<p> Habitat use by federally threatened California Red-Legged Frogs (CRLF; <i>Rana draytonii</i>) is incompletely understood. I captured, PIT-tagged, and radio-tracked CRLFs (n = 20) at Waddell Creek, Santa Cruz County, from July&ndash;December 2012. Limited tracking for movements was also conducted in 2013. Frogs were clumped in deep, complex habitats along the stream within 2 km of breeding ponds near the stream mouth, but most adults were concentrated in the lagoon. Marked and tracked frogs had very small summer home ranges, and most returned to the same home range after breeding. Frogs tended to use good aquatic (e.g., wood, undercut banks, dense willows) and bank cover (e.g., ground vegetation, wood) at all times but used open habitats more at night than during the day. Visual night surveys were biased against cryptic frogs compared to radio-tracking results. Early fall rains increased upland habitat use, but later heavy winter rains were needed to trigger migration to breeding sites and subsequent breeding. Site-specific studies using radio-tracking are needed to design protections for breeding, migration, and nonbreeding habitats.</p>

<p> Humans introduce non-native plants to new areas at an increasing rate with the increased movement across the globe. These invasive species can become mono-cultures and extremely different from the native floral community. Amphibians, at the same time, are facing global declines with approximately one-third of all amphibians threatened or endangered. Due to the importance of amphibians as prey items for many vertebrates including small birds, mammals, and reptiles, and also predator controls over many invertebrates, including some pest species, the decline of amphibians has large implications for many environments. This study looks at a range of interactions between two invasive plants (<i> Typha angustifolia</i> and <i>Phragmites australis</i>) and two native anurans (<i>Lithobates clamitans</i> and <i>Lithobates catesbeianus</i>). </p><p> As ecosystem engineers, plants form the basis of many communities, and sculpt the physical environment by adding complexity to the earth's surface. They also add chemical constituents either actively or passively too ward off other competitors. This change in the environment on both the chemical and physical level leads to complex possibilities for a changed plant community to impact the rest of the ecosystem, including amphibians. I focus on the physical changes by looking at behavior of amphibians in these invasive plant mono-cultures and non-invaded controls, and their appearance in invaded and non-invaded wetlands, both constructed and naturally occurring. On the chemical side of the matter, I monitor water chemistry measures in natural and constructed wetlands that are either lacking invasive plants or have a substantial presence of these plants, and correlate those measures with tadpole growth and survival. </p>

<p> The Brownsberg Nature Park (BNP) in Suriname is home to eight monkey species: <i>Saguinus midas, Saimiri sciureus, Cebus apella, Alouatta seniculus. Pithecia pithecia, Cebus olivaceus, Chiropotes satanas (sagulatus), </i>and <i>Ateles paniscus.</i> Several studies have undertaken the task to better study the feeding and behavioral ecology of these species within the park. However, studies on the black spider monkey (<i>Ateles paniscus</i>) have been absent. As part of my thesis, I decided to conduct a baseline feeding and behavioral ecology study of this species during the period May 2008 &ndash; July 2008. In addition, I developed a field method for determining mercury levels (in parts per million = ppm) in fecal and urine samples of wild monkeys. Since the park is under enormous pressure from illegal gold mining activities, I decided to collect baseline data on potential exposure of wild monkeys to mercury in the environment. I also collected samples from monkeys at the zoo in Paramaribo and monkeys born in captivity at Hiram College in Ohio. I collected data on the frequency of feeding, resting, and traveling by black spider monkey subgroups every 10 minutes during all day follows. Feeding ecology data consisted of identifying fruits eaten by these subgroups. For the mercury analysis I used the OSUMEX LTD. home testing kit. Results from the behavioral data show the following frequencies of activities for the entire study period: 32% feeding, 43% resting, and 25% traveling. The feeding data further justifies spider monkeys as ripe fruit frugivores: 76% of food items consisted of ripe fruit, while 22% consisted of leaves, and 2% was comprised of flowers. The mercury testing results from the Brownsberg and zoo populations ranged between 0.025 ppm to 0.1 ppm (toxic level = 0.8 ppm). The Hiram College monkeys all displayed levels at 0.000 ppm. The results from the mercury analyses indicate that 1) wild monkeys in the vicinity of gold mining activities may not be under the same threat as humans, with regards to mercury exposure through food, and 2) that wild monkeys are still relative exposed to mercury in the environment whether it be natural or anthropogenic.</p>