Northern bobwhite populations have declined concurrent with global warming. The focal period of this study was the 12-d pre-incubation period, when bobwhite eggs remain in the nest without the thermal protection of the incubating parent. This study first established the storage and thermal limits of bobwhite eggs, then investigated how global warming may impact oviparous embryos and how bobwhite embryos react to acute and chronic doses of simulated drought temperatures during pre-incubation. First, the maximum storage limit of bobwhite eggs was determined by storing eggs ≤21 d and measuring hatching success and pH of egg albumen and yolk. Hatching success of stored eggs declined after 14 d, when yolk and albumen pH reached levels detrimental to embryonic development. Secondly, thermal limits were determined by exposing bobwhite eggs to hyperthermic temperatures (38-52 °C). Bobwhite embryos survived 50 °C for 1 h, 49 °C for 3 h and 46 °C for 6 h. Results indicate an adaptation to the naturally occurring temperature extremes that can occur in the bobwhite's southern range during pre-incubation. Subsequently, bobwhite eggs were exposed to either low constant (LC), low fluctuating (LF), high constant (HC), or high fluctuating (HF) temperatures during pre-incubation to determine if the nature of temperatures differentially affected development. Although eggs exposed to high heat loads (HC and HF), and low heat loads (LF and LC) had equal heating degree-hours within groups, they exhibited differential growth during pre-incubation. Oxygen consumption, hatch timing, and hatching success were also affected by the thermal regimes. Eggs in simulated drought (HF) had a 47% lower hatch rate than eggs in simulated non-drought (LF) indicating that thermal stress during pre-incubation may contribute to population declines during drought. Finally, northern bobwhite eggs were exposed to acute or chronic doses of simulated drought temperatures, which tested for critical periods of development during pre-incubation. Collectively, data indicated that the earliest stages of bobwhite development were more affected by hyperthermic temperatures. Indeed, a critical period of development exists during the first 2/3 of pre-incubation during which exposure to hyperthermic temperatures results in aberrant development, hatching plasticity, and reduced hatch rates.

The consequences of early embryonic insults and how they affect subsequent life reflects the emerging concept of "fetal programming". The aim of this project is to study the effects of embryonic insults as they subsequently manifest themselves in adults, with emphasis on the heart and vasculature. My experiments establish that fetal programming operates on the bobwhite quail inducing similar changes as those observed in mammalians and other birds. The quail's fast development provides reliable data in a short period of time than other avian models (e.g. domestic chicken). Data on quail showed a correlation between egg mass and hatchling mass; where small eggs produce small hatchlings but a high mortality made it impractical as a stressor for this study. Hypoxia was used as a stressor during embryonic incubation, where it induced a low hatching weight in quail that was not observable in adult birds. Morphological measurements demonstrated an increased ventricular collagen content and reduced ventricular lumen in birds in adults incubated in hypoxia consistent with hypertension. The hematological analyzes showed few differences indicating organ remodeling instead of hematopoietic compensation. The assessment of vascular reactivity pointed out an impaired endothelium dependent relaxation commonly associated to hypertension in birds and mammals. Fetal programming could be a widespread response to an adverse prenatal environment in endotherms and the resulting data from this work contributes to our understanding of fetal programming in vertebrates and its long term consequences.

Isolated populations of northern bobwhites (Colinus virginianus) have declined causing many quail managers to attempt population restoration by releasing captive-reared bobwhites or translocating wild bobwhites. I evaluated three restoration techniques: (1) release of captive-reared bobwhites, (2) translocation of bobwhites from high densities to low densities, and (3) release of captive-reared and translocated bobwhites acclimated on site prior to release. These results show that captive-reared birds have reduced survival and fewer nesting attempts when compared to translocated birds and that acclimation time was not a factor. I hypothesized that high mortality rates were caused by captive-reared birds exhibiting different predator avoidance behavior than wild birds. Captive-reared and wild-trapped bobwhites were subjected to independent predator simulations and their responses were recorded on high definition video. Threat recognition time, reaction type, and reaction time was recorded for comparative analysis. Pen-reared birds recognized the simulated raptorial and terrestrial predator threats quicker than wild-trapped birds, but reaction times were not different among groups. However, the type of reaction was different among groups where pen-reared birds typically flushed immediately upon recognizing either simulated predator as compared to wild-trapped birds which typically ran or held when subjected to the raptorial threat and showed little to no observable reaction to the terrestrial threat. These results reveal a potential loss of a holding trait in pen-reared birds, resulting in a quicker revealing of their position in the presence of a threat, thereby increasing their risk of predation.

