Thesis (M.S.)--Wildlife and Fisheries Sciences Dept., South Dakota State University, 2009. / Includes bibliographical references. Also available via the World Wide Web.

Thesis (M. Sc.)--Carleton University, 1996. / Also available in electronic format on the Internet.

Utah prairie dogs were transplanted onto the site of a former colony located on Jones Bench in the northwestern corner of Capitol Reef National Park. Shrubs on Jones Bench were significantly taller than those found on active colonies of Ut ah prairie dogs located nearby on the Awapa Plateau. Therefore, the Jones Bench site offered an opportunity to test the hypothesis that shrub height is a major inhibitory factor on occupation of sites by prairie dogs. Four sites of 5 ha each were delimited on Jones Bench prior to the transplanting o~ animals. Vegetation treatments were carried out on three of the sites and the fourth was used as a nonmanipulated control . Mechanical treatments by rotobeating and railing were accomplished in late August, 1978. A herbicidal treatment (2,4-D) was done on the third site in the spring of 1979. Shrub height and percent cover were significantly reduced on all three treatment sites. Post-treatment effects on the vegetation during the first year showed that the greatest percent moisture in herbage was found on the railed site, followed by the herbicide, rotobeaten, and control sites. Herbage production was approximately three times greater on the rotobeaten and railed sites than on the control and herbicide sites. Measurements of the visual obstructions of prairie dogs showed that the rotobeaten site had the greatest visibility followed by the railed, herbicide, and control sites. Prior to release of prairie dogs on the study area, 200 artificial burrows arranged in a matrix, were dug with an enginepowered post-hole auger on each site. In late June and early July, 1979, 200 Utah prairie dogs were live-trapped near Loa, Utah. A total of 50 immature males, immature females, mature males, and mature females were released on each site. The animal's fur was dyed with a specific mark representing their respective transplant site before their release. The transplanted animals were monitored daily for 23 consecutive days following the release of the first animals and biweekly thereafter throughout the summer and early fall. Significant differences were found in the number of animals reestablished on each site except between the herbicide treatment and control site. The majority of all animals transplanted moved onto the rotobeaten site; the railed, herbicide, and control sites were selected in decreasing order. Results indicated that when transplanting animals onto sites of former colonies, particularly sites that are overgrown with shrubs, the chances of a successful transplant could be increased by first reducing shrub height and density. Proof of reestablishment at the Jones Bench site will be evident if reproduction is observed in the spring of 1980.

In cases where refuge acquisition or captive breeding programs are not practical or justifiable, wild caught animals are frequently translocated into areas of suitable habitat. Such management programs seldom are designed to account for the behavioral responses of translocated animals to an unfamiliar habitat, breakup of social units, and/or interactions with existing social units in the new habitat. Ongoing efforts to translocate threatened Utah prairie dogs (Cynomys parvidens) from areas where conflicts with other land uses are occurring to public land sites have met with limited success. This could be due, in part, to behavioral responses associated with disrupting social units and placing animals in an unfamiliar environment. The purpose of this research was to test a series of hypotheses regarding the behavioral responses of Utah prairie dogs to translocation. Focal animal sampling was used to estimate the durations and frequencies of five behavioral variables and five interaction types at four treatments: control, new site, supplemental site, and new population. In Chapter 1, activity budgets were compared among control animals, animals released into a new site versus a supplemental site, and animals already present at a supplemental site. The objective was to evaluate the relative effects of new and supplemental translocations and the effects of translocations on resident animals. In Chapter 2, the frequencies of interactions were compared among these same treatments to evaluate the effects of translocation on the sociality of Utah prairie dogs as reflected by changes in the frequencies of greeting displays, dominance/subordinance displays, and amicable and agonistic interactions. Chapter 3 compares the activity budgets of animals released at a site containing natural burrows (i.e., new population) and animals released into a site containing artificial burrows (i.e., new site) to a control. Habitat measurements for these treatments were also compared to evaluate the importance of habitat characteristics typical of prairie dog colonies to translocated animals. Hotelling's T2 analyses were used to compare behavioral durations between treatments and log-linear analyses were use to compare behavioral frequencies among treatments. Activity budgets were altered by translocation through tradeoffs between the amount of time spent foraging, being vigilant, exploring the unfamiliar habitat, and minimizing conspicuousness. Predicted changes in interactions frequencies as a result of translocations were not observed. Activity budgets of animals released into the site containing natural burrows did not differ from those of control animals . The most important behavioral consideration is the effects of burrow and habitat characteristics in providing centers of activity and effective predator detection and avoidance.

