Rolling Plains Of Texas Research Articles

Soil water dynamics under a warm-season cover crop mixture in continuous wheat

Cover crop technology can potentially benefit monoculture wheat systems in the semi-arid US Southern Great Plains, but the biggest hurdle in such regions where evapotranspiration exceeds precipitation is soil water. Cover crop impact on soil water use and availability is a major cause for concern in water-limited environments. The objective of this study was to evaluate the impact of cover crops, grazing, and intercrops on soil water dynamics under rainfed conditions. Seven treatments were evaluated, including conventional tillage (CT) and combinations of no-tillage (NT) with a cover crop mixture, grazed cover crops, and/or cash crop intercropping. The three-year study was conducted on a long-term NT continuous wheat system in the Texas Rolling Plains. Despite dry periods, the cover crop mixture produced 2141 to 3503 kg ha−1 dry herbage mass. Stored soil water was significantly lower within 60 days after planting for cover crop compared to no cover crop treatments. Stored soil water was 22–26% lower in cover crop plots at time of termination. In the final two years of the study, the positive change in stored soil water from cover crop termination to wheat planting was two to four times greater for cover crop treatments compared to non-cover crop treatments. The greater infiltration and water capture after termination has the potential to make up for the loss in soil water that cover crops used.

Agronomic performance of the lignocellulosic feedstock crop energy cane in the Texas Rolling Plains

AbstractFeedstock genetics and environment are important factors determining biomass yield of biofuel crops. Field studies were conducted to evaluate agronomic performance of four energy cane (Saccharum spp. hybrid) genotypes (TUS11‐62, TUS11‐58, TCP10‐4928, and Ho 02‐113) in the Texas Rolling Plains. In the first study, cane billets were planted in 2015 and data were collected from first (2016) and second (2017) ratoons. A second study was planted in 2016 and data were collected the same year from plant cane. Data collected include biomass, stalk height, stalk population, leaf area index (LAI), and normalized difference vegetation index (NDVI). Biomass yield of ratoons was not significantly different (p > .05) among genotypes. However, TUS11‐58 had the highest plant cane yield. The average biomass yield of plant cane, first, and second ratoons were 20.2, 40.4, and 26.4 t ha−1 respectively. Longer growing period of ratoon (∼8 mo) compared to plant cane (∼5.5 mo) increased biomass. However, low temperatures (−14 to −16 °C) during the dormant phase resulted in lower yield of the second ratoon. Among genotypes, TUS11‐62 had taller stalks, but was cold sensitive. Genotype TCP10‐4928 had higher stalk population and LAI. An exponential relationship was observed between LAI and NDVI (R2 = .67). Overall, there were differences in growth characteristics of energy cane genotypes, however biomass yield was similar in the ratoon phase. The results of this study showed that low temperature tolerance and growing season duration are key factors in determining biomass yield in higher latitude regions such as the Texas Rolling Plains.

"Weight of evidence" as a tool for evaluating disease in wildlife: An example assessing parasitic infection in Northern bobwhite (Colinus virginianus).

The potential of parasites to affect host abundance has been a topic of heated contention within the scientific community for some time, with many maintaining that issues such as habitat loss are more important in regulating wildlife populations than diseases. This is in part due to the difficulty in detecting and quantifying the consequences of disease, such as parasitic infection, within wild systems. An example of this is found in the Northern bobwhite quail (Colinus virginanus), an iconic game bird that is one of the most extensively studied vertebrates on the planet. Yet, despite countless volumes dedicated to the study and management of this bird, bobwhite continue to disappear from fields, forest margins, and grasslands across the United States in what some have referred to as “our greatest wildlife tragedy”. Here, we will discuss the history of disease and wildlife conservation, some of the challenges wildlife disease studies face in the ever-changing world, and how a “weight of evidence” approach has been invaluable to evaluating the impact of parasites on bobwhite in the Rolling Plains of Texas. Through this, we highlight the potential of using “weight of the evidence” to better understand the complex effects of diseases on wildlife and urge a greater consideration of the importance of disease in wildlife conservation.