Northern bobwhites (Colinus virginianus) are an important cultural, ecological, and economical part of the southern Texas landscape. I used radio-telemetry data from 2000?2005, part of a long-term, bobwhite study in southern Texas, to test the nest-concealment hypothesis, develop a stochastic simulation model for bobwhite populations, and evaluate the influence of brush canopy coverage (BCC) on short- and long-term demographic performance of bobwhites. Bobwhite nests tend to be situated in taller and denser vegetation than would be expected if nest-site location was a random process. I compared 4 microhabitat variables between successful (n = 135) and depredated nests (n = 118). I documented similar microhabitat attributes between successful and depredated nests. The discriminant function correctly classified only 48?59% of nest fates into the correct group, but only 18% of the variation in nest fate. Thus, my results did not support the nest-concealment hypothesis. My stochastic simulation model for bobwhite populations is based on difference equations (?t = 3 months) and simulations run for 100 years using STELLA� 9.0.2. The probability of persistence for 100 years for the spring population was 74.2% and 72.5% for the fall population. Simulated population parameters were similar to those observed in the field for 5 of 6 population parameters. Only simulated male adult annual survival differed by 275.0% from field estimates. Despite this difference, my model appears to be a good predictor of bobwhite populations in the Rio Grande Plains of Texas. I estimated bobwhite density, survival, and production (proportion of hens nesting, nesting attempts per hen, and clutch size) in 3 study areas with ~10%, ~25%, and >30% BBC. All demographic parameters were similar among the 3 BCC classes. However, simulation modeling indicated that long-term demographic performance was greater on the ~25% and >30% BCC classes. The probability of fall population persistence was greater in the ~25% (90.8%) and >30% (100.0%) BCC classes than in the ~10% BCC class (54.2%). My study highlights the shortcoming of considering only short-term effects when comparing habitat given that short- and long-term effects of habitat on demographic performance can differ.

Northern bobwhites (Colinus virginianus) are a valued game species that have seen massive population declines in the last few decades. This decline has been attributed to many factors including predation, the topic of this study. I examined the habitat selection, nocturnal movement and potential rate of encounter with quail nesting locations by coyotes (Canis latrans), bobcats (Lynx rufus), and raccoons (Procyon lotor) at the Rolling Plains Quail Research Ranch, a private 19 km2 ranch in the Rolling Plains ecoregion of west Texas. My study had 2 objectives: (1) to compare the habitat use of mesopredators in the Rolling Plains to the nesting habitat of bobwhites, and (2) to characterize the nocturnal paths of these mesopredators and measure their overlap with quail nesting locations. I placed GPS collars on 4 bobcats, 7 coyotes and 11 raccoons during the quail nesting seasons of 2009-2011. I used the chi-square test as well as a modified version of the Ivlev’s Electivity Index (1961) to calculate habitat selectivity. I also measured the proximity of the mesopredators and quail nesting locations to roads, water and quail feeders on the ranch. I used fractal analysis to calculate length and tortuosity of nocturnal paths and assessed potential risk to quail nests by determining the intersection rates of mesopredator paths with quail nesting locations. I found that a large difference existed in selectivity of habitat between bobwhite nesting locations and the bobcats and raccoons. Bobwhites selected for the upland grasslands and shrubs and against rocky ridges. Bobcats selected for riparian zones, while raccoons selected for both riparian zones and rocky ridges, neither of which were selected for by nesting quail. Bobcats and male raccoons additionally showed a propensity for road travel, which quail often nested close to. Coyotes selected strongly for grasslands, utilized their home ranges comprehensively and showed a preference for road usage, and thus had the greatest potential encounter rate with quail nest sites. However, coyotes also showed the most linear and direct movement pattern, potentially reducing their efficiency in finding quail nests. This study indicates that coyotes potentially present the largest threat to the nests of quail and female raccoons the least. Management decisions such as the levels of management needed for the 3 species of mesopredators are discussed.