Doctor of Philosophy / Department of Biology / Jack F. Cully, Jr. / Dispersal remains one of the most important, yet least understood, life history traits. As the vehicle of gene flow among populations, dispersal can both relieve inbreeding depression and prevent local adaptation. Regionally, dispersal can stabilize or destabilize metapopulations, given its critical roles in disease transmission among populations as well as recolonization following local extinction events. Furthermore, in light of climate change and increasing habitat loss and fragmentation, the ability to navigate through unfamiliar, unsuitable habitat between populations is essential to the long-term survival of a species across its range. In my dissertation, I present a multi-scale investigation of factors affecting gene flow and disease transmission among populations of a keystone species and an agricultural pest of the North American prairie: the black-tailed prairie dog (Cynomys ludovicianus). Black-tailed prairie dogs are social, ground-dwelling squirrels that live in spatially isolated populations called colonies. First, we conducted a landscape genetic analysis of black-tailed prairie dogs throughout a large portion of their current range. Our estimates of gene flow indicate that the genetic neighborhood size of both male and female prairie dogs reaches 40-60 km within short-grass prairie, whereas colonies within mixed-grass prairie are more isolated. At a broad scale, we observed isolation-by-distance among colonies and great influence of grassland productivity on genetic connectivity; however, neither distance nor landscape characteristics greatly explained observed genetic differentiation among colonies separated by < 50 km. Last, we investigated whether landscape features could predict disease transmission patterns of sylvatic plague among colonies in short-grass prairie and found evidence that pastures act as corridors for plague transmission. Our results indicate that black-tailed prairie dogs are more resilient to habitat loss and fragmentation than other obligate grassland species and likely capable of transmitting sylvatic plague over long distances. Taken together, these studies illustrate how a multi-scale approach can reveal complexities of dispersal dynamics that would otherwise remain undetected.

Thesis (Ph. D.)--Carleton University, 1997. / Also available in electronic format on the Internet.

