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Lesser prairie-chickens (Tympanuchus pallidicinctus) occur in mixed-grass prairies in the Southern Great Plains of North America. Conversion of native prairie to agriculture, energy development, unmanaged grazing, and recurrent drought have substantively reduced the lesser prairie chicken’s geographic range and abundance, and the species has become a significant conservation priority in recent years. Grasslands enrolled in the federal Conservation Reserve Program (CRP) provide cover for lesser prairie-chickens during the nesting and brood-rearing seasons in the Shortgrass Prairie/CRP ecoregion of their range, which has led to population increases. Lesser prairie-chicken males are known to boom and display in CRP fields in the High Plains of Texas, but little is known about the species’ ecology within CRP in the Sand Shinnery Oak Prairie ecoregion of its range. I investigated lesser prairie-chicken habitat selection, nest survival and ecology, and male and female survival in order to assess the effectiveness of CRP as a tool for prairie-chicken conservation in Texas. I captured 19 male and 6 female lesser prairie-chickens within CRP fields in Bailey and Cochran Counties, Texas during the years 2015-2017. I equipped each individual with a GPS platform transmitter terminal (PTT), which recorded 4 GPS locations per day at ± 18 m accuracy. I used selection ratios to assess lesser prairie-chicken selection between different CRP enrollments, native grassland, and agricultural fields for the breeding and non-breeding seasons, at the second and third orders of selection. At the second order of selection, lesser prairie-chickens selected Conservation Reserve Program fields seeded in non-native grasses (wi = 4.16, 95% CI=1.92 – 6.39) and native grasses and forbs (wi = 3.57, 95% CI=2.41 – 4.73) year-round. Cropland (wi = 0.17, 95% CI=0.07 – 0.27) and native grassland (wi = 0.27, 95% CI=0.05 – 0.49) were avoided, and native grass Conservation Reserve Program fields were used in proportion to their availability (wi = 1.24, 95% CI=0.80 – 1.68) year-round. Only Conservation Reserve Program fields seeded in native grasses and forbs were selected at the third order of selection (wi = 1.33, 95% CI=1.18 – 1.49). I monitored 8 lesser prairie-chicken nests during the course of the study, and all but one were located within CRP fields. I used the nest survival model within Program MARK to estimate nest survival within my study area. Apparent nest success was 50%, and the probability of a nest surviving the incubation period was 0.49 (95% CI = 0.16-0.77). I recorded 16 mortalities during the course of my study, and the majority were attributed to mammalian depredation (63%). Most mortality events (63%) occurred during the second half of the breeding season (June – August). I used known-fate models within Program MARK to estimate lesser prairie-chicken survival for the breeding and non-breeding seasons. The probability of a lesser prairie-chicken surviving the breeding season was 0.61 (SE = 0.08, 95% CI = 0.44-0.78), and the probability of an individual surviving the non-breeding season was 0.82 (SE = 0.11, 95% CI = 0.50-0.95). Survival increased as the proportion of native grass and forb CRP within the home range increased. Based on my results, CRP fields benefit lesser prairie-chickens in the High Plains of Texas. Lesser prairie-chicken home ranges included CRP fields, and my estimates of nest survival and adult survival are consistent with previous studies. Despite the benefits of CRP fields, lesser prairie-chicken abundance within CRP in Texas is currently low. Populations are still recovering from the severe drought of 2011. Also, CRP fields constitute approximately 17% of the study area, and they are often isolated and too small to individually support prairie-chickens. Adding new CRP fields adjacent to existing fields and targeting large agricultural fields for enrollment will increase CRP patch size and serve to connect the lesser prairie-chicken population across the High Plains of Texas. Based on my results, an aggregation of CRP fields totaling 2,500 ha will support multiple LEPC leks. Also, maintaining CRP fields in grasses after contract expiration and actively managing expired fields for prairie-chickens will benefit the species in the distant future.

