Triple Brood Production by Northern Bobwhites

Most aspects of northern bobwhite (Colinus virginianus) life history are well understood and well documented, including their ability to ‘‘double brood’’ (defined as the same hen successfully hatching 2 broods during a single nesting season). Less understood are the ability and/or prevalence of ‘‘triple broods’’ in the life history of bobwhites. Occasional citing in the literature of triple brooding is often unclear as to whether reference is being made to the attempt at hatching 3 broods in a season or actually doing so. This confusion stems from the interchanging use of the words brood and clutch. While Webster defines ‘‘clutch’’ as either 1) a nest of eggs, or 2) a brood of chicks; ‘‘brood’’ is clearly defined as a group of birds hatching at one time. A closer look at the referenced studies reveals incidences of ‘‘triple clutching’’ where a single hen incubated three nests in one summer, but no published record of a true triple brood. The strict definition of triple brood should be: the same hen successfully hatching 3 broods in a single nesting season. Our nest data from radio-tagged birds collected in the Albany, GA area suggest that this phenomenon is extremely rare. From 1992-2016 we radio-tagged and monitored 2,607 hens during the nesting season on our primary study area in Baker County, GA. These birds produced 1,463 incubated nests and hatched 768 broods. Double broods were fairly common (n = 91) and occurred in all but two of the 25 nesting seasons. Only one incidence of true triple brooding has been documented on this study area during this time period. Adult mortality, nest loss, and the limited duration of the nesting season all work against this level of production. While an interesting aspect of the bird’s natural history, the extremely low rate of occurrence makes it insignificant from a population standpoint

Hunting Success on Albany, Georgia Plantations: The Albany Quail Project\u27s Modern Quail Management Strategy

The Albany Quail Project began in March 1992 as a cooperative between Auburn University’s School of Forestry and Wildlife Sciences and the private quail plantation community surrounding Albany, Georgia. The goal of this collaboration was to increase population densities and hunting success of northern bobwhites (Colinus virginianus) on these properties. Issues important to the plantations were investigated via field research techniques (e.g. radio-telemetry) and then modifications in management regimes were put into practice. From 1992-2006 over 8,000 wild bobwhites were radio-tagged to study various demographic and population mechanism of bobwhites. The result has been a change in management style based on science creating the concept of Modern Quail Management (MQM) techniques. Bobwhite population densities and hunting success during the last decade on these properties have been higher and more stable than witnessed during any previous period in their history. On our primary study site during 1980-1996 the average number of coveys seen per hour was 3.9 (SE = 0.265) with a range of 2.7 - 6.5 (CV = 0.28). Following the implementation of MQM techniques this average during 1997-2005 increased to 7.7 (SE = 0.317) with a range of 6.9-9.7 (CV = 0.12) and population density has been maintained at or near 5 birds per ha. This manuscript provides a brief history of the Albany Quail Project, describes how results from these studies have contributed to the evolution of new management philosophies over the last decade, outlines what these changes have been, and describes how they have been successfully applied on numerous properties in the Albany area to improve bobwhite populations and hunting success

Effect of Field Trials on Northern Bobwhite Survival and Hunt Quality on Dixie Plantation

The potential negative effects of horseback field trials on survival and post trial hunting quality of northern bobwhites (Colinus virginianus) have long been debated. Recent acquisition of Dixie Plantation (3,650 ha) by Tall Timbers Research Station provided a unique opportunity to evaluate this interaction as Dixie has been home to the Continental Field Trial since 1937. We monitored radio-tagged bobwhites annually (n = 183; ~20 coveys during fall/winter) on a core study area (640 ha) upon which a portion of the field trial was conducted during January 2015 & 2016. We estimated Kaplan-Meier survival of radio-tagged bobwhites on Dixie before, during, and after the field trial event as well as compared seasonal survival to bobwhite (N = 387) on nearby Tall Timbers Research Station (1,570 ha) during the same time period. Additionally, we recorded the number of coveys seen, coveys pointed, and shots fired during each half-day hunt (n = 133) to evaluate hunt quality before and after the field trial. Bobwhite survival on Dixie was similar (P\u3e0.05) during the two weeks prior to (0.89, SE = 0.026), during (0.93, SE = 0.023), and after (0.92, SE = 0.026) the field trial for the two years combined, as were seasonal survival curves between the two study sites for both years monitored. No differences (P\u3e0.05) were observed in the number of coveys seen per half day hunt before (X = 11.78, SE = 0.39) compared to after (X = 12.35, SE = 0.44), covey rises shot before (X = 6.89, SE = 0.28) and after (X = 7.75, SE = 0.37), or number of shots fired before (X = 23.5, SE = 1.19) versus after (X =24.11 SE = 1.26) the field trial. We were unable to detect any evidence that the type of disturbance generated by this field trial had any effect on either bobwhite survival or post trial hunting quality on our study area

