Progress 03/15/17 to 03/14/21
Outputs
Target Audience:Our primary goal is to elicit changes in bird management practices that both benefit strawberry growers and help conserve nature. As such, our audiences are diverse, including growers, academics, as well as industry officials, local conservation NGOs, and policy-makers. While many of our outreach products and activitiesfocused on growers, our intention is to effectively reach representatives from all of these groups. Below, we list strategies to reach these groups. Academics- We published our work in peer-reviewed journals and presented our findings at academic conferences and in departmentalseminar series. Due to the socio-ecological nature of our work, we targetted our products to both interdisciplinary and disciplinary journals. We also hosted field trips for undergraduate students to our field sites. Growers-Most of our efforts was focused on disseminating our results to growers, with special attention to reachingboth English and Spanish-speaking stakeholders. Working closely with NGO partners (e.g.,the Wild Farm Alliance), we summarized our findings using non-technical language (in English and Spanish) and distributed resulting fact sheets and multimedia presentationsto growers andgrower groups. Wealso presented ourfindings to growers in person and electronically in a series ofworkshops, focused notonly on distributing project findings, but also on training growersto better manage birds on their fields. Finally, we presented at grower conferences (e.g.,EcoFarm), including hosting field trips for participants. Industry officials, conservation NGOs, and policy-makers-To ensure that our findings reached other key stakeholders, we disseminated our findings through popular press and through a series of public-facing talks. Specifically, we worked with our university press offices to develop and disseminatepress releases for our published products. We also presented our work to a series of interested stakeholders, including the UC Davis School of Law, the San Francisco Bay Bird Observatory,and the California District Attorneys Association. Finally, we referenced our work considerable when testifying before the Water Control Board of Monterey County. Changes/Problems:We were surprised when our sociological surveys yielded remarkably little variation in underlying values and identities among the 52 survey participants (all strawberry growers). Indeed, we had planned to use non-hierarchical axial coding to analyze the answers from open-ended survey questions; however, our survey did not capture the diversity of responses needed to perform this analysis. More broadly, it quickly became clear that we would need to reevaluate the hypotheses that were originally detailed in our proposal (i.e., exploring how grower identities and values shape their bird management approaches) and develop a new work plan for addressing our socio-ecological data. We have discussed our new approach in detail in prior interim reports as well as in the final report above. Briefly, however, we decided to: Integrate the economic data from our quantitative grower surveys with our exclusion experiment to quantify the net costs/benefits associated with birds across our farm network. We published our findings in Ecological Applications last year. Couple our qualitative interview data with two similar studies to explore the socio-ecological consequences of food-safety management in the California Central Coast. We published our findings in Frontiers in Sustainable Food Systems last year. Plan a final round of interviews to explore whether results from our studies may change farmer attitudes towards birds as well as their planned bird management strategies. This work is ongoing and we are excited about the potential results. What opportunities for training and professional development has the project provided?PI:PI Karp received this grant just after beginning his assistant professor position at UC Davis. The project was core to Karp's early research activities at UC Davis and helped him recruit personnel and build his lab. It also gave him critical experience in project management. Karp supervised all aspects of the project, including: the development, revision, and implementation of research, data analysis, and manuscript preparation; the execution of the grant budget and progress reports; the coordination of activities among all research partners across five institutions; the supervision of hired personnel; the maintenance of relationships with growers; and the development, revision, and implementation of outreach products. Co-PI: This was also Co-PI Gonthier's firstgrant during hisassistant professor position at the University of Kentucky. This research partially funded his graduate student (Garcia) and supported part of his early researchactivities. Gonthier supervised Garcia through all her research activities, including pointcount, arthropod sampling, experimental design, data management, and data analysis,and manuscript writing. Postdoctoral fellow:We employed one postdoctoral fellow throughout the duration of this project (Elissa Olimpi), who gained key skills and developed professionally in at least four areas. Research: Olimpi was trained in a rich array of methods and research strategies throughout the project. Most notably, she worked closely with our highly interdisciplinary team to design, execute, and publish both ecological and sociological research. Olimpi was also trained in many analytical techniques; for example, analyzing high-throughput DNA sequence data to build bird diet profiles. Finally, Olimpi was afforded opportunities to design her own research projects within our study system, bringing new ideas and directions to our grant. For example, Olimpi investigated the impacts of farm diversification on bird health and physiology. In pursuing this project, Olimpi also learned new field and laboratory techniques from physiologists and epidemiologists