as a collaborator, has provided records of snake removals. Using these records, I investigated taxa-specific habitat trends at two spatial scales. At the neighborhood scale (n = 60), I found that removals occurred in yards with abundant cover opportunities. At the landscape scale (n = 764), nonvenomous snakes were removed from areas of higher urbanization compared to venomous snakes. Clients of Rattlesnake Solutions, LLC, were asked to answer a short survey, designed by K. Larson and colleagues, regarding the circumstances of their snake removal event and their attitudes, perceptions, and experiences with snakes. I used responses from this survey (n =271) to investigate if prior experience with snakes influences reported attitudes towards snakes. Respondents with prior snake experiences reported more positive attitudes towards snakes and were more consistent across their responses than those without prior snake experiences. Continuing inquiry into the urban ecology of these snakes is important to fostering coexistence between snakes and people that call Phoenix home.
ContributorsEnloe, Annika (Author) / Bateman, Heather L (Thesis advisor) / Lewis, Jesse (Committee member) / Larson, Kelli (Committee member) / Arizona State University (Publisher)
Created2023
Description
Riparian areas are an important resource, especially in the arid southwest, for many wildlife species. Understanding species occurrence in areas dominated by non-native vegetation is important to determine if management should be implemented. Saltcedar (Tamarix spp.) is one of the most prevalent non-native trees in riparian areas in the southwest United States and can alter vegetation structure, but little is known about how medium and large carnivores use stands of saltcedar. Three riparian forest types make up the San Pedro riparian corridor: non-native saltcedar, native mesquite (Prosopis spp.) bosque, and a mixture of native cottonwood (Populus fremontii) and willow (Salix goodingii) woodlands. My goals were to determine relative use, diversity, and occupancy of medium and large mammals across forest types to evaluate use of the non-native stands. I sampled mammals along approximately 25.7 river kilometers between July 2017 and October 2018, using 18 trail cameras (six per forest type) spaced 1km apart. I summarized environmental variables around the camera sites to relate them to species occupancy and reduced them to 4 components using a Principal Component Analysis (PCA). I observed 14 carnivore species, including bobcat (Lynx rufus), coyote (Canis latrans), and coati (Nasua narica) over 7,692 trap nights. Occupancy of some species may have been influenced by the different components, but models showed high standard errors, making it difficult to draw firm conclusions. Most mammal species used all three forest types at some level and no surveyed forest type was completely avoided or unused. Coyote tended to have greater use in the mesquite forest while canids trended toward greater use in saltcedar forest. Based on two-species occupancy models as well as activity overlap patterns, subordinate species did not appear to avoid dominant species. No species seems significantly affected by non-native saltcedar at this time.
ContributorsHerzog, Cheyenne J (Author) / Bateman, Heather L (Thesis advisor) / Lewis, Jesse (Committee member) / Cunningham, Stan (Committee member) / Arizona State University (Publisher)
Created2019
Description
The issue of wild horse management in the American West has become prevalent in the media recently and management strategies are often criticized and opposed by the public. Horses have been a core feature of American history and culture nearly since the colonization of the western frontier, and popular media such as television and movies paint a romantic but often unrealistic picture of wild horses. Land management agencies must balance limited resources with an ever-growing wild horse population in order to properly manage public land so that it retains its ecological integrity and is still able to be used by multiple stakeholders, and they also must endure public criticism throughout the process. I used a photo elicitation survey to gather responses to photographic images of wild horses and determine how the public feels about wild horse management, given that horses are seen as a symbol of freedom and the American West. It was revealed that people who are unfamiliar with the issue still have opinions about how the horses should be managed, and these opinions often mirror what can be found in popular media.
ContributorsDuran, Kiana Alexis (Author) / Minteer, Ben (Thesis director) / Schoon, Michael (Thesis director) / Murphree, Julie (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05