ABI 150 Section B - Dawn of the Damselflies: Presentation Day
Today was the day that determined the rest of our lives, or at least the experiment we will work on for the rest of the class. Our MC Caelan started by going over the class itinerary, which included an hour of presentations, time for voting, and then time for Kendall to talk about the schedule for Friday. Caelan graciously gave the class five minutes to collect their bearings before starting on presentations. During this time, Marshall emphasized that we want to provide rigorous critique for each proposal, but the critique should be friendly, because we are all friends in this class. :)
1. After all the students arrived, the Damselflies in Distress group with Mario, Jay, Jessica, and Rosie started their presentation.
Study Question: How do damselflies use permanent and semipermanent wetland habitat? How is habitat used differently by unique species in one ecosystem?
They started by introducing their study organisms, one of which is the Pacific forktail. They can be identified by a blue spot on their lower abdomen, and this species experiences sexual dimorphism. They also focused their study on the vivid dancer, where males are blue and females are brown. From previous observations, the group reported that the vivid dancer was observed in the early hours. They broke up their methods into three sections which include capturing, marking, and releasing. Capturing can be done with butterfly nets, and the damselflies are easy to spot, except the brown vivid dancer females. To mark the damselflies, a person would reach into the net, pinch the damselfly near the base of the wings, and apply a mark on one wing with acrylic marker. The markings should be different colors so that recapture can be identified. To release the damselflies, they should be positioned to perch on the person’s finger, and then they will fly away on their own. Before releasing the damselfly, the time, location, and date should be recorded, as well as the color on the damselfly. After explaining these methods, the group passed around Pacific forktail and vivid dancer specimens in eppendorf tubes to give the class an idea of their size and appearance. However, the specimens look different because they lose their coloration upon death. Their study site is the Yolo Bypass, and the group already captured 7 damselflies and released 6 of them. The group also provided a potential timeline with milestones for future classes (which is very helpful for the next MC). Their budget includes waterproof boots, a field tape measure, and acrylic markers, which add to about $300-500. The group mentioned safety and prevention which includes heat and snakes. The group also calculated that the class will need to achieve a minimum of 15 marks per person over the entire quarter, which is feasible. Finally, they ended the presentation by discussing importance, which includes their role as bioindicators and providing services to the ecosystem.
Questions/Comments After Proposal:
Crystal mentioned that there are two forms of the vivid dancer female, one that mimics the male and the other with a distinct brown color
Marshall asked if it is possible to individually mark the damselflies, and there is a possibility that they could be double marked. We could also use color coding similar to bird bands
The group mentioned that their estimate for the number of damselflies captured was conservative and only included Fridays, but there are people willing to go on weekends
From their previous observations, the group found that semipermanent wetlands had barely any damselflies
The group also clarified that we could make artificial habitats if we want to manipulate certain factors
Study Question: How does water quality, water temperature, species composition, and water strider behavior affect the growth of Aquarius remigis?
They started by introducing the study organism, which is Aquarius remigis or the common water strider. They are found in most still bodies of water such as ponds, creeks, lakes, and swamps. In terms of reproduction, water striders deposit eggs on submerged rocks, the eggs hatch within a couple of weeks, and they take several months to develop. After this background information, the group listed potential study sites where water striders were found which includes the UC Davis Stebbins Cold Canyon Natural Reserve, Putah Creek Fishing Access Site 2, Putah Creek Riparian Reserve, Quail Ridge, and Yolo Bypass. For their methods section, water striders would be collected at each site, taken into the lab and measured to determine development. To test water quality, they mentioned four variables which include pH, temperature, dissolved oxygen levels, and turbidity. All of these factors would be measured with pH strips, a thermometer, a DO probe, and a turbidity tube. To measure species composition, they focused on the prey and predators of water striders. Prey insects would be measured with a composite insect trap, and bird predators would be identified with the Merlin app. Their behavior would be measured with two factors which include their activity level and the type of mating system they exhibit. Both of these factors would be observed by recording the water striders with a GoPro and analyzing video footage. The data would then be analyzed with a Pearson correlation test and an ANOVA test which can both be completed in R. They discussed limitations such as difficulties tracking individual water striders in video footage, the space necessary for traps, and low abundance in certain locations. However, the locations are not located far away and the project is under budget at about $470. Finally, they discussed the importance of the study, because water striders can be indicators of water quality and they are a potential source of pest control.
Questions/Comments After Proposal:
Jay mentioned that songbirds come out in the morning so we would need to visit field sites in the morning to record their presence. Additionally, songbirds are easy to scare so large groups of people may be problematic
Jay also asked about the number of water striders we want to collect, and it would be as many as possible per population
Kaya expressed concern about how many factors would be tested in this experiment, so the group said that certain factors can be subtracted if necessary
Crystal mentioned that it might be more difficult to perform video analysis, but one person mentioned that there are programs available for video analysis. Additionally, we can try marking the water striders as well
Marshall also asked if we thought about how ecological factors affect behavior, and the group mentioned that they could alter the study question to accommodate that idea
Study Question: To what extent can environmental manipulation override typical preferences in terrestrial isopods, also known as Armadillium vulgare, causing individuals to select conditions they would normally avoid?