at UC Davis. Leadership and team management: Olimpi took on a major leadership role and gained key team management experience by coordinating the many moving parts of the project, taking care of field logistics, building our grower network, and maintaining relationships with growers throughout the project. Olimpi also organized regular conference calls with our co-investigators across the 5 institutions collaborating on this project to design, implement, and synthesize our research findings. Finally, Olimpi developed strong data management skills through co-creating a data sharing and management plan with PI Karp. Mentorship: Olimpi mentored 13 undergraduates over the course of this project as well as helped advise and collaborate with 2 PhD students. Among her many activities, Olimpi advertised positions, interviewed applicants, trained students in laboratory and field techniques, helped students design individual projects, and develop reports/presentations based on their findings. She also arranged field trips for an undergraduate agroecology class at UC Santa Cruz to visit one of our participating farms and learn about our research. Outreach: Olimpi was central to all our research outreach activities (discussed below). Briefly, however, Olimpi helped develop partnerships with local NGOs to present our findings in grower workshops. She also worked with a local NGO to create short videos documenting our findings. She synthesized our findings in grower reports and disseminated them to all farmer participants. Olimpi developed press releases and publicized our findings broadly. She also presented our work at grower conferences (i.e.,EcoFarm) and, in doing so, hosted a field trip for >100 growers to visit one of our focal farms. Finally, she also presented our findings to academics, both through departmental seminar series and at conferences. Graduate students: This project provided training opportunities for two graduate students, one of whom (Karina Garcia) centered dissertation work in our study system. Specifically, Garcia strengthened her population monitoring and insect identification skills while also training undergraduates to identify common pests and beneficial insects of the study system. Garcia learned about experimental design and data collection methods. Garcia also strengthened her data management and statistical modelling abilities: she is currently leading an effort to use Bayesian hierarchical modeling to assess impacts of diversification on bird communities. Garcia was also responsible for coordinating with the Spanish-speaking Latinx farmers within the farmer network and assisted in translating key findings to Spanish. Finally, Garcia presented her work to the entomology department at the University of Kentucky as well as at several academic conferences in 2019 and 2020. Alejandra Echeverri, a graduate student at the University of British Columbia, also played a key role in this project. Echeverri worked with multiple project participants to design, execute, and analyze 52 sociological surveys of growers throughout the Central Coast. After administering all surveys in person, she extracted and analyzed key data that was used in subsequent publications; for example, economic analyses of bird impacts on strawberry production. She coauthored papers with our research team and helped disseminate our findings. Undergraduates:This project has helped train 13 undergraduates and provide them with research experiences. In some cases, these experiences translated into individual research projects, honors theses, and awards. Moreover, several students are co-authors on papers that are about to be submitted. During our 2018 field season, four undergraduates were trained in mist-netting and bird identification techniques. Three undergraduates were also trained in GIS and landscape classification. One undergraduate was trained in insect sampling, berry damage and fecal density transect surveys, and insect identification. Finally, two undergraduates were trained basic bird physiological analyses and field methods. Two of the undergraduates that participated in this field work went on to write honors theses from the independent projects they completed. One of these students presented her work at an undergraduate research symposium, received prestigious awards for her thesis, and was accepted into a PhD program. After the 2018 field season, we recruited seven additional undergraduates to participate in laboratory work related to analyses of farm diversification on bird health. Undergraduates learned to fix and stain avian blood smears, identify hemoparasites, and perform differential white blood cell counts on blood smears. Finally, we recruited two more undergraduates to conduct GIS analyses of the landscapes surrounding our farm network. They also classified the diets of birds using next-generation sequence data. Specifically, after being trained in insect ecology and database management, students classified all of the unique arthropods and plants detected in bird feces via DNA sequencing into functional groups (using a grey and published literature) so that we could identify which bird species consumed pests, natural enemies, crops, and/or weeds. How have the results been disseminated to communities of interest?We have sought to share results from our projects widely, through multiple media and platforms, to reach diverse stakeholder groups. To reach growers as well as the broader produce industry, we have collaborated with NGOs to organize and present at multiple field-based workshops. For example, we partnered with the Wild Farm Alliance (WFA; a member of the project's advisory board) for a series of avian conservation workshops where we held bird mist-netting demonstrations and shared our research findings (4 workshops, 290 attendees total). Similarly, we presented our work as part of a workshop hosted in partnership between the Live Earth Farm, the Agriculture and