Northern bobwhite (hereafter, bobwhite; Colinus virginianus) have experienced long-term declines in population abundance throughout most of their breeding range. In 2004, the United States Department of Agriculture (USDA) authorized mid-contract management (MCM) to restore early successional plant communities in aging Conservation Reserve Program (CRP) fields. I evaluated the effects of 3 MCM regimes, including fall strip disking, fall herbicide spraying (hereafter, spray), and fall herbicide spraying in combination with spring legume interseeding (hereafter, spray-seed) on nearly 650 ha of tall fescue (Schedonorus phoenix [Scop]. Holub; nomenclature follows USDA plants database; see USDA 2010b) CRP in south-central Illinois, USA, during 2005-2008. The objectives of this study were to: 1) evaluate the compositional and structural responses of the vegetation community to MCM, 2) determine the structural vegetation and landscape composition variables that influenced adult bobwhite relative densities and brood presence in CRP, and 3) assess foraging rates and arthropod prey selection of bobwhite chicks relative to MCM. Spray and spray-seed treatments were more effective than disking at reducing tall fescue cover, increasing plant species diversity, and enhancing the structural characteristics of the plant community that are essential for nesting and brood-rearing bobwhite. Spray-seed and disked treatments increased the percentage of bare ground by burying the dead and dying vegetative biomass beneath the soil surface. However, spraying alone left large amounts of litter accumulation on the soil surface that resulted in a delay in the timing of some annual forbs to recolonize. Plant species composition in sprayed and spray-seeded fields changed from a dense, monoculture of tall fescue to a diverse assemblage of perennial grasses, annual forbs, and legumes that provided habitat for nesting and brood-rearing bobwhite. Adult bobwhite and broods responded positively to spray and spray-seed treatments in this study. Adult relative densities (i.e., number of adult bobwhite observed / ha) were higher in sprayed and spray-seeded fields than in disked and controls. The probability of higher relative densities was greater in fields with higher plant species diversity, and percentages of bare ground and legumes. Conversely, relative densities were negatively associated with higher percentages of grass cover. At the landscape scale, relative densities were positively correlated higher percentages of cropland and pastureland within a 250 m buffer of CRP fields. Sprayed and spray-seeded fields were 39.6% more likely to have broods present than control fields. Whereas disked fields were only 10.0% more likely to have broods than controls. Brood presence was positively correlated with higher percentages of bare ground and negatively correlated with higher percentages of grass cover. Human-imprinted bobwhite chicks consumed a higher abundance and biomass of arthropods in sprayed and spray-seeded fields than in disked and controls, although the abundance of arthropods available was generally highest in control and disked fields. This suggests, therefore, that bobwhite chicks foraging rates are not limited by arthropod availability, but rather, by the structure of the vegetative community and the ability of the chicks to access the food resources. Chicks consumed a higher proportion of hymenopterans, isopods, and lepidopterans than expected from nonrandom feeding indicating that they were actively selecting for particular prey. This research has added to the understanding of restoring bobwhite habitat to tall fescue CRP, and could assist USDA-Natural Resource Conservation Service personnel and other land managers in restoring and maintaining marginally diverse grassland ecosystems in CRP fields for nesting and brood-rearing bobwhite.

Doctor of Philosophy / Department of Biology / Philip S. Gipson / Northern bobwhite (Colinus virginianus) populations in much of the species range have been declining for the last 35 years. I trapped and equipped bobwhite with radio transmitters and tracked them during 2003-2005. I used these data to examine the effects of landscape configuration on survival as well as the habitat association of bobwhite in southeastern Kansas. I used the nest survival model in Program MARK to determine the effects of habitat configuration on weekly survival of radio equipped bobwhite during the Fall-Spring (1 October to 14 April) and the Spring-Fall (15 April to 30 September) at home range and 500 m buffer scales. Individual survival probability for the Fall-Spring period was 0.9439 (S.E. = 0.0071), and the most parsimonious model for the Fall-Spring period at the home range scale was B0 + percent woodland + percent cropland. At the 500 m buffer scale the most parsimonious model was B0 + percent Conservation Reserve (CRP) program land. The weekly survival probability for the Spring-Fall period was 0.9559 (S.E. = 0.0098). At the home range and 500 m buffer scales there were weak associations of habitat to survival during Spring-Fall with the most parsimonious model for both scales B0 + percent other. Using Euclidean Distances to measure distance from animal location to each habitat, I found that habitat selection was occurring during the Spring-Fall (Wilkes λ = 0.04, F 6,36 = 143.682, P < 0.001) and Fall-Spring (Wilkes λ = 0.056, F 6, 29 = 81.99, P < 0.001). During Spring-Fall bobwhite were associated with locations near cool-season grasses and during Fall-Spring preferred locations near woody cover. Bobwhite also showed habitat selection at a second more refined land use classification level for Spring-Fall (Wilkes λ = 0.006, F 16, 26 = 284.483, P < 0.001) and Fall-Spring (Wilkes λ = 0.004, F 16, 19 = 276.037, P < 0.001). During the Spring-Fall, bobwhites were associated with locations near cool-season grass pastures and roads and during Fall-Spring were associated with locations in close proximity to roads and CRP. Understanding the effects of habitat configuration on bobwhite is an important step in developing a broad-scale management plan.

