Using First Passage Time Analysis to Identify Foraging Patterns of the Northern Bobwhite

Patterns in movement data can reveal important information relating environmental variables to behavioral mechanisms. First passage time analysis (hereafter; FPT) can be used to quantify the spatial and temporal variation in movements by identifying areas of restricted search behavior based on measuring residence time in an area. It is applicable in studies of foraging ecology and habitat selection because it can empirically quantify behavioral decisions without any a priori assumptions of habitat availability. Furthermore, FPT analysis is simple to implement and interpret; however, the technique has yet to be applied to the northern bobwhite (Colinus virginianus, hereafter bobwhite) because telemetry locations in short (e.g., 30 min) successive time intervals are needed. Our primary objective was to better understand patterns in foraging behavior of bobwhites as it relates to habitat use and improve management. Our secondary objective was to test the efficiency of using FPT analysis on telemetry data collected at different time intervals. Bobwhites were captured during the fall of 2013 and 2014 on a private plantation in South Carolina and fitted with very high frequency (VHF) transmitters (n = 143 and n = 148, respectively). We located coveys at 1 hour (2013) and 30 (2014) minute time intervals during daylight. Bobwhites concentrated their searching efforts to a few hours pre-dusk. Search efforts were proximal to supplemental food sources, with some intra-seasonal variation. Advances in global positioning system (GPS) technology will likely increase opportunities for collecting fine-scale movement data for bobwhites. Understanding techniques such as FPT analysis will enhance our knowledge of northern bobwhite ecology and management

Refining the Hunting Zone of Hunter-Covey Interface Models

Regulating harvest is important to sustain northern bobwhite (Colinus virginianus) populations. Direct measures to control harvest such as setting fixed proportions (i.e., percent of fall population) are not typically feasible, thus, indirect measures (e.g., managing access, season length) are more commonly used. However, these measures are predicated on relationships between hunter effort and kill rate (K) which is a function of several parameters including: the probability of encountering a covey (p), where p is a function of the effective area hunted (a) divided by that available (A). Thus, a, is a product of the velocity of hunter movement (v), hours spent hunting (h), and the effective width of the hunting zone (w). Velocity and hours spent hunting are easy to quantify, however, estimating w is more difficult and to-date not undertaken. We focused on w, specifically wded, the distance a dog detects a covey assuming the covey is stationary. We assume stationarity such that evasive behaviors can be estimated separately from the olfaction process. The objective of our experiments was to estimate the influence of weather on wded. We used pen-raised bobwhites placed about 150 meters apart to simulate hunts (n = 13) on two study sites. A handler guided a single birddog through the course, downwind from birds, and recorded the distance from the pointed dog to caged birds. Dogs pointed birds (n = 236) at an average distance of 6.2 m (SD = 4.2). Wind speed was positively associated with detection distance (r = 0.19, P \u3c 0.01), while temperature was negatively associated (r = -0.18, P \u3c 0.05). The hunter-covey interface is a dynamic process driven by a myriad of factors. Our results suggest simple weather parameters influence the effective area hunted, therefore, affecting the kill rate that managers want to control

