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Terrestrial toxicology data are limited for comprehensive ecotoxicological risk assessment (ERA) of ecosystems contaminated by per- and polyfluoroalkyl substances (PFAS) partly due to their existence as mixtures in the environment. This complicates logistical dose-response modeling and establishment of a threshold value characterizing the chronic toxicity of PFAS to ecological receptors. We examined reproduction, growth, and survival endpoints using a combination of hypothesis testing and logistical dose-response modeling of Northern Bobwhite quail (Colinus virginianus) exposed to perfluorohexanoic acid (PFHxA) alone and to PFHxA in a binary mixture with perfluorooctane sulfonic acid (PFOS) via the drinking water. The exposure concentration chronic toxicity value (CTV) representative of the lowest-observable-adverse-effect-level (LOAEL) threshold for chronic oral PFAS toxicity (based on reduced offspring weight and growth rate) was 0.10 ng/mL for PFHxA and 0.06 ng/mL for a PFOS:PFHxA (2.7:1) mixture. These estimates corresponded to an adult LOAEL average daily intake (ADI) CTV of 0.0149 and 0.0082 µg x kg bw-1 x d-1 , respectively. Neither no-observable-adverse-effect-level (NOAEL) threshold and representative CTVs nor a dose-response and predicted effective concentration (ECx ) values could be established for these two response variables. The findings indicate that reaction(s) occur among the individual PFAS components present in the mixture to alter the potential toxicity, demonstrating that mixture effects avian PFAS toxicity. Thus, chronic oral PFAS toxicity to avian receptors represented as the sum of the individual compound toxicities may not necessarily be the best method for assessing chronic mixture exposure risk at PFAS-contaminated sites. This article is protected by copyright. All rights reserved.

Many recent studies have been focused on prevalence and impact of two helminth parasites, eyeworm Oxyspirura petrowi and caecal worm Aulonocephalus pennula, in the northern bobwhite quail (Colinus virginianus). However, few studies have attempted to examine the effect of these parasites on the bobwhite immune system. This is likely due to the lack of proper reference genes for relative gene expression studies. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a glycolytic enzyme that is often utilized as a reference gene, and in this preliminary study, we evaluated the similarity of bobwhite GAPDH to GAPDH in other avian species to evaluate its potential as a reference gene in bobwhite. GAPDH was identified in the bobwhite full genome sequence and multiple sets of PCR primers were designed to generate overlapping PCR products. These products were then sequenced and then aligned to generate the sequence for the full-length open reading frame (ORF) of bobwhite GAPDH. Utilizing this sequence, phylogenetic analyses and comparative analysis of the exon–intron pattern were conducted that revealed high similarity of GAPDH encoding sequences among bobwhite and other Galliformes. Additionally, This ORF sequence was also used to predict the encoded protein and its three-dimensional structure which like the phylogenetic analyses reveal that bobwhite GAPDH is similar to GAPDH in other Galliformes. Finally, GAPDH qPCR primers were designed, standardized, and tested with bobwhite both uninfected and infected with O. petrowi, and this preliminary test showed no statistical difference in expression of GAPDH between the two groups. These analyses are the first to investigate GAPDH in bobwhite. These efforts in phylogeny, sequence analysis, and protein structure suggest that there is > 97% conservation of GADPH among Galliformes. Furthermore, the results of these in silico tests and the preliminary qPCR indicate that GAPDH is a prospective candidate for use in gene expression analyses in bobwhite.

To further characterize avian toxicity to environmental levels of select per- and poly-fluoroalkyl substances (PFAS), we established species- and tissue-specific PFAS chronic toxicity values (CTVs) associated with a lowest-observable-adverse effect level (LOAEL) threshold previously established for northern bobwhite quail (Colinus virginianus) chronically orally exposed via drinking water to either perfluorooctane sulfonate (PFOS) or a simple PFAS mixture. Aided by advances in analytical techniques, the novel avian oral PFAS CTVs reported in the present study are lower than the previously reported toxicity reference values (TRVs) estimated for birds chronically exposed via feed. Thus, current avian PFOS TRVs may not be fully protective of wild avian populations at PFAS-impacted sites. Also, likely due to differences in bioavailability, bioaccessibility, and toxicokinetics among individual PFAS between oral exposure types, we found higher bioaccumulation factors in all assessed tissues from birds exposed via water versus feed. Thus, we propose that future characterization of chemical toxicity due to ingestion exposure initially include a full examination of all probable sources of oral exposure for the most accurate derivation of TRVs and a more complete picture of ecological risk. The avian PFAS LOAEL CTVs established in the present study can be modified with the use of uncertainty factors to derive site-specific avian TRVs for ecological risk assessment at PFAS-impacted sites. From differences observed in the behavior of PFOS when administered as either a single chemical or part of a binary mixture with perfluorohexane sulfonate (PFHxS), we verified that PFOS was absorbed and distributed differently when coadministered with PFHxS and that PFOS likely interacted with PFHxS differently among tissues, helping to explain the differences observed in avian toxicity between exposures. Environ Toxicol Chem 2021;40:899-909. © 2020 SETAC.

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.

The effects of flock size of European starlings (Sturnus vulgaris) was experimentally manipulated to assess the potential of influenza A virus (IAV; H4N6) transmission from a flocking passerine to bobwhite quail (Colinus virginianus) through shared food and water resources to mimic starling intrusions into free-range and backyard poultry operations. Of the three starling flock sizes tested (n = 30, n = 20, and n = 10), all successfully transmitted the virus to all or most of the quail in each animal room (6/6, 6/6, and 5/6) by the end of the experimental period, as determined by seroconversion and/or viral RNA shedding. Although starlings have been shown to be inconsistent shedders of IAVs and when they do replicate and subsequently shed virus they typically do so at low to moderate levels, this study has provided evidence that relatively small flocks (i.e., 10 or possibly a smaller number) of this species can collectively transmit the virus to a highly susceptible gallinaceous bird species. Future work should assess if starlings can transmit IAVs to additional poultry species commonly found in backyard or free-range settings. This article is protected by copyright. All rights reserved.

Per- and polyfluoroalkyl substances (PFAS) are globally distributed and present in nearly every environmental compartment. Characterizing the chronic toxicity of individual PFAS compounds and mixtures is necessary because many have been reported to cause adverse health effects. To derive toxicity reference values (TRVs) and conduct ecotoxicological risk assessments (ERAs) of PFAS-contaminated ecosystems for wildlife, species-specific PFAS chronic toxicity values (CTVs) are needed. The present study quantified PFAS residues from liver and eggs of birds chronically exposed to perfluorohexanoic acid (PFHxA) or a mixture of perfluorooctane sulfonate (PFOS) and PFHxA that produced a no-observable-adverse-effect level (NOAEL) and/or a lowest-observable-adverse-effectlevel (LOAEL). The CTVs we present are lower than those previously reported for birds and should be considered in future regulatory evaluations. From the estimated species- and tissue-specific PFAS CTVs, we found that PFOS and perfluorohexane sulfonate (PFHxS) were more bioaccumulative than PFHxA in avian tissues, but PFHxA was more toxic to reproducing birds than either PFOS or a PFOS:PFHxS mixture. We further determined that avian toxicity was not necessarily additive with respect to PFAS mixtures, which could have implications for PFAS ERAs. The PFAS LOAEL CTVs can be used to predict reproductive and possible population-level adverse health effects in wild avian receptors. Environ Toxicol Chem 2022;41:219-229. © 2021 SETAC.