Growth and development of irrigated cotton in conservation management systems of the Texas Rolling Plains

AbstractConservation tillage and cover cropping are expected to enhance multiple ecosystem services in cotton (Gossypium hirsutum L.) production systems. The few published studies addressing this in the transitional climate of the Texas Rolling Plains region have shown cotton lint yield to be the same in conservation and conventional management systems, though the specific effects of conservation management are still being debated and producer adoption remains low. In this study, in which data was collected in Years 5 and 6 in long‐term management plots, our objective was to make detailed, season‐long measurements of crop development and productivity parameters, identifying diversions among systems, if any. The irrigated cotton management systems included: conventional tillage (CT), no‐till (NT), no‐till with wheat (Triticum aestivum) cover crop (NT‐WC), and no‐till with mixed‐species cover crop (NT‐MC). Several differences were found among systems over discrete timeframes, though these were mostly transient changes without year‐to‐year consistency and did not lead to differences in yield. The only exceptional trend was observed in 2017 in the NT‐MC treatment, as it had relatively great early‐season biomass production and bolls per plant, and greater season‐long plant height relative to the CT system, though these differences did not alter yield. No evidence was found that conservation management negatively affected cotton crop development, productivity, or yield at any point during the two growing seasons. Conservation management practices can be implemented by regional producers for the expected ecosystem services, including reduction of erosion and improved soil health, with no negative effects on the cotton crop anticipated.

Agronomic and economic impacts of cover crops in Texas rolling plains cotton

AbstractCover crops have been proposed as a resource that could enhance the effect of no‐till (NT) cropping systems. Crop yield limitations due to cover crops in the U.S. Great Plains are a concern to potential adopters. This research determined the impact of cover crops on crop yield and economic return compared with conventional practices in dryland systems of the Texas Rolling Plains. The study conducted at the Texas A&M AgriLife Chillicothe Research Station evaluated the following treatments: (a) conventional till (CT); (b) NT, and NT with the following cover crops; (c) Austrian winter pea (Pisum sativum L.); (d) hairy vetch (Vicia villosa L.); (e) crimson clover (Trifolium incarnatum L.); (f) winter wheat (Triticum aestivum L.); and (g) a multi‐species mixture. Cotton (Gossypium hirsutum L.) yields, expenses, and returns were determined over a 4‐yr period (2013–2016). Cover crops increased total seed costs compared to CT and NT. Hairy vetch and the multi‐species mixture increased total expenses over CT and NT. However, no significant treatment effect was determined for crop yield or net return among treatments. A multi‐species mixture did not provide an agronomic or economic advantage compared to single species cover crop approaches. Under dryland conditions in the Texas Rolling Plains, these selected cover crops maintained cotton yields without negatively affecting net returns. Other ecosystem services should be considered prior to implementing cover crops in studied cropping systems. Site‐specific research is warranted in regions of the southern Great Plains where water may be more limited than the Texas Rolling Plains.

Monitoring Northern Bobwhite (Colinus virginianus) Populations in the Rolling Plains of Texas: Parasitic Infection Implications

The Northern bobwhite quail (Colinus virginianus) is an important gamebird among hunters that has been experiencing a nationwide decline for > 50 yr. In West Texas, one of the last regions to experience this downward trend, research on bobwhite populations has focused on habitat variables and, increasingly, on parasitic infection. In bobwhite, two of the most common parasites are the caecal worm (Aulonocephalus pennula) and eyeworm (Oxyspirura petrowi). To better document the state of bobwhite populations in the Rolling Plains Ecoregion, trapping, summer rooster counts, fall covey counts, and parasitic infection assessments were conducted in three counties during 2018. These efforts were compared with previous years for a longitudinal perspective. In 2018, bobwhite populations experienced a widespread decline, although some counties surveyed fared slightly better than others. More effort was required to trap fewer total bobwhite, and fewer roosters and coveys were counted than in previous years. In addition, in 2018, parasitic infection levels of caecal and eyeworms were higher than or similar to levels in previous years. Additional research is necessary to understand which factors influence bobwhite populations in allopatric locations and over time.

Helminth Survey of the Northern Bobwhite (Colinus virginianus) from the Rolling Plains of Texas, U.S.A.

The eyes, breast muscle, and internal organs of 128 hunter-shot northern bobwhites (Colinus virginianus) from the Rolling Plains ecoregion of Texas, U.S.A., were examined for helminths. Six species of nematodes, 1 acanthocephalan, and 1 cestode were found in 120 bobwhites, representing 18,205 helminth individuals. Aulonocephalus pennula was the most common (91% prevalence) and numerically abundant (91% of all individuals) species, followed by Oxyspirura petrowi (66% prevalence and 7% of all individuals). Each of the remaining 6 species was rare (<24% prevalence). Species richness was low compared to studies from the southeastern United States. Of the species found, Tetrameres pattersoni, Cheliospiruraspinosa, and O. petrowi are known to cause pathology in quail. Prevalence and mean abundance of O. petrowi were higher in adults than juveniles. Host age did not influence prevalence of A. pennula, and host sex did not influence prevalence or mean abundance of A. pennula or O. petrowi.