Land-based Training Association (ALBA), Hedgerows Unlimited, and the Resource Conservation District of Santa Cruz County. In addition, we shared our results in an invited talk to the San Francisco Bay Bird Observatory. Our work resulted in key insights into the potential impacts of birds and farm management on foodborne pathogens. As such, PI Karp was called upon to testify before the Monterey County Water Control Board about the impact of riparian buffers on foodborne pathogens around farms. This resulted in subsequent invitations for Karp to discuss project results (as they pertained to food safety) to the California District Attorneys Association and the UC Davis Law School. Project members also presented their work at research conferences. Specifically, PI Karp, Postdoc Olimpi, and PhD Student Garcia presented project results at the American Ornithological Society (2019), the North American Ornithological Conference (two talks in 2020), the Entomological Society of America (2019), the Ecological Society of America (2019 and 2020), and the EcoFarm conference (2019 and 2020). As part of the EcoFarm conference in 2019, Postdoc Olimpi helped organize a field trip for ~150 participants to one of our focal farms where she discussed the project. Project personnel were also invited to present findings in a variety of academic seminar series, including seminars at Tulane University, Michigan Technological University, the University of Wisconsin- Green Bay, and the University of California at Davis (Talks in the Department Wildlife, Fish and Conservation Biology, the Department of Entomology, and the Department of Evolution and Ecology). Project members also reached undergraduate students through hosting two field trips in 2018 and 2019, for an Agroecology course at the University of California at Santa Cruz to visit one of our focal farms. Beyond oral presentations, we also worked with the UC Davis press office to develop press releases that highlighted findings from our project publications. Press releases were picked up by a variety of online news sources. In addition, we worked with the Wild Farm Alliance to develop short videos highlighting our findings and then disseminated them through WFA bulletins and social media. Finally, we wrote reports that synthesized our findings and then disseminated them to all grower participants. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Goal 1: Connecting farmland diversification to bird community composition We established a network of 27 organic strawberry farms, spanning independent gradients in local and landscape-level farm diversification practices across California's Central Coast. We then assessed on-farm diversification by quantifying crop diversity, non-crop vegetation cover, and vegetation complexity in 50m radius plots on each farm. Next, we visually surveyed crops in the field, manually digitized maps of all observed crops within 500 m of study plots, and then calculated their diversity. Finally, we we manually digitized seminatural habitat within 1km of all sites from aerial imagery. We used three approaches to characterize bird occupancy, reproduction, and health across our farm network. First, we surveyed birds on each focal farm using 10 minute, 50m fixed-radius point-count surveys in 2018 and again in 2019. Second, we systemically searched 20 farms for bird nests, scouring seminatural habitats and developed structures. Finally, we captured birds in mist nets, measured their morphology and collected blood samples. Blood samples were used to quantify two proxies for bird health: hematocrit levels and heterophil to lymphocyte ratios. Overall, we detected 7,360 individuals representing 88 unique bird species across 543 point-counts on 26 farms. On average, we detected 11 species per point-count location. Preliminary analyses suggest that local diversification practices and surrounding semi-natural habitat increased species richness. We located 52 nests representing 16 bird species: 27 in natural habitats and 25 in developed areas within the boundaries of 12 farms. After accounting for area searched, nest density was overall greater in developed habitats. Finally, we found that local farm diversification reduced bird stress and improved health indicators, but only in landscapes will little surrounding habitat. On farms surrounded by habitat, local diversification had the opposite effect. This may be because bird densities peaked on diversified farms in diversified landscapes, which may heighten intra-specific competition (thus elevating stress). Goal 2: Shifts in bird-mediated ecosystem services and disservices We coupled meta-barcoding of bird fecal samples with bird exclusion experiments to quantify the ecosystem services, disservices, and net impacts of birds across our strawberry farm network. From May-June 2017-2019, we visited each farm on three consecutive days, placing 10 mist nets within and adjacent to farm fields. Birds were extracted from nets and then transported to a nearby banding station for identification, banding, morphological measurements, and fecal/blood sample collection. In total, we obtained 1327 fecal samples from 1380 birds. In the lab, we extracted DNA and used high-throughput DNA barcoding to create diet profiles for each individual. We also used targeted PCR to determine whether individuals (1) consumed strawberries, blackberries, or raspberries and/or (2) carriedCampylobacterspp.,Salmonellaspp., or Shiga-toxin producingE. coli(STEC). To measure the net effects of birds on strawberry yields, we set up a large-scale bird exclusion experiment, placing three pairs of mesh-net cages and open-frame controls around strawberry plants on 15 farms. In 2018, we sampled insects from each plot and visited exclosures weekly to harvest and score berries for bird and insect damage. We also surveyed three 20m transects per farm for fecal contamination and strawberry damage from birds or insects. Overall, we found