West Nile virus (WNV) has been implicated in regional declines of numerous North American bird species, although its potential impact upon many species, including some game birds, remains unknown. Specifically, information about susceptibility to infection and infection outcome are crucial to assessing health risks. Northern bobwhite quail (Colinus virginianus) are a popular and common game bird across much of the United States, as well as in captive breeding programs and as backyard birds. Two age groups of bobwhites were subcutaneously inoculated with WNV and euthanatized on 15 days postinoculation (DPI). Three of 10 inoculated 5-wk-old and 4/10 inoculated 15-wk-old birds developed detectable viremia titers during 1–5 DPI, with low peak titers (101.7–103.0 plaque-forming units [PFU]/ml). Three of 10 inoculated 5-wk-old and 1/10 inoculated 15-wk-old birds shed low viral titers (peak 100.7–101.8 PFU/swab) either orally or cloacally or both for limited periods from 2 to 6 DPI. All inoculated birds (n = 20) remained apparently healthy and seroconverted by 15 DPI. No infectious virus was detected in select tissues: heart, kidney, brain, skeletal muscle, spleen (15-wk-old group only), and feathers from any of the bobwhites. No sham-inoculated, contact control birds (n = 8) became viremic or had virus isolated from tissues or swabs. The most consistent microscopic lesion was minimal to mild, lymphoplasmacytic myocarditis (6/10 in 5-wk-olds; 5/10 in 15-wk-olds). Immunohistochemical labeling was most often in macrophages in spleen and bone marrow, likely reflective of clearance of infection. There were no statistically significant differences in the peak viremia and shedding titers between age groups and no differences in the development of WNV-associated lesions between the two age groups. These results suggest that WNV is unlikely to pose a health risk to bobwhites and that bobwhites likely are an incompetent reservoir host species in WNV transmission.

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.

The northern bobwhite quail (Colinus virginianus) is a popular gamebird in the Rolling Plains Ecoregion of West Texas. However, there has been a population decline in this area over recent decades. Consistent reports indicate a high prevalence of the eyeworm (Oxyspirura petrowi) and caecal worm (Aulonocephalus pennula), which may be of major influence on the bobwhite population. While research has suggested pathological consequences and genetic relatedness to other pathologically significant parasites, little is known about the influence of climate on these parasites. In this study, we examined whether seasonal temperature and precipitation influences the intensity of these parasites in bobwhite. We also analyzed quantitative PCR results for bobwhite feces and cloacal swabs against temperature and precipitation to identify climatic impacts on parasite reproduction in this region. Multiple linear regression analyses were used for parasite intensity investigation while binary logistic regression analyses were used for parasite reproduction studies. Our analyses suggest that caecal worm intensity, caecal worm reproduction, and eyeworm reproduction are influenced by temperature and precipitation. Temperature data was collected 15, 30, and 60 days prior to the date of collection of individual bobwhite and compared to qPCR results to generate a temperature range that may influence future eyeworm reproduction. This is the first preliminary study investigating climatic influences with predictive statistics on eyeworm and caecal worm infection of northern bobwhite in the Rolling Plains. Keywords: Bobwhite, Caecal, Climate, Eyeworm, qPCR

The Northern bobwhite quail (Colinus virginianus) is a popular game bird that has been experiencing a well-documented decline throughout Texas since the 1960s. While much of this decline has been attributed to habitat loss and fragmentation, recent studies have identified other factors that may also contribute to decreasing quail populations. Parasites, in particular, have become increasingly recognized as possible stressors of quail, and some species, particularly the eyeworm (Oxyspirura petrowi) and cecal worm (Aulonocephalus pennula) are highly prevalent in Texas quails. Eyeworm infection has also been documented in some passerines, suggesting helminth infection may be shared between bird species. However, the lack of comprehensive helminth surveys has rendered the extent of shared infection between quail and passerines in the ecoregion unclear. Thus, helminth surveys were conducted on bobwhite, scaled quail (Callipepla squamata), Northern mockingbirds (Mimus polyglottos), curve-billed thrashers (Toxistoma curvirostre), and Northern cardinals (Cardinalis cardinalis) to contribute data to existing parasitological gaps for birds in the Rolling Plains ecoregion of Texas. Birds were trapped across 3 counties in the Texas Rolling Plains from March to October 2019. Necropsies were conducted on 54 individuals (36 quail and 18 passerines), and extracted helminths were microscopically identified. Nematode, cestode, and acanthocephalan helminths representing at least 10 helminth species were found. Specifically, A. pennula and O. petrowi had the highest prevalence, and O. petrowi was documented in all of the study species. This research adds to the body of knowledge regarding parasitic infections in quail and passerines of the Rolling Plains ecoregion and highlights the potential consequences of shared infection of eyeworms among these bird species.

A flock of captive bobwhite quail (Colinus virginianus) experienced loose droppings, depression, and increased mortality starting at 3 wk of age. Necropsy of the affected birds revealed intestines dilated with frothy and tan fluid. Irregular dark brown fissures within the koilin layer of the gizzard were found in 20%-30% of the birds. Histologically, gizzards showed multifocal koilin degeneration or fragmentation, degeneration and necrosis of the subjacent epithelial cells, and infiltration of macrophages, lymphocytes, and heterophils. Necrotic epithelial cells occasionally contained large, smudgy, basophilic intranuclear inclusion bodies with marginated nuclear chromatin. Adenoviral paracrystalline arrays composed of icosahedral virions (60-70 nm diameter) were seen on transmission electron microscopy in the nuclei of epithelial cells in the gizzard mucosa. Adenovirus was isolated from gizzard, liver, intestine, and trachea by inoculation of specific-pathogen-free embryonated chicken eggs. Homogenates of the gizzard, liver, and intestine were positive for the adenovirus hexon gene by PCR. Sequencing of PCR amplicons confirmed the virus as fowl aviadenovirus A. The study isolates showed more than 99% and 97% nucleotide identity with quail bronchitis virus and with aviadenoviruses from gizzard erosion and ulceration (GEU) in broilers, respectively. The viral isolates showed six substitutions (G1T, C174A, A229G, C513A, T579A, and G621C) of which two were nonsynonymous (G1T and A229G), resulting in a change in the translated amino acid as A1S and S77G, respectively. These results indicate that adenoviruses of the same type or species can cause different clinical presentations in quails, e.g., bronchitis or GEU.

