We report the first data confirming determinate growth in Texas River Cooters, Pseudemys texana, a freshwater turtle. We studied a four species community of freshwater turtles in Spring Lake, Hays County, TX, from 1995 to 2022 where we marked 2236 individuals. Accumulated data made it possible to ascertain whether determinate or indeterminate growth was evident. Data for 843 turtles confirmed that there was no inclination in the asymptotic phase of the general growth curve as determined by regression analysis. The mean difference in carapace lengths of turtles with a minimum of 10 years between first and last captures was less than two mm; thus, indeterminate growth was not observed. This research is important in that it confirms that not all freshwater turtles exhibit indeterminate growth, and that research into this topic would be productive.
Urban environments pose novel challenges for songbirds, and the degree of urbanization can influence nesting success. We used a multi-year (2013-2021) quasi-experimental design to understand the relationship between urbanization and various nesting parameters derived from 380 Black-crested Titmouse (Baeolophus atricristatus; hereinafter BCTI) nests in nest boxes installed across an urbanization gradient (i.e., rural, and low, moderate, and high levels of urbanization) in San Marcos, Texas, USA. The number of eggs, nestlings, and fledglings per nest were negatively influenced by clutch initiation date but not by level of urbanization or year. First clutch initiation date was correlated with level of urbanization, with nests in areas with any level of urbanization being initiated approximately 12 d earlier than rural nests. First clutch initiation dates for all nests were also affected by weather, with warmer mean daily high February temperatures prompting earlier nest initiation. Nest success was similar in rural areas and in areas with low or high urbanization, but was significantly lower in moderately urbanized areas. Nest success was also negatively correlated with clutch initiation date. Overall, our results indicate that BCTI are demonstrating behavioral plasticity to urban environments with earlier lay dates, but that increasing urbanization does not reliably predict changes in nest success. Thus, different degrees of urbanization potentially act as source-sink locations for BCTI populations. Received 8 January 2023. Accepted 12 December 2023.
Sex ratio is an important parameter influencing the demography of wildlife species. Sex ratios are categorized as primary (sex at fertilization), secondary (sex at birth through immaturity), tertiary (sex at adulthood), and quaternary (sex at post-reproductive age). Herein, we examined the secondary(1) (hatchling), secondary(2) (juvenile or subadult), and tertiary (adult) sex ratios of white-winged doves (Zenaida asiatica). Also, because white-winged doves typically hatch two eggs, we also evaluated the secondary sex ratio of co-occurring nestlings. Interestingly, secondary and juvenile sex ratios were significantly male biased, whereas tertiary sex ratios were not biased. Additionally, the ratio of same-sex nestlings was also male biased. The lack of bias at the tertiary level supports Fisher's principle that differential selection for sex ratios of 1:1 exist and lead to more stable populations. Therefore, we conclude that there is some selection mechanism present in this species that selects against males reaching adult status given our findings at the secondary and juvenile sex ratio levels.
Wind turbines are known to cause bat fatalities worldwide. Ultrasonic acoustic deterrents are a potential solution to reduce impacts on bats, but few experimental field studies have been conducted at utility scale wind energy facilities. Our objective was to assess effectiveness of a recently developed deterrent for reducing bat fatalities at wind turbines in southern Texas, USA. We quantified fatalities at control (deterrents off) and treatment (deterrents on) wind turbines from 31 July through 30 October in 2017 and 2018, and assessed deterrent effectiveness using generalized linear mixed models. Our results indicate deterrents significantly reduced bat fatalities for Lasiurus cinereus and Tadarida brasiliensis by 78% and 54%, respectively. We observed no significant reduction in fatalities for other species in the genus Lasiurius. Thus, deterrents represent a potential impact reduction strategy for some bat species, but research is still warranted to improve species-specific effectiveness.
We tested whether individual females of two species of aquatic turtles, Texas cooters (Pseudemys texana) and red-eared sliders (Trachemys scripta elegans), inhabiting headwaters of the San Marcos River, Hays County, Texas, selectively used the same nesting areas within and among years over a 20-year period. The study area was divided into four quadrants, and chi-square analyses confirmed that for within and among years, females of both species selected quadrants unequally. Our results thus confirm that females of both species at the study site exhibited nest area fidelity within and among years.