that birds consume insect pests, but may also consume beneficial insects, damage crops, and occasionally carry pathogens. Most critically, we found that increasing seminatural habitat around farms was associated with more diverse and multifunctional bird communities that maximized services and minimized disservices. For example, birds were less likely to consume strawberries and less likely to carryCampylobacterspp. on farms with more surrounding seminatural habitat. Similarly, though our exclusion experiment indicated that the net effect of birds on crop yields was slightly negative, costs were minimized on farms with more surrounding habitat (and maximized in intensive landscapes). Results from our exclusion experiment were highlighted on the cover ofEcological Applications,and DNA barcoding results have been submitted toScience Advances. Grower interviews (detailed below) indicated that a key barrier to conserving birds and seminatural habitats around farms is the perception that birds may carry foodborne diseases. We supplemented our data with pathogen prevalence data from four other studies to create the largest database of pathogen assays in wild birds to date (>11,000 pathogen tests across 94 species in the Western U.S.). We found thatSalmonellaspp. and STEC are very rare in birds (0.46% and 0.22% prevalences, respectively).Campylobacterspp., however, were more common (8%), and peaked in species associated with livestock. Livestock-associated species were also more likely to intrude into farms and defecate on crops. However, our results also suggested insectivores are less likely to deposit foodborne pathogens on crops, indicating growers could manage their farms to promote pest-eating birds without compromising food safety. The manuscript resulting from this study has been submitted toEcological Applications. Goal 3: Understanding farmer decisions about bird management To understand how and why farmers choose particular bird management strategies, we conducted in-depth, qualitative semi-structured interviews with 17 growers. We then administered a survey to 52 strawberry growers to understand how and why farmers manage birds. We used these data in three ways. First, we combined economic data from our surveys with the bird exclusion experiment to quantify the costs associated with birds on strawberry farms. Second, we discovered many farmers are pressured to exclude birds from their farms and remove surrounding non-crop vegetation for fear that birds may be carrying foodborne pathogens. We thus combined our interviews with data from two related studies to examine grower experiences of food safety reform and its impacts on sustainability. We found that growers perceive some food-safety practices to legitimately mitigate pathogen risks, while others are thought to be ineffective or counterproductive. We published these results inFrontiers in Sustainable Food Systems,where we argued that our findings suggest that growers' experiential knowledge should be integrated into food-safety policy so that outcomes are more effective, equitable, and sustainable. Third, and finally, we are now disseminating short grower reports describing the core findings and management implications that resulted from our work. We will then engaged in a new round of interviews to assess whether our project influenced growers' perception of birds as well as their stated future bird management strategies. Conclusion: Management Implications Our results suggest that conserving or restoring seminatural habitats around strawberry farms may result in the best net outcomes for farmers. Indeed, we found that farms with more surrounding seminatural habitat had more diverse bird communities, less bird damage, and thus lower economic costs from birds. Many farmers may be reticent to conserve habitat due to concerns about food safety. However, our results suggest that STEC andSalmonellaspp. are very rare in birds and thatCampylobacterspp. are actually more prevalent in birds found on intensive farms. Some growers may choose to actively support birds on their farms, either by planting native vegetation or by installing artificial nest boxes and allowing birds to nest on their buildings. Doing so could help promote aerial insectivores which we found often consume insect pests.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Gonthier, D., A. Sciligo, D.S. Karp, A. Lu, K. Garcia, G. Juarez, T. Chiba, and C. Kremen (2019) Bird services and disservices to strawberry farming in Californian agricultural systems. Journal of Applied Ecology. 56: 1948-1959.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Olimpi, E.M., K. Garcia, D. Gonthier, K.T. De Master, A. Echeverri, C. Kremen, A.R. Sciligo, W.E. Snyder, E. Wilson-Rankin, and D.S. Karp (2020) Shifts in species interactions and farming contexts mediate net effects of birds in agroecosystems. Ecological Applications 30: e02115.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Garcia, K., E.M. Olimpi, D.S. Karp, and D.J. Gonthier (2020) The good the bad and the risky: can birds be incorporated as biological control agents into integrated pest management programs. Journal of Integrated Pest Management 11: 1-11.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2021
Citation:
E.M. Olimpi, K. Garcia, D.J. Gonthier, C. Kremen, W.E. Snyder, E.E. Wilson-Rankin, and D.S. Karp. (Submitted) Farmland diversification shapes tradeoffs and synergies in bird-mediated ecosystem services and disservices. Science Advances.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2021
Citation:
Smith, O., E.M. Olimpi, N. Navarro-Gonzalez, K. Cornell, L.O. Frishkoff, T.D. Northfield, T.M. Bowles, A. Edworthy, J. Eilers, Z. Fu, K. Garcia, D.J. Gonthier, M.S. Jones, C.M. Kennedy, C.E. Latimer, J.P. Owen, C. Sato, J.M. Taylor, E.E. Wilson-Rankin, W.E. Snyder, D.S. Karp. (Submitted) A trait-based framework for predicting foodborne pathogen spillover from wild birds. Ecological Applications.
