Game Birds

Contributed Paper
ROOM: HCCC, Room 19

12:50PM Vegetation Attributes of Thermal Refugia Used By Northern Bobwhites
Brandon J. Palmer; Timothy E. Fulbright; Eric D. Grahmann; Fidel Hernández
Northern bobwhites (Colinus virginianus) have exhibited widespread precipitous declines across its geographic range. In Southern Texas, however, populations have increased or remained relatively stable to date. This region, which lies along the western periphery of the specie’s range, is characterized by high heat and erratic precipitation patterns. Temperatures in the summertime often exceed 39°C, the temperature of which bobwhites experience hyperthermia. Although thermal refugia are critically important for bobwhites, the structural attributes of vegetation that provide optimal thermal conditions are unknown. Our objective is to identify and quantify the vegetation structural attributes of thermal refugia used by bobwhites during summer. We captured 49 bobwhites and fitted them with radiotransmitters, obtaining 2-3 locations per week during April-August. Upon locating each bobwhite, we collected ambient, black globe, and ground surface temperatures and measured the vegetation attributes at each location and a paired random location located 10-20 m away. Vegetation measurements included canopy density, vegetation height, and woody cover. During the middle of the day, black globe temperatures at bobwhite locations were numerically lower (37 ± 6°C; mean ± SE), canopy density greater (97 ± 0.1%), and shrub height taller (3.9 ± 2 m) comparted to paired random locations (42 ± 6°C; 91 ± 0.2%, and 3.5 ± 2 m, respectively). Climate change will likely make conservation of thermal cover increasingly important in the future. We recommend that wildlife managers focus their effort on increasing and conserving areas of tall, dense woody vegetation.
1:10PM Survival and Nest-Site Selection of Ring-Necked Pheasants in Western Kansas Spring Cover Crops
Adela Annis; Alixandra Godar; David Haukos; Jeff Prendergast
Upland gamebirds are an economically important revenue source for local and state economies. Ring-necked pheasants (Phasianus colchicus) are popular upland gamebirds with naturalized populations in Kansas. Declines in populations have stakeholders seeking alternative ways to provide necessary nest habitat in agricultural landscapes to increase regional populations. Spring cover crops, planted between primary crop rotations, are a potential strategy to provide pheasants with breeding habitat when commercial agricultural systems are fallow. Spring cover crops in Kansas are planted between March and May, and then terminated in June or July prior to the planting of a cash crop, namely winter wheat (Triticum aestivum). To be effective, spring cover crops must provide vegetative qualities that females cue for nest habitat selection and resources for survival. In 2017 and 2018, we evaluated use of three cover crop mixes, a custom mix, commercial mix, wildlife mix and a chemical fallow control. Pheasants were studied in Graham, (2017, 2018), Norton (2018), and Russell (2018) counties with 33 females captured in 2017 and 38 females in 2018. Females were outfitted with a radio transmitter and tracked using handheld telemetry during the breeding season (March-August). We monitored 36 nests in 2017 including vegetation surveys conducted at the nest site and a random location within the same patch type. Apparent adult survival was 74% in 2017, nest success was 33%; females selected vegetation at the 50% visual obstruction density for nesting, and selected properties enrolled in the federal Conservation Reserve Program for nest locations. Spring cover crops develop structure that females cue for nesting, but after peak breeding season has occurred. Spring cover crops may provide critical brood habitat that is necessary to stabilize and increase local populations, while maintaining agricultural operations.