The Texas kangaroo rat Dipodomys elator is considered a species of conservation concern by state and federal agencies. There have been a limited number of sightings in only seven counties in northern Texas during the past 30 y. The apparent decline of the species has been attributed to habitat loss due to increasing conversion of natural areas into cropland. The magnitude and exact cause of the decline are difficult to determine because of insufficient data on the distribution of the species and its habitat within its relatively small geographic range. Habitat studies have focused on the microhabitat of burrows rather than a coarser-scale identification of habitat and its distribution within the species' historic range. Multiple species of Dipodomys have demonstrated strong associations with certain soil and land-cover types. Therefore our goal was to develop a range-wide map of potential habitat on the basis of the association of D. elator with specific soil and land-cover types. We used the map to guide roadside surveys and also updated the map with information on D. elator distribution obtained during the surveys. Over the course of two summers (2016 and 2017) we documented D. elator at 138 separate point locations in five counties. A geographic information system-based analysis of soil and land-cover data revealed that the species is associated with clay-loam and loam soils and mixed-grass/shortgrass prairie. We also found an unexpected association with cropland, although we do not know the exact extent to which D. elator actually uses cropland. The surveys provide an updated assessment of the species distribution and the maps of potential habitat indicate areas where the species may still exist.
The Gulf Coast kangaroo rat, Dipodomys compactus , is one of five kangaroo rat species occurring in Texas (USA) and probably the least studied. This endemic species has specific habitat requirements, primarily deep loose sand and minimal canopy cover from woody vegetation. On the northern edge of its geographic range, populations of the species are limited to the Carrizo Sands Region and are likely isolated from larger populations farther south. Using a geographic information system (GIS)-based map of suitable habitat coupled with roadside surveys, we determined that habitat of D. compactus is highly fragmented within the Carrizo Sands. Depending on assumed density of individuals we estimated a region-wide population between 50,000 and 240,000 individuals although 50% of this population is expected to be distributed among 11 large (≥ 500 ha) habitat patches. The remainder of the population may be scattered among much smaller habitat patches. In this regard, the overall spatial population structure of D. compactus may be similar to some of the highly endemic Dipodomys species in California (USA). If subpopulations of D. compactus are functionally isolated from one another (due to limited dispersal of individuals) then long-term persistence of the species in the Carrizo Sands region over the next few decades may be in jeopardy. Therefore, distribution and abundance of D. compactus in the Carrizo Sands may need to be routinely monitored particularly if future genetic studies reveal this northernmost population to be genetically unique.
The ability of songbirds to survive and reproduce depends on many factors, one of which is the ability to acquire enough food. We quantified foraging behavior, nesting-habitat vegetation composition, and available arthropod prey of the Vireo atricapilla (Black-capped Vireo) in Texas during 2010 and 2011. We used observational surveys of foraging behavior and vegetation time-use to quantify the Black-capped Vireos' foraging behavior and vegetative use versus availability (i.e., mean proportion of use vs. vegetative species availability). We collected descriptive data on the Black-capped Vireos' foraging use of available vegetative species and compared among vegetative species, year, and within-season sampling periods. In 2010 and 2011, we identified and mapped 49 and 63 breeding territories and repeatedly surveyed 30 and 58 territories for foraging activity, respectively. Data analysis focused on the foraging use of the 3 most commonly used and available tree species: Juniperus ashei (Ashe Juniper). Ouercus sinuata (Shin Oak), and O. fusiformis (Live Oak). Ashe Juniper, Shin Oak, and Live Oak together made up 78.8% and 83.6% of total proportion of substrate for foraging efforts in 2010 and 2011, respectively. Ashe Juniper had the highest proportion (similar to 28-50%) of foraging effort in 2010, 2011, and all but 1 sampling period for both years. We also repeatedly collected branch clippings from within a random subset of surveyed Black-capped Vireo territories to identify potentially available arthropod foods. We evaluated by order richness, total abundance, and dry biomass to make comparisons among vegetative species, year, and within-season sampling periods. We found significant differences in the biomass of arthropod orders Acari and Thysanoptera in 2010 and between orders Acari and Hymenoptera in 2011 among the 3 focal vegetative species. Examination of additional descriptive data suggests seasonal changes in potentially available arthropod foods. Our research underscores the importance of vegetation composition to Black-capped Vireos that may help habitat managers select for potential vegetative species distributions to optimize food resources throughout the breeding season for this species.