Research in grassland ecosystems worldwide has highlighted the crucial role many burrowing herbivore mammals provide as so-called “ecosystem engineers”. Many of these examples come from North America and have mostly been focused on Prairie Dogs (Cynomys sp.), which, due to their burrowing and grazing activities, are considered as a species of high ecological importance. Multiple studies have shown that their loss reduces grassland ecosystem functions and that their activities increase plant, arthropod, bird and mammal biodiversity, grassland heterogeneity, provide benefits to cattle, among many other key ecological roles. However, prairie dog species are distributed throughout multiple landscapes in North America, and most of the studies have been on mixed prairie grasslands. It is therefore not surprising that, when comparing the effects of different prairie dog species across ecoregions, the role of prairie dogs is not as clear and results vary, depending on spatial context, type of grasslands, climate and environmental conditions. Yet, grasslands are considered as some of the most highly threatened ecosystems, having high rates of conversion, desertification and biodiversity loss. Therefore, it is imperative to understand the effects prairie dog species have on the ecosystem. In this thesis, I focus on the Mexican prairie dog (C. mexicanus), a species in drastic decline due to habitat loss, caused by agriculture, overgrazing, human settlement, fragmentation, diseases (e.g. plague) and past eradication programs. C. mexicanus is considered endangered by the IUCN red list of threatened species and The Convention of International Trade in Endangered Species of Wild Fauna and Flora. It is also endemic to the Grassland Priority Conservation Area (GPCA) of El Tokio, located in Northeast Mexico within the Chihuahuan desert ecoregion and designated as a GPCA by the Commission for Environmental Cooperation (a cooperation between Canada, U.S. and Mexico) in 2009. Grasslands within GPCA El Tokio are highly fragmented as a result of many years of intense agricultural practices and other anthropogenic activities and around 90% of the original grasslands have been lost. However, it is considered an area of ecological importance due to its unique vegetation and edaphic associations, as well as being a key habitat for migratory birds. Up until now, very few studies have explored the role C. mexicanus has on plant taxonomical diversity and soil properties. Moreover, no studies focusing on prairie dogs have looked into the effect the species has on plant functional diversity or soil properties. Furthermore, GPCA El Tokio is a data-scarce area. Therefore, at this point, basic information and system understanding are urgently needed in order to identify which conservation efforts are most promising and which specific sites these efforts should focus on. Understanding the influence of prairie dog disturbance on vegetation parameters (taxonomic and functional), soil properties and their interaction with environmental conditions through time, will increase knowledge on the risks and vulnerability of grasslands, promoting solutions that can support grassland management. Furthermore, there is a clear gap in the literature about the varying effects of prairie dogs depending on different grassland types and environmental conditions. To study such conditions, I first classified and controlled for factors that could influence prairie dog ecosystem engineering effects addressing the following two general questions: (1) Which grassland types are present in GPCA El Tokio? (2) Do the different grassland types present in GPCA El Tokio influence prairie dog colony sizes and burrow density? When influencing factors were confirmed, I then assess the effects of prairie dog disturbance on vegetation and soil to answer the following questions: (3) Are there clear distinctions across GPCA El Tokio grassland environmental variables? (4) Do the different grassland types present in GPCA El Tokio influence prairie dog colony sizes and burrow density? To do so I selected a representative sample of sites covering the varying environmental conditions present in GPCA El Tokio grasslands, a data-driven clustering approach was used. Once clusters were defined, average burrow density was estimated from remote sensing imagery. To study vegetation measures I first, sampled plant species (92 species and 28 families and 6 traits) to obtain taxonomical and functional diversity measures, and obtained variables related to nutrient availability, carbon and climate regulation, and water regulation and purification. To study the effects on soil a total of 11 soil properties were obtained (382 samples were analyzed). Field work was done during the wet season and repeated during the dry season to obtain season variations of all measures. Soil measures were further obtained at depths of 0-10cm and 10 to 20cm. Results from the study classify GPCA El Tokio into 8 different grassland types with 4 clusters being the most dominant, named Agriculture, Arid, Calcareous, Mountain. I found agricultural grasslands had significantly lower colony sizes compared to calcareous grasslands when outliers were considered, but no differences when outliers were removed and burrow density varied depending on the grassland type, with mountain grasslands having a significantly lower burrow density compared to agricultural and calcareous grasslands. Regarding the effects of prairie dogs on vegetation and soil my findings suggest that functional metrics and community weighted mean (CWM) analyses responded to interactions between prairie dog disturbance, grassland type and season, whilst species diversity and cover measures were less sensitive to the role of prairie dog disturbance. I found weak evidence that prairie dog disturbance has a negative effect on vegetation structure, except for minimal effects on C4 and graminoid cover, but which depended mainly on season. Grassland type and season explained most of the effects on plant functional and taxonomic diversity as well as CWM traits. In the case of soil properties WOP grasslands tended to have higher nutrient availability than WP grasslands. However, mounds played a key role within WP grasslands. Mounds reduce compaction and increase nutrient levels of soil organic carbon, nitrogen, potassium, magnesium, and phosphorus. Such an effect was particularly present in calcareous and arid grasslands, and in many cases the effect was enhanced under wet conditions. In general, the effect of disturbance on soil property changes was dependent on environmental conditions. Overall, my study shows evidence that grassland type and season have a stronger effect than prairie dog disturbance on the vegetation of this short-grass, water-restricted grassland ecosystem.:3 TABLE OF CONTENTS Declaration of conformity 2 1 Acknowledgments 3 2 Extended Summary 5 4 List of Figures 11 5 List of Tables 13 1 Introduction 1 1.1 Importance of grasslands 1 1.2 Grassland conservation and ecosystem engineers 2 1.3 Prairie dogs: ecosystem engineers of grasslands in North America 3 1.4 Distribution of prairie dogs across North American grasslands 6 1.5 Current threats and conservation of the Mexican prairie dog C. mexicanus 7 1.6 Research questions, aims and objectives 9 2 Scientific background 13 2.1 Differences in grassland definitions and classifications 13 2.2 Dryland biases in grassland research 13 2.3 Research gaps on C. mexicanus 15 2.4 Functional diversity and disturbance 16 2.5 Soil complexity and limited research 17 3 Study Area: Grassland Priority Conservation Area of El Tokio 19 3.1 General overview 19 3.2 Bioregions, geology, topography and soils 20 3.3 Climate 23 3.4 Ecoregions, Land cover and Biodiversity 24 3.5 Anthropogenic activities and environmental issues 28 4 Assessing and classifying factors that could influence prairie dog ecosystem engineering effects 31 4.1 Data-driven identification of grassland types 33 4.1.1 Introduction 33 4.1.2 Methods 33 4.1.3 Results 36 4.1.4 Discussion and conclusion 39 4.2 C. mexicanus colony trends and differences across grassland types 41 4.2.1 Introduction 41 4.2.2 Methods 42 4.2.3 Results 48 4.2.4 Discussion and conclusion 52 5 Prairie dog disturbance effects on vegetation and soil across different grassland types and seasons 55 5.1 General methodology 57 5.1.1 Selection of grassland locations 57 5.1.2 Defining study sites and plots 58 5.1.3 Vegetation and soil sampling design 59 5.2 The effect of C. mexicanus on taxonomical and functional diversity across different seasons and grassland types 61 5.2.1 Introduction 61 5.2.2 Methods 63 5.2.3 Results 65 5.2.4 Discussion and conclusion 72 5.3 Soil property responses to the presence of C. mexicanus and its mounds across different grassland types, seasons and depths 77 5.3.1 Introduction 77 5.3.2 Methods 78 5.3.3 Results 81 5.3.4 Discussion and conclusion 88 6 Synthesis 95 6.1 Key findings 95 6.2 Management and Conservation opportunities 97 6.2.1 Designing management plans to suit existing environmental conditions 97 6.2.2 Functional diversity: an opportunity to identify patterns of vegetation across environmental conditions and scales. 98 6.3 Future research 99 6.3.1 Exploration of spatial and temporal effects 99 6.3.2 Mechanistic understanding of disturbance dynamics 100 6.3.3 A need for plant and soil ecological data 101 7 References 103 8 Appendix 131 8.1 Appendix 1. Prairie dog research reference list 132 8.2 Appendix 2. List of individual colonies with areas and other relevant information 140 8.3 Appendix 3. Historical and present colony data. 142 8.4 Appendix 4. Correlation results 144 8.5 Appendix 5. Top 3 models 146 8.6 Appendix 6. Species list per grassland type. 151 8.7 Appendix 7. Correspondence analysis (CA) for each grassland 154 8.8 Appendix 8. Post-hoc results 155 8.9 Appendix 9. Top 3 dominant species. 157 8.10 Appendix 10. HPD credible interval and ROPE. 159