Elevated parasite burdens as a potential mechanism affecting northern bobwhite (Colinus virginianus) population dynamics in the Rolling Plains of West Texas.

Northern bobwhite quail (Colinus virginianus) are a highly sought-after game bird in the Rolling Plains of West Texas. Unfortunately, bobwhite populations in this area are subject to dramatic fluctuations and have been steadily decreasing over the past several decades. While many factors have been investigated as potential mechanisms of cyclic and declining bobwhite numbers, the effect of parasites on bobwhite populations has historically been undervalued. Between December 2017 and February 2018, we received 21 hunter-shot bobwhite from Garza and Mitchell counties in Texas and found peak caecal worm (Aulonocephalus pennula) and eyeworm (Oxyspirura petrowi) burdens averaging 599 and 44, respectively. These represent the highest average parasite loads we have documented in bobwhite from the Rolling Plains thus far and are coincident with widespread reports of declining bobwhite abundance. These elevated infections also followed a high point in bobwhite populations in the Rolling Plains, and our observations of infection dynamics during this time reflect other instances of potential parasite-induced host mortality. While the sample discussed in this communication is small, our findings highlight the need for additional research into how parasites may affect bobwhite population fluctuations in this region.

Selecting Cool‐Season Forage Grasses for Yield, Seasonal Yield Distribution, and Nutritive Value in the Blacklands and Rolling Plains Ecoregions of Texas

Core Ideas The study evaluated seven cool‐season crops for their forage yield and quality in the Blacklands and Rolling Plains of Texas. There was significant interaction of crop species and environment on forage yield and quality. Triticale has wide range of adaptability in both the Blacklands and Rolling Plains ecoregions. Site‐specific recommendation of best adapted forage crop species would help the producers achieve higher forage productivity and profitability. Selection of suitable cool‐season crop species for winter forage production is a critical management decision in many ecoregions of the United States, including Texas. A study was conducted during 2004 to 2007 in the Blacklands and Rolling Plains ecoregions of Texas using seven cool‐season crops to determine the site‐specific crop choice to maximize forage yield and nutritive value. The seven crop species tested in these two ecoregions included: barley (Hordeum vulgare L.), hard red wheat (Triticum aestivum L.), oat (Avena sativa L.), rye (Secale cereale L.), ryegrass (Lolium multiflorum Lam.), soft red wheat (Triticum aestivum L.), and triticale (×Triticosecale Wittmack). The results indicated that crop choice for maximizing the forage yield and nutritive value varied with environment. In the Blacklands, oat and triticale produced greater forage yields than other crop species (P &lt; 0.05). In the Rolling Plains, ryegrass yielded more forage during years of above‐average precipitation, whereas rye and triticale produced more forage during drier years. Seasonal forage yield distribution varied among different site‐years of the Blacklands and Rolling Plains ecoregions. Triticale was demonstrated to be the crop that performed most consistently at both ecoregions of Texas. Rye and barley had greater nutritive value and mineral composition in the Blacklands, whereas ryegrass had greater mineral composition in the Rolling Plains (P &lt; 0.05). Given this information, producers in the Blacklands and Rolling Plains ecoregions can make informed decisions on selection of suitable forage crops to be grown on their farms to achieve greater forage yield and nutritive value, and to match up their specific management and livestock requirements.

Inadequate thermal refuge constrains landscape habitability for a grassland bird species.