We describe egg production by 88 pairs of randomly selected, mature, wild-caught northern bobwhite (Colinus virginianus) hens housed under optimal conditions of food, water, climate, and a 17-hr photoperiod in a hatchery. We collected eggs daily using an 18-day period to differentiate between clutches. Hens continuously laid eggs until ceasing production. We evaluated number of eggs laid by each hen individually and hens collectively including total number, number/clutch, number/day, hatching success, and egg mass. Eighty-six hens produced 5,888 eggs. Number of eggs produced by individual hens ranged from 0 to 172 over ~ 200 days. Mean number of eggs laid/hen/day was 0.86. Clutch size ranged from 0 (n 1⁄4 2) to 12 (n 1⁄4 1). Mean number of eggs/clutch was 8.57. There was a strong correlation between clutch size and number of clutches. Some hens demonstrated continuous production of several large clutches. Hatching success of 5,793 eggs included for analysis was 61.6% (3,571 hatched, 2,222 failed to hatch). Hatched eggs had a greater mean mass compared to those that did not hatch.
Attempts to restore populations of northern bobwhites (Colinus virginianus) using pen-raised quail have been documented since the early 1900s. Low restoration success, based on low post-release survival rates and long distance dispersal from release sites, have proven the ineffectiveness of pen-raised quail in restoration of wild populations. The Surrogatort, a recent quail propagation tool using pen-raised quail, has been publicized as a method for increasing success rates in restoration of northern bobwhite populations by producing higher post-release survival and minimal dispersal. We tested the hypothesis that the Surrogatort is an effective means of supplementing populations of northern bobwhites in southern Texas. We raised 1,000 northern bobwhites in 2 Surrogators and conducted 2 trials in 2010 on a 990-ha ranch in Wilson County, Texas. Twenty northern bobwhites from each Surrogator were fitted with radio transmitters 12 hrs before release. We attempted to locate each bird daily for 3 weeks upon release from Surrogators followed by a reduced effort of 3 times per week until 100% mortality. Daily survival rates were low in Trial 1 (Surrogator A 1⁄4 0.87 and Surrogator B 1⁄4 0.96) and Trial 2 (Surrogator A 1⁄4 0.83 and Surrogator B 1⁄4 0.87). Mean distances traveled by post-released birds for Trial 1 were 401 and 1,416 m for Surrogators A and B, respectively. The Surrogator is not an effective means of restoring wild populations of northern bobwhites in southern Texas.
In 2000, a resident population of Texas Seaside Sparrows (Ammodramus maritimus) was identified at Laguna Atascosa National Wildlife Refuge on the lower Texas coast, extending its known breeding distribution farther south than previously described. We studied this breeding population of Texas Seaside Sparrows from April 2012 January 2013 on the Laguna Atascosa National Wildlife Refuge to obtain population density estimates and describe habitat associations. We estimated seasonal density during one year using a distance sampling approach. We described plant community characteristics and estimated percent ground cover. Density estimates of Seaside Sparrows by season were 3.49/ha (CV = 8.27) for spring, 3.59/ha (CV = 18.16) for summer, 4.07/ha (CV = 9.69) for fall, and 1.91/ha (CV = 21.92) for winter. The dominant plant species along the intertidal zone transect where Seaside Sparrows were detected included turtleweed (aka saltwort; Balls maritima), saltgrass (Distichlis spicata), and bushy seaside tansy (aka sea oxeye daisy; Borrichia frutescens). Previous studies indicated cordgrasses (Spartina spp.) to be a dominant plant species strongly associated with Seaside Sparrows and a predictor of nest success. However, cordgrasses were absent from the intertidal zone where Seaside Sparrows were detected during our study. Habitat associations and conservation plans for Seaside Sparrows should be revised to include the plant community found in this study.