A captive-bred Bobwhite Quail ( Colinus virginianus) ranch in southern Utah, US experienced high mortality rates in the late summer and fall of 2012. Nine juvenile birds were necropsied at the Utah Veterinary Diagnostic Laboratory. Gross lesions included pale skeletal muscle with multifocal hemorrhages and petechiae in the air sacs and serosal surfaces of most organs. Histologically there was moderate to severe, multifocal, degenerative myositis with intramyofiber schizonts and minimal lymphoplasmacytic infiltrates in the proventriculus, ventriculus, heart, and skeletal muscle. There was also moderate fibrinoid to heterophilic vasculitis in multiple organs with vascular intraendothelial or intravascular merozoites and scattered thrombosis. In the liver and spleen there were multiple degenerative schizonts that had ruptured. Blood smears from three of the birds were stained with Wright-Giemsa stain and examined at a referral laboratory. Although the blood cells were deteriorated (postmortem artifact), life stages (exact stages not specified) consistent with Haemoproteus spp. were identified in erythrocytes. Polymerase chain reaction done on pooled tissues from two birds produced an amplicon in both pooled samples, and direct sequencing confirmed the presence of 533 base pairs of a Haemoproteus sp. in the subgenus Parahaemoproteus. The identification of Parahaemoproteus spp. in quail in southern Utah implies that appropriate Culicoides spp. vectors are present in the state and that there is potential risk to other birds such as zoo and aviary populations, wild turkeys, and other game birds.

Although the relationship between oak mast and Lyme disease incidence in humans is established in the Northeastern U.S., mast-disease relationships have not been explored for longleaf pine in the southeastern U.S. Here, we examine if relationships exist between longleaf pine mast and tick-borne disease incidence in humans using climate, wildfire, and northern bobwhite quail (Colinus virginianus) data as possible influential variables. We examined the relationship between longleaf pine mast data and tick-borne disease incidence for Lyme, Spotted Fever Group Rickettsia (SFGR), and Ehrlichia chaffeensis (ehrlichiosis) using one-sided Pearson's product-moment correlations at ten individual masting locations and for the entire masting region in the southeastern U.S. Region-wide mast from the previous year were positively correlated with northern bobwhite quail and negatively correlated with Lyme disease. Additionally, northern bobwhite quail were negatively correlated with SFGR and ehrlichiosis, and both drought severity and fire were not correlated with the other variables. We posit the nutrient-rich pine seeds that are a major food source for northern bobwhite quail promote above-average quail populations the following year. As quail diet transitions from seeds in cool months to ground-dwelling insects the following spring and summer, we hypothesize the ability of northern bobwhite quail to consume ticks reduces tick populations and significantly reduces disease incidence in humans.

Physaloptera spp. are common nematodes found in the stomach and muscles of mammals, reptiles, amphibians, and birds. Physaloptera spp. have a complicated life cycle with multiple definitive hosts, arthropod intermediate hosts, aberrant infections, and possible second intermediate hosts or paratenic hosts. For example, Physaloptera sp. larvae have been found within the tissues of wild northern bobwhite quail (Colinus virginianus), and it is suspected that quail may serve as paratenic or secondary hosts of these parasites. However, because it is not known what role quail play in the life cycle of Physaloptera spp. and descriptions of Physaloptera spp. larvae are limited, molecular tools may be beneficial when identifying these helminths. In this study, we generated primers using universal nematode primers and obtained a partial mitochondrial cytochrome oxidase 1 (COX 1) sequence. Morphological identification of Physaloptera sp. in bobwhite was confirmed via polymerase chain reaction (PCR), and a phylogenetic tree was constructed using the maximum likelihood method. BLAST analysis revealed a strong identity to other Physaloptera spp. and the phylogenetic tree placed all Physaloptera spp. in the same cluster. We also documented a marked increase in Physaloptera infections in bobwhite from 2017 to 2018, and the similarity of these parasites to Onchocerca volvulus and Wuchereria bancrofti may give insight into the increased prevalence we observed. This study demonstrates the usefulness of molecular techniques to confirm the identity of species that may lack adequate descriptions and provides new insight for the diagnosis and potentially overlooked significance of Physaloptera sp. infections of bobwhite in the Rolling Plains ecoregion of 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.

Aulonocephalus pennula is a heteroxenous nematode that commonly infects a declining game bird, the northern bobwhite quail (Colinus virginianus). There is a lack of information on the life cycle of A. pennula and the potential effects of infection on bobwhites. In order to better understand the life cycle of this parasite, various species from the order Orthoptera were collected from a field site in Mitchell County, Texas. Using polymerase chain reaction (PCR), nine potential intermediate hosts were identified from the 35 orthopteran species collected. Later, ten live specimens were collected to identify larvae within the potential intermediate hosts. Larvae were present in three of these and were sent for sequencing. Similarly, the presence of larvae was confirmed from extra tissues of samples identified as positive with PCR. This was the first study to document potential intermediate hosts, but future studies are needed to confirm that these species are capable of transmitting infection to bobwhite. However, this study demonstrates that PCR has increased sensitivity and may be a valuable tool when determining intermediate hosts.

Most antioxidants have multiple functions; in addition to minimizing oxidative damage, many antioxidants have immune-modulating properties. For example, biliverdin is produced in the liver and spleen from the breakdown of heme, and has putative immune-suppressing and antioxidant properties. However, the majority of these properties have been investigated in vitro or in mammalian models, in which biliverdin reductase converts virtually all biliverdin to bilirubin. Thus, biliverdin's physiological roles remain largely untested. Here, we investigated whether biliverdin has immunomodulating roles by injecting Northern Bobwhite quail (Colinus virginianus) with either a vehicle control, lysed and rinsed pig red blood cells (pRBC) that contain erythrocyte antigens but no heme, or intact pRBC that contain both erythrocyte antigens and hemoglobin, thus increasing the amount of heme that can be converted to biliverdin. We then quantified hemagglutination and hemolysis ability, and biliverdin concentration in the liver and spleen, on 3, 6, and 9 days post-injection. We found that hemagglutination was greater in individuals that received intact pRBC, but not in those injected with heme-removed pRBC, demonstrating that biliverdin does not suppress immune function at this dosage. Biliverdin levels of liver and spleen were correlated within individuals, suggesting organism-level variation in biliverdin production. Lastly, individuals injected with intact pRBC had a reduced biliverdin concentration in the spleen, suggesting that immune challenges may reduce biliverdin production or accumulation. This initial investigation demonstrated that biliverdin may have more nuanced physiological roles than previously reported, supporting the value of further investigations into the physiology of biliverdin.

