Grand Lake Watershed Conference 2010

GRDA has provided the necessary infra-structure and resources to address the complex issues threatening the integrity and function of our watershed. GRDA’s state-of-the-art water quality and research lab located within the new Ecosystems and Education Center and subsequent longterm partnerships with the University of Oklahoma and Oklahoma State University are laying the foundation to address the challenges facing natural resource scientists in the 21st Century.


Rush for Brush Improves Habitat for Fish

Authors

Darrell E. Townsend II, Ph.D.,  Brent Davis

Abstract

The Grand River Dam Authority’s (GRDA) annual “Rush for Brush” program is designed to rehabilitate aging lakes associated with its two hydro projects in northeastern Oklahoma. This program encourages local individuals to volunteer as partners in conservation by helping GRDA staff construct and deploy artificial structures (also known as spider blocks) to enhance fishery habitat throughout two Oklahoma lakes.


Using supplemental food and its influence on survival of northern bobwhite (Colinus virginianus)

Authors

Darrell E. Townsend II, Robert L. Lochmiller, Stephen J. DeMaso, David M. Leslie, Jr., Alan D. Peoples, Scott A. Cox, and Edward S. Parry

Abstract

Biologists have debated the effectiveness of supplemental feeders as a management tool for the northern bobwhite (Colinus virginianus), but few extensive evaluations have been conducted. We examined 783 crops from harvested bobwhites during 1992-1996 to determine effects of climatic stress in winter on use of supplemental feeders and their impact on survival rate in winter. Crops of bobwhites harvested from areas with supplementa l feeders contained 28.2% supplemental food compared with 5.5% (P<O.OOl) for those from areas without supplemental feeders. Winter climate was not a significant predictor of the proportional use of supplemental feeders. Rates of winter survival were greater on areas with supplemental feeders compared with non-supplemented areas in winters 1992-1993 (P:::O.001) and 1993-1994 (P:::O.002), but in 1994-1995, rates were greater on nonsupplemented areas (p:::O.032). Causespecific mortality rates indicated that supplemental feeders did not predispose bob
whites to hunter harvest or predators. Results suggested that bobwhites can gain nutritional benefits from supplemental feeders during times of severe winter stress.


Evaluating Relationships between Spatial Heterogeneity and the Biotic and Abiotic Environments

Authors

Darrell E. Townsend II, Samuel D. Fuhlendorf

Abstract

While most studies of heterogeneity have focused on describing patterns of species or communities, few have focused on the relationships between biotic and abiotic environmental landscape-level gradients. Our study was designed to determine relationships between grazing (heavy, moderate, ungrazed), topographic position (upland vs. riparian), vegetation structure and the thermal environment (i.e., soil-surface temperatures) and determine the influence on landscape patterns of heterogeneity. Biotic and abiotic patterns of heterogeneity were evaluated by establishing 200-m transects that were centered on and perpendicular to a riparian zone so that spatial patterns of variability could be determined along each transect which transcends the maximum level of landscape heterogeneity. Vegetation cover and structure and soil-surface temperatures were recorded at 1-m intervals along the transect. Bare ground increased and leaf litter, grass cover, vegetation heights and angle of obstruction decreased with grazing intensity. However, mean soil-surface temperatures did not differ between grazing treatments. Tree canopy cover associated with riparian areas generally reduced soil-surface temperatures 20 C below that of upland temperatures. In fact, 96% of observations of riparian soil-surface temperature were ≤ 39 C, while 94% of upland soil-surface temperatures were ≥ 40 C regardless of grazing intensity. Vegetation characteristics and soil-surface temperatures were correlated (P , 0.05), but correlation coefficients were small because soil-surface temperature was highly variable. Grazing influenced patterns of landscape heterogeneity, but effects were inconsistent among biotic and abiotic variables. Although grazing had little influence on moderating mean soil-surface temperatures, results suggest that grazing intensity influences thermal heterogeneity at a variety of spatial scales. For instance, thermal heterogeneity (in moderately grazed treatments) is highest at smaller (lag distances ≤ 20 m) and larger (lag distances ≥ 48 m) spatial scales but was lowest at moderate scales (lag distances 22–45 m). For all variables, other than soil-surface temperature and forb cover, semi-variances of moderately grazed sites generally lie intermediate between heavy and ungrazed sites. Nearly all ungrazed vegetation characteristics, except leaf litter, fit a spherical model that reached a sill at a lag distance # 20 m and became spatially independent thereafter, while heavily and moderately grazed sites typically fit an exponential model, indicating a high degree of continuity. Patterns of thermal variability (on uplands) are not related directly to any one vegetation variable, hence, landscape patterns based on vegetation parameters alone are of limited value since patterns of thermal variability are effected by the integration of vegetation and environmental variables within the ecosystem.