Master of Science / Department of Biology / Jack F. Cully, Jr. / Black-tailed prairie dogs (Cynomys ludovicianus) are a species of management and conservation concern. Prairie dogs have lost both habitat and occupied area due to plague, which is caused by the bacterium Yersinia pestis, pest control, and habitat conversion to agricultural land. Our goals were to estimate survival rates and dispersal rates, and to compare methods for estimating abundance of black-tailed prairie dogs for both management and conservation. We trapped black-tailed prairie dogs at four small National Parks from April 2009 through August 2011. Prairie dogs were trapped and marked for two trapping sessions per year in order to estimate seasonal rates of apparent survival. Apparent survival rates were estimated using the package RMark in R to construct models for program MARK. We found estimates to vary according to field site, sex, year, and season (summer or winter). Possible reasons for the differences in survivorship among sites could be presence of disease, quality of forage, predation, or frequency of dispersal. Visual counts were also conducted each trapping session beginning in April of 2010 to estimate abundance. Mark-recapture, mark-resight, and visual counts were compared to determine which method would be the most effective for estimating abundance of prairie dogs. We found mark-resight to produce the most precise estimates of abundance. While it costs more money to conduct a mark-resight estimate than visual counts because of repeated sessions, they produced significantly different results from one another 75% of the time, which was especially apparent on sites that had some form of visual barriers such as tall vegetation and uneven ground. However, if further information is needed in terms of sex ratios, age ratios, or the exact number of prairie dogs, then mark-recapture is the only method that can be used. Land managers need to address the level of accuracy needed, topography, and vegetation height before choosing which sampling method is best for the prairie dog towns in question. Finally, we looked at rates of intercolony and intracolony dispersal by placing 149 VHF collars and 6 GPS collars on prairie dogs at three colonies. Intracolony dispersal was also monitored through visual observation and trapping records over the three years of the study. We found 23 intracolony and eight intercolony dispersal events. Combined, these three studies offer insight not only into monitoring of prairie dog populations but also potential influence by plague both within and among colonies of prairie dogs.

A majority of the arid grasslands in the western U.S. have been dramatically altered by anthropogenic influences resulting in degradation and desertification. Within the arid grasslands of North America a guild of burrowing herbivorous rodents that includes kangaroo rats (Dipodomys spp.) and prairie dogs (Cynomys spp.) is often considered integral to arid grassland maintenance. As part of the larger guild of burrowing herbivorous rodents, kangaroo rats are considered to be an important keystone guild whose role as ecosystem engineers and habitat modifiers complements that of prairie dogs. Together these species organize and structure arid grassland ecosystems and the biodiversity therein, by providing a mosaic of microhabitat patches, thus increasing overall heterogeneity. In an area where black-tailed prairie dogs (C. ludovicianus) were reintroduced, I used Giving-up Density (GUD) to assess the indirect effects black-tailed prairie dogs might have on the foraging patterns of resident kangaroo rats (D. spectabilis and D. merriamii). My objective was to compare and contrast kangaroo rat foraging GUD within and along the boundary of a on a recently established black-tailed prairie dog colony with that in the surrounding unmodified native habitat. This enabled assessment of whether black-tailed prairie dogs had an influence on the perceived quality of the habitat by kangaroo rats. Kangaroo rats visited off-colony feeding trays more frequently, and collected a greater mean mass of seed per tray as well. This indicates that the kangaroo rats perceived the area off the prairie dog colony as having a lower foraging cost than on the colony or along the colony edge. I conclude that from the perspective of the seed-eating kangaroo rat, the colony is not viewed as high quality habitat. What impact the reintroduction and management of one keystone species might have on another keystone species deserves additional consideration as we attempt to restore arid grassland ecosystems.