Aulonocephalus pennula is a nematode living in the caeca of the wild Northern bobwhite quail (Colinus virginianus) present throughout the Rolling Plains Ecoregion of Texas. The cytochrome oxidase 1 (COX 1) gene of the mitochondrial genome was used to screen A. pennula in wild quail. Through BLAST analysis, similarity of A. pennula to other nematode parasites was compared at the nucleotide level. Phylogenetic analysis of A. pennula COX1 indicated relationships to Subuluridae, Ascarididae, and Anisakidae. This study on molecular characterization of A. pennula provides new insight for the diagnosis of caecal worm infections of quail in the Rolling plains Ecoregion of Texas. Keywords: Aulonocephalus pennula, Caecal worm, Northern bobwhite, Phylogeny, PCR, COX1

Selective attention to different properties of stimulation provides the foundation for perception, learning, and memory. The Intersensory Redundancy Hypothesis (IRH) proposes that early in development information presented redundantly across two or more modalities (multimodal) selectively recruits attention to and enhances perceptual learning of amodal properties, whereas information presented to a single sense modality (unimodal) enhances perceptual learning of modality-specific properties. The present study is the first to assess this principle of unimodal facilitation in non-human animals in prenatal development. We assessed bobwhite quail embryos’ prenatal detection of pitch, a modality-specific property, under conditions of unimodal and bimodal (synchronous or asynchronous) exposure. Chicks exposed to prenatal unimodal auditory stimulation or asynchronous bimodal (audiovisual) stimulation preferred the familiarized maternal call over a novel pitch-modified maternal call following hatching, whereas chicks exposed to redundant (synchronous) audiovisual stimulation failed to prefer the familiar call over the pitch-modified call. These results provide further evidence that selective attention is recruited to specific stimulus properties of events in early development and that these biases are evident even during the prenatal period.

This study investigated the effect of mismatching incubation and posthatch temperatures in northern bobwhite quail hatchlings. Quail embryos were incubated at 35.5° or 37.5°C. Metabolic rates were then measured in hatchlings acclimated to either the same or the opposite temperature treatment. While hatchlings expressed higher oxygen consumption when posthatch temperature did not match incubation temperature, the effect of mismatching temperatures was significant only when posthatch temperature was higher than incubation temperature. Our data suggest that bobwhite quail hatchlings may express increased metabolism due to mismatches between incubation and posthatch temperatures. More specifically, the nature or direction of the mismatch can determine the magnitude of the metabolic effect. These findings highlight the importance of considering the context of specific conditions experienced throughout ontogeny when observing phenotypic outcomes.

Sensory-motor development begins early during embryogenesis and is influenced by sensory experience. Little is known about the prenatal factors that influence the development of motor coordination. Here we investigated whether and to what extent prenatal light experience can influence the development of motor coordination in bobwhite quail hatchlings. Quail embryos were incubated under four light conditions: no light (dark), 2h of total light (2HR), 6h of total light (6HR), and diffused sunlight (controls). Hatchlings were video recording walking down a runway at three developmental ages (12, 24, and 48h). Videos were assessed for forward locomotion, a measurement of motor coordination, falls, a measurement of motor instability, and motivation to complete the task. We anticipated a linear decline of coordination with a reduction in prenatal light experience and improved coordination with age. Furthermore, as motor coordination becomes more laborious we anticipated motivation to complete the task would decline. However, our findings revealed hatchlings did not uniformly improve with age as expected, nor did the reduction of light result in a linear reduction in motor coordination. Instead, we found a more complex relationship with 6HR and 2HR hatchlings showing distinct patterns of stability and instability. Similarly, we found a reduction in motivation within the 6HR light condition. It appears that prenatal light exposure influences the development of postnatal motor coordination and we discuss these finding in light of neurodevelopmental processes influenced by light experience.

Parasitic nematodes that infect quail have been understudied and long been dismissed as a problem in quail management. Within the Rolling Plains ecoregion of Texas, an area that has experienced quail population “boom and bust” cycles and ultimately a general decline, the need to determine why Northern bobwhite (Colinus virginianus) populations are diminishing has increased in priority. Previously, caecal parasites have been documented to cause inactivity, weight loss, reduced growth, inflammation to the caecal mucosa, and even death. The caecal worm Aulonocephalus pennula is an intestinal nematode parasite that is commonly found within the caecum of quail, as well as many other avian species. In the Rolling Plains ecoregion, A. pennula has been documented to have as high as a 98% prevalence in bobwhite quail samples; however, the effect it has on its host is not well understood. The present study documents A. pennula causes no pathological changes within the caeca of the Northern bobwhite. However, there is concern for disruption of digestion and the possible implications of infection for wild bobwhite quail survival are discussed.

Per- and poly-fluoroalkyl substances (PFAS) are a broad class of environmentally persistent chemicals that include thousands of potentially toxic synthetic organic molecules. Some PFAS have been shown to cause adverse health effects including decreased total cholesterol, birth weight, and reproductive success in laboratory animals; however, a lack of chronic toxicity data exists for PFAS in avian ecological receptors. The present study reports on the chronic toxicity of perfluorooctane sulfonic acid (PFOS) and a mixture of PFOS and perfluorohexane sulfonic acid (PFHxS) to northern bobwhite quail (Colinus virginianus) via oral exposure from drinking water. Female weight gain was adversely affected at an average daily intake (ADI) of 3.10 × 10-3 ± 0.15 × 10-3 mg PFOS:PFHxS (1.2:1) mixture × kg-1 body weight × d-1 . Successful liberation from the shell once pipped was adversely affected at an ADI of 2.45 × 10-3 ± 0.01 × 10-3 mg PFOS x kg-1 body weight × d-1 . These values are comparatively much lower than the current dietary avian toxicity reference value (TRV) derived from birds that were exposed via feed, suggesting the need for updated avian TRVs. Relationships between test chemical (PFOS) and test substance (PFOS:PFHxS) showed that PFOS and PFHxS have possible interacting effects in avian receptors and likely differing mechanisms of toxicity depending on chemical co-occurrence and dose. Both the single-chemical and mixture exposures produced similar and possibly additive toxicity values. Environ Toxicol Chem 2020;39:1101-1111. © 2020 SETAC.

Maternal nesting behavior, which includes periods of patterned inattention, provides key elements essential for avian embryonic development, including regulation of temperature and light. For example, avian research consistently shows the importance of prenatal light exposure for several developmental processes; however, this research has primarily focused on artificial light regimens (i.e. 24 hr, 0 hr light). Comparatively less is known about how exposure to naturally occurring light patterns during incubation influence motor performance, body composition (i.e. body mass, bone length), and developmental age (incubation length). Here we conducted two experiments which investigated the effects of prenatal light exposure on developmental age, body composition, and gait performance in 1-day-old bobwhite quail. Experiment 1 investigated crepuscular light exposure during the last two days of incubation under two light duration treatments (2 hr & 6 hr) compared to a 12 hr continuous light schedule. Results indicated crepuscular prenatal light experience extended the incubation period for 2 hr exposed embryos, but not for 6 hr exposed embryos and negatively influenced postnatal body composition and postnatal gait performance when compared to 12 hr continuous light embryos. Experiment 2 examined the influence of prenatal light duration (2 hr vs 6 hr) and light presentation (crepuscular vs sporadic). Results demonstrated sporadic light presentation improved gait performance in 2 hr exposed hatchlings, but not 6 hr exposed hatchlings, improved body composition in 6 hr exposed hatchlings, but not 2 hr exposed hatchlings, and did not alter incubation length when compared to crepuscular light counterparts. This study provides further evidence for the importance of maternally regulated sensory stimulation during the prenatal period on early postnatal motor development.

