Cheadle Center for Biodiversity and Ecological Restoration

The University of California, Santa Barbara’s Cheadle Center for Biodiversity and Ecological Restoration is distinctive in its dual mission of ecological restoration and natural history collection curation. The Center offers an experiential undergraduate course called Introduction to Curation of Natural History Collections, which provides hands-on learning activities in the Cheadle Center’s invertebrate, vertebrate, and vascular plant collections. Each quarter, the class alternates between professors and collections, and students can take it multiple times, allowing them to gain experience in different collections from professors with different backgrounds. Undergraduate students are fundamental to supporting the Cheadle Center’s mission of restoration and conservation through the curation class as well as successive opportunities. After completing the course, students can apply for competitive curatorial internships that provide experience in menteeship. This opportunity teaches students how to acquire internships and develop professional interpersonal and technical skills, offering a valuable introduction to the professional world of Natural History Collections curation. The collection curation course is a unique opportunity for students to determine whether they are well suited to the field. This benefits the Cheadle Center because it invests in students that are already committed to and passionate about curation work. Missing from this curatorial experience, though, is taxonomic training. While inessential, and allowing for more students to get involved in the work, this is a disadvantage for those who intend to enter the Natural History Collections field. Taxonomic training is a barrier to entry and makes a major difference in hiring for career positions. However, taxonomy is no longer taught at the University and inaccessible to non-Biology students. Online taxonomy workshops typically have limited space and prioritize professional seniority, but reserving some space for early career students would aid their professional preparedness. The Cheadle Center is considering developing taxon training or supporting student participation in existing programs.

Presented at SPNHC 2025

The genus Hybanthus of the Violet Family (Violaceae) is non-monophyletic, meaning that not all species of Hybanthus share a most recent common ancestor. Previous phylogenetic analysis in the Violet Family suggested that Hybanthus concolor from eastern North America was resolved as a sister taxon to a clade of two Hybanthus species from the Caribbean region (Wahlert et al., 2014). The two clades display distinct differences in morphology, climate, and geographic distribution. In this project, we conducted expanded DNA sequencing of North American and Caribbean Hybanthus species to test the hypothesis that these two groups represent distinct evolutionary genera.

The Cheadle Center for Biodiversity and Ecological Restoration (Cheadle Center) at the University of California, Santa Barbara (UCSB) restores North Campus Open Space (NCOS), an area previously converted from wetlands and uplands to a golf course. Invasive plants are a persistent problem on site and must be managed using restoration techniques, but localized methods like hand or flame weeding can be time and resource intensive. Short-term rotational sheep grazing was utilized to reduce thatch and invasive species seed banks and biomass to encourage native species growth in the spring. To investigate immediate impacts of grazing on the abundance of key species and assess the efficacy of the sheep grazing regime in reducing thatch and invasive species biomass, pre-grazing and post-grazing biomass samples were collected and compared. The seed viability of key species was also evaluated by collecting sheep pellets, spreading them over soil-covered flats, and observing plant growth from January-May 2025.

Bee wings experience mechanical stress and collisions over time through an accumulation of flying, foraging, mating, and predator attack events. As such, wing wear has been used as a measure for relative age in bees and has also been found to be related to an increased risk of mortality. This relationship allows wing wear to be used as an indicator for bee health of individual bees and of their respective colonies. Little is known about how additional factors–like size, sex, and diet breadth– contribute to wing wear in bees. The aim of this study is to investigate the variation in wing wear between mid-size Santa Barbara county specialist and generalist bees using two techniques: manual scoring and a computer vision model. This program is an image segmentation model that uses shape analysis data to assign a wing wear score from photographs. The study will also assess the accuracy of these computer generated scores relative to manual scoring and the reliability of these scores within and between bee species.  The information derived from this study can inform conservation efforts, particularly for specialist bees that are more vulnerable to habitat loss and climate change which reduces availability of their mutualistic plant species. The application of computer vision models automate wing wear scoring and may be extended to conduct additional wing wear research on bee health and behavior with respect to location, wing structure, and more.

Rare plants are often dependent on pollinators to maintain their populations. In some cases, the pollinators themselves are of high conservation value, resulting in a system that has inherently high value for conservation. The North Campus Open Space (NCOS) at UCSB is home to such a system, where the Federally Endangered Salt Marsh Bird’s Beak (Chloropyron maritimum) is pollinated by recently listed Crotch’s Bumblebee (Bombus crotchii) along with other bumblebee, and insect species.

Monitoring pollination events is time-consuming, and researchers are looking to automated cameras to capture images of pollination events and machine learning to help extract pollinator identifications from the captured images.

Presented at the URCA Poster Colloquium 5/14/2025

Damage to bee wings commonly occurs during ecologically-essential foraging and flight activities of bees. Interactions and collisions with native environmental conditions such as wind and vegetation leave wings exposed to potential wear and tear. Morphological traits influence bee flight performance, as bees with larger body sizes demonstrate increased flight distance capacity and foraging range. We analyze the degree of wing wear as an indicator of these activities, predicting that larger bees will accumulate more wing damage from extended exposure to environmental wear. We imaged wings across bee species native to Santa Barbara County. By manually creating masks to isolate the wing, we trained a computer vision model with ground-truth data to identify pixels in wing images and separate them from the background. This image segmentation model allows for shape analysis and comparison of degree of wear in the wing’s margin across various species through this large-scale collection of qualitative data. We also created a manual wing wear scoring index to compare accuracy with this model. Genera such as Bombus and Xylocopa that tend to have larger body sizes are predicted to be assigned, on average, higher scores of wing wear compared with smaller species being assigned lower scores to indicate experiencing less wear. By comparing wear patterns, these correlations could offer insight on species resilience in their native habitats, suggesting that species with larger body sizes may be more vulnerable to environmental stresses that require more demanding flight and foraging efforts. This model could then have potential research applications as bioindicators of the local foraging ecology and environmental stress/fragmentation.