Use of Spring Whistle Counts to Predict Northern Bobwhite Relative Abundance

Spring whistle counts are commonly used to index northern bobwhite (Colinus virginianus) breeding populations and make inference about relative autumn abundance. They are relatively cheap and easy to implement and provide the advantage of surveying bobwhite populations from multiple points daily and early in the year. This could prove useful on properties available for potential lease, purchase, or as translocation sites; as well as to monitor population trends. Our objective was to determine whether spring whistle counts reliably forecast autumn covey numbers on a wide range of sites, years, and densities on 6 properties in southwestern Georgia from 2006 to 2015. We conducted spring whistle counts weekly during peak calling activity (late May–early Jun, for 4–6 consecutive years) on an average of 7 points/property (range = 5–9). We conducted autumn covey counts using these same sampling points as an index of relative abundance. Peak number of males heard in spring and number of coveys heard in autumn was strongly correlated (R2 = 0.791, n = 198) for all points combined, indicating that spring whistle counts are a reliable tool for assessing bobwhite relative abundance on sites where autumn covey counts are precluded or the information is needed prior to autumn

Factors Influencing Northern Bobwhite Hunting Success on Two South Georgia Plantations

Success of wild northern bobwhite (Colinus virginianus) management programs on private lands is most often measured by the rate of coveys pointed during the hunting season. Thus, managers of these properties are keenly interested in factors that influence hunting success. We examined how coveys pointed/hour, a measure of hunting success, was influenced by time of hunting season, time of day, weather parameters, and supplemental feeding on 2 intensively-managed plantations over 4 years. There were significant annual differences in the number of coveys pointed/hour among the 4 study years, but hunting success did not vary during the hunting season. Afternoon hunts had consistently higher success rates than morning hunts; however, the effect size was variable from year to year. The selected weather model indicated an interaction between 12-hr barometric pressure change and starting air pressure; hunting success increased with a rapid pressure increase that resulted in a high pressure value at the start of the hunt. A secondary weather model documented a negative relationship between starting air temperature and hunting success. The number of days since supplemental feed was spread had no significant effect on hunting success in 5 of 6 years for the 2 plantations over 3 years. Knowledge of how these variables influence hunting success should improve hunting and provide realistic expectations of hunt success for a given set of circumstances

Breeding Season Survival and Reproduction in a High-Density Bobwhite Population: A case study

The demographic behavior of northern bobwhite (Colinus virginianus; hereafter, bobwhite) populations at high densities could provide important insights into why bobwhite populations fluctuate. Therefore, we documented breeding season demographics of bobwhites to understand how prebreeding density influenced reproductive effort and postbreeding density on an intensively managed property in Leon County, Florida, USA, 2002–2006. We estimated prebreeding bobwhite density each April using multi-observer strip-transects and postbreeding densities each November using covey call grid surveys. We radio-tagged 217 bobwhites in March and located bobwhites at least 5 days/week, 15 April–30 September to determine vital rates. Prebreeding density ranged from 1.5–8.6 birds/ha, peaking in 2002, declining through 2005, then increasing in 2006. Breeding season survival was 0.55, 0.17, 0.20, and 0.59, and nesting rate was 0.47, 0.67, 0.80 and 0.89, 2002–2005, respectively. Postbreeding density ranged from 5.2–13.6 birds/ha, also peaking in 2002 and declining through 2004 before increasing beginning in 2005 and 2006. High breeding season survival and nesting success (\u3e0.55) resulted in greater chick production during periods of population growth. Nesting rate was inversely related to prebreeding density. Declines in bobwhite nesting rate at high prebreeding densities appeared to regulate population growth near population peaks. Lower adult survival and nesting success appeared to cause population declines. We suggest density-dependent intraspecific competition limited population growth at high bobwhite densities by reducing nesting rate while predation of adults and nests explained population fluctuations