Ecologists have long recognized the influence that environmental conditions have on abundance and range extent of animal species. We used the northern bobwhite (Colinus virginianus; hereafter bobwhite) as a model species for studying how microclimates serve as refuge against severe weather conditions. This species serves as an indicator or umbrella species for other sensitive ground-nesting, grassland obligate species. We conducted a mensurative field experiment in the rolling plains of Texas, USA, a semi-arid ecosystem on the southwestern periphery of bobwhite range, to determine whether native bunch grasses, apparently suitable for bobwhite nesting, could reduce ambient temperature below levels harmful for eggs. During the nesting season, we compared temperature and relative humidity readings at daily heat maxima (i.e., the 3 h during each day with highest temperatures) during the nesting season over the course of two years at 63 suitable nest sites paired with 63 random locations (n = 126) using two sensors at ∼10 and ∼60 cm above ground level. Mean temperature at nest height was 2.3% cooler at nest sites (35.99 °C ± 0.07 SE) compared to random locations (36.81 °C ± 0.07 SE); at ambient height, nest sites were slightly cooler (32.78 °C ± 0.06 SE) than random location (32.99 °C ± 0.06 SE). Mean relative humidity at nest sites was greater at nest height (34.53% ± 0.112 SE) and ambient height (36.22% ± 0.10 SE) compared to random locations at nest (33.35% ± 0.12 SE) and ambient height (35.75% ± 0.10 SE). Based on these results, cover at sites that appear visually suitable for nesting by bobwhites and other ground nesting birds provided adequate thermal refuge in the rolling plains by maintaining cooler, moister microclimates than surrounding non-nesting locations. Post-hoc analyses of data revealed that habitat conditions surrounding suitable nest sites strongly influenced thermal suitability of the substrate. Given that eggs of bobwhites and probably other species would experience lethal temperatures without these thermal refuges in the context of proper habitat condition, nesting vegetation is a critical component of niche space for bobwhites and other ground nesting birds in semi-arid regions. Many contemporary land uses, however, degrade or destroy bunch grasses and grassland systems, and thus decrease landscape inhabitability. Conservationists working with obligate grassland species that require bunch grasses in semi-arid regions should develop land management strategies that maximize the availability of these thermal refuges across space and time.

An evaluation of northern bobwhite translocation to restore populations

ABSTRACTNorthern bobwhite (Colinus virginianus) populations have been declining in Texas during the last 2 decades. This decline also is occurring in areas with apparently ample habitat such as the Rolling Plains of Texas, USA. The goal of our study was to examine the efficacy of translocating wild‐trapped bobwhites into recently depopulated areas in the eastern Rolling Plains as a method of restoring population size. Our objectives were to document survival (spring‐summer and annual), reproductive efforts, and site fidelity of translocated bobwhites and compare relative abundance of bobwhites between release and control sites to evaluate the efficacy of translocation. We translocated 409 wild bobwhites (n = 186 radio‐marked F) to 2 sites in Shackelford and Stephens counties, Texas, during March 2013 and 2014. Spring‐summer (Mar–Sep) survival ranged between 0.32 and 0.38 (n = 186 bobwhites), and annual survival ranged between 0.19 and 0.23 (n = 186 bobwhites) during 2013–2015. Seventy‐four percent of translocated females that entered the nesting season (i.e., May 1; n = 112 bobwhites) produced a nest, resulting in 125 nests with an apparent nest success of 46.1% and a nesting rate of 1.1 ± 0.1 (SE) nests/female. Site fidelity post‐translocation was moderate to high; 67.7% (n = 44 bobwhites) and 85.1% (n = 40 bobwhites) of translocated bobwhites did not disperse &gt;2 km from their release point during the summers of 2013 and 2014, respectively. Despite this strong demographic performance, relative abundance of bobwhites did not differ between the release and control sites after 2 years as indexed by covey‐call counts (2.7 ± 0.6 vs. 3.0 ± 1.2 coveys/point, respectively; P = 0.71) and helicopter surveys (0.9 ± 0.2 vs. 0.7 ± 0.2 bobwhites/km, respectively; P = 0.64). Thus, translocation of bobwhites failed to increase the bobwhite population beyond that of the control during this study. Future translocation research should aim to increase translocation success by investigating methods for increasing survival during the 1‐month period following translocation (e.g., soft‐release, vitamin E and selenium injections) and for improving site fidelity using conspecific attraction. Future research should incorporate genetic measures to assess genetic contribution of translocated individuals to improve evaluation of translocation success. © 2017 The Wildlife Society.