Temperature extremes alter development, growth, hatching, and survival of eggs of ground-nesting birds, particularly during pre-incubation (egg laying) when eggs are left unattended and exposed to the environment for days or weeks before parental incubation begins. The northern bobwhite quail is a ground-nesting bird whose eggs experience high temperatures (≥45° C) during pre-incubation. It is known that chronic high temperatures during pre-incubation alter development and reduce hatching and survival of bobwhite eggs, but it is not known if acute doses of high temperatures during pre-incubation have the same effect. In this study, the 12-d pre-incubation period was divided into thirds. Fresh bobwhite eggs were exposed to either a commercial holding temperature for all 12 d (serving as a control), or a high oscillating temperature regimen for 4 d (one third of pre-incubation) either in the early, middle, or late third of pre-incubation, with a low oscillating temperature regimen during the remaining 8 d. The timing of acute exposure to high oscillating temperatures significantly affected bobwhite development. Eggs exposed in the first 2/3 of pre-incubation developed twice as much as eggs exposed late in pre-incubation, even though all eggs received the same amount of heating degree-hours. Thus, a critical window of thermal susceptibility exists for developing northern bobwhites. Acute exposure to high oscillating temperatures resulted in reduced hatchling mass, hatching success, survival, and compromised hatching synchrony. Thus, acute hyperthermic nest temperatures during pre-incubation could result in the observed reductions in the percentage of juveniles in natural populations during hot and droughty years.

Background Oxyspirura petrowi (Spirurida: Thelaziidae), a heteroxenous nematode of birds across the USA, may play a role in the decline of the northern bobwhite (Colinus virginianus) in the Rolling Plains Ecoregion of West Texas. Previous molecular studies suggest that crickets, grasshoppers and cockroaches serve as potential intermediate hosts of O. petrowi, although a complete study on the life-cycle of this nematode has not been conducted thus far. Consequently, this study aims to improve our understanding of the O. petrowi life-cycle by experimentally infecting house crickets (Acheta domesticus) with O. petrowi eggs, feeding infected crickets to bobwhite and assessing the life-cycle of this nematode in both the definitive and intermediate hosts. Methods Oxyspirura petrowi eggs were collected from gravid worms recovered from wild bobwhite and fed to house crickets. The development of O. petrowi within crickets was monitored by dissection of crickets at specified intervals. When infective larvae were found inside crickets, parasite-free pen-raised bobwhite were fed four infected crickets each. The maturation of O. petrowi in bobwhite was monitored through fecal floats and bobwhite necropsies at specified intervals. Results In this study, we were able to infect both crickets (n = 45) and bobwhite (n = 25) with O. petrowi at a rate of 96%. We successfully replicated and monitored the complete O. petrowi life-cycle in vivo, recovering embryonated O. petrowi eggs from the feces of bobwhite 51 days after consumption of infected crickets. All life-cycle stages of O. petrowi were confirmed in both the house cricket and the bobwhite using morphological and molecular techniques. Conclusions This study provides a better understanding of the infection mechanism and life-cycle of O. petrowi by tracking the developmental progress within both the intermediate and definitive host. To our knowledge, this study is the first to fully monitor the complete life-cycle of O. petrowi and may allow for better estimates into the potential for future epizootics of O. petrowi in bobwhite. Finally, this study provides a model for experimental infection that may be used in research examining the effects of O. petrowi infection in bobwhite.

Precocial avian species exhibit a high degree of lateralization of perceptual and motor abilities, including preferential eye use for tasks such as social recognition and predator detection. Such lateralization has been related, in part, to differential experience prior to hatch. That is, due to spatial and resulting postural constraints late in incubation, one eye and hemisphere-generally the right eye / left hemisphere-receive greater amounts of stimulation than the contralateral eye / hemisphere. This raises the possibility that the left hemisphere may specialize or show relative advantages in integrating information across visual and auditory modalities, given that it typically receives greater amounts of multimodal auditory and visual stimulation prior to hatch. The present study represents an initial investigation of this question in a precocial avian species, the Northern bobwhite quail (Colinus virginianus). Day-old bobwhite chicks received 5 min training sessions in which they vocalized to receive contingent playback of a bobwhite maternal call, presented with or without a light that flashed in synchrony with the notes of the call (i.e., bimodal versus unimodal exposure, respectively). Chicks were trained with or without eye patches that allowed them to experience the visual component of the bimodal stimulus with only the left eye (LE), right eye (RE), or both eyes (i.e., binocular; BIN). Finally, the light was placed in various positions relative to the speakers playing the maternal call across three experiments. 24 hrs later chicks were provided a simultaneous choice test between the familiarized and a novel bobwhite maternal call. Given that the right eye and ear typically face outward and are thus unoccluded by the body during late prenatal development, we hypothesized that RE chicks would show facilitated learning under bimodal conditions compared to all other training conditions. This hypothesis was partially confirmed in Experiment 1, when the light was positioned 40 cm above the source of the maternal call. However, we also observed evidence of suppressed learning in chicks provided BIN exposure to the bimodal audio-visual stimulus that was not present during auditory-only training. Experiments 2 and 3 demonstrated that this was likely related to activation of a left-hemisphere dependent fear response when the left eye was exposed to a visual stimulus that loomed above the auditory stimulus. These results indicate that multisensory processing is lateralized in a precocial bird and that these species may thus provide a unique model for studying experience-dependent plasticity of intersensory perception.

Debilitating ocular diseases are often reported in avian species. By and large, helminth parasites have been overlooked in avian diseases and regarded as inconsequential. The decline of Northern bobwhite quail (Colinus virginianus) in the Rolling Plains ecoregion of Texas has prompted an investigation of the factors influencing their disappearance. Infection by the eyeworm (Oxyspirura petrowi) has been documented in many avian species; however, the effect it has on its host is not well understood. Heavy eyeworm infection has been documented in Northern bobwhites throughout this ecoregion, leading to eye pathology in this host species. The present study further documents and supports the pathological changes associated with O. petrowi in bobwhites., Graphical abstract Image 1, Highlights • O. petrowi infection caused adenitis in Northern bobwhites. • Histological sections demonstrated lesions associated with O. petrowi infection. • Corneas appeared to be cloudy and have early ulcerative erosions. • Inflammation and glandular atrophy were associated with O. petrowi infection.