1:30PM Evaluating the Efficacy of Translocation to Recover Northern Bobwhite in New Jersey
Philip M. Coppola; Christopher K. Williams; Kaili R. Stevens; Theron M. Terhune II; John P. Parke; John Cecil
Northern Bobwhite (Colinus virginianus) populations have been declining across much of North America for over a century due to landscape-level habitat deterioration and fragmentation. Some of the greatest declines have occurred in the Mid-Atlantic region, near the periphery of their geographic range, with functional extirpation resulting in some states. Translocation of wild-caught birds is a promising population restoration technique for the species, when coupled with habitat management at release sites; however, there is no study of true reintroduction (i.e. no conspecifics at release area). The objective of this research is to evaluate the efficacy of translocation as a means to restore Northern Bobwhite populations in the New Jersey Pine Barrens, a fire-dependent coastal plain pine ecosystem in southern New Jersey that historically supported bobwhites and was highlighted by the National Bobwhite Technical Committee as having a high potential for recovery. Release sites were in intensively managed upland pine forests on Pine Island Cranberry Co. property (>6,800 ha; largest private land holder in the state) near the geographic center of the Greater New Jersey Pine Barrens Ecosystem. For three consecutive years (2015—2017) prior to breeding season, we translocated eighty VHF radio-collared Northern Bobwhite (40 male, 40 female) from wild populations in southwest Georgia and monitored survival, reproduction, and habitat use via telemetry. Pooled Kaplan-Meier adult survival estimates for the breeding season (1 April – 30 September) and non-breeding season (1 October – 31 March) were 0.274 (95% CI = 0.218 – 0.343) and 0.449 (0.291 – 0.691), respectively. Breeding season survival was reduced and nest initiation delayed for release-year birds, likely due to acute effects of translocation. Non-breeding survival was likely a legacy effect of the low number of released birds and lack of conspecifics. This study provides our first insights into the limiting factors of Northern Bobwhite reintroduction efforts nationally.
1:50PM Pheasant Habitat Selection: Logical Or Mysterious
Alixandra J. Godar; Adela Annis; David Haukos; Jeff Prendergast
Declining ring-necked pheasant (Phasianus colchicus) populations across the Midwest have united landowners and managers to develop new management strategies to balance human and wildlife needs across the landscape. A potential, agriculture-friendly source of wildlife habitat is planting spring cover crops to convert barren, chemical fallow fields into alternative sources of food and cover for wildlife. Our research was to determine if pheasants select for spring cover crops. We captured and fitted female pheasants with VHF transmitters within close proximity to spring cover crop treatment fields in three counties in Kansas. Fields were divided into 4 treatments consisting of 3 cover crop seed mixes and a chemical fallow control plot. Our cover crop mixes included Chick Magnet (a warm-season, broad-leafed forb mix designed for precocial chicks), GreenSpring (an agricultural forage mix with cool-season peas and oats), and a Custom Mix (designed to be adaptive with ten species). We monitored vegetation in cover crop fields and at pheasant locations using Daubenmire frames and Robel poles. We compared vegetation structure in cover crop fields to traditional grassland habitat using a MANCOVA and found spring cover crops differed from chemical fallow and Conservation Reserve Program fields, offering a different set of resources to pheasants. Pheasants selected for grasslands over the other cover types at the second and third selection levels. Use of the cover crops fields increased as the vegetation grew and peaked in June, when the cover crops were terminated. We used a resource selection function to assess the relative influence of a series of vegetative structure, vegetative composition and physical variables at used sites and random sites. Spring cover crops provide additional resources to pheasants and other wildlife. Variation among treatments emphasizes the importance of selecting an appropriate seed mix for cover crop if producers are interested in providing pheasant habitat.
2:10PM Factors Influencing Northern Bobwhite Population Recruitment with Implications for Population Growth
Mark D. McConnell; Adrian P. Monroe; Richard Chandler; William E. Palmer; Shane D. Wellendorf; L. Wes Burger; James A. Martin
Understanding and quantifying demographic parameters that influence population growth is necessary to maintain population persistence in the presence of recent changes in climate and land use. We used a combination of capture-recapture and harvest information from a 42-year dataset to create an integrated population model (IPM) that estimates population abundance, annual survival, and per-capita recruitment of Northern Bobwhite (Colinus virginianus). We evaluated the associations of commonly reported population metrics (age ratios from harvests, annual survival, and recruitment) on population growth rate using correlation analysis. We also modeled the effects of population abundance, breeding season temperature, breeding season precipitation, Fall minimum temperature, and Fall precipitation on recruitment. Recruitment averaged 1.55, ranging from 0.82 – 2.21 and was most strongly correlated with population growth (r = 0.78; 95% CI [0.63, 0.88]) followed by annual survival r = 0.38; 95% CI [0.09, 0.61]). We found weak correlation between Fall age ratios and population growth ratio (r = 0.11; 95% CI [-0.19, 0.40]). Recruitment exhibited non-linear, negative density dependence (β1 = -0.13; 95% Credible Intervals (CRI) [-.0.17, -0.08] and β2 = -0.03; 95% CRI [-0.07, 0.004]). Breeding season maximum temperature and breeding season precipitation had a significant, positive effect on recruitment (β3 = 0.15; 95% CRI [0.11, 0.19] and β4 = 0.10; 95% CRI [0.05, 0.16], respectively). Fall minimum temperature and Fall precipitation both had effects on recruitment (β5 = -0.03; 95% CRI [-0.08, 0.01] and β6 = -0.02; 95% CRI [-0.07, 0.01], respectively) but less so compared to weather in the breeding season. Our results illustrate that recruitment can be estimated without data on fecundity and chick survival using integrated population models. We also show that recruitment is estimable and highly correlated with bobwhite population growth. We encourage natural resource managers to focus on actions that increase bobwhite recruitment.