Northern Bobwhite Population Response to Intensive Modification of a Farm Landscape in Middle Georgia (Poster Abstract)

Region wide population declines of northern bobwhite (Colinus virginianus) are well documented and believed to be primarily associated with landscape level changes in land use patterns across the southeast. While these declines have not occurred in the traditional ‘‘plantation belt’’ of southwestern Georgia, they are certainly evident throughout much of the rest of the state. In an effort to test the effectiveness of intensive bobwhite management techniques outside their traditional area, we used radio-telemetry, GIS, replicated whistling cock counts, and a fall covey census to monitor population response on one such typical middle Georgia farming landscape that is being intensively modified to benefit quail. Whitehall Plantation is a 3,734-ha farm in Laurens and Bleckley counties, Georgia whose history mirrors that of most of middle Georgia as well as much of the southeast. After many years of high populations and good quail hunting through the 1970s, most of the old fencerows were cleaned up to make way for bigger farm equipment. This was followed by a population decline throughout the 1980s that was made worse when the property was cleaned up even more to make way for center-pivot irrigation. The early 1990s marked a low point in the quail population with the landowners records showing only 10 coveys on the 567-ha core study area (1 bird/4 ha). The property at this point was made up of approximately 55% crop fields, 40% unmanaged woodlands, and 5% houses/pasture/ponds. Efforts to rebuild the population began in 1995 when all the dry land crop acreage was planted into longleaf pines, 15-m borders were developed around all the irrigated crop fields, and no-till farming practices were initiated. These efforts intensified in 1998 when the Albany Quail Project became associated with the property. At this time, all the agricultural fields were divided up with 15-m terraces, fall disking for brood range was initiated, and all the woodland acreage was silviculturally treated as needed. The goal was to make as much of the uncultivated acreage as possible usable space for quail. This has resulted in a landscape that is now 22% agriculture, 21% managed woodlands, 21% planted longleaf, 12% hedgerows and old fields, 10% mature hardwoods, 9% houses/pasture/pond, and 5% fallow land. In addition to these landscape modifications and habitat improvements, a year-round supplemental feeding and nest predator trapping program were initiated. Response to these efforts has been dramatic. Replicated whistling cock counts in June have increased 191% and a fall covey count census now shows approximately 45 coveys on this same 567-ha (1 bird/ha), a 400% increase. Year-round monitoring of a cumulative total of 440 radiomarked birds began in fall 1998 and has provided insights into the mechanisms behind this population response. A majority of the winter covey ranges, nest sites, and brood ranges are in planted longleaf, managed woodlands, or field borders/hedgerows, all habitats that did not exist five years ago. Kaplan-Meier survival estimates for Fall-Spring (58%), Spring-Fall (36%), and annual (21%) are well above those reported for similar southeastern landscapes and rival those of the intensively managed woodland hunting plantations farther south. Landowner satisfaction is high, as his perception is that his quail population and hunting success are as good now as they have been in his lifetime

Additional Evidence Against Radio-handicapping of Northern Bobwhites

The validity of radio-telemetry to produce reliable information (e.g., survival estimates) has recently been challenged. Radio-telemetry is a widely used technique in studies of numerous species, therefore, concerns regarding potential bias in these estimates warrant further investigation. As such, and as part of a larger study, we investigated 3 aspects of potential radio-bias: 1) variation in survival distributions among treatment (newly radio-tagged) and control (previously radio-tagged) groups; 2) proportion of trapped animals censored during the traditional 7-day censor period; and 3) ramifications to cause-specific mortality through estimation of harvest rate. Kaplan-Meier survival, based on 30-day post trapping, was similar between treatment (n = 901) and control (n = 293) bobwhites for all but 1 of 8 trapping sessions during 2000-2004. In this case, treatment bobwhites (0.970, SE = 0.015) had higher survival than control birds (0.878, SE = 0.042). We determined the effect of censoring relative to sample size was inconsequential for our analysis because the proportion of bobwhites (18 out of 1,350; 0.013) meeting the criteria for censoring, i.e., dying during the first 7 days, was minimal. Censoring of these data influenced survival estimates by an average of only 0.016 (SE = 0.004; range: 0.00 - 0.04). We evaluated harvest rate by comparing first year recovery rates of banded verses radio-tagged birds during thirteen hunting seasons occurring between 1992 and 2005. Annual recovery rate was not different (P \u3c 0.05) for banded birds and radio-tagged birds where harvest averaged 6.68% (range 3.3 - 11.7) and 6.65% (range 3.4 - 11.1), respectively. These findings are consistent with previous research demonstrating that radio-telemetry can provide reliable demographic information. However, we recommend that future researchers test for these potential effects among their data before making biological inferences