Lesser prairie-chickens (Tympanuchus pallidicinctus) have experienced a decline in population numbers and distribution throughout the central and southern Great Plains, which led to their status as a threatened species under the United States Endangered Species Act of 1973. However, the listing was vacated in September 2015 by a federal judge in Texas. Regardless, the lesser prairie-chicken remains a species of conservation concern and ecological data are pertinent to understanding mechanisms driving population demography. Populations in the Sand Shinnery Oak (Quercus havardii) Prairie are located in the southwestern-most portion of their distribution, isolated from their core distribution in the Mixed-Grass Prairie, Sand Sagebrush (Artemisia filifolia), and Short-Grass Prairie ecoregions. The climate within the species’ distribution is characterized by frequent droughts that negatively affect population numbers, but the effects of weather variables and future climate change on lesser prairie-chicken populations between isolated and core populations are unknown. Additionally, populations are subject to the effects of anthropogenic-driven landscapes, but effects of land use and anthropogenic structures among and between both regions are unknown. To address these concerns, I modeled survival of males, females, broods, and nest from the Sand Shinnery Oak Prairie and Mixed-Grass Prairie ecoregions as a function of a priori models composed of biologically relevant temperature and precipitation parameters. I then modeled the effect of land cover classifications such as croplands, bare ground, shrublands, grasslands, Conservation Reserve Program (CRP) lands, and trees on lesser prairie-chicken lek attendance. In addition, I modeled the effect of anthropogenic structures such as transmission lines, oil and gas wells, improved and unimproved roads, wind turbines, and oil and gas wells with a five-year time lag on lek attendance. Finally, I created an Integrated Population Model (IPM) to assess the potential effect of climate change given different Representative Control Pathways on lesser prairie-chickens populations. My findings suggest that weather variables associated with extreme temperatures and precipitation influence lesser prairie-chicken vital rates in both ecoregions. I modeled the effect of weather parameters on male, female, nest, and brood survival in the Sand Shinnery Oak Prairie Ecoregion (1999–2012) and the Mixed-Grass Prairie Ecoregion (1999–2015). When modeled as a function of weather variables, the monthly probability of male survival during the study period (March 1 to September 12) was 0.80 (SE = 0.004, 95% CI: 0.75–0.84) in both ecoregions. Female survival differed among ecoregions, and the probability of females surviving two-week intervals during the study period was 0.77 (SE = 0.05, 95% CI: 0.71–0.81) in the Sand Shinnery Oak Prairie Ecoregion and 0.96 in the Mixed-Grass Prairie Ecoregion. Likewise, nest survival differed between the two ecoregions, and the probability of a nest surviving the 28-day incubation period was 0.32 (SE = 0.004, 95% CI: 0.28–0.43), and 0.24 (SE = 0.004) in the Sand Shinnery Oak Prairie and Mixed-Grass Prairie ecoregions, respectively. Finally, brood survival differed between ecoregions, and the probability of broods surviving the 30-day brooding period was 0.16 (SE = 0.01, 95% CI: 0.04–0.29 and 0.74 (SE = 0.005, 95% CI: 0.55–1.00) in the Sand Shinnery Oak Prairie and Mixed-Grass Prairie ecoregions, respectively. All demographic groups exhibited positive associations with breeding season extreme temperature variables and non-breeding season temperature variables. Although weather had no significant effect on brood survival in the Sand Shinnery Oak Prairie Ecoregion, broods in the Mixed-Grass Prairie responded positively to extreme hot temperatures the first two weeks of brooding. The response of lek counts to anthropogenic structure dispersion differed between ecoregions. I found no significant relationships between lek counts and anthropogenic structure dispersion in the Sand Shinnery Oak Prairie Ecoregion; however, lek counts exhibited a negative relationship with transmission lines (≥ 69-kV; β = -1.93; 95% CI: -3.29–-0.71) and unimproved roads (β = -0.92; 95% CI: -1.43–-0.42) in the Mixed-Grass Prairie Ecoregion. The response of lek counts to land cover patches differed across the ecoregions with negative responses primarily associated with increasing monocultures of shrublands (β = -0.20; 95% CI: -0.30–-0.11) in the Sand Shinnery Oak Prairie Ecoregion and CRP lands (β = -0.83; U; 95% CI: -1.23–-0.43) in the Mixed-Grass Prairie Ecoregion. Although, the IPM can be improved with more informative parameters, I found that populations in the Sand Shinnery Oak Prairie Ecoregion were predicted to no longer persist after 2036 while populations in the Mixed-Grass Prairie Ecoregions were predicted to decline through 2100. Lambda values for populations in the Sand Shinnery Oak Prairie Ecoregion given all emission scenarios were 0.50 from 1996–1997, spiked to above one in 1999, and stayed at 0.50 from 2000–2009. In 2011, lambda trajectories dropped to < 0.3 and populations became extinct between 2012–2036. Although populations were not projected to become extinct in the Mixed-Grass Prairie Ecoregion, lambda values remained below one from 1995–2100 indicating that the population would continue to decline given every emission scenario. My results indicate that outlook for lesser prairie-chicken populations in both ecoregions will not be sustainable or cease to persist within the 21st century. To ensure population persistence, management efforts should focus on maintaining sufficient vegetation cover at the landscape level while ensuring landscape heterogeneity to curb the effects of more frequent and intense drought events given future climate change.