Assessing the hydrologic and water quality impacts of biofuel‐induced changes in land use and management

AbstractThe Southern High Plains (SHP) of Texas, where cotton (Gossypium hirsutum L.) is grown in vast acreage, and the Texas Rolling Plains (TRP), which is dominated by an invasive brush, honey mesquite (Prosopis glandulosa) have the potential for biofuel production for meeting the U.S. bioenergy target of 2022. However, a shift in land use from cotton to perennial grasses and a change in land management such as the harvesting of mesquite for biofuel production can significantly affect regional hydrology and water quality. In this study, APEX and SWAT models were integrated to assess the impacts of replacing cotton with Alamo switchgrass (Panicum virgatum L.) and Miscanthus × giganteus in the upstream subwatershed and harvesting mesquite in the downstream subwatershed on water and nitrogen balances in the Double Mountain Fork Brazos watershed in the SHP and TRP regions. Simulated average (1994–2009) annual surface runoff from the baseline cotton areas decreased significantly (P &lt; 0.05) by 88%, and percolation increased by 28% under the perennial grasses scenario compared to the baseline cotton scenario. The soil water content enhanced significantly under the irrigated switchgrass scenario compared to the baseline irrigated cotton scenario from January to April and August to October. However, the soil water content was depleted significantly under the dryland Miscanthus scenario from April to July relative to the baseline dryland cotton scenario. The nitrate‐nitrogen (NO3‐N) and organic‐N loads in surface runoff and NO3‐N leaching to groundwater reduced significantly by 86%, 98%, and 100%, respectively, under the perennial grasses scenario. Similarly, surface runoff, and NO3‐N and organic‐N loads through surface runoff reduced significantly by 98.9%, 99.9%, and 99.5%, respectively, under the post‐mesquite‐harvest scenario. Perennial grasses exhibited superior ethanol production potential compared to mesquite. However, mesquite is an appropriate supplementary bioenergy source in the TRP region because of its standing biomass and rapid regrowth characteristics.

Response of Northern Bobwhites to Habitat Improvement on Private Lands in the Rolling Plains of Texas

Northern bobwhites (Colinus virginianus) in the Rolling Plains of Texas have experienced significant declines in recent years. Examination of the Texas Parks and Wildlife Department Quail Roadside Counts reveals a steep decline since 2007 in the Rolling Plains of Texas. Biologists only detected 2.91 birds/counting route in 2013. This number marked 2 years in a row of record lows (counts started in 1978) below the long-term mean of 19.7 birds/route (Texas Parks and Wildlife 2015). These numbers are not surprising given the historically damaging drought Texas has suffered. Texas Parks and Wildlife Department counts improved to 7.5 bobwhites/counting route in 2014. This increase is linked to improving precipitation levels preceding and during the 2013 and 2014 breeding seasons. Though population growth is controlled primarily by rainfall (Jackson 1962), a reduction in the acreage of suitable habitat has also played a role in the bobwhite decline. Many areas on the Rolling Plains of Texas have become choked with invasive brush species, such as honey mesquite (Prosopis glandulosa) and juniper (Juniperus spp.), because of excessive grazing and a lack of fire (Mcpherson et al. 1988, Ansley et al. 1995). Asner et al. (2003) estimated woody cover increased as much as 500% in some areas of northern Texas between 1937 and 1999. Mesquite and juniper encroachment can occur to the point they become a steady-state, dominant vegetation that shades out grasses and other vegetation (Ansley and Weidemann 2008). Woody cover encroachment exceeding 70% canopy cover is not uncommon (Mirik and Ansley 2012). This heavy brush cover is not suitable habitat for bobwhites and limits population expansion even in years of adequate rainfall (Jackson 1969, Kopp et al. 1998). The millions of acres of brushdominated rangeland in Texas represent areas that can become usable habitat for bobwhites when brush coverage is reduced to suitable levels. Mechanical removal using a dozer or track hoe is a common method of reducing canopy coverage of mesquite and juniper. This method allows a manager to selectively remove brush in the quantity and distribution that is desired while leaving beneficial shrub species such as lotebush (Ziziphus obtusifolia) or skunkbush sumac (Rhus trilobata) undamaged. We received funding from a Texas Parks and Wildlife Habitat Enhancement Grant to mechanically remove excessive brush cover on private lands with the objective of expanding bobwhite populations. We selected treatment sites that were currently inhabited by quail or were adjacent to sites inhabited by quail, but whose populations appeared to be limited by excessive brush cover and unable to expand or increase. These sites were located on ranches enrolled in The Quail-Tech Alliance research program. We treated 404 ha spread across 7 different properties during 2014 and 2015. Depending upon the site, brush removal was accomplished using either a bulldozer or track hoe to mechanically grub mesquite and juniper trees or in some instances a combination of both tree species. In some instances landowners used their own equipment while in others private contractors were hired to accomplish the reduction project. We worked with individual landowners to incorporate their overall wildlife management objectives. Consequently, the pattern and canopy coverage of brush remaining after mechanical reduction varied among projects and was influenced by the brush density of the treatment area. Some landowners removed strips of brush while others left brush mottes throughout the landscape. All projects resulted in increased acreage of suitable bobwhite habitat with a resulting brush canopy coverage ranging from 5% to 30% depending upon the project. The soil disturbance and subsequent beneficially timed rainfall caused treated areas to be revegetated with desirable forbs and grasses within 60 days posttreatment. Bobwhites were observed using the treatment areas within a few months of treatment. Though favorable rains in 2014 and 2015 played a role in this response, it would not have been possible for bobwhites to use the treatment areas before brush reduction. Bobwhite populations will positively respond to mechanical brush removal treatments in the Rolling Plains of Texas. This project increased the acreage of suitable habitat for bobwhites; showing the value of habitat restoration programs.

