Quail and rain: does management matter?

Rainfall is a strong driver of quail populations on southwestern rangelands and may account for a large portion (70–90%) of the variability in regional quail production and abundance. Landowners have attempted to moderate these boom-and-bust fluctuations via management, but presently it is unknown whether quail management indeed can increase or stabilize northern bobwhite (Colinus virginianus) populations on semi-arid rangelands characterized by erratic rainfall. The objective of my research was to evaluate the efficacy of bobwhite management at mitigating the effects of unpredictable rainfall on semi-arid rangelands. This study was conducted in the Rio Grande Plains (n = 6 ranches; ≈20,000 ha total) and Rolling Plains (n = 4 ranches; ≈15,000 ha total) of Texas. I estimated quail density on each ranch during a 5-year period (December 2014–2018) using helicopter surveys within a distance-sampling framework and obtained annual rainfall data from a Parameter-elevation Regressions on Independent Slopes Model (PRISM). I also quantified intensity of quail management via landowner questionnaires to categorize ranches into 3 relative categories of management intensity: low, medium, or high. In the Rio Grande Plains, mean bobwhite density pooled over the 5-yr period was numerically greater on ranches with high-intensity management (1.78 ± 0.45 bobwhites/ha; mean ± SE) than low-intensity management (1.53 ± 0.36 bobwhites/ha). However, variation in bobwhite density among years was high for both high-intensity management (CV: 57%) and low intensity management ranches (CV: 52%). Similarly, mean bobwhite density in the Rolling Plains pooled over the 5-yr period was numerically greater in ranches with highintensity management (1.59 ± 0.60 bobwhites/ha) than low-intensity management (0.85 ± 0.29 bobwhites/ha) and also exhibited moderate-to-high variation within management levels (CV:75% vs. 67%, respectively). These results suggest that management may increase quail density beyond that of less managed properties but may not completely eliminate the inter-annual fluctuations