Research Statement

My goal is to find ways to better manage wildlife populations by investigating issues of anthropogenic disturbance and natural resource management.

Humans have a large effect on our environment through a variety of disturbances such as climate change, habitat alternation and fragmentation, environmental enrichment, and pollutants. I use multidisciplinary approached - integrating wildlife ecology, landscape ecology, biogeochemistry and ecology - and combine modeling with field and laboratory experiments and correlational field studies - to address these issues in a variety of systems.

My mission is to improve the practice of natural resource management.

Conservation Planning for Climate Change


The greatest challenge facing natural resources management is planning for and responding to increasingly variable conditions, caused by global climate change. Changes in water availability and temperature are influencing system function through changing the abiotic setting, which in turn affects organismal physiology and behavior, which has further consequences on ecological relationships. These complex relationships make managing our natural resources problematic. Hence, understanding sensitivity and vulnerability of multiple levels of biodiversity (e.g. genetic, species, processes) is key to creating effective climate adaptation strategies for natural resource managers. Further, direct communication with managers is essential for identifying knowledge gaps and providing a conduit of information between the research and application for our wildlife and ecosystems.

Biodiversity and Ephemeral Water Sites in the Sonoran Desert

 Sonoran tinajaCrew and their escorts summer 2012 BMGRJordan GoettingJoseph Drake measuring 'canopy cover'

Water is a critically limiting resource for many species of wildlife especially in arid regions. Federal and state land management agencies have established water developments throughout the nation to improve water availability for a variety of target species. These water sources are especially important in the arid southwest because of the changing climate, which is significantly altering habitat quality and availability for many species. Even the most conservative climate models predict that the southwestern U.S. will become hotter and rainfall more unpredictable causing increased scarcity of reliable water sources. These changes in temperature and water availability are increasing the stress on wildlife populations, especially for species that are relatively non-vagile (not able to travel relatively long distances). Water developments appear to be successful in providing reliable water for charismatic mammals; however, large mammals are not the only creatures that use these water developments. Other species (e.g., amphibians and invertebrates), some of which are prone to population declines, may also benefit from the increased availability of water in arid-lands, but these sites have not been studied in such a way as to evaluate the effects of water additions on habitat quality, population sustainability, or biodiversity. We are working to evaluate the effects of these water developments in arid lands on organisms with complex life cycles within a spatial context. It is important to predict areas that need water developments as the southwest warms and surface waters become scarcer. The ability to incorporate species-based information into spatial ecology is an effective planning tool for management of biodiversity in the context of climate change.

Rangeland Management and Amphibian Conservation

  Jornada LTERFrog tank on the Jornada LTERTadpoles on the Jornada LTERDr Griffis-Kyle playing in cattle tanks on the Jornada LTER

Seventy percent of the western United States is grazed and studies have demonstrated desert grasslands and other arid regions have been significantly affected by this grazing. Livestock grazing can alter the structure, composition and function of rangelands through direct impacts of removing plant cover and trampling soils and indirect effects (e.g. changing the distribution of nutrients, changing species composition), resulting from these direct disturbances. With such a large percentage of the land mass in a single type of management, it is essential that biologists and land managers examine effects of grazing and grazing management on the biota.

Reports on the effects of cattle grazing and grazing management on amphibian populations are conflicting. Land managers have established dirt livestock watering tanks throughout the western United States, especially in areas with limited water availability. The establishment of dirt tanks has increased the number and distribution of potential breeding sites for many species of amphibians. This increased availability of breeding sites, especially in areas with no previous surface water, has probably enlarged the geographic ranges for some species, particularly the spadefoot toads (Pelobatidae). Many of these tanks dry by the end of the summer making them uninhabitable to a number of the exotic predators (e.g. crayfish and bullfrogs) which require permanent water. Thus, many of these dirt tanks offer breeding sites to native anurans that are free of these exotic predators which decimate native amphibian populations. Conversely, grazing practices that concentrate cattle at water sources may have negative effects on adult amphibians and amphibian embryos and tadpoles.

We are evaluating the effects of livestock and livestock management on anuran reproduction in a desert grassland system of the southwestern United States including how the spatial arrangement of potential breeding sites and the characteristics of the matrix habitat surrounding breeding ponds affect adult use of breeding areas, and how the environment at the breeding pools affects the survival and development of anuran embryos and tadpoles. We are identifying indicators, especially important to breeding amphibians and developing young, that can be managed for healthy amphibian communities in the context of healthy rangelands and cattle production.

