William P. Kuvlesky, Jr.

Three Year Post Treatment Effects of Habitat Management on a Wintering Grassland-bird Community in South Texas

Ecologically sound habitat management will be essential to reverse the current decline of grassland birds. The objective of this study is to evaluate the effects of two habitat management practices: (1) summer prescribed fire [SF], (2) a combined treatment of roller chopper, summer prescribed fire, and chemical application [CT], and (3) an open grassland [C] as “control” on wintering grassland-shrub bird community composition and abundance. Line transects of variable lengths were used to assess the bird community structure. Grassland bird species richness during first season was 31 and 15...

Microhabitat Structure of Winter Turkey Roosts in South Texas

We located 18 Rio Grande wild turkey (Meleagris gallopavo intermedia; RGWT) winter roost sites and 18 random sites at three study areas in Brooks and Kennedy Counties from December 2006 to February 2008. Our objective was to determine microhabitat structural characteristics of RGWT winter roosts that distinguished them from random locations in south Texas. At each roost, we measured tree height, diameter at breast height (dbh), canopy cover, and tree density. Variables were tested for normality using a Kolmogorov-Smirnov test. A t-test was used to examine differences between roost and...

Exotic Grass Impacts on Northern Bobwhite Habitat in South Texas

There is growing concern about the impacts that exotic grasses may have on northern bobwhite (Colinus virginianus) and other grassland birds. Large areas of South Texas have been seeded to or have been invaded by several species of exotic grasses including Guinea grass (Urochloa maxima), Bermuda grass (Cynodon dactylon), King Ranch bluestem (Bothriochloa ischaemum), Kleberg bluestem (Dichanthium annulatum), buffelgrass (Pennisetum ciliare), and Lehmann lovegrass (Eragrostis lehmanniana). Impacts of exotic grasses on northern bobwhite are largely unknown. While exotic grasses such as...

Detectability of Rio Grande Wild Turkeys in South Texas

Detection estimates of Rio Grande wild turkey (Meleagris gallopavo intermedia, RGWT) are lacking and little research has focused on the development and evaluation of survey techniques for estimating RGWT populations. The objective of this study was to compare RGWT detection rates using aerial (Cessna 152) and roadside surveys in different vegetation communities in south Texas. Decoy flocks were randomly set 0-100 m from roads prior to surveys. Detection rate was estimated as (n decoys observed/n decoys available) x 100. Surveys were conducted in February and March 2007 and in November and...

Problems of Estimating Northern Bobwhite Populations at Low Density

A known population density was established for northern bobwhites (Colinus virginianus) on a lOO-ha pasture. Line transects were walked twice/day for 5 days to obtain a density estimate. Twelve density estimators using the linetransect data were compared to the known bobwhite density. On our study area, 6 estimators overestimated bobwhite density and 6 of them underestimated density. Because few coveys were flushed, individual transect replicates had to be pooled to provide estimates. This pooling of replicates did not enable us to calculate a mean density and specific variances for each...