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Progress 03/15/19 to 03/14/20
Outputs
Target Audience:During the third reporting period, our efforts have focused on 1) maintaining our relationships with growers in the study region; 2) sharing our research results with the agricultural community and the public; 3) training and mentoring undergraduate student researchers; and 4) publishing our findings. We have maintained positive relationships with participating growers, and have continued to share our research results with them. We have also shared our research results with the broader agricultural community, including other growers, researchers, and technical assistance staff, and the public through a series of talks and workshops (see specific activities below). Finally, we have recruited and trained four new undergraduate students (3 at UC Davis, 1 at University of Kentucky) in lab techniques relevant to insect identification and processing biological samples, and will continue to mentor one of these students in developing an independent research project. Changes/Problems:As described in our previous annual report, our sociological surveys did not yield sufficient variation for our planned analyses on how values and identities shape farmer attitudes towards birds. We will instead explore how farm characteristics and avian communities shape grower's attitudes and choices about avian management practices. What opportunities for training and professional development has the project provided?This project has provided training for 13 undergraduates to gain hands-on experience with multiple aspects of our research. During this period, three undergraduates (UC Davis) were trained to identify hemoparasites and perform differential white blood cell counts on avian blood smears. One of these undergraduate students continue to receive mentorship from our team as they work toward completing an independent research project on avian health and pesticide loads. One additional undergraduate (University of Kentucky) was trained in insect identification. In addition to undergraduate training and mentorship, Project Postdoc Olimpi gained experience publishing with a large group of collaborators. She designed and co-led a collaborative synthesis on the impacts of food safety reform, and led a manuscript leveraging findings from our exclosure experiment on the net effects of birds. Project Postdoc Olimpi arranged a field trip with one of our participating growers and an agroecology class at UC Santa Cruz, built partnerships with other conservation and agricultural organizations, and has utilized these new partnerships as a platform to share research results through workshops and public talks. Finally, this project has provided significant training opportunities for an early-career PhD student at the University of Kentucky (Karina Garcia). Project PhD Student Garcia presented her first two talks at professional meetings. She is also being trained in basic statistical analyses, and has begun learning modeling strategies for analyzing exclosure and point count data. How have the results been disseminated to communities of interest?The 2019 field season also presented an opportunity to partner with an agroecology class at UC Santa Cruz. We worked with a participating grower to coordinate a fieldtrip and informed students of our research design, questions, and initial findings (26 students, 1 staff). Although we are still processing and analyzing data, we have shared preliminary research results with our grower network through phone conversations. We have also shared our research results through a series of invited talks and workshops. In the spring of 2019, we partnered with the Wild Farm Alliance (a member of the project's advisory board) for a series of avian conservation workshops where we held a bird mist-netting demonstration and shared our research findings (3 workshops, 210 attendees total). Specifically, PD Karp participated in one of these workshops at a diversified farm in Nevada City, CA (100 attendees), and the Project Postdoc (Elissa Olimpi) participated in two workshops at vineyards in Napa County (90 participants) and Los Gatos (30 participants), CA. In June 2019, PD Karp traveled to Anchorage, AK to present results at the American Ornithological Society Meeting. Project PhD Student Garcia presented results in August 2019 at the Ecological Society of America Annual Meeting and in November 2019 at the Entomological Society of America Annual Meeting. In January 2020, Project Postdoc Olimpi presented results from our bird exclosure experiment during an avian conservation workshop, facilitated by the Wild Farm Alliance, at the EcoFarm conference (75 attendees). The 2019 field season also presented an opportunity to partner with an agroecology class at UC Santa Cruz. We worked with a participating grower to coordinate a fieldtrip and informed students of our research design, questions, and initial findings (26 students, 1 staff) What do you plan to do during the next reporting period to accomplish the goals?Our focus over the next reporting period will be to analyze several datasets, and distill our findings into a series of publishable manuscripts. We have designed and will prepare the following manuscripts from our ecological data over the next year: Assessment of how ecological network structure (bird-insect and bird-plant interactions) shifts in response to local and landscape diversification gradients (data from: mist net data and fecal analyses) Determine how local farm and landscape diversification features influence the probability that birds will vector pathogens, provide pest control, serve as