Conservation and Ecology of Birds – Game Birds II

Contributed Paper
ROOM: Room 230 – Pecos
SESSION NUMBER: 57
 

10:30AM Thermally Usable Space May Become Limiting for Northern Bobwhites
Benjamin R. Olsen; Timothy E. Fulbright; Fidel Hernandez; Eric D. Grahmann; David B. Wester; Michael W. Hehman
Understanding how temperature influences resource selection by northern bobwhites (Colinus virginianus: hereafter bobwhite) is becoming increasingly important with predicted increases in temperature associated with climate change. We sought to determine (1) influence of time of day on thermal resource use, and (2) influence of plant community on black globe temperature. We radio-marked 40 bobwhites and relocated them 2-3 times a week during April to September 2014 – 2016. We recorded black globe and ground surface temperature at the bird relocation (organism-centered) level and at locations 20 m away in a random direction. Additionally, we deployed 48 black globe thermal arrays in each of 6 different plant communities to record black globe temperature every 30 minutes from June – August 2014. Bobwhite locations were cooler than random sites for black globe and ground surface temperatures between 0736 – 1948 h and 0800 – 1900 h, respectively. Thermally usable coverts are limiting in our study area based on our findings that mean black globe and ground surface temperatures at used sites are near the upper tolerance bounds for use in late summer during the afternoon. Midday black globe temperatures were lowest in Riparian communities. Midday black globe temperatures were highest plant communities dominate by exotic grasses. In August 2014, only 8 of 48 thermal arrays across all plant communities recorded a mean black globe temperature below 42.5° C (the upper tolerance bound for bobwhites) at 1400 h. Future climate warming may reduce habitat space that bobwhites may occupy making management for more thermal cover and conservation of plant communities that provide thermal cover critically important.
10:50AM Spatiotemporal Variation in Multiscale Space Use by Wild Turkeys
Ryo Ogawa; Jerrold L. Belant; Adam B. Butler; Scott A. Rush; Darren A. Miller; Guiming Wang
Spatiotemporal variation in space use is critical to understanding how individual animals respond to changes in resource heterogeneity across space and time. In particular, variation in space use across landscapes is of interest to wildlife ecologists and managers to determine mechanistic understanding of resource use under varying resource availability. However, there have been few comprehensive analyses on wild turkeys (Meleagris gallopavo silvestris) across ecogeographic regions. Our objective was to determine whether wild turkeys exhibited a common habitat selection pattern across regions or region-specific habitat selection patterns. Ninety-four adult female wild turkeys from seven study sites in five ecogeographic regions of Mississippi were relocated using very high frequency telemetry from March to August, 1991–2011. We computed proportions of all forests, including both hardwood and non-hardwood forest, and hardwood forests as landscape variables at three spatial scales: daily; seasonal; and annual home range sizes using the National Land Cover Database. We used generalized linear mixed models for habitat selection analysis with individual and site as random effects. Wild turkeys exhibited region-specific selection for all forests at daily home range scales, whereas individual variation or functional response in habitat selection was best supported for hardwood forests at seasonal home range scales. Additionally, in a two-stage analysis, selection for all forests and hardwood forests decreased with increasing availabilities of all forests and hardwood forests, respectively, at the seasonal home ranges scale. Our results demonstrated that functional responses of turkey habitat selection to hardwood forests were scale dependent. Therefore, management of hardwood forests is important to wild turkey management.
11:10AM Density Estimation and Habitat Modeling for Pheasant Population Restoration in Pennsylvania
Lacey Williamson; Scott Klinger; Duane Diefenbach; David Walter
