Project Outline

Phase I Projects

  • Virology
    • Prevalence of Arboviral Infectious and Zoonotic Pathogens – Presley
    • Viral pathogens in Texas Bobwhites – Lupiani
  • Parasitology
    • Major Protozoan Parasites in Bobwhite Quail – Zhu
    • Survey for Trichomonas gallinae and Assessment of Helminth Parasites in Bobwhites from the Rolling Plains Ecoregion – Fedynich
  • Contaminants and Pesticides
    • Contaminant Analysis in Quail Tissues – Kendell
  • Environmental
    • The influence of landscape conditions and environmental factors on northern bobwhite abundance at multiple spatial scales in the Rolling Plains of Texas – Peterson

Phase II Projects

  • Determining LifeCycle and Transmission Dynamics of Oxyspirura Petrowi in Rolling Plains Orthopteran species consumed by Northern Bobwhite Quail – Presley
  • Kendall

Phase III Projects

  • Treatment of Parasitic Nematodes in Wild Bobwhite Quail –  Kendall



“The role of wildlife disease in wildlife has probably been radically under-estimated.” –  Aldo Leopold, 1933

Surprisingly, this quote from Aldo Leopold, the father of the field of wildlife biology in North America, still rings as true today as it did in 1933. Wildlife professionals have largely been dismissive of disease as a factor in population declines or cycles and the body of scientific literature concerning quails reflects that. However, as General George Patton once said, “If everyone is thinking alike, then somebody isn’t thinking.” It was in this vein that we turned our attention to disease-related research questions in the fall of 2010.   

At that time the Rolling Plains and locations elsewhere in Texas were reeling from the revelation that although we had received decent rainfall and the habitat appeared good, fall quail populations had failed to respond. That prompted us to ponder: what factors might we be overlooking? Rick Snipes, president of the RPQRF board at the time, gave us a charge: design and conduct a comprehensive scientific survey into disease (in the broadest context) as a possible explanation for the decline of bobwhite and scaled quail in the Rolling Plains.  The RPQRF Board approved $2 million for this new endeavor and, like the starship Enterprise, we were about to boldly go where no man had gone before, on a scale as large as the Rolling Plains and beyond.

We brought together a team of 10 scientists from Texas A&M, Texas A&M-Kingsville, Texas Tech University, and the University of North Texas whose specialties ranged broadly within the wildlife epidemiology world. We also involved the Oklahoma Department of Wildlife Conservation (ODWC) to expand our reach in the Rolling Plains beyond the borders of Texas. Together, we identified potential pathogens and parasites, and the procedures and collaborations that would be necessary to pull it all off. The studies we funded were designed to look for all manner of potential diseases in quail. The samples we would collect were to be inventoried at the Central Receiving Laboratory on the grounds of the Texas Institute for Environmental and Human Health (TIEHH) at Texas Tech University, then disseminated to our team of researchers.

Over the next three years, Phase I of Operation Idiopathic Decline (OID) was a logistical triumph. Six trapping teams went forth from Big Lake (TX) to Buffalo (OK) and 33 other sites in between.  Each team spent 2.5 days on each of six ranches or Wildlife Management Areas. The logistics of trapping and sampling, then couriering the samples within 24 hours to the Central Receiving Laboratory took late hours, red eyes, and thousands of miles of driving. Our total tally was 2,615 quail sampled: 2,186 bobwhites and 429 scaled quail. We are deeply indebted to the many landowners who granted us trespass rights for trapping. Their contribution was notable considering how low quail abundance was in most areas.

As a result of this exhaustive sampling and wide range of potential pathogens, we uncovered several avenues of research that warranted investigation. These included the presence of antibiotic-resistant, pathogenic bacteria, exposure to quail bronchitis virus, avian paramyxovirus, and avian influenza, a high prevalence of coccidian parasites (up to 48%), and the presence of organochlorine pesticides. Particularly notable among these was the high incidence of helminth (i.e., worm) parasites, i.e., eyeworms and cecal worms. We commonly found infection of 50% for eyeworms and 90% for cecal worms.  Based on these findings and the knowledge that cecal worms (a different species than quail have) have been proven to regulate red grouse populations in Scotland, we funded additional research (Phases II and III) to further investigate the level of infection, pathological effects, and potential treatments for helminth parasites.