Hunter-Covey Interactions Using Pointing Bird Dogs

Hunting northern bobwhites (Colinus virginianus) with pointing dogs is a long-standing tradition in the Southeastern United States. Despite this rich hunting legacy, a paucity of empirical, behavioral information exists on the interaction between bobwhite coveys, pointing dogs and humans. As such, the efficiency of using pointing dogs to locate bobwhite coveys or an individual covey’s behavioral response to hunting is poorly understood. During 2013 – 2015, we conducted hunts (n = 192) by mode of foot on Tall Timbers Research Station (TTRS, ~1,570 ha) in Leon County, Florida and horseback on a private property (2,023 ha) in Georgetown County, South Carolina. We captured bobwhites (n = 741) and fitted them with activity-switch enabled radio-transmitters, and we tracked coveys prior to, during and after hunts. We used 2 types of global positioning system (GPS) units to collect route data from dogs and hunters (via horseback or foot). We recorded encounter information (e.g., behavior, encounter type such as covey point or wild flush) in the field using a pre-configured application on an iPad and linked spatial data using a geographic information system (i.e., ArcGIS). On average, 52% of all radio-tagged coveys were available (within a dog’s scent radius) during a hunt of which 73% were detected by pointing bird dogs. The overall probability of observing a covey on a hunt was 38% suggesting that most coveys within a hunting course go undetected. Vegetation density did not appear to be an impediment to bobwhite mobility or an important factor in detection of coveys by bird dogs. The potential reduction or manipulation of existing habitats may help to constrain where bobwhite coveys can escape to and covertly improve hunting efficiency. Furthermore, our results imply that a relatively high bobwhite density is required for sportsman to frequently encounter bobwhite coveys during a hunt

Cascading Effects of Hunting Disturbance on Northern Bobwhite Behavior, Physiology, and Survival

The northern bobwhite (Colinus virginianus; hereafter, bobwhite) is an important gamebird across the United States and has been in decline for several decades. As a commonly hunted prey species, the bobwhite provides an ideal study species to investigate the use of proactive and reactive antipredator behaviors in response to hunting pressure. We designed an experiment to understand how late-season hunting affects bobwhite demographics using fecal glucocorticoid (fGCM) concentrations, foraging and movement behaviors, survival, and breeding season metrics. Our results show that bobwhite responded to increased interactions with a shotgun through proactive responses. After one encounter with a discharged shotgun, bobwhite began foraging farther from supplemental feed where the risk of encountering a hunting party was the greatest (β = 0.21, 95% Bayesian credible interval [CrI]: 0.06–0.36). Bobwhite responded to increased hunting pressure, particularly late-season hunting pressure, via reactive responses through increased fecal glucocorticoid metabolite (fGCM) concentrations (β = 2.18, 95% CrI: 0.21–4.15), resulting in decreased survivorship in non-harvested individuals (β = -0.42, 95% CrI: -0.77 to -0.07) and decreased fecundity (β = -0.17, 95% CI: -0.31–0.09). These results can help inform hunting season regulations and management decisions aiding in bobwhite recovery

Northern Bobwhite and Fire: A Review and Synthesis

Our understanding of the relationship between northern bobwhite (Colinus virginianus; hereafter, bobwhite) and fire began with Herbert Stoddard’s work in the early 20th century. Research on the topic has continued, but our application of fire is deeply rooted in Stoddard’s work, even as it has become evident that fire regimes must be adapted to variable environmental conditions that are evolving with a changing landscape and climate. A comprehensive review and synthesis of the literature on this topic would help formalize research advancements since Stoddard and identify knowledge gaps for future research. Results from experiments suggest fire creates favorable local habitat conditions for bobwhite such as plant composition, bare ground, and plant structure. Frequent prescribed fire is closely tied to where bobwhite populations are at their greatest (e.g., Red Hills region of Georgia and Florida, USA). However, an empirical gap exists between patch-level conditions and the bobwhite-landscape ecology interface. For example, it is well established that a 2-year fire return interval in pine savanna ecosystems with fertile soil is best for bobwhite. But causal evidence is limited for areas of different soil types, precipitation, and past land use across the bobwhite range. We review the extant literature describing prescribed fire use for bobwhite management, focusing on documented effects of fire on life-history characteristics of bobwhite under different environmental conditions. Habitat outcomes of fire management depend on fire frequency, seasonality, scale, and interaction with other management, and different strategies should be employed depending on the environment and desired effects. Adaptive management strategies will be necessary to address the challenges of rising temperatures associated with a changing climate, which are likely to alter the conditions under which burns occur and increase the difficulty of meeting basic burn criteria. Positive public attitudes toward prescribed fire will be key to developing a policy and management framework that supports efficient prescribed fire application. Our review elucidates range-wide processes and patterns to better inform the site-specific application of fire

