The reintroduction of captive-bred animals has been increasingly utilized for the conservation of many species. However, few studies have focused on the importance of environmental factors and resource availability in the success of wildlife reintroductions. The goal of this study was to see if location influences the short-term reintroduction success of captive-bred Texas horned lizards (Phrynosoma cornutum). Specifically, I monitored diets, growth rates, and survival of over 250 lizards reintroduced to 2 locations in Mason Mountain Wildlife Management Area (Mason County, TX) for 3 months. Diet, growth rates, and survival all differed between the two locations. The findings of this study suggest that environmental factors can play an important role in the reintroduction success of Texas horned lizards. Future research will focus on identifying specific habitat characteristics that may contribute to the observations of this study such as prey availability, vegetation, thermal habitat quality, and soil permeability.

Changes in thyroid hormones levels have been associated with alterations in somatic development and growth. However, recent studies have shown that alterations in thyroid hormone levels during early life stage (ELS) development can lead to long-term changes in reproduction. Specifically, fathead minnows that have been exposed to propylthiouracil (PTU) experienced a 50% reduction in fecundity. The purpose of this study was to determine if ELS thyroid disruption led to an alteration of reproductive behaviors in male fathead minnows. To accomplish this, larval fathead minnows were exposed to PTU and reproductive behaviors were quantified. Results showed that PTU-exposed fish demonstrated significantly fewer reproductive behaviors than those in the control group. This data provides an explanation for the previously observed 50% decrease in fecundity in the fathead minnows exposed to PTU and provides further evidence that ELS thyroid disruption can interfere with the display of key and ecologically-relevant behaviors later in life.

The rainbow trout, Oncorhynchus mykiss, is a partially migratory organism, that has been used recently to study the genetic control of migration. Much of this research has taken place at a unique site in Sashin Creek, Alaska, where the resident O. mykiss population is completely isolated from the migratory population. However, it is unknown the extent to which findings here are shared with other populations. Here we used a fine-scale genome-wide sequencing approach known as pooled sequencing to gather genetic data from 174 fish in two locations – Sashin Creek, Alaska and Little Sheep Creek, Oregon. Four sequenced pools were developed based on phenotype and population. We then measured differentiation between the populations to identify regions that may be correlated with the resident or migratory phenotype in both populations. We were able to locate 8 genes in 16 regions of shared elevated FST, and 17 genes over 16 regions with a significant Tajima’s D value that were specific to either the migratory or resident phenotype. These findings indicate specific genes and chromosomal regions that may be important in the regulation of migratory tendency in this species.

The student hasn't submitted any abstract yet.

For this project, I mapped potential river otter habitat in the Dallas/Fort Worth metroplex based on literature data on known river otter habitat preferences in Texas. I will use this data along with GIS data on land use/cover/vegetation and distance from suitable water bodies, to determine where in the DFW river otters may prefer to live. This project is interesting and informative because in recent years more urban run-ins with river otters have been documented in the DFW. So knowing where they might like to be is good information for citizens to have, as river otters continue to make a comeback in numbers in the state of Texas.