Behavior of Walk-Hunters and Pointing Dogs During Northern Bobwhite Hunts

Abstract: Data on the behavior of walk-hunters and pointing dogs aids in understanding and managing quail harvest. We collected Global Positioning System track logs and recorded behaviors of hunters and dogs on northern bobwhite (Colinus virginianus) hunts in Oklahoma (n = 43), Texas (n = 43), and Missouri (n = 7), USA, during the 2005–2006 and 2006–2007 hunting seasons. Hunter velocity averaged 0.8 ± 0.03 (SE) m/second both seasons (n = 85) and pooled (95% CL overlap) velocity of bird dogs was 2.5 ± 0.07 (SE) m/second (n = 154). Hunters spent 60.5 ± 2.4% (SE) of their time walking in 2005–2006 (n = 45) versus 75.2 ± 3.5% (SE) in 2006–2007 (n = 48); respective figures for ranging by dogs were 50.2 ± 2.2% (n = 57) versus 82.0 ± 1.3% (SE; n = 97). Mean duration of a hunt declined from 82.3 ± 8.16 (SE) minutes (n = 45) to 50.2 ± 5.1 (SE) minutes (n = 48) between seasons. Variation in bobwhite abundance was the primary cause of seasonal variation in hunter and dog behaviors because covey-associated activities declined as quail abundance declined. With our results and those of previous workers, managers have first-generation estimates of all variables in hunter-covey interface models for managing bobwhite harvest on discrete areas.     

The Effects of Landscape Characteristics on Northern Bobwhite Density

The northern bobwhite (Colinus virginianus) is an ecologically and economically valuable species in the United States. Managers rely on autumn density estimates to set harvest regulations, balancing the interests of hunters and long-term bobwhite population viability. Spatial capture-recapture (SCR) is a useful framework for estimating population size and modeling spatial variation in density. We used SCR to quantify the effect of landscape structure on spatial variation in density for a population of bobwhites on the Di-Lane Wildlife Management Area in Waynesboro, Georgia, USA. Without additional telemetry or nesting data, we were also able to estimate a spatially explicit metric of productivity. To sample the population, we deployed a fixed array of 395, 262, and 268 funnel traps in 2016, 2017, and 2018, respectively. We estimated age structure, with the highest density of juveniles (0.32 birds/ha, 95% CI = 0.28–0.37) and adults (0.10 birds/ha, 95% CI = 0.08–0.12) estimated in 2016. In our top model, density was negatively related to the proportion of closed canopy hardwoods. To increase bobwhite density on the landscape, managers should reduce the amount of closed canopy hardwood forest. Furthermore, the spatially explicit age ratio we estimated could be used to target management towards increasing the recruitment of chicks into the autumn population. An SCR approach may require additional logistical and financial resources relative to other data collection methods, but it makes modeling spatial variation in density straightforward and can be used to gather data to simultaneously understand population structure, vital rates, and movement. © 2021 The Wildlife Society.     

Separating Components of the Detection Process With Combined Methods: An Example With Northern Bobwhite

Abstract: There are various methods of estimating detection probabilities for avian point counts. Distance and multiple-observer methods require the sometimes unlikely assumption that all birds in the population are available (i.e., sing or are visible) during a count, but the time-of-detection method allows for the possibility that some birds are unavailable during the count. We combined the dependent double-observer method with the time-of-detection method and obtained field-based estimates of the components of detection probability for northern bobwhite (Colinus virginianus). Our approach was a special case of Pollock's robust capture-recapture design where the probability that a bird does not sing is analogous to the probability that an animal is a temporary emigrant. Top models indicated that observers' detection probabilities were similar (0.78–0.84) if bobwhite were available, but bobwhite only had an approximately 0.61 probability of being available during a 2.5-minute sampling interval. Additionally, observers' detection probabilities increased substantially after the initial encounter with an individual bobwhite (analogous to a trap-happy response on the part of the observer). A simulated data set revealed that the combined method was precise when availability and detection given availability were substantially lower. Combined methods approaches can provide critical information for researchers and land managers to make decisions regarding survey length and personnel requirements for point-count-based surveys.