As the trend towards urbanization continues, natural areas near dense human populations can be impacted by development, and increased recreational use of these natural areas may increase disturbance of wildlife. Many waterbirds use areas that are generally subject to elevated levels of human disturbance and some species consequently are often considered highly susceptible to disturbance. In 2013 and 2014 we assessed the effects of human recreational disturbance on Green Herons (Butorides virescens) through the use of focal observations at sites of varying disturbance. We collected behavioral data (n = 154 observations) along the headwaters of the San Marcos River located in Central Texas. We built 15 linear regression models to assess the potential influence of human disturbance as well as potential influence of habitat differences between study sites on each of five response variables (four foraging behaviors plus foraging efficiency). Using Akaike's Information Criterion model selection, we found that differences in foraging habitat provided the best explanation for the observed variation in four of the five response variables measured. Our results suggest Green Heron foraging behavior was influenced more by habitat than human disturbance events; however, foraging efficiency was the highest in least disturbed site. It is possible these birds have become habituated to disturbance (i.e., more tolerant of human presence) and perhaps now only modify their foraging technique in order to maximize their foraging efficiency to suit a specific location. These findings are noteworthy because it is important to distinguish cases where human disturbance impacts a species from cases where human disturbance has less of an effect.
Overland movement is an important aspect of freshwater turtle ecology. Turtles make overland excursions searching for mates, to find new aquatic habitats, in response to drought, or during nesting. Here, we tested how environmental factors may influence the excursion events of adult Red-eared Sliders (Trachemys scripta elegans). We found that 85% of turtles made overland movements at least once, which is higher than previously reported, and some turtles made multiple movements (2-6) during a single season. Rain and drought events were significant predictors of overland movements. While sex did not appear to be a significant factor, there was an indication that movement may depend on seasonal temperatures. In addition, we showed that turtles immigrated to depopulated ponds in a short period of time after a simulated harvest event. However, after a second harvest simulation, our experimental pond was not repopulated to its original abundance. Our results call for caution when implementing spatially controlled harvest regimes. Ponds depleted by harvesting might not be repopulated by immigrating turtles if source population sizes also decrease due to the regular dispersal to sink populations and subsequently slows overall reproduction rates.
Freshwater turtles are appropriate organisms for studying maternal investment in offspring because, unlike most long-lived vertebrates, turtles show high fecundities and most provide no parental care. We studied reproductive patterns of two emydine freshwater turtle species, the Texas river cooter (Pseudemys texana) and the red-eared slider (Trachemys scripta elegans) at Spring Lake, Hays County, Texas during the 2009 nesting season. Forty-six percent of all nesting Texas river cooters and 25% of all nesting red-eared sliders nested twice, with some Texas river cooters nesting more than twice. Mean egg mass, egg length, and egg width decreased in subsequent clutches in Texas river cooters. However, there was an insufficient sample size of subsequent clutches (n = 6) to draw conclusions for red-eared sliders. Red-eared sliders did not show a positive relationship between clutch size and body size. We found that in both species there was a positive relationship between egg width and egg mass in relation to maternal body size. However, only Texas river cooters showed a positive relationship between clutch size and maternal size, while only red-eared sliders showed a positive relationship between egg length and maternal size. By comparing reproductive parameters of these two coexisting populations, we concluded that the members of these two species allocate resources differently for reproduction.
Behavioral changes of migratory species have been globally documented in recent decades. However, there is a paucity of research on changes in migratory bat species. Brazilian free-tailed bats (Tadarida brasiliensis) roost in central Texas from March to November. These bats have historically migrated south in late fall, leaving summer roosts unoccupied during winter. Recently, overwintering populations have been discovered in central Texas. The objectives of our study were to determine presence or absence of overwintering free-tailed bats at six known summer roosts, obtain baseline population estimates, and evaluate microclimates of roosts during winters of 2010-2011 and 2011-2012. We used data loggers to monitor temperature and humidity hourly. We estimated population sizes with digital images using ImageJ software, previously established roosting densities, or both. Our results indicated that occupied roosts were colder, had less stable temperatures, and had a stronger correlation between internal and external temperatures vs. unoccupied roosts. Population sizes increased at all occupied roosts from 2010 to 2011.
