Over three consecutive breeding seasons I examined the breeding system of Eastern Kingbirds in Malheur National Wildlife Refuge in SE, Oregon. To assess genetic paternity, I optimized seven microsatellite markers and determined that extra pair paternity was common. Extra-pair young were present in approximately 60% of nests, representing 47% of young. I examined implications of extra-pair paternity from three perspectives. First, I examined the impact of extra-pair paternity on the opportunity for sexual selection within a socially monogamous system and identified correlates of male reproductive success. Some males were successful at the expense of others, and 24% of males did not sire any young. Thus, variance in male reproductive success was more than nine times greater than female variance, indicating that sexual selection operates strongly in this system. Extra-pair success was positively related to tarsus length and inversely dependent upon dawn song start time. Within-pair success was positively related to nest defense intensity during the incubation period. Second, I assessed the four genetic hypotheses proposed to explain female cooperation in extra-pair copulations. Extra-pair young were not distributed randomly among broods. Cuckolded within-pair males were not more closely related to females than were extra-pair sires. Pair wise comparisons indicated males with specific song and morphological traits were chosen as sires. Brood success (proportion of brood to fledge and recruit) was unrelated to thenumber of males who sired young in the brood. Extra-pair young were larger and heavier than their within-pair half-siblings. These results unambiguously support the 'good genes' hypothesis of female extra-pair mating. Last, I examined the influence of breeding date and parental condition (mother, social father and genetic sire) on offspring sex ratio. Given that male variance in reproductive success is much greater than that of females, I predicted the characters of genetic sires would be the most important factor influencing offspring sex ratio. Contrary to my prediction, male traits did not influence offspring sex ratio. However, more males hatched early in the season and females in better condition produced more sons. I also found that male nestling survival to the next breeding season was inversely related to date.

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Feral horses occupy 31.6 million acres throughout western North America. Feral horses share similar habitats with a wide range of animal species, including pronghorn. Since horses are larger and often more aggressive than other animals of this region, they are generally socially dominant over all other native ungulate species. Pronghorn share water sources with horses in areas where both occur. In situations where horses exclude pronghorn from water, pronghorn fitness may be impaired, especially during the hottest months of the year when water is limited. The purpose of this study was to investigate interference competition between pronghorn and feral horses at water sources. During spring and summer 2010-11, we placed motion-sensitive cameras at water sources across the Sheldon National Wildlife Refuge in northwest Nevada. Cameras were used to examine the overlap of water use by pronghorn and horses and to determine the occurrence of spatial or temporal partitioning of water between these species. Additionally, we made direct observations of horses and pronghorn at high-use water sources to record the occurrences and outcomes of pronghorn/horse interactions as well as differences in pronghorn behavior in the presence and absence of horses. Pronghorn spent more time on vigilance behavior and less time foraging or drinking in the presence of horses than in their absence. Nearly half of pronghorn/horse interactions at water resulted in pronghorn exclusion from water. Our data also suggest that temporal partitioning of water between horses and pronghorn on an hourly basis may be occurring.

Restoration of abandoned, nonnative species-dominated agricultural lands provides opportunities for conserving declining shrubland and grassland ecosystems. Land-use legacies, such as elevated soil fertility and pH from agricultural amendments, often persist for years and can favor nonnative species at the expense of native species. Understanding the factors that limit native species establishment on abandoned agricultural lands can provide important insights for restoration and conservation of native species on human-modified lands. I conducted two field experiments on abandoned agricultural lands: a former pasture on Martha’s Vineyard, MA and a former citrus grove at Merritt Island National Wildlife Refuge (MINWR) in Titusville, FL. In these experiments I tested how soil chemical properties affect native and nonnative species abundance and how different methods of removing nonnative, invasive species affect native and nonnative species abundance. In the first experiment, specifically I tested how restoration treatments affect competition between existing nonnative agricultural plant species and native plant species that are targets for sandplain grassland restoration on Martha’s Vineyard, MA. At MINWR, I examined how lowering soil fertility with carbon additions and lowering soil pH by applying sulfur affects nonnative species richness and cover (in two former citrus groves that were historically scrub/ scrubby flatwoods. Overall, I found that biotic factors, such as competition with nonnative species, play a stronger role in limiting native species establishment than soil chemical properties. Likewise, control of nonnative, invasive species is most effective with mechanical treatments to physically reduce cover, rather than altering soil chemical properties

Habitat destruction and modification are major causes cited for the decline of amphibians worldwide (Wake and Morowitz 1991). Depressional wetlands on Pinckney Island NWR in Beaufort County, South Carolina were ditched and drained during the 1950?s for agricultural development. Wetlands were restored by filling ditches with existing spoil. I surveyed herpetofaunal and vegetation communities to determine responses to wetland restoration on Pinckney Island from 2004-2005. I selected ten wetlands each in pine and maritime habitats, sampling prior to and after restoration. I recorded 14 reptile and 9 amphibian species using time-constrained searches and funnel trap arrays. I documented (first record on the Island) Fowler?s toad (Bufo woodhousei) and many-lined salamander (Stereochilus marginatus). There were differences between amphibian species richness recorded using time constrained surveys and funnel trap arrays, amphibian species abundance between pine and maritime forest, and between number of Eastern spadefoot toads (Scaphiopus holbrooki) before and after restoration.

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Human/wildlife interactions at the Bosque del Apache National Wildlife Refuge were investigated in this research. Personal interviews and a mapping exercise were used to examine a variety of questions about recreational use. These included visitor backgrounds (their recreational histories, socioeconomic profiles, and past refuge visits), their perceptions (of current and proposed management policies, and visitor effects on wildlife), and their experiences of the refuge (their activities, most memorable experiences and exploration of the environment). Most visitors questioned were middle-aged individuals who resided in New Mexico. The refuge's unique character--its diversity of wildlife and landscape features--was perceived as its greatest asset. Visitors saw the refuge as a wildlife sanctuary, protected and controlled by officials who prevented visitors from having damaging impacts on the resource. While visitors differed by season of visit and purpose of visit, most did agree that the refuge should be managed for the sake of wildlife first. After that, visitors felt that it should be managed for the sake of recreation. Snow Geese responses to certain visitor behaviors were also examined. Simulations of visitor behaviors were made in the presence of small groups of geese. Behavioral observations of geese were made prior to, during, and after simulations. Environmental factors (weather, habitat, and temporal) were also examined. This analysis revealed a general tendency among geese to respond to visitor simulations in characteristic ways. However, variations in geese responses were also observed. Several factors may have most strongly influenced geese behavior. The predictability of visitor behaviors as perceived by geese influenced their patterns of response. Then too, certain environmental factors (habitat and temporal) were important, as well as the particular nature of the animal behaviors themselves. This research indicates that significant transactions occur between people, animals, and the environment. Understanding them is crucial in managing natural resources for ecological as well as recreational values.

In this study, I modeled the suitability of habitat on the Mississippi Sandhill Crane National Wildlife Refuge for the federally endangered Mississippi Sandhill Crane (Grus Canadensis pulla). Habitat type and suitability changed over time due to seasonality of vegetation and succession in the absence of burning. Cranes used highly suitable habitat more in the non-growing than in the growing season, and may have been more constrained by resource availability during winter months. Cranes used some less-suitable areas including cypress drains, which provide roosting sites, and supplemental food plots. The mismatch between predicted quality and crane use suggests that no single habitat provides all resources required for the population to persist. Prescribed burning to maintain grassland habitat is essential for maintaining high quality habitat for cranes. The relative availability of food on supplemental food plots and grasslands, as well as the behavior of cranes toward roads, require additional investigation.