intraguild predators, and damage crops directly (data from: fecal analyses, nest searching). Linking bird traits to functional role in strawberry systems to predict which species provide ecosystem services and disservices (data from: point count surveys, mist net data, fecal analyses). Bird community analysis focused on the influence of diversification practices on bird diversity, richness, abundance, and functional community shifts in beneficial, pest, and vector species (data from: point count surveys and fecal analyses). Evaluate how farm characteristics and avian communities shape grower's attitudes and choices about avian management practices (data from: point count surveys, grower surveys). Finally, we will conduct additional interviews with key informants, including NGO representatives, food safety specialists and inspectors, and extension professionals. The purpose of these interviews is the triangulation of the qualitative data gleaned from previous interviews with farmers, to better understand the complexities of bird and wildlife management among strawberry growers in California's Central Coast region. We plan to transcribe all interview recordings, and then code our findings with NVivo qualitative data analysis software for key themes. These data will be used to illuminate farmer motivations and experiences regarding bird management.
Impacts
What was accomplished under these goals?
In the spring of 2019, we called or visited all of the growers in our network to update them on the preliminary results from our 2018 field season, and presented our upcoming research plan. We selected farms that cover a gradient of local and landscape practices. We began our field season by nest searching on 20 farms that include both seminatural vegetation (grasses, shrubs, trees) and developed structures (buildings, greenhouses, hoop houses). We divided our nest search efforts into two, two-week periods to account for differences in the timing or reproduction across bird species. During the summer of 2019, we used avian point count surveys and mist-netting efforts to characterize and obtain samples from bird communities. We collected fecal samples for diet analyses and pathogen screening from one additional farm. We conducted point count surveys (1 - 6 point counts per farm, depending on farm size) at 20 farms, and repeated these counts for three days. We will combine point counts from 2018 and 2019 and use occupancy models to determine how diversification influences avian community composition. We will also pair these models with sociological surveys to predict avian composition on the farms of survey respondents. We will then use survey results to map grower preferences for different birds onto abundance trends of preferred versus maligned birds on each farm. We obtained 1,168 fecal samples (from 1,303 bird mist-net captures) that will be used to create dietary profiles and screen for pathogen presence. These data will be used to identify beneficial, pest, and vector bird species, and will eventually be paired with point count data to understand how diversification practices shift the functional role of avian communities. Co-PI Rankin's lab has extracted DNA and finished sequencing all samples. We have begun preliminary analyses on the diet data and are optimizing our data pipeline to achieve the best taxonomic resolution of diet items. We identified both insect pests and natural enemies in bird diets, and our preliminary analyses indicate that many birds are neither pests nor beneficial, but some combination of both. Co-PI Snyder's lab developed pathogen screening protocols (forSalmonella,Campylobacter, andEscherichia coli) and finished screening all samples. Preliminary analyses indicate low rates of pathogen incidence similar to two other studies conducted in agricultural systems in the western US. Of the 1,286 fecal samples screened for pathogens, 4.0% (52 samples) tested positive for at least one of five genes potentially associated with enterohemorrhagicE. coli, and only two of these samples tested positive for genes linked to shiga toxin production. We found a similarly low rate ofCampylobacterincidence: 3.7% (47 samples) tested positive for one of four strains ofCampylobacter. In contrast to other studies, we did not detectSalmonellain any of our samples. Our next step will be to determine how local farm and landscape features influence pathogen presence. Our manuscript on the net effects of birds in strawberry systems was recently accepted at the journalEcological Applications. We found that birds had only a slightly negative overall impact on strawberry production, reducing economic value by 3.6%. Surprisingly, direct bird damage and intraguild predation contributed equally to this net effect, underscoring the importance of indirect trophic interactions that may be less apparent to growers. In simple landscapes (e.g., low proportions of surrounding seminatural habitat), birds provided pest control in the interiors of farm fields, and costs from bird damage to crops peaked at field edges. In complex landscapes (e.g., high proportions of seminatural habitat), birds were more likely to disrupt pest control by feeding as intraguild predators. Nonetheless, seminatural habitat dampened bird services and disservices, and our models predicted that removing habitat around farm fields would increase costs from bird damage to crops by up to 76%. Fecal contamination of crops was extremely rare (0.01%). However, both fecal contamination and bird damage did increase on farms with higher densities of fencing and wires, where birds often perch. Our results demonstrate that maintaining seminatural habitat around