The Power of Restoration Oklahoma’s Indian Territory Chapter partners with power company for quail

Author

Darrell E. Townsend II, Ph.D.

Summary

Oklahoma’s Indian-Territory Chapter is partnering with the Grand River Dam Authority (GRDA) to establish quality quail habitat on about 30,000 acres of company right-of-way in Northeast Oklahoma and portions of Arkansas, Kansas and Missouri.


Heterogeneity of Thermal Extremes Driven by disturbance or inherent in the landscape

Authors

Ryan F. Limb, Samuel D. Fuhlendorf, Darrell E. Townsend

Abstract

Ecologists are beginning to recognize the effect of heterogeneity on structure and function in arid and semiarid ecosystems. Additionally, the influences of temperature on ecosystems are widely documented, but landscape temperature patterns and relationships with vegetation are rarely reported in ecological studies. To better understand the importance of temperature patterns to the conservation and restoration of native ecosystems, we designed an experiment to investigate relationships among soil surface temperature, landscape heterogeneity, and grazing intensity. Grazing intensity did influence the vegetation structure and composition. Heavy treatments had the greatest bare ground and the least vertical structure.  Ungrazed treatments had the most litter and live grass cover. However, average temperatures among the three grazing treatments were not different and ranged less than 2°C during midday summer periods. The temperature difference between riparian and upland landscapes within grazing treatments was 21°C. Landscape position (riparian vs. upland) did have a significant influence on soil surface temperature and produced a variation in temperature 11 times greater than grazing intensities. Thermal heterogeneity did not differ among grazing treatments. Lower soil surface temperatures (associated with riparian areas) may provide a critical thermal refuge for many animals in arid and semiarid ecosystems on hot summer days, when air temperatures can exceed 37°C. Riparian zones, specifically riparian vegetation, are an important component in ecosystem management.


The Effect of Quail Feeders on Northern Bobwhite Density In Western Oklahoma

Authors:

Stephen J. DeMaso, Darrell Townsend II, Scott A. Cox, Edward S. Parry, Robert L. Lochmiller, Alan D. Peoples

Abstract

We investigated the effect of quail feeders on northern bobwhite (Colinus virginianus) covey size and density from 1 October 1991 to 1 October 1996 on the Packsaddle Wildlife Management Area (WMA) in western Oklahoma. Thirty-two quail feeders filled with milo were located near the center of every 8.1 ha on a 283.3-ha treatment area. An adjacent 283.3-ha control area contained no quail feeders. Line-transect methodology was used to seasonal1y determine covey size and density on each area. Transects were traversed on horseback during October and March of each year. Mean fall covey size was similar (t = 0.19, df = 1, P = 0.8525) between the control (14.0 ± 1.2 birds/covey) and treatment (14.2 ± 1.1 birds/covey) areas, pooled over years. Mean spring covey size was similar (t = 10.18, df = 1, P = 0.9999) between the control (9.4 ± 1.9 birds/covey) and treatment (6.6 -±. 1.5 birds/covey) areas, pooled over years. Pooled over treatments, mean covey size was similar (F = 1.30, df = 4, P = 0.2798) among years, but differed (F = 40.56, df = 1, P = 0.0001) between spring (7.6 ± 1.2 birds/covey) and fall (14.1 ± 0.8 birds/covey). Mean bobwhite density, pooled over
seasons and years was similar (t = -3.55, df = 1, P = 0.9125) between control (1.28 ± 0.43 birds/ha) and treatment (1.38 ± 0.44 birds/ha) areas. We conduded that quail feeders had no effect on mean covey size or density of bobwhite populations on our study area in western Oklahoma.


