Life Sciences Commons^™

Can Providing Positive Interactions With Snakes Change A Person’S Perception Of Dangerous Wildlife Interactions?, Bethany Walker

Theses

Due to a long co-evolutionary history between placental mammals and reptiles, primates demonstrate aversive responses to snakes. In humans, this can result in ophidiophobia, or the fear of snakes which can arise due to cultural backgrounds, traumatic experiences, or fear instilled by others. However, these reptiles fill essential roles in ecosystems. Conservation and outreach efforts are important to help our population understand snakes’ role in our lives and the state’s broader biodiversity. Negative experiences or preconceptions about snakes can make this message hard to share with the public. Educators can help prevent intentional harm to some of these organisms through …

The Influence Of Pollinator Behavior On Patterns Of Pollen Dispersal And Its Implications For Floral Evolution, Alex Lascher

Theses

Despite a storied history of pollination research, little information exists on how the unique characteristics of individual pollinators effect patterns of pollen dispersal. As these patterns of pollen dispersal inform our understanding of floral evolution, filling in this knowledge gap is imperative. I attempted to do so by analyzing two different outcomes of pollen dispersal: 1) pollen carryover, and 2) geitonogamy (i.e., intra-plant movements). For the pollen carryover, I analyzed the results of an experimental study in which bats in flight cages removed pollen from the male flower of a Burmeistera glabrata plant, and then visited 10 female flowers of …

Zygomorphic Flowers May Reduce Extinction Rates By Allowing Angiosperms To Occur In Low Abundances, Maria Belen Alvestegui

Theses

The high species richness that angiosperm show has been extensively correlated with key floral innovations. Key floral traits contribute to species boundaries and the origin of new species. However, how these relate to extinction remains largely untested. Among the multiple theories that attribute diversification to floral innovations, the reduced extinction model predicts that floral specialization allows the persistence of small populations and avoids their loss. Bilateral symmetry (zygomorphy) is a trait that has evolved recurrently in angiosperms. It is a form of floral specialization that restricts pollination to fewer visitors and precisely places pollen to ensure more effective transmission of …

Historical Ecology Of The San Diego Sport Fishery: Catch Composition, Species Trends, And Fishing Effort From 1959 To 2011, Rebecca Schwartz Lesberg

Theses

Like ocean systems around the world, species targeted by the San Diego sportfishery are subject to myriad threats from human activity, with several species already showing documented decline. However, long-term fisheries datasets are often lacking, limiting natural resource managers’ ability to appropriately manage these ecologically and economically important species. Therefore, this study used daily reports published in two Southern California newspapers to examine changes in catch composition, effort, and catch per unit effort (CPUE) from 1959-2011 for the San Diego commercial passenger fishing vessel (CPFV) sportfishery. This study then tested the relationship between those patterns and three large scale oceanographic …

Using Aerial Photogrammetry And Sexually Dimorphic Measurements To Investigate Seasonal Differences In School Composition Of Delphinus Spp. Off Southern California, Samantha Gm Leander

Theses

Insights into school composition can provide a means to understand basic biology and ecology, including reproductive patterns. They can also be applied to conservation assessments, allowing for better understanding of the potentially differential vulnerability of demographic groups to natural or anthropogenic disturbances that may influence their populations. However, the two subspecies of common dolphins in the waters off California (Delphinus delphis delphis and D. d. bairdii) form large, energetic groups that make characterization of school composition difficult. Remotely controlled drones now offer the opportunity for the study of school composition in Delphinus spp., allowing for precise morphometric measurements …

Otolith Microchemistry Reveals Low Habitat Connectivity Of California Killifish (Fundulus Parvipinnis) Across A Range Of Spatial Scales, Lisa Robison

Theses

As wetlands face continued fragmentation worldwide, an understanding of habitat connectivity and how fishes that rely on these environments is imperative to conduct effective marine management. Site fidelity and habitat connectivity are vital measures of the interdependence of fish populations living in neighboring marshes (or in regions of a single marsh).

Here, we examine the habitat connectivity, site fidelity, and movement of California killifish (Fundulus parvipinnis) within and among three estuaries in Southern California through otolith microelemental analysis. Assessing the site fidelity of estuarine fishes is important to determine the level of connectivity between spatially distinct populations within …

Diet Of An Important Wetland Resident, The California Killifish, Fundulus Parvipinnis, In A Natural And Created Marsh Habitat In Mission Bay, California, Katie Robinson-Filipp

Theses

The California killifish, Fundulus parvipinnis Girard, is an ecologically important marsh resident. Fundulus parvipinnis is a low-level carnivore, displaying high-site fidelity and occurring in high densities across a range of environmental conditions. Despite the importance of F. parvipinnis to the ecosystem functions of the threatened coastal wetlands of southern California and the Baja California Peninsula, there are critical gaps in our knowledge of this species. In particular, information on their diet and food habits is lacking.

Understanding wetland food web linkages, interactions, and trophic transfer is essential for informing effective habitat management and contributes to our ability to evaluate the …