REU Students

Intern Project Examples

Bear Culver (Cherokee Nation)

Historically the Yurok tribe used fire as a management tool for suppressing unwanted growth in prairies, and for promoting the growth of vegetation they depended on for food as well as material resources. This also provided nutritious forage and habitat for Black-tailed deer (Odocoileus hemionus columbianus), which is especially critical for young deer. Due to the fire suppression regime of the U.S Government in the early 1900’s, the once vast prairie systems on Yurok tribal lands have become encroached upon by invading species such as Douglas fir (Pseudotsuga menziesii) and Himalayan Blackberry (Rubus armeniacus). The aim of this study is to confirm or deny the relevance of open prairie systems with respect to wildlife, specifically black-tailed deer. We hypothesized that the fire suppression of prairies would influence the presence and activity of black-tailed deer and other native fauna, predicting that black-tailed deer and other wildlife would have a higher frequency of detection in open prairies than in encroached upon prairies. Data was gathered on Yurok tribal lands using 21 camera traps across 7 sites and 3 habitats- taking note of the scat, browse, and encroachment levels along game trails. A total of 209 detections of wildlife were recorded from the cameras; 68 detections in the open prairies, 56 detections in the encroached areas, and 85 detections in the historically forested areas. Black-tailed deer had a higher frequency of detection in the open prairies than in any other habitat, supported by a chi-squared test of the composition of species across habitat. Black-tailed deer scat also had the highest observed levels in the open prairies. Black bear (Ursus americanus) and other carnivores did not favor any one habitat, and small mammals had a higher frequency of detection in the historically forested areas. The level and type of encroachment seems to influence the presence of wildlife, but more data will be needed to understand this relationship. This study can provide an introduction into the trends of wildlife of fire-suppressed prairies. The reintroduction of fire management to these prairie systems would provide advantageous habitat to black-tailed deer and promote the growth of traditional plants, all of which is culturally important to the Yurok tribe.

Eldon Kinney (Hupa and Yurok)

My research was to survey present grassland prairies conditions, within Yurok Ancestral Territory, then compare my study sites to historical aerial photographs of grassland prairie from 1944-48 when fire suppression was implemented. My results concluded that increased tree and shrub encroachment on grassland prairie habitat has severely impacted grassland vegetation, wildlife habitat, and cultural significance uses. After gathering of baseline data of current grassland prairie conditions, the Yurok Tribe will continue the efforts to further identify and decide which prairies to manage for restoration efforts utilizing my sample modeling. 7 sites were surveyed to produce baseline data to inquire about the conditions of present prairies. These sites were chosen for cultural significance by the Yurok Council & Yurok GIS Dept. in assisting with the current efforts the Tribe is examining for future prairie restoration. My research experience worked with many department agencies within the Yurok Tribe and federal agencies in a group effort of joint-collaboration in managing/restoring landscape within Yurok Ancestral Territory.

Suzy Homsombath

Competition for limited suitable territory sites may be one of the primary factors that regulate salmon and trout populations. Dominant individuals are identified by aggressive behavior toward subordinates. However, it is not clear whether patterns of dominance (i.e. access to preferred territory sites) observed in short trials between pairs of fish hold up over longer time scales and when fish are in larger groups. To test this, I performed an artificial-stream experiment using twelve young of the year juvenile steelhead trout from hatchery stock at Cal Poly Humboldt Fish Hatchery. Fish were allowed to compete in one stream for the duration of the study (4 weeks) when not in observation and were fed 2.5% of total body mass per day. Dominance was assessed in pairs using a pairwise comparison method (66 trials) and in groups of four (37 trials). Dominants were identified by successful delivery of unreciprocated nips, chases and typical rank coloration. Observations of aggressive displays from the pairwise trials were used to construct a dominance hierarchy. The dominant (rank 1) became the largest fish, but was not the largest in the beginning. Dominants grew 67% faster than subordinates and gained access to the preferred site approximately 82% of the time. The site allowed the individual to monopolize food resources and may also have had lower metabolic costs (cover, low velocity). Aggressive behavior determines the winner in the outcome of a contest. However, further research assessing differences in aggression between high ranked dominants is needed.

Ariel Dasher

The Eel River is the third largest watershed completely contained in California and was once the third largest salmonid producing river. Currently the salmonid population is 1-3% that of historic levels. Cape Horn Dam and Scott Dam were built in 1906 and 1922, respectively as part of the Potter Valley Project (Fig.1) to divert water from the Eel River to the Russian River. Scott Dam prevents fish passage and is up for relicensing in 2022. If the Potter Valley Project were to be modified or removed, it would potentially open up many miles of habitat for anadromous salmonid species, particularly threatened steelhead trout (Oncorhynchus mykiss). The goal of my project was to determine habitat suitability for juvenile steelhead upstream of Scott Dam by measuring pool dimensions and temperature.

Courtney Brown (Navajo and Laguna Pueblo)

Observing Treated and Untreated Forest Stands and Their Effects of Understory Vegetation. The purpose of this research was to achieve a better understanding of the understory vegetation species diversity at Whiskeytown National Recreational Area its response forest stand treatment in the context of multi-year drought conditions. It was hypothesized that stands that have been treated will have a higher percentage of vegetative cover compared to untreated stands. Variables used during the research process to test the hypothesis included: the presence and ascents of life forms, canopy cover, stand density, and the species richness in the understory.