Alan M. Fedynich’s research while affiliated with Texas A&M University – Kingsville and other places

Community ecology historically focused on plants and free-living organisms; 22 however, problems such as defining habitat boundaries and obtaining adequate sample sizes arise 23 when evaluating such communities. The unique nature of host-helminth systems allows parasite 24 community ecologists to avoid these problems when testing ecological hypotheses. Unlike free-25 living communities that have artificially constructed boundaries, parasite communities have 26 well-defined unambiguous boundaries within host individuals. Due to the inherently complex 27 and dynamic nature of ecological systems, traditional experimental methods often require 28 expensive, long-term trials beyond time and resource budgets of investigators. Conversely, a 29 system dynamics approach facilitates learning about such systems via simulation of ecosystem 30 processes integrated with historical data (both quantitative and qualitative). There have been 31 relatively few studies focusing on parasites in south Texas although research on avian host-32 parasite systems has shown parasites can potentially regulate host populations. The northern 33 bobwhite (Colinus virginianus; hereafter bobwhite) is a game species of ecological, economic, 34 cultural, and recreational importance in Texas that is unfortunately experiencing a long-term, 35 widespread decline. To holistically examine the bobwhite-helminth system in south Texas, we 36 created a system dynamics model capturing the feedback relationships between a south Texas 37 bobwhite population, a grasshopper population, and the corresponding cecal worm 38 (Aulonocephalus pennula) populations on a hypothetical 1,000-acre ranch in south Texas. The 39 model structure, constructed in Vensim © PLE 7.2 software, integrates the hypothesized biotic and 40 abiotic drivers (precipitation, parasite load, insect abundance, and quail density) unique to the 41 host-helminth system over a seven-year period (2012-2019). Our specific objectives were (1) 42 develop a working baseline model to replicate the synergistic population dynamics among 43 bobwhite, grasshopper, and cecal worm populations and then (2) test hypotheses about each 44 population's boom-and-bust cycles resulting from environmental stressors (e.g., drought). 45 Applications of the model can provide landowners and natural resource managers with a better 46

Populations of northern bobwhites ( Colinus virginianus ; hereafter bobwhite) have been declining across their geographic range in North America, prompting consideration of the role parasites may play. We conducted this study to learn about the helminth fauna in South Texas, a region that supports a sustainable bobwhite population. Helminths were examined from 356 bobwhites collected during the 2014–2015 ( n = 124) and 2015–2016 ( n = 232) hunting seasons, when increasing trends in precipitation were observed in comparison with the previous two years. Ten helminth species were found, consisting of 14,127 individuals. Of these, all are heteroxenous parasites and three are pathogenic ( Dispharynx nasuta , Tetrameres pattersoni and Oxyspirura petrowi ). Aulonocephalus pennula numerically dominated the component community (81% prevalence, 99% of the total helminths found), whereas each of the remaining species occurred rarely (≤9% prevalence) and contributed few individuals (≤0.4%) to the helminth community. Prevalence and abundance of A . pennula were not influenced by host age, sex or body mass, but abundance was higher during the 2014–2015 than the 2015–2016 hunting season. Our findings indicate that the helminth community in bobwhites from South Texas can vary during long-term, highly variable precipitation conditions and these communities are more similar to those found in the Rolling Plains of Texas than those found in the eastern part of the bobwhite's geographic range in the US.

Helminths were examined from 145 scaled quail ( Callipepla squamata ) collected during the 2012–2013, 2013–2014 and 2014–2015 hunting seasons from a semi-arid region of Texas that spans four ecoregions. Helminth infracommunities were species poor, averaging 1.7 (range 1–4) species. Six species occurred within the component community of which one ( Oxyspirura petrowi ) is known to be pathogenic to quail. Aulonocephalus pennula was most abundant (9991 individuals, 95% of total) followed by O. petrowi (391 individuals, 4%). Each of the remaining four species was rare (≤21% prevalence) and contributed few individuals (<1%). In the High Plains ecoregion, prevalence of O. petrowi was higher in host collections made during the 2013–2014 hunting season than either hunting seasons 2012–2013 or 2014–2015 and was higher in the High Plains ecoregion than the Edwards Plateau ecoregion during the 2013–2014 hunting season. Mean abundance of A. pennula and O. petrowi was higher in scaled quail from the High Plains ecoregion than the Edwards Plateau ecoregion. Our results provide new information about helminth fauna in scaled quail, persistence of indirect lifecycle helminth species within a semi-arid region, and the occurrence of pathogenic helminth species within this host species.