Trends in midwinter waterfowl survey data, collected by Texas Parks and Wildlife (TPWD), indicate an increase in annual abundance estimates of waterfowl in the Rolling Plains Ecological Region since 1997. Stock ponds created within in the Rolling Plains provide small, but regionally widespread features, and currently supply aquatic habitat in this semi-arid rangeland landscape; however, limited data exists regarding the availability of resources for nonbreeding waterfowl on stock pond systems. In an effort to address existing information gaps associated with waterfowl use and stock pond systems in the Rolling Plains, research was initiated from August 2014 through March 2015. My objectives for the study were to: 1) investigate and define aquatic invertebrate and vegetative communities, 2) estimate energetic carrying capacity for dabbling ducks, 3) provide waterfowl use inferences from waterfowl survey data, and 4) suggest stock pond management recommendations for state agencies and landowners interested in managing for waterfowl. In an effort to assess the first and second objective, data were collected from 32 study ponds to target potential forage items through quadrat sampling for mature seeds, and water-column and benthic sampling methodologies for aquatic invertebrates. From the collected data, a bioenergetics model was applied to estimate energetic carrying capacity, which is based on energy supply and demand relationships. Three stock pond construction types were recognized during the research effort: embankment, excavated, and combination, and the relationships of forage provision were compared between construction types. Waterfowl visual ground surveys were conducted to provide a baseline for potential waterfowl use relationships for inference toward the third objective. After incorporating food items sampled from three forage groups (water-column invertebrates, benthic invertebrates, and seeds) into a Duck-Energy-Day (DED) model, I yielded conservative carrying capacity estimates of 12,495 DED, moderate estimates from 23,057 – 32,955 DED, and liberal estimates of 45,478 DED among the study stock ponds. The results suggest high variability regarding stock pond forage availability and provision. While some stock ponds displayed a relative high capacity to support nonbreeding waterfowl, others contributed less than 2% of the total DED estimates within each of the three forage categories. Trends associated with construction type partially explain DED estimates, where embankment type are generally greater contributors to total DED. Characteristics associated with each construction type likely influenced differences in DED provision. Additionally, seasonal averages of water-column invertebrate abundances, for excavated ponds, were approximately 50% or less, than those of other construction types. Differences were observed between waterfowl average abundance data and construction type (F 2, 29 = 9.771; P = < 0.001), where embankment pond type was significantly different from combination (P < 0.001) and excavated types (P < 0.001); however, excavated and combination type did not differ (P = 0.753). Information collected over the duration of this project suggests that embankment construction types may provide more waterfowl forage and thus, more attractive to nonbreeding waterfowl.

As urban areas expand to accommodate a growing population, urban planners are tasked with building Urban Green Spaces (UGS) that support both ecological services and public recreation, also considered multi-purpose UGS areas. In Lubbock, Texas, Urban Water Bodies (UWB) have been used for storm water catchment and some have been incorporated into public UGS. The purpose of this study was to evaluate recreation in UGS that include UWB by: 1) observing recreational activities at UGS/UWB, and 2) analyzing stakeholders’ value and perceptions of UWB/UGS. To identify UWB with an associated UGS, data were used from multiple sources. Visual observations of recreational activities were conducted at 24 study sites over a 24-month period, and interviews and written surveys were conducted to gain stakeholder perspectives. Documenting current UWB types provided useful information for planning future UWB/ UGS in a semi-arid environment. Visual observations of study sites aided in discerning human usage of UWB/UGS, and feedback received from UWB/UGS stakeholders provided a user’s perspective of the multi-purpose UWB/UGS. Results of this study can aid direction of future studies on human activity presence in multi-purpose UGS. In addition, knowledge of human UGS preferences can help urban planners while preserving water related ecological services in a multi-purpose UGS/UWB area.