High severity forest fires are increasing in large areas of the southern and western United States as the climate becomes warmer and drier. Given their strong roles in ecosystem dynamics, documenting the response of bird communities to wildfires is important for improving our understanding and management of post-wildfire ecosystems. However, because wildfires are unplanned events, relatively few studies have been conducted to assess local-scale impacts on forest bird communities. In this study, we had the opportunity to use a before-after, control-impact (BACI) approach to assess the response of resident birds to high severity wildfires that occurred in the Lost Pines ecoregion of Texas in September and October 2011. We replicated a previous study using point count surveys to assess summer and winter bird community changes ca. 1 year after the wildfires. We found that total number of detected individuals did not change following the wildfires, but winter bird species richness increased in burned habitat. Changes were apparent at the foraging guild-level for the winter bird community, with an increase in aerial insectivores and decrease in bark insectivores. Summer and winter bird community composition changes were apparent at the species-level and generally agreed with species-specific habitat preferences. For example, species such as eastern bluebirds and chipping sparrows that prefer open woodlands were positively associated with burned habitat. Our results provide quantitative evidence that high severity forest fires increased habitat suitability for many resident bird species. At the landscape-scale, fire-induced increases in habitat heterogeneity could result in higher bird diversity in the Lost Pines ecoregion. We expect bird community composition will be dynamic in the Lost Pines ecoregion over the next few decades as the burned habitat continues to change through successional processes and post-fire management actions. (C) 2015 Elsevier B.V. All rights reserved.
Problems with the efficacy of second-generation antipsychotics on negative symptoms and cognition have highlighted the need for further development of drugs targeting central nervous system neurotransmitter systems other than dopamine. One target in development is neurokinin 3 (NK3) tachykinin receptors, which are coreleased and interact with dopamine. This study investigates the efficacy, tolerability, and cognitive effects of AZD2624, a selective, orally active NK3 receptor antagonist, in symptomatic patients with schizophrenia. Patients were randomly assigned to 1 of 3 treatment groups: AZD2624 40 mg, placebo, or olanzapine 15 mg. Treatment lasted for 28 days, and the Positive and Negative Syndrome Scale, the Clinical Global Impression Severity Scale and Improvement Scales, and cognition as assessed by CogState were used as primary outcome measures. There were no significant differences in patients treated with AZD2624 versus placebo on change in Positive and Negative Syndrome Scale total score and Clinical Global Impression Severity Scale; in addition, no change in CogState measures was found. Results of the trial do not support a role for the NK3 antagonist AZD2624 as a therapeutic treatment for acute schizophrenia when used as monotherapy.
We studied the morphological characters of the keeled earless lizard, Holbrookia propinqua, in Guadalupe County, Texas, near its type locality (Wilson County, Texas) and at the northern extension of its range. Adults of this population were similar to those of other mainland populations but significantly smaller than adults of coastal island populations. Juveniles of the population in Guadalupe County and a coastal population showed no significant differences in size. Tail length of males did not differ among mainland populations but differed significantly from those of the island populations.
s are arranged by presentation order. Constraints and opportunities for ecological restoration in the Rio Grande Valley, Texas. Alex Racelis, United States Department of Agriculture-Agricultural Research Service, alex.racelis@ars.usda.gov Few areas in the United States have experienced a more precipitous population growth than the Lower Rio Grande Valley (RGV). This growth has lead to rapid urbanization that has dramatically changed land cover and land use patterns in the area. Only a small fraction of natural vegetation remains, and much of which is under constant ecological pressure from invasive species such as salt cedar (Tamarix sp.), giant reed (Arundo donax) and other non native grasses. These undeniable trends of growth undoubtedly will continue to have a tremendous impact on native biodiversity and ecosystems, requiring novel attempts to enhance the health of our local environment and conserve the important ecosystem services it provides. In this talk, I present some of the key challenges for conservation and ecological restoration in the RGV and provide examples of promising strategies and directions that may help stem these trends, which include the biological control of invasive species, the enhancement of biodiversity values of urban and agroecological areas, and the promotion of opportunities for citizen science and citizen-driven conservation in the Lower Rio Grande Valley. Defining vegetative characteristics of ocelot (Leopardus pardalis) habitat. Amy Tsay 1 , Thomas R. Simpson 2 , M. Clay Green 2 , John Young. 