farms may constitute a win-win by enhancing bird diversity and mitigating bird damage without increasing food-safety risks. We also show that the net effects of birds depend on farming context and vary in complex ways in relation to locations within a farm, local farm attributes, and the surrounding landscape. We published an invited synthesis on the socioecological effects of evolving food safety pressures in the California Central Coast in the journalFrontiers in Sustainable Food Systems.We traced reforms in food safety policy to social and ecological outcomes for agriculture, drawing on the perceptions and experiences of Central Coast growers to highlight a series of disjunctures between farm management practices and food safety requirements. During our 2018 field season, Co-PI De Master conducted in-depth, qualitative semi-structured interviews with 17 growers, and we combined these interviews with data from two other related studies to examine grower perceptions and experiences of food safety reform and its impacts on environmental and socioeconomic sustainability. We identified three disjunctures between food safety regulations and farming realities in practice: 1) Growers perceive that some food safety practices legitimately mitigate risk, while others fail to reduce or even accentuate risk; 2) Food safety requirements can create contradictions in the co-management of food safety and environmental protection; and 3) Food safety requirements may foster impediments to regional food systems sustainability. Finally, Co-PI De Master plans to conduct additional interviews with diverse key informants, including food safety professionals, to increase understanding of the impacts of regional food safety reform. During our 2018 field season, Co-Investigator Echeverri surveyed 52 growers to understand how and why farmers manage birds. We plan to combine grower survey data with occupancy models (developed from avian point count surveys) to assess how farm characteristics and avian communities shape grower's attitudes and choices about avian management practices. We will test if predicted avian community composition predicts variation in growers' perceptions of birds and bird management actions. If growers' perception of birds do not reflect our ecological findings, these analyses will allow us to identify opportunities where outreach efforts could help to align conservation and production goals.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2020
Citation:
Olimpi, E.M., K. Garcia, D. Gonthier, K.T. De Master, A. Echeverri, C. Kremen, A.R. Sciligo, W.E. Snyder, E. Wilson-Rankin, and D.S. Karp (In Review) Shifts in species interactions and farming contexts mediate net effects of birds in agroecosystems. Ecological Applications.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Olimpi, E.M., P. Baur, D. Gonthier, D.S. Karp, C. Kremen, A. Sciligo, and K.T. De Master (2019) Evolving food safety pressures in Californias Central Coast region. Frontiers in Sustainable Food Systems 3:102
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Progress 03/15/18 to 03/14/19
Outputs
Target Audience:During the second reporting period, our efforts have focused on 1) strengthening our relationships with growers in the study region; 2) sharing our research results with the agricultural community and the public; and 3) training and mentoring undergraduate student researchers. We have continued to expand our grower network and have maintained positive relationships with participating growers. As we prepare to begin our second field season in April 2019, we are reconnecting with grower participants and sharing preliminary research results. We have also shared our research results with the broader agricultural community, including other growers, researchers, and technical assistance staff, and the public through a series of talks and workshops (see specific activities below). Finally, our summer 2018 field season provided an opportunity to recruit, train, and mentor four undergraduate students (2 UC Davis, 2 UC Berkeley). The data that we collected in 2018 has also provided an opportunity for 5 additional undergraduates (4 UC Davis, 1 University of Kentucky) to be trained in lab techniques relevant to processing biological samples. Changes/Problems:As noted above, we were surprised when our sociological surveys yielded remarkably little variation in underlying values and identities across growers. Indeed, we had planned to use non-hierarchical axial coding to analyze the answers from open-ended survey questions; however, our survey did not capture the diversity of responses needed to perform this analysis. These findings have caused us to reevaluate our hypotheses and develop a new work plan for integrating our socio-ecological data. Now, rather than analyzing how variation in values and identities shape farmer attitudes towards birds, we will instead explore how farm characteristics and avian communities shape grower's attitudes and choices about avian management practices. Specifically, we will identify farm parcels associated with each farmer respondent and characterize the landscape composition surrounding those farms. We will use bird community models (see above) to predict avian composition on those farms. We will then use survey results to map grower preferences for different birds onto abundance trends of preferred versus maligned birds on each farm. Ultimately, we will attempt to predict variation in stated attitudes towards birds- as well as management practices- based on the (1) the surrounding landscape composition, (2) key farm attributes [e.g., farm size], and (3) predicted bird community composition. We