Landscape-Scale Land-Cover Change and Long-Term Abundance of Scaled Quail and Northern Bobwhite in Texas

Between 1978 and 1998, scaled quail (Callipepla squamata) abundance in the Rolling Plains ecological region declined (r1 = -0.85, P \u3c 0.001), while no trend (P = 0.74) was exhibited in the South Texas Plains. Northern bobwhites (Colinus virginianus) exhibited no trend (P \u3e 0.10) in either ecological region. Changes in land-cover between 1976 and 1998 indicated a loss of Savannah and Shrubland and an increase in Parkland cover types in the Rolling Plains. In the South Texas Plains, Woodland and Brush/Shrubland decreased between 1976 and 1998, whereas Brush/Shrub Parkland and Parkland increased. We examined land-cover change as a possible component in the scaled quail decline in the Rolling Plains. Loss of the Shrubland cover type may explain the decline of scaled quail in the Rolling Plains. Our results further suggest intraspecific spatial usability boundaries. These boundaries differed by species, with scaled quail associated with dense structure near the ground, whereas northern bobwhite were less abundant in areas dominated by scattered shrubs and trees, and large expanses of short, close-canopy cover types. A method is proposed for quickly obtaining data on land-cover changes on time

Use of Extinguish Plus™ to Reduce Red Imported Fire Ants and Increase Northern Bobwhite Abundance

Populations of northern bobwhite (Colinus virginianus) have been declining throughout Texas since at least the 1970s. The red imported fire ant (RIFA, Solenopsis invicta) was introduced from South America and reached Texas by the 1950s. Previous studies have documented the negative effects of RIFA on northern bobwhite populations through both direct predation and indirect reduction of small invertebrates. In 2013, 2014, and 2015, large areas (1,490 ha in 2013 and 2,380 ha in 2014 and 2015) of the 3,744-ha portion of the Attwater Prairie Chicken National Wildlife Refuge (APCNWR) in Colorado County, Texas, were aerially treated with Extinguish Plus™, a chemical pesticide and reproductive inhibitor that targets ants. Our study took place on APCNWR and our objectives included evaluation of the impacts of RIFA treatment on 1) RIFA abundance, and 2) northern bobwhite nest success and brood survival. We trapped, banded, and radiocollared northern bobwhites in areas treated and not treated with Extinguish Plus from May 2014 through August 2016. We also collected RIFA abundance data using baited Petri dishes on areas treated and nontreated areas during these periods. Treatment reduced RIFA presence on the refuge by 73.4% during 2014 and 2015, but did not reduce RIFA presence during 2016 possibly because of displacement of RIFA colonies due to heavy flooding on the refuge. We detected a difference (χ21 = 11,009, P = 0.0009) in the number of females sighted with and without broods between treated (19.5% F with broods) and nontreated areas (35.7% F with broods). We also found a difference (t12 = 2.51, P = 0.027) in mean number of chicks per brood sighted within treated (4.7) versus nontreated (9.3) areas for 2014 and 2014; but in 2016, we found no difference (t12 = 0.32, P = 0.754) in mean number of chicks per brood sighted within treated (7.7) and nontreated (8.4) areas, which was possibly due to extensive flooding in the nontreated area in April that destroyed most first nests. Our data suggested treatment with Extinguish Plus did not increase northern bobwhite abundance on the APCNWR during the 2014, 2015, and 2016 bobwhite nesting seasons. Our results differ from previous studies, possibly because of time since treatment and differences in environmental factors between treated and nontreated areas such as ecological site, vegetation composition, and predator abundance

Echoes of the Chisholm Trail: Texas: A Biological Crossroads

Texas: A Biological CrossroadsThe Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Grassland Composition Affects Season Shifts in Seed Preference by \u3ci\u3ePogonomyrmex barbatus\u3c/i\u3e (Hymenoptera: Myrmicinae) in the Edwards Plateau, Texas

The effects of season and community composition as generated by livestock herbivory of differing intensity on seed species preference by Pogonomyrmex barbatus (F. Smith) were studied in a semiarid savanna on the Edward’s Plateau, TX. Seasonal differences in nutrient requirements of the colony could lead to differential preferences for seeds harvested in spring and fall. Field cafeteria studies were conducted to test the hypothesis that late successional species, with their high nutrient content, would be chosen regardless of grazing intensity or season. Commercial seeds of known nutrient content were used to test the hypothesis that high protein levels would be chosen in spring and high carbohydrate levels in the fall. Naturally occurring seeds were differentially harvested and some were preferred regardless of relative availability. Total seed harvest in cafeteria experiments was higher in spring than in fall. Commercial seeds were harvested equally among treatments within a season; thus, nutrient selection was indistinguishable. Preference for native species was significantly different in both seasons but was influenced by a significant interaction with grazing treatments. Bouteloua curtipendula, a late successional mid-grass, was harvested significantly more in the spring than the fall and at higher rates in the heavily grazed treatment, rejecting the hypothesis that they would be chosen regardless of treatment or season. Seed preference for late successional grasses within heavily grazed communities may slow succession after grazing. During disturbance recovery, late successional species may be reduced by forager preference and rates of spring harvest