This poster was presented at the UCSB Undergraduate Research Symposium 2025, and at the UCSB URCA Poster Colloqium 2025.

Variance in body size of bees can affect multiple factors including pollination ability, floral handling, and response to evolving environmental conditions. Likewise, body size itself is influenced by a range of climate and location-specific environmental factors. Islands represent distinct habitats with unique ecological and climate conditions. Many animals differ drastically in body size in island habitats, but the extent to which this effect occurs in insects is unknown. This phenomenon is known as the “island rule” in which animals are considerably larger on islands when compared to their mainland counterparts. Recognizing these patterns enhances our understanding of how differing environmental conditions between islands and mainlands can drive long-term evolutionary changes in species. I measured body size for each specimen, accounting for sex and missing body parts. In this study, we drew data from the sweat bee, agapostemon subtilior, and measured their body size by mass. My findings suggested that insects, specifically agapostemon subtilior, have evolved to greater sizes on the mainland than on the island. These surprising findings both raise new questions and help clarify the role between habitat factors and body size variation in this important native pollinator.

This poster was presented at the UCSB EEMB Undergraduate Research Symposium 2025.

Macroinvertebrates play a key role in aquatic ecosystems as indicators due to their sensitivity to changes in environmental conditions. Regular macroinvertebrate sampling is conducted in the Deveroux slough at the University of California, Santa Barbara (UCSB) to monitor species abundance and diversity and assess the ecological health of the system. We examined how salinity and dissolved oxygen (D.O.) influenced the abundance and diversity of four macroinvertebrate species: Amphipods, Diptera Chirominid, Ostracods, and Copepods. We predict a higher abundance of invertebrates when salinity levels are low and D.O. levels are high. Samples were taken across sixteen (16) different sites at Deveroux Slough. Filter beakers and mesh sweep dipnets were used to collect samples, with algae and core samples taken by CCBER. Data was transferred to an Excel spreadsheet, and R Studio was used for data analysis. Amphipods and Chironomids were most abundant at low-salinity, moderate D.O sites, Ostracods at low to moderate salinity, high D.O sites, and Copepods at high salinity, high D.O sites. The slough has the most abundance when salinity is low and DO is moderate and when salinity and DO levels are high. This is likely due to the invertebrate biological niches fitting under either of those extremes. Tracking species abundance in the slough is critical for future restoration projects. Ongoing research still needs to be conducted to understand the ecosystem as it stands today, and will continue to do so in the future. 

This poster was presented at the University of California, Santa Barbara (UCSB) EEMB Undergraduate Research Symposium on May 3rd, 2025.

Although California native bees are key pollinators for fruits and crops, they remain understudied compared to the Western honey bee. Examining morphological traits in native bees, such as pilosity, or hairiness, to understand taxonomic variation among species can inform and support conservation efforts. Three subspecies of long-horned bees, Melissodes tepidus timberlakei, M. tepidus yumensis, and M. tepidus tepida, occupy distinct regions across the western United States (e.g., California, Nevada, Oregon, and Arizona), but their morphological distinctions remain unclear. Pilosity, or hairiness, is a critical trait for thermoregulation, pollen collection, and species recognition, and may offer key insights into subspecies differentiation. I hypothesize that the three Melissodes tepidus subspecies differ significantly in pilosity coverage and lightness as adaptations to their unique ecological niches and climates. To test this hypothesis, I captured, stacked, and analyzed lateral images (both left and right sides) from five specimens per subspecies (totaling 30 images). Using a convolutional neural network explicitly trained for bee hair segmentation, I quantified hair coverage (percentage of hair pixels relative to body surface area) and lightness (numerical value of pixel lightness on a grayscale continuum). ANOVA analyses revealed no statistically significant differences among subspecies in either hair coverage (p = 0.129) or lightness (p = 0.207). Still, visual representations, such as boxplots and swarmplots, demonstrate M. tepidus yumensis to be hairier than M. tepidus tepida and M. tepidus timberlakei. This trend suggests that increasing the sample size may strengthen statistical significance and highlight pilosity differences. In the future, incorporating additional factors, such as sex differentiation, behavioral evidence, and genetic data, will enhance our understanding of subspecies divergence and inform more accurate conservation strategies.

Bee body size affects their ability to forage, carry pollen, and adapt to environmental conditions. Body size is influenced by environmental factors such as food availability and temperature. As these conditions continue to change, it is crucial to accurately measure body size and determine whether particular body measurements can predict size variation across and within species. Measuring body size is challenging as bees are often small and may be missing body parts. In this study, we examined ten different bee species across three different families. We compared body and wing measurements as proxies for dry weight for both damaged and non-damaged bees. We used fitted vs. residuals and QQ plots to test for normality and linearity, along with performing simple linear regression using R version 4.4.0. We determined that intertegular distance (ITD) and head width to be the most significant predictors of dry weight across species and within most species, suggesting that these measurements may be used to accurately estimate dry weight. We also found that intertegular distance significantly predicted dry mass even in specimens missing body parts, suggesting that this measurement is somewhat robust to specimen damage. These findings contribute to the understanding of the relationship between dry weight and body measurements and provide guidelines for accurately estimating body size within and across species, for a range of applications in ecological research and conservation efforts. Presented at UC Santa Barbara CSEP Summer Colloquium