Central Receiving Laboratory

Texas Institute for Environmental and Human Health (TIEHH), Texas Tech University

The Central Receiving Laboratory (CRL) provided field logistic and sample acquisition support to Phases 1 and 2 of the overall OID research program. The CRL  focused on three specific objectives: 1) provide complete support to include personnel, vehicles and material resources, as well as coordination and logistical support to quail trapping teams and associated activities, 2) provide a central laboratory capable of receiving and processing field-collected specimens from quail, as well as arthropod specimens that are potential vectors of disease-causing microorganisms, and 3) provide a central laboratory capable of necropsying and disseminating processed quail specimens and samples to collaborating researchers for further analyses.


Prevalence of Arboviral Infectious and Zoonotic Pathogens
Steve Presley, TIEHH, Texas Tech University

Objectives: 1) determine the prevalence of specific infectious and zoonotic pathogenic microorganisms, 2) determine influence of arthropod vectors and the prevalence of specific infectious and zoonotic pathogenic microorganisms.

Blood and other tissue samples from bobwhite quail were used to screen for the presence of active infection or indications of prior infection with specific infectious and zoonotic pathogens. We screened for specific infectious and zoonotic pathogens in quail tissues and arthropods including: various Flaviviruses (West Nile virus, St. Louis encephalitis virus), Western equine encephalitis virus, Quail pox virus, Coxiella burnetii, Franciscella tularensis, and Pasturella multocida. These diseases were selected for investigation because each has been previously reported to cause pathology in wild quail populations, and they have the potential to be easily disseminated across large geographic regions through arthropod vectors or quail translocation. However, all samples were negative. It may be noteworthy that these studies occurred during historical drought (e.g., 2011) hence few mosquitoes (i.e., potential vectors) were available.

Viral pathogens in Texas Bobwhites
Blanca Lupiani, Veterinary Medicine and Biomedical Sciences, Texas A&M University

Objective: determine which avian viruses are present in bobwhites that may contribute to population decline, either as a primary agent or an underlying factor.

Samples were screened for Newcastle disease virus, avian influenza virus, avian adenovirus, and reticuloendotheliosis virus (REV). Results indicated a low prevalence of exposure to avian adenovirus (quail bronchitis), avian paramyxovirus, and avian influenza. The significance of these results, particularly in relation to the population decline, remains to be determined.


Prevalence of Bacterial and Fungal Pathogens in Bobwhite Quail
Shuping Zhang, Veterinary Medicine and Biomedical Sciences, Texas A&M University

Objectives: to determine 1)  the prevalence rates of potential respiratory and intestinal microbial pathogens in bobwhites and 2) the antimicrobial susceptibility of opportunistic pathogenic bacteria isolated from wild bobwhites, including Escherichia coli (E. coli) and Pseudomonas aeruginosa as well as human commensal bacteria, Neisseria species.

PCR assays were used to screen for Mycobacterium spp., Mycoplasma spp., Aspergillus fumgatus, Ochroconis gallopavum, Salmonella spp., Clostridium colinum, Clostridium perfringens, and Macrorhabdus ornithogaster. A few respiratory and intestinal pathogens were found at low levels. With exception of E. coli (30% prevalence) and Pseudomonas aeruginosa (17.3% prevalence). Notably, Salmonella and Clostridium species were not detected. Surprisingly, human commensal bacteria were isolated from the cecal and cloacal samples of these bobwhites. Tracheal colonization by Pseudomonas aeruginosa and intestinal colonization by E. coli and human commensal organisms warrant further investigations on the virulence properties and sources of these bacterial species.

Further results showed that 100% of E. coli strains were resistant to multiple common antibiotics. Pseudomonas aeruginosa strains were resistant to 13 of the 18 antimicrobial agents tested. All Neisseria isolates (n=6) exhibited resistance to 2 antibiotics. In summary, high-level resistance to multiple commonly used antibiotics was detected in both opportunistic and commensal quail bacteria. These findings highlight the need of further investigation on the source of antimicrobial resistance encountered in the wild populations.


Survey for Trichomonas gallinae and Assessment of Helminth Parasites
Alan Fedynich, Caesar Kleberg Wildlife Research Institute, Texas A&M University – Kingsville

Objectives: 1) assess the helminth community and relate it to parameters such as bobwhite age, sex, month, year, body weight, and location as well as identify potential pathological responses caused by the eyeworm Oxyspirura petrowi, 2) determine presence of the protozoan, Trichomonas gallinae (commonly found causing mortality in doves).