Long-Term Grass Dynamics Within a Mixed-Grass Prairie

Western portions of the Edwards Plateau are dominated by a grass mosaic which consists of a rhizomatous midgrass, tobosagrass [Hilaria mutica (Buckl.) Benth.], and two stoloniferous short grasses, common curlymesquite [Hilaria belangeri (Steud.) Nash] and buffalograss [Buchloe dactyloides (Nutt.) Engelm.]. Permanent 0.3 m x 6 m belt transects were established on three major soil series (Tobosa, Ozona. Valera) across several grazing treatments on the Texas Range Station near Barnhart, Texas, and the distribution of perennial grasses was mapped in 1951 (pre-drought), 1953 (drought), 1957 (post-drought), and 1987. Cover showed no consistent trends in relation to grazing. Total grass cover and composition within each soil series was found to be similar in 1951 and 1987, but cover was reduced by 20 to 56% during the drought period due primarily to a decrease in short-grass cover. This grassland mosaic exhibits a high degree of resistance and resilience to climatic variability

Habitat Use of Monk Parakeets in Dallas and Tarrant Counties, Texas

Monk parakeets (Myiopsitta monachus) are native to South America and were exported as popular caged birds during the legal pet bird trade. Due to accidental and intentional releases, monk parakeets established naturalized, self-sustaining populations in the United States (US). This species is the only member of the parrot family (Psittacidae) that builds large, communal twig nests and uses them for both breeding and roosting year-round. In the US, monk parakeets often construct their nests on anthropogenic structures, most notably electric utility structures. This nesting behavior causes economic damage and management strategies have been unsuccessful addressing this persistent problem. From 2010–2012, we investigated monk parakeet habitat use, food habits, and nest-site selection in Dallas and Tarrant counties, Texas, US, to determine which variables and spatial scales influenced the selection of electric stations as nest sites. We located \u3e50 colonies and found 76% of the nest structures on electric utility structures. We tracked 20 radio-tagged birds at 3 sites and recorded 962 locations. We calculated 85% kernel density estimators and found no differences between sexes (P = 0.50). Winter core activity areas (x̅ = 49 m, 95% CI = 39 m–59 m) were significantly larger than summer (x̅ = 25 m, 95% CI = 13 m–36 m) or fall (x̅ = 15 m, 95% CI = 5 m–25 m). There were no differences in foraging distances between sexes (P = 0.72). Winter foraging distances (x̅ = 579 m, 95% CI = 510 m–648 m) were farther than summer (x̅= 339 m, 95% CI = 246 m–433 m) or fall (x̅ = 303 m, 95% CI = 210 m–397 m). Monk parakeets utilized 33 plant species from 22 families as food sources. Southern live oak (Quercus virginiana; 20.3%) was the most important food resource. However, monk parakeet diet was diverse and seasonal, suggesting that food is not a limiting factor. Analysis of land use/land cover (LULC) classifications (pavement, building, canopy, grass, and water) on 3 scales (1250 m, 625 m, and 100 m) buffered around electric stations (n = 28 pairs, with and without nests) revealed LULC impacted monk parakeet nest-site selection only at the 100 m scale. Pavement and building rooftops appeared important for pooled water for drinking and bathing. Further analysis at the local scale revealed that monk parakeets selected electric stations with flat, multiple-angled construction, small fenced enclosures, large canopy trees within 100 m, and an active colony within 2.5 km (AICc = 37.30, wi = 0.82). Our results suggest that wildlife managers who want to prevent monk parakeets from nesting on electric utility structures should focus on modifying or replacing existing construction and redesigning future construction

Spring Habitat Requirements of Captive-Reared Attwater’s Prairie Chicken

During the summer of 1996, 50 radio-tagged, pen-reared Attwater’s prairie chickens (Tympanuchus cupido attwateri) were released on Attwater Prairie Chicken National Wildlife Refuge in a restoration effort to supplement a wild population. We evaluated fine-scale habitat use of pen-reared Attwater’s prairie chickens during the 1997 nesting season based on 4 variables: obstruction of vision, plant height, litter depth, and percentage of bare ground. Low obstruction of vision (mean = 1.5 dm), plant height (mean = 67.3 cm), and litter depth (mean = 2.7 cm) characterized preferred habitats. Bare ground averaged 16.5% at Attwater’s prairie chicken locations compared with 8.2% at random locations. Use locations differed from random locations with respect to visual obstruction (P 16.5%), the preferred habitat of pen-reared Attwater’s prairie chickens.  The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 2020Legacy DOIs that must be preserved: 10.2458/azu_rangelands_v58i3_morro

Flooding-induced landscape changes along dendritic stream networks and implications for wildlife habitat

a b s t r a c t Severe low frequency natural disturbances along stream networks can substantially alter urban and rural landscapes and impact habitat and population dynamics of wildlife species. In 1978, severe flooding along the North Prong of the Medina River significantly altered the habitat for the Rio Grande wild turkey and may have contributed to the decreased abundance of this species observed during recent decades in the southeastern Edwards Plateau, TX, USA. The objective of our study was to examine the changes in landscape structure caused by this flooding event and their potential impact on wild turkey habitat. Aerial photography from 1972, 1984, and 1995 was used to quantify habitat changes in riparian zones and adjacent bottomlands along the Medina River. We documented substantial reductions in habitat suitability and connectivity caused by the flooding, followed by a partial recovery over 17 years. Analysis using patch-level metrics in conjunction with class-level metrics, provided insights to the pattern and possible mechanisms of the landscape changes. Habitat along higher-order streams was most affected, reducing not only the suitable habitat locally, but also the habitat connectivity throughout the riparian network. This loss of connectivity rendered numerous habitat patches along lower-order streams unavailable to Rio Grande wild turkeys as this species depends on riparian corridors for dispersal and movement among habitat patches. Our results illustrate the critical importance of multiple-scale analysis based on hierarchical dendritic structures of river networks when assessing habitat changes and their impact on populations of terrestrial wildlife species dependent on riparian habitats in semi-arid landscapes