The wildlife ranching industry relies on providing supplemental grain to game animals to enhance wildlife viewing and hunting opportunities. Unfortunately, environmental climate and storage conditions can create the production of aflatoxins, a toxic fungal metabolite. Our objective was to determine temporal differences in aflatoxin concentrations of grain (i.e., corn) maintained in common storage practices by wildlife ranching enterprises. We placed bags of wildlife corn in open air, barn, and pavilion environments, and kernel corn in metal, aluminum, and plastic wildlife feeders. We determined weekly aflatoxin levels and grain moisture content within each storage practice. In addition, we monitored weather parameters (daily temperature, relative humidity, and dew point) inside and outside of each storage structure. Grain moisture and aflatoxin concentrations fluctuated weekly within each type of storage container (F150, 700 > 7.23, P < 0.0001) and ranged from 10.4–97.5% and 0–1,200 ppb, respectively, due to ‘hotspots’ of fungal growth and subsequent metabolite production. Each storage type contained corn samples that exceeded recommended aflatoxin levels deemed safe for wildlife within 2 weeks. After 5 weeks of storage, aflatoxin concentrations increased significantly in each storage method. Condensation build-up within metal storage containers increased mold growth on corn, which subsequently resulted in greater aflatoxin concentrations of corn along the sides of such containers compared to corn sampled within the center of the same container. Freezing grain halted aflatoxin production while corn was in storage; however, due to immediate condensation on grain once removed from the freezer, corn exceeded safe aflatoxin concentrations within 24 hours of being spread on ranch roads. Relationships between aflatoxin concentrations and environmental conditions (i.e., temperature, relative humidity, dew point) and time were highly variable; and therefore, could not be easily predicted. We recommend storing grain <2 months and to thoroughly clean and dry wildlife containers and feeders often. Grain intended for wildlife should be tested immediately before being provided to animals and grain that exceeds 50 ppb be destroyed.

One hundred and sixty-one northern bobwhites ( Colinus virginianus ; hereafter ‘bobwhite’) were examined from the Rolling Plains ecoregion of Texas and western Oklahoma from 2011 to 2013. Complete necropsies yielded 13 species, of which two are new host ( Gongylonema phasianella ) and region ( Eucoleus contortus ) records and three ( Dispharynx nasuta , Tetrameres pattersoni and Oxyspirura petrowi ) are known to cause morbidity and mortality. Of the species found, Aulonocephalus pennula commonly occurred, Oxyspirura petrowi was intermediate in prevalence, and the remaining species were rare. Species richness was similar compared to studies from the southeastern U.S., but higher than studies from the same region. In addition, 12 of the 13 species were heteroxenous helminths, supporting the theory that heteroxenous helminths in semi-arid regions are more successful than monoxenous helminths. Prevalence and abundance of A. pennula and O. petrowi were higher in adult bobwhites than in juveniles. Abundance of A. pennula and O. petrowi was higher at southern locations compared to northern locations in the study area. Our study is the first to provide a current assessment of the bobwhite helminth community across the Rolling Plains ecoregion of the U.S.

Mesocestoides spp. have a cosmopolitan distribution with zoonotic potential. Mesocestoides tetrathyridia were found under the pericardial sac, on the surface of the crop, and in the peritoneal cavity of a hunter-harvested northern bobwhite ( Colinus virginianus) and a scaled quail ( Callipepla squamata) collected during the 2016-2017 quail hunting season in northwest and southern Texas, respectively. Molecular analysis indicated that the tetrathyridia from the birds likely belonged to an undescribed species and are identical to pretetrathyridium stages recently found in Scincella lateralis skinks in Oklahoma. This is the first report of Mesocestoides from North American birds.