Invertebrate Abundance at Northern Bobwhite Brood Locations in the Rolling Plains of Texas

Northern bobwhite (Colinus virginianus), a bird of significant ecological and economic importance throughout the Rolling Plains region of Texas, has experienced significant population declines. Bobwhites have been the focus of extensive research for decades but little is known about foraging ecology of adults and chicks during post-hatch. Invertebrates are a key summer diet component for chicks, and supply the necessary proteins and minerals needed to fuel rapid body development. We examined brood-foraging sites to investigate invertebrate abundance. We radiomarked 121 bobwhite hens during winter-spring 2008 and 2009 and subsequently monitored 14 broods post-hatch. We collected invertebrate samples from 34 brood points and random paired-locations using sweep nets. Samples were sorted by Order to ascertain abundance and diversity. There was no difference in total abundance, abundance of Coleoptera, Hemiptera, Orthoptera, and Order diversity between brood and random locations. Northern bobwhite hens do not appear to select foraging sites based upon invertebrate abundance in the Rolling Plains of Texas.

Effects of Source Population and Release Strategy on Survival and Dispersal of Translocated Scaled Quail in the Rolling Plains of Texas—A Preliminary Report

Scaled quail (Callipepla squamata) have declined 3.5% annually in Texas from 1966-2013, but declines have not been uniform across the state. The Rolling Plains Ecoregion has experienced a 6.8% decrease during this period, while the western Edwards Plateau has remained stable. Habitat loss that has contributed to scaled quail decline also inhibits recolonization. Translocation has become an increasingly popular tool to reestablish populations for recreational or conservational purposes. Overall success rate of translocations is low and has prompted research into factors that contribute to the establishment of a self-sustaining population. Source population and release strategy are two translocation tactics that may influence the success of scaled quail translocation efforts. Best practices for translocation are often species and location specific and, thus, it is critical for translocation techniques to be tested across a variety of species and landscapes. We used radio-tagged quail to estimate survival and dispersal of translocated, wild-caught scaled quail as a function of source ecoregion and a delayed release treatment using multi-state models in Program MARK. Specifically, we compared quail sourced from within the Rolling Plains and from the Edwards Plateau, as well as a delayed release treatment consisting of 4–8 week holding periods on site.

Genetic Structure of Northern Bobwhite in the Rolling Plains

The recent declines in northern bobwhite quail populations in the Rolling Plains of Texas have raised concerns about habitat connectivity and gene flow. In addition, bobwhites have several life history traits that make them likely to display high levels of spatial genetic structure including low survival, high reproductive rates, and low dispersal rates. To determine if populations within the Rolling Plains have limited gene flow, we investigated the genetic structure of northern bobwhites within the ecoregion. Blood samples were collected at 16 ranches, encompassing 22 million acres, between February 2010 and April 2013. Bobwhites were also samples at a ranch in South Texas to serve as an outgroup. Samples (n = 647) were genotyped at 14 microsatellite loci that averaged 19.00 ± 5.07 alleles per loci. Global Fst indicated significant genetic structure (p = 0.001) between ranches with no isolation by distance signal (p = 0.079). Program STRUCTURE, however, indicated many (n = 30) overlapping subpopulations with no ranch constituting a single subpopulation and individuals from the outgroup ranch were included in 11 subpopulations. It appears that bobwhites within the Rolling Plains have few restrictions to gene flow and dispersal is not limited by the dominant habitat, xeric rangeland. These results suggest that populations in the Rolling Plains are not in danger of becoming isolated nor are bottlenecks present due to the recent decline.