1 Cox|McLain Environmental Consulting, Inc., acstar.amy@gmail.com 2 Texas State UniversitySan Marcos The ocelot (Leopardus pardalis) was placed on the United States federal endangered species list in 1982 because of habitat loss. Previous research has demonstrated that ocelots prefer habitats of dense shrubs with greater than 95% canopy cover. However, little else is known about the total composition of vegetation in their habitat. The objectives of our study were to compile GIS information of vegetation, soil and satellite imagery for seven counties (Willacy, Cameron (Laguna Atascosa National Wildlife Refuge), Starr, Hidalgo, Jim Hogg, Kenedy, and Zapata) in South Texas to enhance prior research and define areas suitable to support ocelots. Ground-truthing on vegetation transects on public and private land across these counties was performed using densiometer, vegetation profile board (VPB), and daubenmire frame techniques to determine key vegetative parameters that benefit ocelots. Through principal components analysis (PCA), we analyzed VPB measures, percent canopy cover (overstory), percent grass, litter, bare ground, and forbs from Daubenmire frames, woody plant density, woody plant diversity, and average woody plant height per transect. We found the majority of ocelot habitat was characterized by greater plant diversity, greater vertical cover density at ground level, greater canopy cover, smaller shrubs, and more ground litter than habitat not occupied by ocelots. Along an east-west gradient in South Texas, eastern sites were similar to ocelot habitat. Comprehensive vegetation information (i.e. plant density, percent grass, etc.) is lacking on satellite/ land-use images. Therefore, comparing habitat data through PCA analysis would be more effective in delineating ocelot habitat. Survival of planted star cactus, Astrophytum asterias, in south Texas. Charlotte M. Reemts 1 , Patrick Conner, Gena K. Janssen 2 , and Kimberly Wahl 3 1 The Nature Conservancy, creemts@tnc.org 2 Janssen Biological 3 U.S. Fish and Wildlife Service, Lower Rio Grande National Wildlife Refuge Star cactus, Astrophytum asterias, is one of several rare cacti found in the southwestern United States. We planted 308 star cactus individuals on private ranches where existing populations were reduced or destroyed. Overall mortality was 48% with herbivory accounting for 34% of the mortality (50 out of 148). Mortality varied among planting sites, but was not influenced by initial size, even when cacti killed by herbivory were excluded. Mortality was highest during times with low precipitation and/or high temperatures. Surviving cacti on two sites increased in average size. Future reintroduction attempts should investigate the interaction between soil type and mortality, and test the efficacy of supplemental water. Planting of nursery-grown individuals should also be explored for additional cactus species. Evaluation and Development of Texas Native Seed Sources. Tony Falk, Forrest Smith, Colin Shackelford, and Mia McCraw, Caesar Kleberg Wildlife Research Institute, Texas A&M University Kingsville, Colin.Shackelford@tamuk.edu The Texas Native Seeds program established 6 common garden studies evaluating 60 native seed varieties in south, central, and west Texas. At each site, 30 transplants of each seed variety were established in 3 replications of 10 plants. Under irrigated conditions in 2011 and 2012, we scored each replication for 9 performance characteristics including plant vigor, variety uniformity, seed production, and biomass production. We also measured plant height, canopy cover, biomass production, and seed quality. In addition, we seeded 3 small plots of each species and measured seedling emergence and vigor under rain‐fed conditions. Results from year one of the study indicate several plants are capable of performing very well for early restoration needs outside of what was thought to be their range of adaptation. We have also identified several geographic areas where additional native seed source development work should be undertaken in order to provide suitably adapted native plant material. Most notably is our planting near Imperial (west) Texas where just 5 of 60 available native seed varieties survived the first year, even under irrigation. In other areas, a lack of adapted early successional grass species and forbs is apparent. Texas Native Seeds is also making field collections of 33 grasses and 13 forbs across 67 counties in central Texas, 35 counties in south Texas, 37 counties in west Texas. These collections will be used by TNS, and collaborators from the USDA NRCS Plant Materials Program and Texas AgriLife Research to develop additional native plant materials for commercial production and use in native plant community restoration in Texas. Establishment of the Restoration Greenhouse and Seed Collection Program at Fort Worth Nature Center & Refuge. Michelle Villafranca, Fort Worth Nature Center & Refuge, michelle.villafranca@fortworthtexas.gov Fort Worth Nature Center & Refuge staff has embarked upon a project to develop a plant materials program for the park. Known as the Restoration Greenhouse & Seed Collection Program, it has evolved in incremental steps since its inception. The program’s primary mission is propagating native plants that are then out-planted at restoration and landscape sites around the park. Planning, collection and propagation protocols, restoration, monitoring, and involvement of volunteers will be discussed in this presentation as it covers the natural progression from idea to implementation and expansion of a restoration greenhouse program. Applying the diversity-invasion hypothesis to test restoration as biocontrol Kelly G. Lyons, Department of Biology, Trinity University, klyons@trinity.edu Evidence from small-scale experimental investigations suggests that species diversity and introduced species success are negatively correlated and that resident species identity can determine the strength of this interaction. In this study, we assess the applicability of the diversityinvasion hypothesis to restoration. We hypothesize that, following management efforts, richness of restored plots are a determinant of invasive species re-establishment and, furthermore, that some restored species and species combinations will be more effective than others. We employed a two-way factorial experiment in a randomized complete block design where richness and native species composition were manipulated in 1 x 1 m plots. Richness levels include 1, 2, 3, and 4 species with all possible species combinations at richness levels 2 and 3. Each block was replicated four times. Restored species were native, perennial grasses widely used in restoration projects in Central Texas. They included: big bluestem (Andropogon gerardii), Indian grass (Sorghastrum nutans), sideoats grama (Bouteloua curtipendula), and little bluestem (Schizachyrium scoparium). These species were plug planted in January 2010 following removal of the target invasive KR bluestem (Bothiochloa ischaemum; hereafter referred to as KR) using a prescribed burn in fall 2009. Restored species established at an overall rate of 60%. Nonetheless, rates of establishment varied greatly among species. Re-establishment of KR was negatively correlated with restored species cover and establishment success as well as the average and total restored species ellipsoid plug area. We also found significant differences among species as determinants of KR re-establishment. We found no significant relationship between assigned or actual richness and KR re-establishment. KR establishment was negatively correlated with plot over-yielding, suggesting that species combinations that perform better than the highest performing species grown in monoculture were effective in invasion control. We aim to utilize this study to inform local land management efforts in restoration regarding the suppressive effects of native species combinations. The influence of myccorhizal fungi and nitrogen addition on competition between a native and invasive perennial grass species. Afflerbach, C., Banick, K., Rabat, R., and Lyons, K.G., Department of Biology, Trinity University, San Antonio, TX, afflerb@trinity.edu The C4 grass King Ranch Bluestem (Bothriochloa ischaemum) was originally planted throughout much of Texas to restore degraded rangeland; however the species has since become
Drug-induced kidney injury (DIKI) results in attrition during drug development; new DIKI urinary biomarkers offer potential to detect and monitor DIKI progression and regression, but frequently only in rats. The triple reuptake inhibitor (TRI) PRC200-SS represents a new class of antidepressants that elevate synaptic levels of serotonin, norepinephrine, and dopamine and is expected to produce more rapid onset and better antidepressant efficacy than single or dual inhibitors. Although preclinical studies and recent clinical trials lend support to this concept of superior efficacy for TRIs, there is little information on the safety profile of this class of compounds. Using histopathology and DIKI biomarkers, in single- and repeat dose toxicological studies in cynomolgus monkeys, PRC200-SS demonstrated dose-proportional kidney toxicity. Characterization of the histopathological lesions, using a combination of immunohistochemistry (IHC) and urinary biomarker analysis, indicated that the compound is a distal tubule and collecting duct toxicant. Segment specificity for the lesions was shown using a newly developed triple IHC combination method with antibodies against calbindin D28, aquaporin 2, and aquaporin 1. Urinary biomarker analyses, using multiplex immunoassays, confirmed a dose-proportional increase in the excretion of calbindin D28 and clusterin in compound-treated monkeys with levels returning to baseline during the drug-free recovery period. These results constitute the validation of distal nephron DIKI biomarkers in the cynomolgus monkey and demonstrate the utility of calbindin D28 and clusterin to monitor the progression of distal nephron DIKI, representing potential early biomarkers of DIKI for the clinic.