Northern Bobwhite Population Response to Intensive Mechanical Hardwood Clean-Up (Post Abstract)

Habitat degradation for northern bobwhite (Colinus virginianus) has occurred in many fire-maintained pine forests of the southeastern Coastal Plain due to encroachment of undesirable hardwoods over time. This is especially true for old-field lands where the highly combustible native groundcover has been eliminated. A management technique gaining in popularity recently is the removal of these hardwoods to improve habitat conditions for bobwhites. We used radio-telemetry and plantation hunting records to measure population parameters and hunting success on 1 such property before, during, and after an intensive mechanical hardwood ‘‘clean-up.’’ An 800-acre hunting course on Nilo Plantation near Albany, Georgia was the study area for this project and is a site where we have maintained a continuous year-round sample of radiomarked bobwhites since fall 1993, that now cumulatively totals \u3e 500. These telemetry studies have revealed that bobwhite survival and reproductive output were declining and had reached low points the year prior to the initiation of hardwood clean-up. The clean-up operation consisted of mechanical felling of most mature hardwood in the pine uplands, followed by piling with root rakes, and then burning the piles. Kaplan-Meier survival estimates prior to the clean-up were Spring-Fall (15%), Fall-Spring (37%), and annual (6%). Cause specific mortality from avian depredation for the 2 Fall-Spring periods prior to clean-up averaged 35%. Broods produced per hen alive on 15 April was 0.42. During the 2 years since clean-up was completed, survival estimates have increased 2- to 5-fold now averaging: Spring-Fall (44%), Fall-Spring (73%), and annual (34%). Broods produced per hen alive on 15 April has almost doubled to 0.72. Cause-specific mortality from avian depredation during Fall-Spring has averaged only 6%. Plantation hunting success on this course had declined to a 20-year low of 3.2 coveys/hour but has since shown an almost 3-fold increase to a record high of 9.4 coveys/hour. This intensive hardwood clean-up has certainly improved the quality of the habitat on this site. We believe it also altered the predator context there by making the environment less suitable to the bobwhite’s natural enemies which contributed to the increased survival and reproductive output

Efficiency of Pointing Dogs in Locating Northern Bobwhite Coveys

We studied the efficiency of pointing dogs in locating coveys of northern bobwhites (Colinus virginianus) using radiotelemetry from 1992-1997 on 2 private hunting plantations in southwest Georgia. During these 5 hunting seasons, 169 hunts generated data on 838 encounters with 254 separate radio-marked coveys. Pointing dogs located 53% of the available coveys, 25% of which were never seen by the hunters due to evasive behavior by the birds. An additional 12% of encountered coveys were seen by the hunters even though they were never located by the dogs. This resulted in the hunters seeing a total of just over half (53%) and shooting into approximately one-third (32%) of the total radio-marked coveys they encountered. An evaluation of false pointing was conducted by examining cases when dogs pointed radio-marked coveys that were never seen by the hunters. Most (58%) of these unproductive points were caused by coveys running away from pointing dogs, but were also attributed to wild flushes (28%) and pointed coveys that held tight and refused to flush (14%). The percentage of radio-marked coveys seen by hunters was highly variable from day-to-day (x = 53%, range = 0-100%), but fairly consistent between years (x = 53%, range = 40-63% ). Information obtained using pointing dogs appears to be more practical for measuring population trends than it is as a census technique