Efficacy of a Soft Release Strategy for Translocating Scaled Quail in the Rolling Plains of Texas

Scaled Quail (Callipepla squamata) populations have become locally extinct and spatially fragmented in the Rolling Plains ecoregion of Texas. Translocating Scaled Quail from core to declining populations could augment populations or re-establishing extinct populations. Although translocations of scaled quail have been attempted in Texas, none have been documented and none have attempted to identify best practices. Release strategy (i.e., hard or soft release) is a factor that can influence the success of a translocation. Our objective was to compare daily apparent survival of scaled quail translocated to the Rolling Plains between 2 release treatment groups: hard- and soft-release. We estimated a daily apparent survival rate (DASR) for radio-marked hens during the breeding season as a function of age, release treatment, and a time trend. We found evidence of a positive effect of the soft release treatment and higher DASR in adult hens. Overall, DASR of translocated hens was low compared to reported estimates of survival in established resident populations. Using a soft release strategy and translocating a greater proportion of adults may improve future translocation success for scaled quail.

Nesting of Northern Bobwhites on Rangeland Versus Conservation Reserve Program Habitats in the Rolling Plains of Texas

Conservation Reserve Program (CRP) contracts account for about 1.7 million ha in Texas, and are often touted as habitat for upland game birds. We compared nest site locations, hatch rates, and arthropod abundance for northern bobwhites (Colinus virginianus) on CRP versus rangeland habitats at the Rolling Plains Quail Research Ranch (RPQRR), Fisher County, Texas from 2008 to 2011. Nest sites were monitored via radio-marked females. Simulated nests (n 1⁄4 144/yr) were used to evaluate hatch rates between the 2 habitat types. Arthropod abundance (as an indicator of brood habitat) was measured annually in August using sweep nets and pitfall traps. We documented 103 nest sites, 14% were in CRP while the remaining 86% were in rangeland; bobwhites neither selected nor avoided CRP as nesting habitat. ‘Survival’ of simulated nests (i.e., percent intact at 28 days exposure) across the 4 years averaged 63.2% for CRP and 74.4% on rangelands. Arthropod availability was greater in rangeland in 3 of the 4 years studied. CRP pastures dominated by kleingrass (Panicum coloratum) were used for nesting in proportion to their availability, but rangeland provided better brood habitat.

Parent-Reared Bobwhite Survival in the Texas Rolling Plains

Considerable research has been accomplished over the past 6 decades on the possible reasons for decline in the northern bobwhite (Colinus virginianus), henceforth known as the bobwhite. Restoring or restocking bobwhite populations by augmentation in areas that once held significant numbers has been a focus for many wildlife agencies and managers. Three main methods for augmentation of bobwhites currently exist: release of pen-raised birds, release of juvenile birds reared by Surrogator®, and translocation of wild bobwhites from one area to another. Of these 3 methods, only translocation has accomplished the goal of reestablishing bobwhite populations. Recently a new model developed by Tall Timbers Research Station in Tallahassee, Florida, USA, has successfully produced parent-reared bobwhite chicks from wild strain, which are raised by a surrogate parent in a simulated wild habitat environment. These birds have been released into the southeastern United States and successfully established new bobwhite population in areas of restored habitat. We designed a study to determine the viability of this rearing and release method for restoring depleted bobwhite populations in the semiarid, Rolling Plains of Texas. One hundred fifty nine radiomarked, parent-reared bobwhites were released in 2013–2014 on 8 ranches. One hundred five radiomarked, parent-reared bobwhites were released in 2014–2015 on 6 ranches. The survival rates were low for both years of the study with only 4 radiomarked birds surviving the first year and no birds surviving the second year. An apparent lack of predator-avoidance skills appears to be responsible for the high mortality rates that we estimated.

Evaluation of Population Indices and Estimators for Scaled Quail in the Rolling Plains of Texas

Accurate and precise population indices and estimators are important to gain reliable knowledge and make appropriate management decisions. Indices and estimators for scaled quail (Callipepla squamata), however, have not been evaluated thoroughly. Our objectives are to compare relationships among 8 years of roadside counts, spring call counts, and mark-recapture data obtained from the Rolling Plains Quail Research Ranch in Fisher County, TX, USA. Furthermore, we assess the efficacy of distance-based helicopter surveys as a method for scaled quail density estimates as compared to mark-recapture estimates for 2016–2017.