Playa Systems and Wind Power

   Playa picture from LauraSandhill cranes and wind turbinesSandhill crane picture taken by Laura Navarette's father

Wetland ecosystems like playa lakes in the Texas High Plains are of critical importance to Texas biodiversity because they are the primary source of surface water. These systems have undergone significant modification, mainly through increased agricultural usage, but have still remained vitally important habitat for migrating birds. Installation of wind turbines for energy production has been expanding and will continue to expand in this region potentially altering bird use of playa wetlands. My laboratory is examining the risks posed to various migratory bird species based on species behavior. Additionally, we are partnering with Dr. Blake Grisham's Lab examining crane use of wintering habitat and projecting the impacts of climate and landuse change.

 Mineral Nitrogen and Embryonic and Larval Amphibians

  Field enclosures in MinnesotaJeff CrockerMelanie HarschTadpole measurements

Many amphibian populations have declined over the past several decades, often in response to anthropogenic stressors, one of which may be mineral nitrogen (N). Increasing N enrichment of the environment has become one of the largest and most pervasive environmental threats. Over the last century, increased fossil fuel consumption, fixation of previously unavailable gaseous N2 for fertilizer, as well as other anthropogenic activities have doubled the amount of available N in the environment. This mineral N can have both direct and indirect toxic effects on aquatic organisms.

We used a series of laboratory experiments to demonstrate that nitrite exposure can have large impacts on amphibians. In aquatic systems nitrite can accumulate if there is an asymmetry in chemical transformations in either nitrification or denitrification. We showed that early nitrite exposure can not only cause mortality, but can also have a delayed effect on later larval survival. This is particularly important because large fluxes of N during early spring arrive coincident with embryo and early larval development and can cause mortality later in ontogeny. We also demonstrated that nitrite slows growth and development throughout embryonic and larval development. In a whole-pond fertilization experiment in a series of ponds, I demonstrated that mineral N can reduce survival and growth of amphibians in the wild, in addition to causing decreases in the overall number of frog tadpoles in the ponds. We have demonstrated that ammonium and nitrate plus nitrite can remain high enough in surface waters to cause toxic reactions in amphibians that manifest on both population and community levels.

Overall, my research demonstrates that mineral N can increase amphibian mortality and slow growth and development in embryonic and larval stages and is important to consider when managing amphibian populations, especially in amphibians that breed in ephemeral pools where mineral N concentrations can be elevated into the summer and delays in development can lead to catastrophic failures in reproduction.

Environmental Stewardship and Urban Wildlife

  Juvenile cottontail May 3, 2018Connor Steel and Jacob Doskocil measuring vegetationDe-vegetated patch during the dry winter months on The Rawls Course, Lubbock TexasDarby Johns and Jorge Arreola collecting data for distance sampling while spotlighting for cottontails and jackrabbitsDead

Habitat fragmentation as a result of urbanization is a growing issue as urban environments are the fastest growing type of habitat. Investing in environmental stewardship of this habitat is important both for conserving biodiversity as well as engaging the public in positive ways with their natural resources.  I have taken advantage of the proximity of urban field sites to create a research program in which I can collaboratively engage students and the community with research.

The short grass prairies of the Southern High Plains have been increasing encroached upon by shrubs. As more attention is being placed on restoration of these sites, even within a highly fragmented landscape, there continues to be questions about how wildlife respond to the restoration and habitat alteration. The Texas Tech, Department of Natural Resources, Native Rangeland provides a stage for experimental restoration treatments in a way that allows us to test mechanisms controlling species responses to the treatments. This research is still in process, but check back for updates as we complete some of our projects

Additionally, The Griffis-Kyle lab is collaborating with The Rawls Course expert in golf course management, Superintendent Mr. Rodnie Bermea, and others to support collegiate education and research in environmental stewardship. The Griffis-Kyle lab is currently working on the following initiatives: (1) evaluating the role that golf courses play in supplying urban ecosystem services, (2) assessing lagomorph populations and evaluating spatial patterns and environmental correlates of habitat selection, (2) habitat manipulation to improve nesting opportunities for raptors, and (3) creating laboratory exercises to train students in natural resources data collection for Texas Tech’s NRM 3407 Plant Inventory and Wildlife Techniques.