Empirical Tests of Hunter–covey Interface Models

Abstract

Quail hunting consists of a complex set of behaviors that involve humans, pointing dogs, and wild birds. The recent development of models known as Hunter-Covey Interface (HCI) theory provides an opportunity to analyze how we perceive, understand, and manage quail hunting. There are 2 groups of HCI models: static and dynamic. The static HCI model predicts daily hunting mortality based on the velocity of the hunt and area covered during a hunt. The dynamic HCI models estimate the probability of flushing a covey given a set of circumstances that revolve around the potential rate of which quail learn to avoid hunters. We quantified the variables required to test whether the static and dynamic models of HCI theory provide meaningful results. We used spatial data on hunting velocity and area covered during >100 quail hunts, along with estimates of quail population density, mortality, and movements from 2 areas in south Texas, to evaluate output from HCI models. The static model predicted average daily harvest rates that ranged from 5 to 50 birds. This average is within the range of average daily bag of south Texas quail hunters in groups of 2-4. Output from the dynamic models suggested that quail populations on our study areas were subjected to relatively low hunting intensities with a corresponding low avoidance behavior and learning rate, which is a scenario that matched 1 of 4 predictions by Guthery (2002). We found it difficult to meet basic assumptions of HCI theory. For example, hunting pressure was potentially redundant, coveys were not always randomly distributed in space, and the extent to which quail are naive at the beginning of a hunting season was unknown. However, both the static and dynamic HCI models appeared robust to violation of these assumptions. Application of HCI theory may provide meaningful results that can be used to manage quail hunting pressure, optimize harvest, and sustain populations. JOURNAL OF WILDLIFE MANAGEMENT 69(2):498-514; 2005

Developing the Concept of Estimating Bobwhite Density With Pointing Dogs

“…We We collected all locations in the track file at 7-second intervals. Hardin et al (2005) showed the 7-second interval was favorable for 2 reasons. First, the interval allowed the GPS units to record data continuously for about 4 hours, which allowed all information from a hunt to be collected on one unit.…”

“…Second, turning angles of dogs showed little difference between the 7-second interval and longer intervals. Therefore, the 7-second interval optimized data collection for each hunt (Hardin et al 2005). We converted GPS tracks to Universal Transverse Mercator coordinates and downloaded to a spreadsheet using Department of Natural Resources Garmin 5.1.1 software (Minnesota Department of Natural Resources, St. Paul, MN).…”

“…Sisson et al (2000) observed that pointing dogs detected 53% of available coveys. Similarly, Hardin et al (2005) reported a 56% detection rate. Bobwhites missed by dogs would negatively bias density estimates under the assumption that use of dogs resulted in total counts on an area of known size.…”

“…Invention of Global Positioning System (GPS) technology in the 1970s and the increase in accuracy that occurred throughout the 1990s (Anonymous 2000) has made it possible to estimate area searched by a dog if its effective search radius is known. However, unlike human observers dogs often searched an area multiple times (Hardin et al 2005). These redundant areas occurred within a dog's search pattern and also between search patterns when multiple dogs were hunted.…”

Demographic Sensitivity of Population Change in Northern Bobwhite

“…Provision of supplementary food in feeders or food plots may increase winter survival if bobwhites are better able to cope with inclement weather with additional food or body reserves Kemp 1997, Doerr andSilvy 2006). However, potential benefits of improved cover and supplemental feeding could be negated by higher mortality rates if hunters or natural predators concentrate their effort near food plots or habitats preferred by bobwhites (Roseberry 1979, Williams et al 2000, Madison et al 2002, Haines et al 2004, Hardin et al 2005). Exposure to harvest may also increase natural mortality if bobwhites incur greater predation risk after disturbance by hunters or during movements from small to larger coveys (Curtis et al 1988, Williams et al 2003b.…”