2:30PM Refreshment Break
3:20PM Surveillance for West Nile Virus in Pennsylvania Ruffed Grouse Habitat – Pilot Results and Management Implications
Lisa Williams
Surveillance for West Nile Virus in Ruffed Grouse Habitat – Results and Management Implications West Nile Virus (WNV) is increasingly implicated in population declines of Ruffed Grouse (Bonasa umbellus) in Pennsylvania, however little is known about the WNV transmission cycle in the remote woodland habitat occupied by grouse. Nearly all mosquito surveillance efforts occur in urban, suburban and other peri-domestic environments for the purpose of monitoring risks to human health. Using human-focused surveillance efforts, therefore, does not provide information on the timing, vector(s), and prevalence of WNV in forested settings. The objectives of this pilot study were to identify potential vectors of WNV in grouse habitat and evaluate whether DEP surveillance data reflects WNV viral activity in woodlands. Mosquito surveillance was conducted in 8 sites on State Game Lands 176 for 12 weeks from mid-June through mid-September. Paired traps (gravid + CO2) were used in order to capture a wide array of mosquito species on each site. Larval surveillance was also used to identify important production sites for WNV vector species. More than 15,000 adult mosquitoes of 25 species were captured. The known WNV-vector Culex restuans made up 22% of the adult sample, and C. restuans samples tested positive for WNV beginning in mid-July. This data suggests that C. restuans is the predominant vector of WNV in woodland habitats and that information on distribution of this species may be useful in developing a management response to the threat of WNV for ruffed grouse and other susceptible woodland birds.
3:40PM Effects of Vegetation Type and Human Activity on Space Use of Wild Turkey
Allison Rakowski; Dwayne Elmore; Craig Davis; Samuel Fuhlendorf
The use of unconventional oil and gas extraction is transforming millions of hectares of grasslands into more industrialized landscapes. As oil and gas demands continue to rise, wildlife may be subjected to unprecedented levels of energy infrastructure and associated fragmentation of landscapes. Within the context of avifauna, several studies have focused on the effects of energy development on resident ground nesting Galliforms and have come to varying conclusions. To better understand how Rio Grande wild turkey (Meleagris gallapavo intermedia; hereafter wild turkey) respond to management practices and energy development, we attached GPS transmitters to 36 wild turkey from March 2015 to February 2018. Wild turkey selected for the most recent time since fire category (0-6 months) during the breeding season. Oil/gas wells were avoided in both the breeding and non-breeding seasons, while high traffic roads were avoided and low traffic roads were selected for in the breeding season. However, forest vegetation was by far the most influential factor in space use of wild turkey throughout the year. Therefore, our data indicate that vegetation type is the primary driver of wild turkey space use but that anthropogenic features and activity do have an effect. Consideration of wild turkey should be taken into account when planning oil and gas development, particularly in landscapes where forest cover is limited as is often the case where Rio Grande wild turkey occur. Though wild turkey show limited avoidance of anthropogenic structures, they may not be as susceptible to energy development as reported for other galliform species.
4:00PM Reducing Gillnet Bycatch: Sea Duck Underwater Hearing Thresholds and Auditory Deterrent Devices
Kathleen McGrew; Christopher Williams; Alicia Wells-Berlin
As diving foragers, sea ducks are vulnerable to underwater anthropogenic activities, including naval sonar activity, and gillnet fisheries. Bycatch in gillnets is a principle driver of mortality for sea ducks, killing hundreds of thousands of seabirds annually. To avoid this, we proposed studying underwater hearing in affected species. Understanding hearing in diving birds can be directly applied to mitigation strategies for reducing gillnet bycatch through the use of acoustic deterrent devices. Additionally, knowledge of underwater acoustic sensitivity is important to current regulatory and management priorities in order to evaluate the impact of noise pollution. In order to determine underwater hearing sensitivities for diving birds vulnerable to bycatch, we used psychoacoustic techniques to train captive ducks to respond to sound stimuli. We raised long-tailed duck (Clangula hyemalis), surf-scoter (Melanitta perspicillata), and common eider (Somateria mollissima) ducklings at Patuxent Wildlife Research Center’s breeding facility, and trained ducklings to participate in underwater hearing tests in the center’s dive tanks. Underwater threshold data obtained from two years of duckling cohorts suggest that these species share a common region of greatest sensitivity, from 1000 to 3000 Hz. This area of sensitivity is outside the range of frequencies of existing commercial pingers, warranting the need for further product development.