Contingency perception is critical during infancy, providing the basis for the continuous learning (and re-learning) of the relation between the developing body, self-produced actions, and the environment. Nevertheless, relatively few studies have systematically examined the spatiotemporal parameters that optimize learning during development. Here, we present a series of experiments exploring a novel timing-specific deficit in auditory learning in an animal model, the bobwhite quail (Colinus virginianus). In this paradigm, chicks vocalize to hear playback of an unfamiliar maternal call and are later tested for their filial preference for that call over a novel maternal call. Rather than a simple, hyperbolic decline in learning with increased delay between chick vocalization and playback, we found a window—450–900 msec after chicks ceased vocalizing—in which chicks appeared to have difficulty learning and forming a preference for the maternal call. This deficit nonetheless occurred only when the spatial location of call playback switched semi-randomly during training, suggesting an attentional explanation for this deficit. Our findings indicate that optimization of the temporal parameters in operant paradigms with infants can be complex, particularly if tasks requiring the switching of attention between spatial locations. Our findings may thus be instructive for other developmental research with infants employing operant components.

The northern bobwhite quail (Colinus virginianus) is a game bird experiencing decline throughout much of its range. There are limited species-specific and age-specific hematologic data for bobwhite quail. Complete blood cell counts in eighteen 49-day-old captive-raised quail of unverified sex were used to contribute data to reference intervals for the species as juvenile animals. Values for packed cell volumes, total solids, red and white blood cell counts, and white cell differential calculations were recorded for each animal. Bobwhite quail of this age were found to be primarily lymphocytic, but considerable variability was observed. White blood cell counts were obtained by estimates from blood smears and Phloxine B stain. White blood cell counts performed with ×1000 magnification did not compare well with other white blood cell methods, including Phloxine B stain.

An effective immune response results in the elimination of pathogens, but this immunological benefit may be accompanied by increased levels of oxidative damage. However, organisms have evolved mechanisms to mitigate the extent of such oxidative damage, including the production and mobilization of antioxidants. One potential mechanism of mitigating immune-challenge-induced changes in oxidative physiology is increasing biliverdin production. Biliverdin is chemically an antioxidant, but within-tissue correlations between biliverdin concentration and oxidative damage have never been directly examined. To test how biliverdin tissue concentrations are associated with physiological responses to an immune challenge, we exposed northern bobwhite quail (Colinus virginianus) to one of four treatments: an injection of a non-pathogenic antigen, (i.e., either lipopolysaccharide or phytohaemagglutinin), a control injection of phosphate buffered saline, or a sham procedure with no injection. Twenty-four hours later, we quantified oxidative damage and triglyceride concentration in the plasma, and biliverdin concentration in the plasma, liver, and spleen. We found that both types of immune challenge increased oxidative damage relative to both non-injected and sham-injected controls, but treatment had no effects on any other metric. However, across all birds, oxidative damage and biliverdin concentration in the plasma were negatively correlated, which is consistent with a localized antioxidant function of biliverdin. Additionally, we uncovered multiple links between biliverdin concentration, change in mass during the immune challenge, and triglyceride levels, suggesting that pathways associated with biliverdin production may also be associated with aspects of nutrient mobilization. Future experiments that manipulate biliverdin levels or oxidative damage directly could establish a systemic antioxidant function or elucidate important physiological impacts on body mass maintenance and triglyceride storage, mobilization, or transport.

Avian eggs contain maternally derived hormones, including testosterone and progesterone. Little is currently known about the effects of these hormones on early behavioral development. We assessed the effects of elevated levels of progesterone levels on prenatal perceptual learning and postnatal emotional reactivity in Northern bobwhite quail. Prior to incubation, eggs received an injection of either progesterone (P) or oil vehicle (V). In P eggs, levels of progesterone were elevated two standard deviations above the mean based on ELISA analysis of progesterone yolk concentrations from a previous study. A third group of eggs served as controls and received no injection (C). Chicks hatched from P eggs displayed elevated levels of emotional reactivity compared to V and C chicks in a tonic immobility task and a hole-in-the-wall emergence task. Chicks from P eggs also failed to demonstrate a preference for a familiarized bobwhite maternal call that had been presented prenatally. In contrast, the V and C chicks demonstrated a significant preference for the familiarized maternal call following hatching, indicating prenatal auditory learning. Our results are consistent with previous findings from precocial birds demonstrating that hormones of maternal origin can influence prenatal perceptual learning as well as emotional reactivity in the period following hatching. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 57: 255–262, 2015.

Northern bobwhite quail (Colinus virginianus), a popular gamebird among hunters, have been declining over recent decades in the Rolling Plains ecoregion. Investigations in the past few years have revealed a high prevalence of eyeworms (Oxyspirura petrowi) and caecal worms (Aulonocephalus pennula) in this ecoregion, prompting a need to better understand their host–parasite interaction and other factors that influence infection. In this study, the efficiency of a mobile laboratory was tested by deploying it to three field sites in the Rolling Plains between July and August of 2017 and collecting cloacal swabs from bobwhites. The DNA was extracted from swabs for quantitative PCR and was run in the mobile and reference laboratory to specifically detectA. pennulaandO. petrowiinfection. When compared with the Wildlife Toxicology's reference laboratory, the mobile laboratory had a 97 and 99% agreement forA. pennulaandO. petrowi, respectively. There were no significant differences in infection levels between field sites. Due to its efficiency, it is proposed that the mobile laboratory would be an effective way to monitor infection levels, in addition to factors that may affect infection such as climate, diapause, and intermediate host populations.

Non-genetic maternal influences on prenatal development have a significant effect on the development of early life behavior. This study assessed the behavioral effect of elevated prenatal progesterone on postnatal emotional reactivity, or underlying fear and stress, in embryos of Northern bobwhite quail ( Colinus virginianus) . Test groups of progesterone treated eggs, vehicle treated, and no injection were exposed to three measures of emotional reactivity at 48 and 96 hours after hatch: an open field, an emergence test, and a tonic immobility test. Heightened levels of emotional reactivity in the tonic immobility emergence tasks, and decreased levels of emotional reactivity in the open field suggest that elevated prenatal progesterone modifies post natal emotional reactivity up to 96 hours of age.

