Bat Activity within Urban and Rural Landscape in Arcata, CA

Gonzalo Ayala, Wildlife Undergraduate Student

College of Natural Resources & Sciences

Bats are found in urban and natural habitats, although their presence and behavior may differ depending on the environment. Bats can also be affected by various anthropogenic factors such as land conversion, and displacing their establishment. I determine the activity of 3 bat species: California myotis, silver-haired bat, and Mexican free-tailed bat, within urban and natural landscapes found throughout Arcata, CA. Urban landscapes were determined by the presence of buildings in every cardinal direction. This research approach can help determine how bats use valuable habitats which can be incorporated into urban planning.

Bee abundance and composition in native vs non-native urban gardens

College of Natural Resources & Sciences

I studied the abundance of non-native European honey bees, and native bumble bees and others in gardens with mostly non-native plants and those with all native plants. The non-native European honey bee may be better suited to take advantage of urban, non-native gardens than native bee species due to anthropogenic support and domestication. Thus, I made the hypotheses that native bees will be more abundant in in native gardens, and that European honey bees will be more abundant in the non-native gardens. I also predicted that European honey bee abundance would be constant over the study period due to more urban resources from ornamental flowering plants.

Benthic Macroinvertebrates as Bioindicators of water quality on the Mad River

College of Natural Resources & Sciences

This project sampled benthic macroinvertebrate communities present at three locations in Humboldt County, California totaling 1642 individuals across 19 families. The composition of taxa differed significantly between upstream and downstream sites (p < 0.0000). Pollution taxa sensitive (Caenidae, Perlodidae, Pteronarcyidae, and Lepidostomatidae were present in the upstream sites and absent from the downstream site.

Benthic Microplastic Distribution in Humboldt Bay, Northern California: A Comparative Study of Surface Sediments Based on Proximity from the Shore

College of Natural Resources & Sciences

This study focused on microplastic concentrations in and around Humboldt Bay, CA. Microplastics do not have a universal size class, but for the purpose of this study, microplastics were categorized as any plastic piece from 0.335 mm to 4.75 mm. Samples were taken on Humboldt State's research vessel "Coral Sea", and by foot on land. Both water and sediment samples were collected and analyzed to find the amount of microplastic particles per mass sampled. Visual microscopy was utilized to create counts for each station.

Bio-Renewable Hydrogel Polymers from Modified Chitosan: Progress Toward Three Dimensional Cell Growth Scaffolds

College of Natural Resources & Sciences

Hydrogels are water-containing gels that have a hydrophilic polymer network and can absorb a large quantity of water without the dissolution of the polymer network. The current research focuses on producing hydrogels from chitosan, a bio-renewable polymer, and trans-cinnamic acid. The resulting solutions are photo-crosslinked in a catalyst-free environment under broad band ultra-violet (UV) radiation to produce hydrogels. The hydrogels show an average 75% swelling capacity in H2O. Initial cell growth studies have been carried out on sterilized hydrogels. Current efforts are being directed towards optimization of gels towards cell growth.

Bio-Renewable Hydrogel Polymers from Modified Chitosan: Progress Towards Three Dimensional Cell Growth Scaffolds

College of Natural Resources & Sciences

The current research focuses on producing hydrogels from chitosan, a bio-renewable bio-compatible and bio-degradable polymer. Hydrogels are used as contact lenses, drug delivery systems, and biomedical applications such as tissue engineering. Chitosan is the deacetylated form of chitin, an abundant biopolymer found in the exoskeletons of crustaceans and insects. Amino acid coupling, using 1-Ethyl-3-(3- dimethylaminopropyl) carbodiimide (EDC), is employed to covalently attach trans-cinnamic acid to the free amine of chitosan. Modified chitosan is then cross-linked under UV irradiation to produce hydrogels. The swelling capacity and sterilizability are currently under investigation.

Bird Diversity and Habitat Preferences: A Comparative Analysis of Humboldt Campus and Arcata Community Forest

Edwin Ramirez, Wildlife Undergraduate Student

College of Natural Resources & Sciences

This study will look at the abundance and richness of birds on the Cal Poly Humboldt campus and in the Arcata Community Forest. The primary objective is to understand how various environmental factors could influence bird population in these two locations. Studying the abundance and richness of birds in urban environments, forest edges, and forest interiors could provide important insights into conservation and management strategies.

Bird Diversity in Arcata, California: A Study on Urban Influence

Brittany Ocheltree, Wildlife Undergraduate Student

College of Natural Resources & Sciences

In this study, the primary goal was to observe the effects of urbanization on bird species diversity and composition of native and non-native species in Arcata, California. Methods include fixed radius 75-meter point counts for ten minutes, within thirty predetermined study sites, where I counted bird species and the abundance of birds, landscape features (e.g., building density), along with noting any human activity that may occur. I hypothesized that non-native species would increase with increasing building density. In conjunction with that species diversity would decrease with building density.

Black bears in suburban areas consume more anthropogenic foods

College of Natural Resources & Sciences

Consumption of human food by black bears (Ursus americanus) is a common and challenging problem for wildlife managers dealing with the species, because bears will readily use human-associated foods as an easily attainable energy source, especially when natural food sources are scarce .The result of human expansion is increased rates of encounters between humans and bears, particularly if bears are being forced to search farther and wider outside their home ranges for food. In this study I assessed variation in anthropocentric foods in bear diets. To accomplish this, I compared scat samples collected in Humboldt, CA from suburban and rural areas.

Black Phoebe Forage Rates

blake hefner, Wildlife Undergraduate Student

College of Natural Resources & Sciences

An analysis of how foraging rates in Black phoebe differs in wetland environments vs urban environments