4:20PM Simulated Effects of Heterogeneity in Catchability on Population Inferences for Wild Turkeys
Joanne C. Crawford; Bryan Stevens; William F. Porter
Harvest management programs commonly rely on indices to monitor changes in populations. Traditionally, harvest data has been used to index populations of many small game species, with the critical assumption that hunting will remove the same fraction of the population (or the same fraction per-unit of hunter effort) over time and in different management regions, and thus harvest-indices will reliably track spatial-temporal changes in populations. However, if hunter effectiveness or behavior changes systematically through space or time, then the fraction of the population removed per-unit of hunter effort (hereafter catchability) also changes, and catch-per-unit-effort (CPUE)) indices may not accurately reflect population change. Therefore, our objective was to evaluate the impact of heterogeneity of catchability on inferences obtained from CPUE abundance indices commonly used for management. We used harvest and effort data for eastern wild turkeys (Meleagris gallopavo silvestris) from two Midwestern states and simulated plausible changes to catchability to assess realistic effects on resulting inferences about spatial-temporal population change. Using observed county-scale harvest and effort data and simulated q values, we reconstructed turkey abundances that would produce the observed CPUEs, and compared spatial-temporal patterns in reconstructed abundances to those obtained assuming q was constant through space and time. We examined scenarios in which q increased or decreased incrementally over time and across space. Cases in which catchability increased or decreased resulted in increasingly large differences in reconstructed abundance over time and inferences about spatial patterns of abundance also changed with low or high values of q. Discrepancies in the accuracy of inferences about patterns of abundance resulting from heterogeneous q suggest that unmeasured changes in catchability can result in incorrect inferences about population change, which could in turn result in over- or under-harvest when CPUE indices are used to guide decision making in wild turkey harvest management.
4:40PM Testing Influence of Food Resources and Hunting-Related Disturbance on Mallard Habitat Use and Movement
Brendan Shirkey; Matt Palumbo
North American Waterfowl Management Plan (NAWMP) habitat goals are stepped-down regionally by Joint Venture’s that develop conservation strategies assuming food resources limit abundance and distribution of waterfowl during the non-breeding season. We hypothesize mallard (Anas platyrhynchos) movements in autumn are likely influenced by trade-offs between seeking food and seeking refuge as hunters exploit food resources to target waterfowl. We tested relative influence of food availability and hunting-disturbance on mallard movements and developed two a priori predictions: 1) If food resources are the limiting factor influencing mallard movements, we predict movements between hunted and non-hunted time periods will be similar and birds will first exploit habitat patches with greatest food availability (Ideal Free Distribution) 2) If hunting-disturbance is the limiting factor, we predict movement to be significantly different between hunted and non-hunted periods and mallards will not distribute based on food availability during hunted periods. We estimated “movement” as whether a mallard switched habitat types within paired observations and what factors (i.e., habitat type, diurnal/nocturnal, period of the hunting season) influenced switching. We found mallards were more likely to switch during day-to-night (P = 51%) movements than during day-to-day (P = 21%) and night-to-night (P = 8%) movements, exploiting refuge during the day and foraging habitat at night. Furthermore, ducks were least likely to switch during the non-hunted “preseason” period (P = 16%). Our results suggest mallard movement is limited more by hunting-disturbance than current conservation strategies suggest. If our observations are true at regional scales it is possible to encourage wetland management focusing on mitigating disturbance rather than providing food (row crops, intensive moist soil management), and this could be more compatible with ecological goods and services (e.g., flood water retention, improved water quality) identified in NAWMP as vital to engaging the non-hunting public on wetland importance.


Contributed Paper
Location: Huntington Convention Center of Cleveland Date: October 8, 2018 Time: 12:50 pm - 5:00 pm