Hematology and its regulation in developing birds have been primarily investigated in response to relatively short-term environmental challenges in the embryo. Yet, whether any changes induced in the embryo persist into adulthood as a hematological form of “fetal programming” is unknown. We hypothesized that: 1) chronic as opposed to acute hypoxic incubation will alter hematological respiratory variables in embryos of bobwhite quail (Colinus virginianus), and 2) alterations first appearing in the embryo will persist into hatchlings through into adulthood. To test these hypotheses, we first developed an embryo-to-adult profile of normal hematological development by measuring hematocrit (Hct), red blood cell concentration ([RBC]), hemoglobin concentration ([Hb]), mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration, as well plasma osmolality. Hct, [RBC] and [Hb] in normoxic-incubated birds (controls) steadily increased from ~22%, ~1.6 × 106 μL−1 and ~7 g% in day 12 embryos to almost double the values at maturity in adult birds. Both cohort and sex affected hematology of normoxic-incubated birds. A second population, incubated from day 0 (d0) in 15% O2, surprisingly revealed little or no significant difference from controls in hematology in embryos. In hatchlings and adults, hypoxic incubation caused no significant modification to any variables. Compared to major hematological effects caused by hypoxic incubation in chickens, the hematology of the bobwhite quail embryo appears to be minimally affected by hypoxic incubation, with very few effects induced during hypoxic incubation actually persisting into adulthood.

Quail is an important and interesting group of galliform birds. The Common quail (Coturnix coturnix); the Japanese quail (Coturnix japonica); the Panda quail (Coturnix japonica); the Dotted white quail (Coturnix japonica) and the Bobwhite quail (Colinus virginianus) were used in this study. PCR-RFLP and SDS-proteins were performed to reveal the genetic characterization and genetic relationship of the studied quails. Analysis of fragments generated by digestion of PCR product with restriction enzyme NlaIII recorded highly polymorphic restriction profiles. There is a wide intraspecific COI, SEMA3E and TLX genes variability among the studied quails. Protein bands varied from10 to 18 between quails with minimum number of bands were in the Dotted white quail (10 bands) and the maximum were in the Japanese quail (18 bands) as measured by SDS-polyacrylamide gel electrophoresis. The Dotted white quail revealed the lowest similarity to the Bobwhite with a coefficient of 0.18 while The similarity coefficients between the Common quail and each one of the other quails were 0.67, 0.62, 0.45 and 0.42 for the Japanese, Panda, Dotted white and the Bobwhite quails, respectively. The results indicate that, PCR-RFLP and protein analyses are good techniques to evaluate genetic characterization and genetic relationship of these quails.

The Northern bobwhite quail (Colinus virginianus) is an economically significant gamebird that has experienced a decline throughout the Rolling Plains ecoregion of Texas. Recent surveys of this area have revealed a high prevalence in eyeworm (Oxyspirura petrowi) and caecal worm (Aulonocephalus pennula) infection that may contribute to this decline. In order to further understand these parasites role in bobwhite populations, a time-, and cost-effective multiplex quantitative PCR (qPCR) assay was developed in this study to detect eyeworm and caecal worm infection through egg detection using the ITS2 and COX1 gene region, respectively. Method validation for the qPCR involved bobwhite fecal samples from the Rolling Plains as well as samples spiked with eyeworm, caecal worm, and bobwhite DNA. Results showed an observed increasing qPCR parasite egg detection with increasing worm burdens. Future uses with this assay can also provide insight to seasonal parasite infection and the life cycles of eyeworm and caecal worm.

World Health Organization (WHO) toxic equivalency factors are used to calculate toxic equivalent (TEQ) concentrations of complex mixtures of dioxin-like compounds (DLCs), such as polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls (PCBs), for mammals, fish and birds. The TEQ concept assumes that all species of a taxa respond with similar sensitivity to individual DLCs, but several reports do not support this assumption for birds. Our laboratory is conducting research to attempt to uncover the fundamental mechanism(s) underlying the reasons why avian species differ in sensitivity to DLCs. The present study determined concentration-dependent effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) and 3,3',4,4',5-pentachlorobiphenyl (PCB 126) on ethoxyresorufin-O-deethylase (EROD) activity in primary cultures of northern bobwhite quail (Colinus virginianus) hepatocytes. Bobwhite quail were studied because (1) this species is used in the laboratory for toxicity testing and (2) the amino acids at all locations within the ligand binding domain (LBD) of aryl hydrocarbon receptor 1 (AHR1) in bobwhite quail and ring necked pheasant (Phasianus colchicus) are identical. Because earlier work indicated the importance of the identity of amino acids at key sites within the AHR1 LBD, we hypothesized that bobwhite quail and ring necked pheasant hepatocytes should have similar sensitivity to EROD induction by DLCs. ECthreshold-based relative sensitivity of the bobwhite quail compared to chicken for TCDD, PeCDF and PCB 126 was 0.11, 0.17 and 0.02, respectively. The rank order of potency was PeCDF > TCDD > PCB 126. The results confirm that bobwhite quail and ring-necked pheasant hepatocytes have similar sensitivity to EROD induction by TCDD, PeCDF and PCB 126.

Over the last few decades, there has been a decline in Northern bobwhite quail (Colinus virginianus) throughout their native range. While there are various factors that may be influencing this decline, it is suggested that parasites should be taken into consideration as a potential contributor in the Rolling Plains Ecoregion. High prevalence of the eyeworm (Oxyspirura petrowi) and caecal worm (Aulonocephalus pennula) in bobwhite of this region, coupled with a continuous decline, creates a need to assess infection through alternative methods for regional surveillance. Previous studies have developed a qPCR method and mobile research laboratory as an option for nonlethal procedures. However, there is still a need for standardization of these techniques. Therefore, this study builds on previous protocols to develop an application that considers factors that may influence qPCR results. In this study, cloacal swabs are collected from bobwhite in three locations throughout the Rolling Plains and scaled based on amount of feces present on the swab. This data is compared to qPCR standards as a limit of quantification for both eyeworm and caecal worm to define parasitic infection levels. Binary logistic regressions confirm that the probability of detection increases for both eyeworm (Odds Ratio: 2.3738; 95% Confidence Interval: [1.7804, 3.1649]) and caecal worm (Odds Ratio: 2.8516; 95% Confidence Interval: [2.2235, 3.6570]) as swab score increases. Infection levels for eyeworm and caecal worm are based on the generated cycle threshold value averages of qPCR standards. Based on the results of this study, this method can be applied in the mobile research laboratory to quantitatively assess regional parasitic infection in bobwhite throughout the Rolling Plains. Keywords: Bobwhite, Caecal, Eyeworm, Rolling plains, Surveillance, qPCR

We surveyed scavenger species on Nantucket Island, MA, using motion-activated wildlife cameras baited with carcasses of either a Mus musculus domesticus (House Mouse) or Colinus virginianus (Bobwhite Quail) in the summer of 2016. We aimed to identify vertebrate scavenger species, measure how long carcasses remained available, and examine differences in carrion consumption between grassland and shrubland vegetation types. This information is important for management decisions concerning a reintroduced population of a federally endangered obligate scavenger, Nicrophorus americanus (American Burying Beetle), on Nantucket Island. Carcasses were removed or consumed within 2.7 ± 1.8 d, and vertebrates removed the carcass in 74% of trials. Carcasses persisted for similar lengths of time between the 2 vegetation types, but avian scavengers were significantly more common on Bobwhite Quail carcasses in grassland, and mammalian scavengers were significantly more common on House Mouse carcasses in shrubland habitats. Avian species appear to be significant competitors for carrion appropriate for American Burying Beetle reproduction.