Developing a Database to Track Structures on the Shoreline of a Reservoir

Author

Dr. Darrell Townsend II, Ph.D.

Abstract

Monitoring and permitting more than 10,000 boat docks, water intakes, retaining walls, and other hazardous structures along the shoreline of Grand Lake in Oklahoma is a size-able task.  To simplify the process and maintain more accurate information, the Grand River Dam Authority Developed a database using geographic information system software.


Transmitter height influences error of ground-based radio-telemetry

Authors

Darrell E. Townsend II, Stephen S. Ditchkoff & Samuel D. Fuhlendorf

Abstract

Although accuracy of wildlife radio-tracking systems have been measured intensively, little attention has been given to error associated with varying transmitter heights that would occur because of species size or life history (e.g. arboreal species ). Our objective was to simulate the approximate transmitter height of three extensively studied game species to determine their influence on bearing accuracy.


Fitness Costs and Benefits Associated with Dispersal in Northern Bobwhites (Colinus virginianus)

Authors

DARRELL E. TOWNSEND II, DAVID M. LESLIE, JR., ROBERT L. LOCHMILLER, STEPHEN J. DEMASO, SCOTT A. COX AND ALAN D. PEOPLES

Abstract

Movements and dispersal distances are fundamental aspects of ecology and evolutionary biology. Northern bobwhites (Colinus virginianus) generally are considered the
least mobile of all gallinaceous species, but dispersal events of bobwhites (commonly referred to as “shuffling”) are well known. Although dispersal may be a key component in regulating population densities and inbreeding avoidance, few studies have attempted to explain relationships between dispersal, mortality and nest success in northern bobwhites. To examine these relationships, we monitored 957 radio-marked bobwhite from 1991 to 1996. Mean dispersal distance did not differ between sexes (P _ 0.699). Mean dispersal distances of adults (2821 m) were shorter than those of juveniles (3411 m; P – 0.042). We found no sex or age-related differences in survival rates among dispersers and non-dispersers. Despite associated risks with increased movement activity in unfamiliar areas, survival rate was 1.5-times greater for dispersers (5 .- 0.72) than non-dispersers (5 =- 0.50). Further, we found no relationships between nest success and dispersal distance. suggesting that dispersal distance had little influence on reproductive output of bobwhites. Thus, dispersers may play a key role in bobwhite population dynamics whereby declining populations escape extinction through recruitment from productive populations.


Characteristics of nest sites of northern bobwhites in western Oklahoma

Authors

DARRELL E. TOWNSEND II, RONALD E. MASTERS, ROBERT L. LOCHMILLER, DAVID M. LESLIE, JR., STEPHEN J. DEMASO AND ALAN D. PEOPLES

Abstract

Previous authors have described nesting habitat of the northwestern bobwhite (Colinus Virginianus) throughout its range, but few have compared structural or compositional differences of vegetation between nest sites and random non·use sites, and successful and non-successful nests. From 1996–1998, we compared cover and structure of 85 plant species from 80 nest sites of northern bobwhite in western Oklahoma.  Nest sites were consistently associated with greater structural complexity than what was available at random. Bobwhites selected nest sites with a greater coverage of grass (ca. 50%) and woody (ca. 20-30%) vegetation with a relatively low percentage of bare ground, presumably because these attributes maximize their chance for successful reproduction by providing protection against weather and predators. Successful nests were more concealed during 1996 and 1997 (12.37 and 10.74% visibility, respectively) than non·successful nest sites (21.6 and 27.65% visibility), but levels of concealment did not differ during 1998. We found no significant differences in vegetation composition or structure between successful and non#successful nest sites.