The impact of the relative richness or poverty of the external environment on development has been demonstrated in a variety of species and for a number of physical and cognitive processes. However, a dichotomy exists in the present literature, wherein the physical and social environments are compartmentalized. The present study investigated the potential longitudinal interaction between the social and physical environments on early cognitive development and emotional reactivity. Bobwhite quail (Colinus virginianus) were exposed to different part-time combinations of social and physical enrichment over the first 96 hours following hatch. Developmental trajectories were explored using repeated non-identical maze tasks. The experiment was inconclusive as to the effects of enrichment; however a distinct trend arose as a main effect of age. Chicks were significantly less willing to explore and solve the maze at 72 and 96 hours. Potential explanations concerning experience and physiological maturation are discussed along with sources of variability.

As human populations rise exponentially, agricultural production systems must be adapted to sustain ecosystem function. Government administered agricultural conservation programs may actualize greater gains in ecosystem services, including wildlife population gains, if conservation practices designed to target specific environmental outcomes are implemented strategically in agricultural landscapes. I evaluated multi-scale, multi-species, and multi-season avian population responses to a targeted native herbaceous buffer practice (CP33: Habitat Buffers for Upland Birds) under the continuous sign-up Conservation Reserve Program administered by the U.S. Department of Agriculture. CP33 is the first conservation practice targeted directly to support habitat and population recovery objectives of a national wildlife conservation initiative (Northern Bobwhite Conservation Initiative). I coordinated breeding season, fall, and winter point transect surveys for northern bobwhite (Colinus virginianus), priority early-succession, and overwintering birds on ≈1,150 buffered and non-buffered fields in 14 states (10 ecoregions) from 2006-2009. I also assessed northern bobwhite-landscape associations within each ecoregion to determine effects of landscape structure on observed northern bobwhite abundances. Breeding season and autumn northern bobwhite densities were 60-74% and 52% greater, respectively, over all survey points in the near term (1-4 years post-establishment). However, breeding season and autumn response and associations between northern bobwhite abundance and landscape structure exhibited substantial regional variation, suggesting northern bobwhite conservation and management should be implemented on a regional basis. Breeding season densities of dickcissel (Spiza americana) and field sparrow (Spizella pusilla) were up to 190% greater on buffered fields, whereas overwintering densities of several Emberizid sparrow species were up to 2,707% greater on buffered fields. Species sensitive to patch area or those requiring vegetation structure different from that provided by buffers exhibited limited, but regionally and annually variable responses to buffered habitats. Increased bird densities of several species in several seasons suggest wildliferiendly farming practices delivered strategically and requiring minimal change in primary land use can benefit species across broad landscapes when conservation practices are targeted toward specific recovery objectives. Targeted conservation systems combining multiple conservation practices to provide an array of ecosystem services may be a mechanism for meeting multifarious conservation objectives and enhancing biodiversity in agricultural landscapes.

United States Department of Agriculture’s Farm Bill conservation programs provide landowner incentives to remove less productive and environmentally sensitive lands from agricultural production and re-establish them in natural vegetation to achieve conservation objectives. However, removal of arable land from production imposes an opportunity cost associated with loss in revenue from commodities that otherwise would have been produced. The Habitat Buffers for Upland Birds practice (CP-33) under the Continuous Conservation Reserve Program is a targeted conservation practice designed to increase northern bobwhite populations in agricultural landscapes. However, establishing CP-33 buffers on profitable farmland may be incompatible with economic objectives of landowners. To determine how CP-33 enrollment influenced field profitability and bobwhite abundance; I simulated CP-33 buffers on crop fields across a range of commodity prices and modeled profitability and predicted bobwhite abundance. CP-33 increased field revenue on a percentage of fields at all commodity prices and increased bobwhite abundance up to 30%.