Conservation and Ecology of Birds – Game Birds I

Contributed Paper
ROOM: Rooms 16 – Acoma, 32 – Teseque and 15 – Zuni Combined
SESSION NUMBER: 39
 

10:30AM Lesser Prairie-Chicken Brood Ecology in Response to Land Management in the Sand Shinnery Oak Prairie Ecoregion
Daniel U. Greene; Blake A. Grisham; Sarah R. Fritts; Clint W. Boal; David A. Haukos; Robert D. Cox; Willard R. Heck
The lesser prairie-chicken (Tympanuchus pallidicinctus) has declined in geographic range and population size due to land-use change and extended periods of drought. Within the sand shinnery oak (Quercus harvardii) prairies at the southwestern extent of the species’ range, efforts to conserve the species have been constrained by limited baseline information, including how population recruitment is influenced by vegetation cover, weather, and land management practices. To aid conservation efforts, we radio-tagged hens and located their nests and broods during 5 breeding seasons. We evaluated how vegetation structure, invertebrate abundance and richness, and weather influenced brood-site selection and brood survival among sites treated with combinations of livestock grazing (short-duration, rotational) and herbicide (shrub control with tebuthiuron) used to restore sand shinnery oak prairies, and associated control sites lacking both grazing and herbicide application. At treatment sites, all broods were in areas either had an herbicide application or were grazed. Brood survival was positively influenced by overhead vegetative cover, grass height, and hot, but not extreme (e.g., >42°C) temperatures coupled with increased precipitation during brood-rearing. Invertebrates, a primary food source for chicks, had greater abundances and richness at treatment sites, were influenced by increased winter precipitation, and occurred more frequently in open areas (< ~25% shrub cover) that had higher forb, grass, and litter cover, and lower shrub cover and visual obstruction. Only 16% of nests produced broods, and 62% of broods failed within the first 14 days, with at least 75% failing within 30 days. Despite intensive survey efforts, the low abundance of lesser prairie-chickens, their dynamic, inter-annual boom-bust reproductive strategy, and subsequent few successful broods during our study resulted in sparse datasets. Nevertheless, our results indicated starvation and thermal cover are 2 proximate mechanisms that limited brood recruitment of lesser prairie-chicken populations on the Southern High Plains.
10:50AM “Flushing Out” the Relationship between Grasslands, Conservation Reserve Program Enrollments and Greater Prairie-Chicken Populations in Minnesota
Kalysta I. Adkins; Charlotte Roy; David E. Andersen; Robert G. Wright
The Conservation Reserve Program (CRP) has multiple objectives, one of which is to provide habitat for wildlife, especially for species of conservation concern. Greater prairie-chickens (Tympanuchus cupido pinnatus) are a target species of the CRP, but how greater prairie-chickens respond to abundance, distribution, and quality of CRP grassland is not well understood. To better understand greater prairie-chicken—CRP grassland relations, we evaluated population responses to CRP enrollments using population indices (males/lek and leks/km2) derived through annual monitoring efforts in Minnesota. We quantified land cover during the period 2004-2016 in survey blocks where systematic greater prairie-chicken surveys were conducted during the same period. We used land cover metrics of composition, contiguity, and fragmentation to evaluate the contribution of CRP enrollments to available grassland cover types and simulated changes through time resulting from scheduled CRP expirations. Greater-prairie chicken abundance was most related to amount of grassland on the landscape, the type (e.g., upland prairie and herbaceous wetland cover types) and management (e.g., publicly managed vs. CRP) of grassland present, how well connected grassland was in the landscape, and degree of fragmentation of grassland cover types. In addition, we measured vegetation and other characteristics related to establishment and management of CRP grassland categories and used them to develop a predictive map of greater prairie-chicken habitat quality. Our results provide a better understanding of greater-prairie chicken—habitat relations at a landscape scale and will aid the Farm Service Agency (FSA) and other organizations in targeting conservation programs that are most beneficial to greater prairie-chickens and where they will be most effective.
11:10AM Lesser Prairie-Chicken Habitat Selection During Extreme Temperature Events
Jonathan Lautenbach; David Haukos; Blake Grisham
As Earth’s climate continues to change, temperatures are predicted to increase, increasing the number of days that species experience thermal stress. Thermal stress can negatively influence survival and reproduction for many wildlife species, including the lesser prairie-chicken (Tympanuchus pallidicinctus), an imperiled prairie-grouse native to the southwestern Great Plains. The Great Plains is considered a climate change hotspot, and expected to see an approximate 10° C increase in average temperatures during spring and fall. Understanding how the species copes with intensifying conditions will help inform managers on how to create landscapes that minimize thermal stress. We captured female lesser prairie-chickens during the spring and attached transmitters to track their movements. We sampled vegetation and microclimate conditions using Maxim Integrated Semiconductors at lesser prairie-chicken midday loafing locations and random locations across the landscape to identify