Eleven species of helminths have been identified with Aulonocephalus pennula (cecal worms) (85% infected), O. petrowi (eyeworms) (53%)and Tetrameres pattersoni (proventricular worms) (21%) being the most frequently occurring species. The most extensive infections found in single hosts were 84 eyeworms and 1,1,62 cecal worms. Eye tissue (eye surface and intra-orbital glands) from infected and uninfected bobwhites was collected and processed to assess damage caused by the worm. Preliminary results show corneal scarring and inflammation in the intra-orbital glands. All samples were negative for Trichomonas gallinae.

Major Protozoal Parasites in Bobwhite Quail
Guan Zhu, Veterinary Medicine and Biomedical Sciences, Texas A&M University

Objectives: 1) determine the prevalence of Coccidia and Crytosporidium species, 2) assess prevalence and pathology of cecal worm infections, and 3) determine prevalence of gut microsporidia and blood hematozoa.

Infection rates among samples were 25% – 48% for the coccidia and 5% – 16% for Cryptosporidium species. Variation in positive rates suggested seasonal variations of infections between adult and juvenile birds. Preliminary study indicates that all coccidial sequences analyzed so far belong to avian Eimeria species.

Collected samples were heavily loaded with cecal worms that were identified as Aulonocephalus pennula. Histology analysis of quail intestines loaded with cecal worms revealed an immune response and tissue inflammation in response to the parasite presence. 

A new nested PCR protocol has been recently developed for detecting microsporidial parasites in the fecal samples. Preliminary data showed that fecal samples from bobwhites collected in 2012 at RPQRR had an infection rate at ~10%, which indicates that microsporidia are less likely to be important pathogens in quail.


Survey of Organochlorine Pesticides in Quail from the Rolling Plains
Ronald Kendall, The Institute of Environmental and Human Health, Texas Tech University

Objective: Test for presence and determine level of contamination of organochlorine pesticides (OC)

Amounts were below reporting limits (around 10 ng/g) and therefore suggest that any potential effects to quail are related to secondary mechanisms (i.e. immune suppression, endocrine disruption) rather than direct OC toxicity. It is impressive to note that some of the most troublesome OCs, DDE for example, are found in almost all samples. This indicates that DDT has deteriorated in the environment and/or that the quail (like many birds) have a preferential metabolic mechanism for converting DDT to DDE. The abundance of lindane is also interesting, as it may be coming from past and recent use as an insecticide for livestock. These effects may not cause direct mortality, but may result in indirect effects that make can make wildlife more vulnerable to predation. They may also cause quail to be more susceptible to parasites due to immunosuppression.

mal and vegetative aspects of usable space for bobwhites. This will improve knowledge regarding bobwhite ecology in semi-arid ecosystems, where large numbers of wild bobwhites still persist despite long-term declines in abundance and range extent, thereby enabling better management decisions for bobwhite conservation.


A Scalar Approach to Northern Bobwhite Abundance
Markus J. Peterson, Department of Wildlife and Fisheries Sciences, Texas A&M University

Kelly Reyna, Department of Biological Sciences, University of North Texas

Objective: This research focused on the intersection of environmental variables as they affect quail species at micro and macro scales. Specifically, are temperature, relative humidity, and precipitation are experienced differently at two scales: ranch and region?

With regard to the focus of Operation Idiopathic Decline (OID) on the factors contributing to the decline of bobwhites, it is essential to fully understand the multiple scales at which environmental variation impacts bobwhites. On the ranch-scale, estimates of quail abundance were correlated with environmental variables, vegetation, and soil data. Regionally, abundance data obtained from TPWD annual counts was correlated with climatic data obtained by NOAA and the PRISM Climate Study Group at Oregon State University.

Phase II Projects

Eyeworm Impacts on Northern Bobwhite Foraging and Flying Efficiency
Ronald Kendall, The Institute of Environmental and Human Health, Texas Tech University

Objective: Test the hypothesis that eyeworms can affect bobwhite foraging and/or flying efficiency to establish data determining if the eyeworm infection leaves the birds visually impaired or not.

Birds will be subjected to flying experiments to test navigation ability as well as other experiments to evaluate the ability to find and secure food in established time frames.