A simple clinical scoring system to improve the sensitivity and standardization of the diagnosis of mycosis fungoides type cutaneous T-cell lymphoma: logistic regression of clinical and laboratory data

Background  The diagnosis of mycosis fungoides (MF) is notoriously difficult to establish because in the early stages, histological features may be nonspecific or merely suggestive. Objectives  To standardize the diagnosis of MF. Methods  We studied 138 patients with suspected MF referred over a 7-year period to a university department of a dermatology-based cutaneous lymphoma clinic. Six diagnostic criteria were evaluated: clinical morphology, clinical distribution, skin biopsy T-cell receptor gene rearrangement (TCR-GR), skin biopsy pan T-cell marker loss ≥ 2, skin biopsy CD4/CD8 ratio ≥ 6, and skin biopsy diffuse epidermal HLA-DR expression. These six clinical and laboratory criteria were compared by logistic regression analysis in patients with histologically diagnosed MF and those with benign disease. Results  Of the 138 patients, 74 had histology of MF, 47 of benign dermatoses and 17 were indeterminate. Close associations were found between a histological diagnosis of MF and TCR-GR (odds ratio 14·4), classical morphology (7·5), classical distribution (2·5) and diffuse epidermal HLA-DR expression (2·8). Logistic regression models were developed depending on the availability of data (either TCR-GR or HLA-DR). Probabilities for correctly diagnosing MF compared with histology as the ‘gold standard’ were derived from these logistic regression models. A scoring system assigning point values based on these probabilities was then created in order to assist the clinician in making the diagnosis. If using TCR-GR data, a positive TCR-GR = 2·5 points, the presence of classical morphology = 2·0 points, and the presence of classical distribution = 1·5 points. A total score of ≥ 3·5 points assigns a high probability (> 85%) of having MF. If using HLA-DR expression, then the presence of classical morphology = 2·5 points, a positive diffuse epidermal HLA-DR expression = 2·0 points, and the presence of classical distribution = 1·5 points. In this case, a total score of ≥ 4·0 points assigns a high probability (> 85%) of MF. Conclusions  The logistic regression models and scoring systems integrate clinical and laboratory assessments, allow rapid probability estimation, and provide a threshold for the diagnosis of MF in an objective, standardized manner.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75520/1/j.1365-2133.2003.05458.x.pd

Using the Conservation Planning Tool to Effectively Recover Northern Bobwhites: An Example for States to Effectively Step-Down the NBCI Plan

The National Bobwhite Conservation Initiative (NBCI) 2.0 provides a sound foundation for recovering northern bobwhites (Colinus virginianus) range-wide, regionally and, to some extent, even locally. However, the NBCI does not provide detailed guidance to states on how to step-down the plan for efficacious delivery of on-the-ground management actions prescribed via biologists within the plan itself. States often must incorporate multiple planning efforts (e.g., state wildlife action plans) and geospatial layers not directly included in the NBCI plan (see NBCI Appendix in these Proceedings) to make tenable decisions which best guide allocation of resources and benefit multiple species of greatest conservation concern. The Conservation Planning Tool (CPT), developed as part of NBCI 2.0, provides the infrastructure for states and conservation organizations to capture biologist information coalesced in the plan while incorporating other data (e.g., species emphasis areas, current CRP implementation, etc.) germane to conservation planning. We use 3 states (Kansas, Florida, and Virginia) to demonstrate the utility of the CPT and to develop a step-down implementation plan, via creation of a habitat prioritization model, for recovery of bobwhites in each state. We explore the implications associated with creation of focal areas with respect to high versus medium ranked areas and underscore the importance of inclusion of major land-use opportunities and constraints prescribed within the plan to garner successful bobwhite recovery. We propose a framework for the integration of monitoring efforts into the step-down model to assess bird response and evaluate NBCI success through estimating bobwhite population density