They began by introducing their study organisms which include Armadillium vulgare or the common pillbug, and powder blue woodlice. The common pillbug was found along Putah Creek in moist soil, and they are identified based on their rounded backs and rolling ability. Powder blue woodlice are found at Yolo Bypass in moist soil, and unlike the common pillbug they have flat bodies with legs turned outward. These species are important as bioindicators for soil quality, they can detoxify soil, and they serve as model organisms for behavior because they can roll. The group aims to collect roughly 60 isopods in total from the field and bring them into the lab. Each isopod will be kept separately and they will be examined for sexual differences as well as body size. While reading previous studies, the group found that research has not been conducted on whether preferences can be manipulated in pillbugs and whether they have a significant effect. For example, pill bugs prefer dark places, moist areas, and cooler spots, so could an environmental change make them choose the opposite conditions? The group did not calculate a budget because their items were low in cost. Then, the group discussed different preliminary trials, such as testing the pillbug preference for light or dark habitats, moist or dry habitats, areas with food or no food, and the types of smells they prefer such as mint or vinegar. After conducting these tests, then we would determine whether environmental factors change their behavior. Then the group discussed feasibility, mentioning that powder blue woodlice and pill bugs are easy to spot and they are easy to keep in a lab. Also, the scope of the experiment is realistic because we would test sex differences instead of age. Additionally, studying pill bugs does not require IACUC approval, and the experiment is low cost with accessible materials. Finally, they are an ideal organism for science education.
Questions/Comments After Proposal:
The group was asked how individual isopods would be identified, and they could be marked on their back
One person asked what would happen to the isopods after the study, and they can be kept in captivity as pets
The study would not include field observations because we want to measure causation, so there would only be collection in the field
The group selected different spots on the map for collection, and the location of the isopods could be recorded but it adds another variable
If there is a lab experiment, we can come into the lab space when Marshall is not present
The last question was how Mia’s weekend went, and it was good :)
Study Question: How do invasive crayfish utilize the environment and fit into the food webs of Northern California Riparian forests and wetlands?
The group started by mentioning that the Shasta crayfish is the only native species in California, and they are outcompeted by invasive crayfish. In fact, there has been a population decline by 90% in the last 40 years. They are on the brink of extinction, and this can occur within our lifetime. They propose an observational study of wetland environments and riparian corridors. For their methods, data collection would be recorded for 30 minutes once a day at the same time in the afternoon with four underwater cameras placed 15 meters apart. They want to record footage twice weekly, and it will be analyzed for different species as well as behavior. Behavior classifications would include foraging, fleeing, hiding, temperature regulation, predating, scavenging, and being preyed on. Additionally, basic habitat characteristics will be recorded such as water flow and vegetation. The group focused on the invasive signal crayfish and Louisiana crayfish, which are known to alter habitat structure, compete with native species, and change species composition. The materials necessary may include a GoPro Hero and SD card if there are no GoPros available, and 2 pairs of water boots which would put the budget at roughly $300. The group found crayfish at Putah Creek and Yolo Bypass, which will both be study sites. For feasibility, they mentioned that IACUC does not apply to crayfish, the methods include minimal disturbance, and they are within budget at 300 dollars. Finally, when identifying crayfish, they are clear white on the claws and live crayfish can be found by the presence of nearby dead crayfish.
Questions/Comments After Proposal:
The group specified that we can purchase a cheaper SD card, and it depends on how much footage is necessary
Jay suggested that scat and dissections are great methods for determining the predators of crayfish. The group replied that scat dissolves easily in water and that scat recovery would be difficult. However, we could set up trail cameras for predators
Marshall asked which crayfish was the burrowing one and whether they rear their young in the burrows, because we may be able to place cameras in the burrows
Another classmate mentioned that different times of day will affect crayfish behavior
After these riveting presentations, Caelan went to the front of the class and displayed the QR code for rank choice voting of the best proposal. After one round of voting, it was clear that Damselflies in Distress were the winner by a landslide with 10 first choice votes! Pill Bug Personality Test came in second, then Froggit About It, and finally We are the Water Striders in last.
After the big reveal, Kendall discussed a preliminary schedule for Friday. With the damselfly proposal as the winner, the class will all be going to Yolo Bypass. The specific sites have not been planned yet, but Kendall will mark semipermanent and permanent aquatic systems on the map of Yolo Bypass and pose a question to the class about which sites to visit. Kendall also mentioned that we would view a demo from the damselfly group on how to mark specimens, then practice the technique in groups. Each group will also write a pro and con list regarding the methods proposed by the damselfly group, and if there are significant issues with the current methods then the class can brainstorm solutions.
Tentative Schedule for Friday:
Arrive at Yolo Bypass
View a demonstration of the damselfly marking technique from the damselfly group which includes Mario, Jay, Jessica, and Rosie
Break into groups and go to the different semipermanent and permanent aquatic sites to practice the marking technique
Record information on a list of environmental variables provided by Kendall at the site each group visits
Preliminary data can also be collected after successfully marking a specimen
The class will reconvene and discuss any issues with the methods, and brainstorm possible solutions. Each group will also share the data they collected on the different environmental variables to determine which variables fluctuate the most between sites. Those variables can then be measured for our study in the future and they can inform us on how damselflies utilize their habitat
Regroup and head back to Davis
What to Do Before Friday:
Review the damselfly proposal methods, skim the scientific papers cited at the end of the damselfly proposal slides, and find your own paper on either of the damselfly species. One possible topic of interest is the dimorphism in female vivid dancer morphology, or how they interact with their environment
The damselfly group should collectively prepare a short demo on how to mark damselflies to present at the field site
Share your opinion in Discord about which field sites we should visit
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