Determining Lifecycle and Transmission Dynamics of Oxyspirura petrowi in Rolling Plains Northern Bobwhite Quail
Steven Presley, The Institute of Environmental and Human Health, Texas Tech University

Objectives: Identify the intermediate host(s) of O. petrowi in northern Texas, and better understand its transmission dynamics.

We detected O. petrowi DNA in 38% of wood cockroaches tested, in 27% of field crickets, and in 31% of grasshopper species tested. Our findings are new to the scientific community, as there are no published reports of O. petrowi occurring in grasshoppers. Additionally, we screened bobwhite fecal pellets using PCR techniques to develop a method for a less invasive method of determining infestation with O. petrowi. A total of 80 fecal pellets (from 80 different birds) were screened for O. petrowi DNA, resulting in 74% (59/80) being positive

Parasitological Survey of Scaled Quail Collected from the Rolling Plains
Alan Fedynich, Caesar Kleberg Wildlife Research Institute, Texas A&M University – Kingsville

Objectives: 1) determine prevalence, abundance, and intensity of helminth parasites in scaled quail from the Rolling Plains and Permian Basin and to document the pathological response of infected tissues, 2) correlate helminth parasite prevalence, abundance, intensity to host age, host sex, body weight, and estimates of scaled quail population density, 3) compare helminth parasite prevalence, abundance, and intensity of hunter collected scaled quail of the Rolling Plains and Permian Basin to South Texas hunter-collected scaled quail, and 4) create a database of helminth community ecology.

Seven helminth species were found. Cecal worms dominated numerically (95% of total) followed by eyeworms (4% of total). Assessment of the intraorbital glands found an immune response and atrophy in the Harderian glands sampled when eyeworms were present. Additionally, cecal villi of samples with cecal worms displayed an immune response. This study provides baseline information that will benefit parasitologists, biologists and managers in future helminth research and management.

Eyeworms (Oxyspirura petrowi) in Northern Bobwhites from South Texas and the Rolling Plains
Alan Fedynich, Caesar Kleberg Wildlife Research Institute, Texas A&M University – Kingsville

Objectives: Compare parasite prevalence and infection intensity between bobwhites in the South Texas and Rolling Plains.

Complete necropsies revealed 6 helminth (worm) species in South Texas and 8 in the Rolling Plains. Helminth infections were common with 85% of bobwhites from South Texas infected and 94% from the Rolling Plains infected. Noteworthy helminth species documented in both regions in Texas were the cecal worm, eyeworm, and proventricular worm. Cecal worms were prevalent (85% in South Texas; 91% in Rolling Plains) and abundant in both regions, although more prevalent in the Rolling Plains. Bobwhites were often infected with 100+ cecal worms. The pathogenicity of this parasite is unknown. Eyeworms were more prevalent in the Rolling Plains (66%) than South Texas (8%). Recent research indicates that eyeworm infections cause tissue damage to the surface of the eye and glands associated with the eye. Proventricular worms, a known pathogen of bobwhites, were more prevalent in the Rolling Plains (24%) than South Texas (5%). All of the helminth parasites encountered in both regions use intermediate hosts (e.g., insects) to complete their lifecycles. The regional differences in bobwhite helminth infections may be attributed to differences in habitat and subsequently insect abundance and species composition. Additionally, South Texas has a dynamic, harsh climate that may be less suitable for helminth parasites. Additional research is needed to determine the pathogenicity of eyeworms and cecal worms and to determine the intermediate hosts of these parasites.

Phase III Projects

Molecular Assessment of Parasitic Infection in Northern Bobwhite Quail Utilizing a Mobile Laboratory Platform
Ronald Kendall, The Institute of Environmental and Human Health, Texas Tech University

Objectives: 1) identify areas of high, medium, and low parasitic infection in quail populations in the Rolling Plains, 2) identify larvae presence in insect intermediate hosts relative to these areas, and 3) analyze seasonal variations affecting parasite activity in quail.

As technology has progressed, multiplex quantitative PCR (qPCR) has emerged as a widely accepted method to non-lethally assess humans and animals for parasitic infection.  It is a cost-effective and time-efficient technique to accurately detect parasite infection using fecal samples. A mobile research laboratory has been developed in congruence with this multiplex qPCR method to specifically test for these parasites’ eggs in bobwhite quail feces and test insect intermediate host for the infective larvae of these parasites.