vegetation characteristics and landscape features lesser prairie-chickens use to minimize thermal stress. We found that female lesser prairie-chickens selected cooler microclimates for daytime loafing compared to random points; up to 17° ­C cooler in some instances. Lesser prairie-chickens primarily selected midday locations based on vegetative composition and structure. Females selected locations characterized by >75% grass and <10% forb cover, or >60% forbs and <25% grass cover. In addition, female selection of an area increased with increased visual obstruction. Currently, lesser prairie-chickens seek thermal refugia during the hottest days (>30° C); with continued warming, the frequency and intensity of these days is predicted to increase, increasing the need for thermal refugia. Identifying a management practice that increases overall vegetation cover (visual obstruction) and spatially heterogeneity with an abundance of forbs will be important to provide important thermal refugia for lesser prairie-chickens.
11:30AM A Tale of Chicken Little and Little Brown Jobs: Umbrella Species Conservation for the Lesser Prairie- Chicken and Grassland Avifauna of the Southern Great Plains
David C. Pavlacky; Anne M. Bartuszevige; Richard Iovanna; Christian A. Hagen; Fawn E. Hornsby
Long-term population declines have elevated the recovery of the grassland avifauna to among the highest conservation priorities in North America. Because a large percentage of the southern Great Plains are privately owned, the recovery of grassland bird populations depends on conservation initiatives with strong partnerships between private landowners and resource professionals. Umbrella species and landscape management are two approaches for conserving multiple species, but monitoring is needed to assess the effectiveness of practices for increasing populations of grassland birds. Our research objectives were to 1) evaluate the effectiveness of conservation practices for the lesser prairie-chicken (LEPC, Tympanuchus pallidicinctus) to increase the species richness of grassland birds, and 2) test the umbrella species hypothesis that LEPC occupancy predicts avian species richness. We studied core practices under the Lesser Prairie-Chicken Initiative (LPCI), including ranches enrolled in prescribed grazing and Conservation Reserve Program (CRP). We sampled grassland birds using the Integrated Monitoring in Bird Conservation Regions program and used multi-species occupancy models to predict species richness according to LEPC occupancy. We found species richness of grassland obligates was greater on LPCI rangelands than reference grasslands. In contrast, the species richness of grassland generalists was lower on LPCI rangelands than reference grasslands. The species richness of grassland obligates was greater on native CRP plantings than introduced plantings, but the richness of grassland generalists was lower on native CRP plantings than introduced plantings. Overall, the species richness of grassland birds increased with LEPC occupancy, and the site occupancy of sparrows (Emberizidae) was strongly correlated with LEPC occupancy. A preliminary investigation of conservation practices suggest LEPC occupancy increased with land enrolled in CRP and LPCI prescribed grazing. Our findings suggest voluntary conservation practices for the LEPC on private lands have wider implications for the conservation of avian biodiversity in the southern Great Plains.
11:50AM Tradeoffs of Nest and Brood Habitat Availability for Lesser Prairie-Chickens
Daniel S. Sullins; Joseph M. Lautenbach; David A. Haukos
Most gallinaceous birds have precocial young that begin feeding on their own immediately after hatching. In contrast to the dense litter and thick cover required for optimal nesting conditions, chicks need permeable grassland cover types through which they can move and forage on small insects. For a gallinaceous bird, such as the lesser prairie-chicken (LEPC, Tympanachus pallidicinctus), to successfully reproduce, females must select nest sites in grasslands exhibiting some level of heterogeneity. However, subtle differences among the two habitat types may lead to tradeoffs in nest and brood survival because we expect that grasslands that are more permeable for chicks would also be more permeable for predators. To examine the tradeoff in the effect of brood and nest habitat availability on recruitment and identify the optimal composition of habitats, we used an agent-based model in NetLogo 5.2. Agents included nesting LEPC hens and chicks. Patches were of either average quality nesting or brooding habitat based on concurrent vital rate estimates. In 2,100 simulations, we placed 10 LEPC females in virtual landscapes of varying nest and brood habitat composition and estimated fecundity per female. Hens expended energy to find nest habitat and, once found, established nests with a daily survival rate of 0.98 over a 35-day nesting period. Then, females with hatchlings had to find brood habitat within 2X the average brood movement distance (600 m) or the chicks would die. Our results indicated that fecundity rates were greatest in landscapes having 25-70% nesting habitat with maximum rates in landscapes having 45% nesting and 55% brood rearing habitat (6.85 young/adult female). The predicted optimal range of nesting habitat composition encompassed nesting habitat availability (29.6%) estimated among study sites in Kansas and Colorado from 2013-2016 and suggests that management devoted purely to providing nest habitat would be counterproductive.

 

Contributed Paper
Location: Albuquerque Convention Center Date: September 25, 2017 Time: 10:30 am - 12:10 pm