Multiyear Survey of Coccidia,Cryptosporidia, Microsporidia,Histomona, and Hematozoa in Wild Quail in the Rolling Plains Ecoregion of Texas and Oklahoma,USA

We developed nested PCR protocols and performed a multiyear survey on the prevalence of several protozoan parasites in wild northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) in the Rolling Plains ecoregion of Texas and Oklahoma (i.e. fecal pellets, bird intestines and blood smears collected between 2010 and 2013). Coccidia, cryptosporidia, and microsporidia were detected in 46.2%, 11.7%, and 44.0% of the samples (n = 687), whereas histomona and hematozoa were undetected. Coccidia consisted of one major and two minor Eimeria species. Cryptosporidia were represented by a major unknown Cryptosporidium species and Cryptosporidium baileyi. Detected microsporidia species were highly diverse, in which only 11% were native avian parasites including Encephalitozoon hellem and Encephalitozoon cuniculi, whereas 33% were closely related to species from insects (e.g. Antonospora, Liebermannia, and Sporanauta). This survey suggests that coccidia infections are a significant risk factor in the health of wild quail while cryptosporidia and microsporidia may be much less significant than coccidiosis. In addition, the presence of E. hellem and E. cuniculi (known to cause opportunistic infections in humans) suggests that wild quail could serve as a reservoir for human microsporidian pathogens, and individuals with compromised or weakened immunity should probably take precautions while directly handling wild quail.     

Population Irruptions of Northern Bobwhite: Testing an Age-Specific Reproduction Hypothesis

Abstract: Age-specific reproduction has been suggested for northern bobwhite (Colinus virginianus) and has been hypothesized as a factor contributing to population irruptions. However, little research has been conducted on the subject. We conducted a laboratory and field study to determine if age-specific reproduction occurred in northern bobwhites. Our objectives were to compare 7 reproductive measures (% F nesting, date of first incubated nest, egg-laying rate, nesting rate, clutch size, egg mass, and egg hatchability) between first- and second-year breeders and determine if differential reproduction was impacted by diet quality. The laboratory study consisted of a 2 × 2 factorial experiment with age and diet quality (low protein [12%] and high protein [24%]) as the factors. Data for the field study represented a 6-year data set of bobwhite reproduction (May-Sep 2000-2005) obtained from an ongoing radiotelemetry study in southern Texas, USA. We documented similar productivity (i.e., % F laying, egg-laying rate, and egg mass) and timing of laying (i.e., date of first egg) between juvenile (n = 33) and adult bobwhites (n = 27) in our laboratory study. However, females on the high-protein diet exhibited a greater egg-laying rate than females on the low-protein diet. Under field conditions, we also documented no difference in productivity (% F nesting, nesting rate, clutch size, egg hatchability) and timing of nesting (date of first incubated nest) between age classes (n = 59 juv and 32 ad). Our findings do not support early suppositions of age-specific reproduction in quail. Quail irruptions should not be influenced by population age structure as it relates to age-specific reproduction.     

A population model to simulate northern bobwhite population dynamics in southern Texas

Models are important tools that can help managers and researchers understand the population dynamics of a species and how different habitat or population management scenarios impact that species. We used radio-telemetry data from northern bobwhites (Colinus virginianus) in southern Texas from 2000 to 2005 to develop a stochastic simulation model for bobwhite populations. Our model is based on difference equations, with stochastic variables drawn from normal and Weibull distributions. We simulated bobwhite populations to 100 yr and evaluated our model by comparing results with independent estimates of 4 population parameters (spring and fall density, finite rate of increase in the fall population [λ], and winter juv:ad age ratios). Using a quasi-extinction criterion of ≤40 birds (density = ≤0.05 birds/ha), probability of persistence to 100 yr was 88.3% (106 of 120 simulations) for the spring population and 96.7% (116 of 120 simulations) for the fall population. Using a less restrictive quasi-extinction criteria (≤14 birds), probability of persistence was 93.3% (112 of 120 simulations) for the spring population and 98.3% (118 of 120 simulations) for the fall population. Simulated population parameters were similar to independent estimates for 4 of 4 population parameters. Winter age ratios differed between our model ( juv:ad, n = 120, SE = 0.32) and empirical age ratios from harvested bobwhites on our study area ( juv:ad, n = 25, SE = 0.24). However, when we corrected harvest age ratios for bias in juvenile harvest ( juv:ad, n = 25, SE = 0.32) simulated and empirical estimates were similar. Our model appears to be a reliable predictor of bobwhite populations in the southern Texas. Our simulation results indicate that bobwhite hunters and managers can expect excellent bobwhite hunting (fall populations ≥2.2 birds per ha) in about one of 10 yr. © 2011 The Wildlife Society