Ring-necked pheasants (Phasianus colchicus) reached peak abundance in Pennsylvania in the 1970s and declined most likely due to a lack of suitable habitat. From 2007 to 2014, the Pennsylvania Game Commission translocated 2,328 pheasants from South Dakota and Montana to 10 areas in Pennsylvania closed to pheasant hunting. We investigated habitat use of pheasants and estimated whether population densities met the agency’s goal of 3.86 hen pheasants/km2 during 2013–2016. We used crowing counts at randomly selected points, corrected for crowing frequency and detection probability, and the sex ratio of flushing counts to estimate density of hen pheasants on each study area. Only one study area met the hen density goal (4.1 hens/km2 SE=0.89) with all other study area densities achieving <2 hens/km2. We mapped microhabitat data within a 0.56 km radius of 113 crowing-count points in 2013 and 178 points in 2014. We used the density estimates and microhabitat data to model habitat use and identify habitat characteristics that had the most influence on pheasant density. The variables that best explained hen densities were proportion of Conservation Reserve Enhancement Program (CREP) habitat with a positive relationship and the proportion of forest with a negative relationship. Our results will be used for making more efficient management decisions when identifying potential pheasant habitat and improving habitat for wild pheasant populations. We studied pheasants in a landscape that had up to 22% forested habitat. Our model indicated we would need as much as 24% of cropland to be enrolled in CREP to reach a density goal of 3.86 hens/km2 within a landscape that is 10% forested.
11:30AM Wild Turkey Space Use and Movement in Response to Temperature
Allison Rakowski; R. Dwayne Elmore; Craig A. Davis; Samuel D. Fuhlendorf
Thermal environments place physiological and behavioral constraints on organisms. Ground nesting birds in the southern Great Plains are particularly vulnerable to temperature because of their predominately diurnal behaviors, nest location, and exposure to ambient temperature often exceeding 30C°. To better understand how organisms respond to thermal extremes, we assessed movement and space use of Rio Grande Wild Turkeys (Meleagris gallopavo intermedia; hereafter turkey) on Packsaddle Wildlife Management Area in Oklahoma during June-August, 2016. We placed 20 backpack-style GPS transmitters on female turkeys. Each of the transmitters recorded 7 daytime locations (every 2 hours from 0800-2000) daily. We measured black ball temperature from (21°C-54°C), which incorporates both ambient temperature and the effect of solar radiation. Data indicates a tremendous thermal variation across the landscape. At an ambient temperature of ~34°C, black ball temperatures range from 30°C to 53°C, providing a wide array (23°C) of thermal options to organisms. We also found that during peak heating (1200-1600 hours), locations where turkeys loaf (1400 hour turkey locations) were up to 5°C cooler than the locations at which turkeys feed (0800 hour turkey locations) and that these locations vary in vegetation structure. Additionally, turkeys moved an average of 90m less between successive locations during the hours of peak heating (1200-1600 hours) on days >30°C than on days where temperature remained <30°C. These findings suggest that turkeys may be using the thermal variation across the landscape to help mitigate thermal extremes during the hours of peak heating and are modifying behavior to minimize exposure to high heat.
11:50AM Resource Selection by American Woodcock During Fall Migration at Cape May, New Jersey
Brian B. Allen
Migration may expose birds to hazards at intensities greater than those during any other life stage, and effective conservation of migratory species requires an understanding of space use during migration. From 2010 to 2013 we conducted a radio-telemetry study of American woodcock (Scolopax minor) on the Cape May Peninsula, New Jersey, which is an important stopover site for migratory woodcock in the eastern flyway. Our research objectives were to 1) describe diurnal cover-type characteristics used by woodcock, and 2) evaluate second-order habitat selection during the fall migration period. We nightlighted fields to capture birds and attach VHF radio-transmitters. Ten to 15 individuals were marked each week and were tracked twice weekly until departure, death, or the end of the field season. Over four years we radio-marked 271 individual woodcock and collected 1,949 GPS point locations from these birds (Range = 0 – 21 points per individual). We used GIS and resource selection functions in the form of a generalized linear mixed model to compare habitat features at the used locations to features at random locations distributed across our study landscape at multiple extents. We found support for selection or avoidance of the cover-types considered at two of the five extents evaluated. We used results to develop a multiscale predictive model of habitat distribution at Cape May as continuous and discrete surfaces. Our model predicts the likelihood of woodcock to select an area to increase as proportions of deciduous wetland forest, old fields, and shrub covered wetlands increases, while avoidance of an area increases with the proportion of deciduous forest, conifer forest, and distance from a field. Our study improves our understanding of American woodcock habitat selection during the fall migration period, which has been generally understudied, in the eastern U.S

 

Contributed Paper
Location: Albuquerque Convention Center Date: September 26, 2017 Time: 10:30 am - 12:10 pm