The Ogallala Aquifer is one of the largest aquifers in the world underlying parts of eight states in the United States. This aquifer is considered to be a non-renewable resource because of the low rate of natural recharge compared to the amount of groundwater extracted every year. Due to the large scale of production of agricultural commodities, irrigated agriculture on the Southern High Plains of Texas (Texas High Plains) relies heavily on groundwater extracted from the Ogallala Aquifer. Concerns about the high rate of depletion of the aquifer in this region in recent years have led to the enactment of policies designed to slow down water extraction and increase the usable life of this resource. However, policy implementation has not been uniform across the aquifer, leaving some farmers in portions of the aquifer with no effective groundwater extraction guidelines only a short distance away from areas where farmers face regulatory limits. This dissertation addresses two sets of issues related to groundwater utilization in the Texas High Plains through two different but related studies. The first study investigates the effects of policy implementation uncertainty on the extraction of groundwater. In this first study, a seemingly unrelated regression (SUR) model is estimated for harvested acreage of the three major crops produced in six representative counties of the Texas High Plains. Corn acreage (an irrigation-intensive crop) is used as a proxy for groundwater use. In five of the six counties evaluated, corn acreage would be expected to increase (along with total groundwater use) upon the enactment of an unenforced groundwater extraction policy. After controlling for price and climate effects, it was concluded that there is strong evidence that groundwater use policy uncertainty is likely to increase groundwater extraction in the Texas High Plains region. The social desire to achieve perpetual sustainability of groundwater resources in the study region, or at the very least to prolong the life of the Ogallala Aquifer, has resulted in discussions about alternative groundwater management policies. Producers, in their concern about the implementation of policies to slow down groundwater extraction, may tend to use as much water as they can in the short-run to maximize profits before groundwater use restriction policies are enforced. For this reason, the second study conducted in this dissertation addresses possible factors that could contribute to lengthen the usable life of the Ogallala Aquifer. Specifically, in the second study a county-wide Texas High Plains representative time-varying non-linear optimization model that considers farm-level decision making with respect to groundwater use is used to evaluate the tradeoffs between time value of money and future agricultural productivity enhancements. The results of the second study reveal that the sooner economic agents who possess the property rights to the groundwater resources in the Texas High Plains realize the likely benefits associated with higher agricultural productivity in the future, the sooner water conservation goals could be fulfilled.

Urban areas are not what is usually thought of as quality habitat for wildlife, however as urbanization increases wildlife are forced to use the urban environment. By studying the way bird richness is affected by different aspects of the city could prove useful in future management of the urban environment. First, I compared bird diversity to vegetation coverage in neighborhoods across Lubbock, Texas. The second objective was to study bird diversity and vegetation coverage differences throughout the area. My final objective was to observe the way house prices differ when considering bird diversity and vegetation coverage. I performed bird point counts during the summer of 2014, recording every bird seen and heard. I also performed vegetation surveys from May to October 2014 recording number, height, and species of trees as well as other vegetation variables within the urban area of Lubbock, Texas. Recently-sold house prices were obtained from local real estate agents. Simple and multiple linear regressions were performed to determine the effect of vegetation and house spatial placement on bird richness. T-tests were also performed to discover differences in vegetation and bird richness between two areas of Lubbock, TX that are socio-economically different. My findings supplement knowledge of bird use of urban neighborhoods in Lubbock, Texas. My study protocols identify methods and habitat variables that could be used to predict bird diversity in urban areas beyond Lubbock, Texas.

Pronghorn (Antilocapra americana) in Texas are assessed every year by the Texas Parks and Wildlife Department (TPWD), via aerial survey, to determine population size, spatial distribution, and harvest recommendations. Delineated herd units in the Panhandle/High Plains wildlife district (District 2) form the basic spatial unit of the TPWD’s pronghorn population assessment and harvest management goals. To determine the impact of anthropogenic and climatic factors on pronghorn population growth and distribution in District 2, I analyzed pronghorn population dynamics by assessing the population-level effects of hunter-harvest and precipitation on pronghorn population size via a multivariate analysis of covariance (MANCOVA) and a canonical discriminant function analysis (CDFA). I then evaluated pronghorn distribution by generating a presence-only spatial model of suitable habitat for pronghorn in District 2 in the MAXENT modeling environment using the following environmental variables: land cover, precipitation, vegetation greenness, distance to agriculture, distance to woodland, and distance to water. Lastly, I evaluated habitat connectivity within District 2 via CIRCUITSCAPE using the habitat suitability model as the primary input. I found that pronghorn populations vary significantly between herd units, especially herd units with larger population sizes. Precipitation and harvest, however, had a minimal effect on pronghorn populations. Additionally, very little highly suitable habitat remains in District 2, and the biggest risk to pronghorn habitat is woodland encroachment. Habitat is most connected in the northern-most portion of the Distirct 2, but connectivity is restricted by major roadways, which may isolate some pronghorn populations. In District 2, pronghorn populations experience minimal hunting pressure and a tolerance to changes in precipitation levels. Pronghorn habitat quality and connectivity, however, may become limiting factors for pronghorn in the future. Ensuring that suitable pronghorn habitat is conserved will assist in maintaining healthy pronghorn populations in District 2 as will the mitigation of barriers to pronghorn movement.