Research

Important areas of research in wildlife habitat management at the Caesar Kleberg Wildlife Research Institute include: 1) White-tailed deer habitat, with emphasis on impacts of range management practices such as brush management and livestock grazing on habitat, discovering ways that these practices can be applied to improve or maintain wildlife habitat, and interactions between white-tailed deer and their habitat; 2) effects of exotic grasses on wildlife; and 3) restoration of wildlife habitat.

Wildlife Habitat Research

I. Effects of Population Density on White-tailed Deer and Their Habitat

Principal Investigators: Charles A. DeYoung, David G. Hewitt, and Timothy E. Fulbright

Graduate Students Focusing on Habitat Relationships: Master of Science - - Blaise Korzekwa, Lindsey Phillips, Lindsay Roberts, Justin Pierce Young, Ashley Wilson, and Onalise Hill.

Funding: Private donors, Houston Safari Club

Our research team consisting of Drs. Charles DeYoung, David Hewitt and Timothy Fulbright along with Don Draeger of the Comanche Ranch are conducting research to determine effects of increasing deer density on white-tailed deer productivity, population dynamics, and vegetation. The specific focus of graduate students working on habitat within the larger study are the effects of deer density on space use by deer and vegetation dynamics. Results of this research are critically needed to help landowners set target white-tailed deer densities that will not result in habitat degradation.

II. Cattle-deer Interactions: Forb Standing Crop and Stable Isotope Ratios

Principal Investigators: Timothy E. Fulbright, J. Alfonso Ortega, and David Hewitt

Graduate Students: Stacey Hines and Ramon Saenz

Funding: The Tom T. East, Sr., Alice K. East, Alice H. East, and Robert C. East Wildlife Foundation and the Houston Safari Club

The debate regarding cattle grazing impacts on deer, are they positive or negative, is centuries old. Many studies have been completed on cattle and deer interactions, but the debate persists. There have been few studies completed on the impacts of cattle grazing on preferred forbs for white-tailed deer and dietary niche overlap. The objective of this project is to 1) complete a literature review of cattle and deer interactions in North America; 2) determine impacts of cattle grazing on preferred deer forbs; and 3) estimate seasonal dietary niche overlap between cattle and deer.

An extensive literature review will be completed on cattle grazing impacts on deer behavior and dietary overlap of cattle and deer in North America. To determine cattle grazing effects on preferred deer forbs, 50 one and one-half-m2 vegetation enclosures were randomly allocated for installation at each of six 2 500-ha-study sites. Every autumn and spring, plant species inside each enclosure will be compared to a paired outside plot. In addition, every autumn vegetation biomass will be determined in the following categories 1) grasses; 2) preferred forbs; and 3) nonpreferred fobs. Twenty fecal samples/species/study site will be collected during spring, autumn, and winter for stable isotope analysis to determine dietary overlap. This project will synthesize pertinent literature and reveal possible trends, determine if cattle grazing promotes or hinders growth of preferred deer forbs, and surmise competition between species based upon dietary niche overlap.

III. Habitat Selection by Scaled Quail

Principal Investigators: Timothy E. Fulbright, Fidel Hernandez, and Eric Grahmann

Graduate Students: Holley Kline

Scaled quail are declining in abundance in south Texas. We hypothesize that habitat fragmentation caused by brush management and the spread of exotic grasses is one of the causes of the decline in scaled quail. One objective of our study is to determine patterns of habitat use by scaled quail. We will determine the extent to which scaled quail use or avoid areas dominated by exotic grasses.

Wildlife Habitat Restoration Research

I. Quail Habitat Restoration on the Hixon Ranch

Principal Investigators: Timothy E. Fulbright, Forrest Smith, Fidel Hernandez, Eric Grahmann, and David Wester

Graduate Students: Monika Burchette, Tony Henehan, Ben Olsen, and Matthew Wojda

Funding: George C. “Tim” Hixon and the Hixon family, Texas Parks and Wildlife Department, South Texas Charity Weekend, Inc., South Texas Chapter of the Quail Coalition, EXXON-Mobil Summer Internship Program, Coastal Bend Audubon Society.

The ability of many Texas rangelands to support diverse and abundant wildlife in the future will depend on our ability to restore degraded habitat. Millions of acres of native rangeland have become invaded by non-native grasses which has resulted in habitat loss and reduced wildlife abundance. Quail, grassland birds, and pollinators occur at low abundance on these degraded areas and are experiencing contintental declines. These species are important components of ecosystems given that they serve as indicator species or perform critical ecosytem services.

Methods for re-establishing native plants have been well researched, but most of this work has been conducted on small plots (< 2 hectares) and over short time frames (<2 years). To date, no large-scale (>40 hectares), long-term (5 years) habitat-restoration project has been conducted in monotypic stands of buffelgrass-Old World bluestem. Consequently, it is unknown whether large-scale restoration plantings actually recover widlife diversity and, more importantly, restore ecosystem function to its prior state. This lack of data limits our understanding of the realized benefits and limitations of rangeland restoration. Understanding ecosystem response to large-scale restoration is important given the substantial area of Texas rangelands that are being altered by oil-and-gas development along with the continued increase of non-native grasses.

A comprehensive, large-scale restoration project is needed to quantify the ecological response and benefits of native-grassland restoration. Our objectives are to:

1. 1) Restore a 120 hectare buffelgrass-Old World bluestem stand to a native grassland containing a diverse mix of native grasses, forbs and mixed-brush;
2. 2) Document the vegetation dynamics on the restoration site;
3. 3) Quantify quail abundance and space use before, during, and after restoration; and
4. 4) Quantify the faunal-community response (e.g., grassland bird, small mammals, pollinators) before, during, and after restoration.

Native grass species to be planted include Arizon cottontop (Digitaria californica ), shortspike windmillgrass (Chloris subdolichostachya), hooded windmillgrass (Chloris cucullata), four-flower trichloris (Trichloris pluriflora), slender grama (Bouteloua repens), sideoats grama (Bouteloua curtipendula), hairy grama (Bouteloua hirsuta), and little bluestem (Schizachyrium scoparium). Native forb species include huisache daisy (Amblyolepis setigera ), Indian blanket (Gaillardia pulchella), bush sunflower (Simsia calva), prairie acacia (Acacia angustissima), and orange zexmania (Wedelia hispida). Native brush species to be planted include coma (Bumelia celastrina), brasil (Condalia hookeri), lotebush (Ziziphus obtusifolia ), granjeno (Celtis pallida), prickly pear (Opuntia engelmannii), and Texas persimmon (Diospyros texana).

The 5-year goal is to have a functioning grassland that is dominated by native grasses, forbs, and mixed brush where quail, grassland birds, pollinators and other community species are common.