Northern bobwhite quail, Colinus virginianus (L.) (Galliformes: Odontophoridae), population declines are well documented, but pinpointing the reasons for these decreases has proven elusive. Bobwhite population declines are attributed primarily to loss of habitat and land use changes. This, however, does not entirely explain population declines in areas intensively managed for bobwhites. Although previous research demonstrates the negative impact of red imported fire ant (Solenopsis invicta Buren) (Hymenoptera: Formicidae) on northern bobwhites, the mechanisms underlying this effect are largely unknown. To meet the protein demands of early growth and development, bobwhite chicks predominantly consume small insects, of which ants are a substantial proportion. Fire ants alter ant community dynamics by often reducing native ant diversity and abundance while concurrently increasing the abundance of individuals. Fire ants have negative effects on chicks, but they are also a large potential protein sour...

SUMMARY Limited information exists concerning management and nutritional requirements for commercially produced bobwhite quail (Colinus virginianus). In an experiment, we investigated the effects of delayed placement after hatching on livability and performance. Bobwhite quail eggs (n = 1,000) were placed into incubation on 2 consecutive days and all hatchlings were removed on d 25 and identified as either normal- (NP) or late (LP)-pull hatchlings. Normal-pull hatchlings (d 0) were significantly heavier compared with the LP hatchlings (6.95 vs. 6.15 g/bird). However, by 7 d of age, LP birds were significantly heavier than NP birds (17.60 vs. 15.31 g/bird). This effect carried through to d 28, where LP birds were significantly heavier than NP birds (85.54 vs. 81.85 g). Feed consumption was also significantly greater for the LP versus NP birds during the 28-d experimental period (173.5 vs. 167.0 g/bird, respectively). At 28 d of age, birds were assigned to 1 of 4 dietary regimens: 22% CP/0.50% Met; 22% CP + Met; 18% CP/0.41% Met; 18% CP + Met, resulting in an increased Met level of 0.12 and 0.09% for the 22 and 18% diets, respectively. No differences in BW, gain, feed consumption, or FCR occurred due to treatment. Based on qualitative feather scores obtained at termination of the experiment at 70 d of age, the 18% CP (without Met) group had a significantly lower score compared with the other treatments.

SUMMARY Limited information exists concerning the dietary requirements of bobwhite quail (Colinus virginianus), and producers who rear this species for sport shooting and stocking could benefit from such information. In this experiment, 576 two-week-old bobwhite quail were divided among 6 treatment groups and randomized into 8 replications with 12 birds/replicate. A 26, 24, or 22% CP diet (2,810 kcal of ME/kg) was fed to 4 or 6 wk of age, followed by the introduction of a 20% CP diet (2,810 kcal of ME/kg) fed through 8 wk of age. Birds and feed were weighed on a biweekly basis. No differences were observed in BW or gain of birds fed the 3 CP regimens from 2 wk until introduced to a 20% CP diet. Feed consumption was significantly decreased in the 22% CP group that was introduced to the lower CP diet (20%) after 2 wk. Although this treatment exhibited a marginally low protein intake as compared with the other treatments, growth performance remained uncompromised. Period FCR appeared to be unaffected by dietary CP regimen, but overall FCR for the 8-wk period was highest for birds on the 26% CP regimen (3.824), whereas the 22% CP regimen was intermediate (3.768), and the 24% CP regimen provided the best FCR (3.639). Therefore, bobwhite quail appear to be unaffected by major dietary changes in protein level and a 26% CP diet may provide adequate nutrition for the 0- to 2-wk starting period, followed by a 24% CP diet for a 2- to 4-wk period, and a 20% CP diet thereafter.

SUMMARY Limited information exists concerning the requirements for brooding bobwhite quail (Colinus virginianus) chicks to maintain livability and health. Three short-term (14-d) studies were conducted to evaluate brooding temperature requirements on early performance and livability. In experiments 1 and 2, birds were brooded at either 85 or 95°F (29.4 or 35.0°C). Birds subjected to the 85 vs. 95°F brooding temperature exhibited significantly decreased BW gains of 1.84 (P = 0.026) and 1.78 g (P = 0.090) for experiments 1 and 2, respectively, during the 0- to 7-d period. In experiment 1, birds maintained on the 85°F regimen compensated with a significant (P = 0.002) increase in BW gain compared with birds brooded at 95°F during the 7- to 14-d period (18.10 vs. 16.83 g, respectively). In experiment 3, bobwhite quail were brooded at 90, 95, or 100°F (32.2, 35.0, or 37.8°C). For 0 to 7 d, birds maintained at 95°F gained 9.65 g/bird compared with those maintained at 90 and 100°F, which gained 9.11 and 9.10 g/bird, respectively (P = 0.536). During the 7- to 14-d period, birds maintained at 90°F gained 18.1 g/bird (P = 0.001) compared with 95 and 100°F, which gained 15.80 and 15.31 g/bird, respectively. Feed consumption for the 7- to 14-d period was greatest (P = 0.066) in the 90°F versus the 100°F group (31.28 vs. 26.96 g/bird, respectively), as the 95°F group remained intermediate (29.15 g/bird). In conclusion, bobwhite quail require a brooding temperature of 90 to 95°F (32.2–35.0°C) from 0 to 7 d, followed by a reduction to 85 to 90°F (29.4–32.2°C) during the 7- to 14-d period posthatch.

SUMMARY Native bobwhite quail (Colinus virginianus) populations have declined during the previous 40 yr, and as a result, about 20 million birds are produced commercially to fulfill hunting needs. Limited information exists concerning the dietary requirements of bobwhite quail, and producers could benefit from such information. In experiment 1, a 26% protein starter diet (2,810 kcal of ME/kg) was fed from 7 to 21, 28, 35, or 42 d of age followed by 20% protein grower diet (2,810 kcal of ME/kg) introduced at the appropriate time and fed to 56 d of age. In experiment 2, a 26% protein starter diet was fed from 7 to 42 d of age where dietary treatments were control, phytase enzyme, mannan oligosaccharide, and penicillin. Afterward, a 20% grower diet containing no additives was fed from 42 to 56 d of age. In experiment 1, early growth was significantly (P < 0.05) delayed in birds fed the starter diet to 21 d of age. However, by 56 d of age, BW and FE averaged 149 g/bird and 4.51, respectively, with no differences between treatments. Therefore, bobwhite quail subjected to a decrease in protein intake are responsive to compensatory gain. In experiment 2, feed additives had no effect on improving BW gain, feed consumption, or FE under the conditions of this experiment. By 56 d of age, average BW and FE were 148 g/bird and 4.42, respectively.