predict that farmers that hold land with more species that act as pests or disease vectors (identified through fecal analyses) will possess more negative attitudes towards birds and engage in more severe bird management practices (e.g., habitat removal). Finally, we will also leverage our interview and survey data to write a review on the socio-ecological consequences of food-safety management in the California Central Coast. Indeed, we have been invited to submit a peer-reviewed article to Frontiers in Sustainable Food Systems. Given our past and ongoing work in the region, we believe that we are well-poised to discuss how evolving food safety pressures are affecting growers of all types. What opportunities for training and professional development has the project provided?This project has provided training for 9 undergraduates to gain hands-on experience with multiple aspects of our research. During our field season, three undergraduate students were trained in mist-netting and bird identification and processing techniques, mist-net site selection, using a dewar (portable -80oC freezer) to store sensitive biological samples, and use of handheld GPS units. Two undergraduates were trained in how to manually classify aerial imagery in Google Earth and export files to ArcMap, and one undergraduate was trained in insect sampling with a bug vac, berry damage and fecal density transect surveys, and insect identification. Two undergraduates were trained in how to use a centrifuge to spin down bird blood samples and take hematocrit readings, and how to measure plasma protein concentration from avian blood. One undergraduate student was trained to fix and stain avian blood smears, and five undergraduates were trained to identify hemoparasites and perform differential white blood cell counts on avian blood smears. Two of these undergraduate students continue to receive mentorship from our team as they work toward completing their honors undergraduate thesis projects. Finally, one undergraduate was trained in insect taxonomy, identification, and database management. In addition to the wide range of skills undergraduates learned as part of this project, the project post doc gained leadership and team management experience by coordinating the many moving parts of the project, taking care of field logistics, building our grower network, and communicating with project collaborators to develop protocols, ship samples, and initiate next steps for various projects. She also arranged a field trip with one of our participating growers and an agroecology class at UC Santa Cruz, built partnerships with other conservation and agricultural organizations, and has utilized these new partnerships as a platform to share research results through workshops and public talks. Finally, this project has provided significant training opportunities for an early-career PhD student at the University of Kentucky (Karina Garcia). Garcia was trained in bird survey techniques, in addition to myriad other field and laboratory techniques relevant to the project (vegetation surveys, landscape classification, arthropod identification, etc.). She is also being trained in basic statistical analyses, and has begun learning linear mixed modeling strategies for analyzing exclosure data. *Note: In the participants section of this project, we only record effort for personnel that received grants from the lead institutions(UC Davis). Funds were allocated to other faculty (summer salary) and students at other other institutions. In addition, many undergraduates and other scientists volunteered their time on this project. How have the results been disseminated to communities of interest?Although we are still collecting data and waiting on results, we have shared the preliminary research results with our grower network through phone conversations. We have also shared our research results through a series of invited talks and workshops. In December 2018, PD Karp traveled to Washington D.C. to present our project and results at the annual project director's meeting. In January 2019, the project postdoc presented results from our bird exclosure experiment during a tour of High Ground Organics Farms as part of the EcoFarm conference (150 participants, 2 growers). In February 2019, the project postdoc was invited to present research results at two different venues: 1) as part of a workshop hosted in partnership between Live Earth Farm, the Agriculture and Land-based Training Association (ALBA), Hedgerows Unlimited, and the Resource Conservation District of Santa Cruz County; and 2) a public talk on bird conservation science hosted by the San Francisco Bay Bird Observatory (40 attendees). The 2018 field season also presented an opportunity to partner with an agroecology class at UC Santa Cruz. We worked with a participating grower to coordinate a bird banding demonstration, taught students basic banding techniques, and informed students of our research design and questions (26 students, 1 faculty, 1 staff). Additional workshops are planned for the spring of 2019 in partnership with the Wild Farm Alliance (a member of the project's advisory board). What do you plan to do during the next reporting period to accomplish the goals?Beginning in April of 2019, we are planning a second year of fieldwork. We will repeat point count surveys in order to build a robust data set that we can use to parameterize multivariate occupancy models. We will also search for nests at 10 natural habitat sites adjacent to farms, and 10 developed sites (with buildings and other farm structures) on or adjacent to farms. We will characterize nest sites to understand nesting requirements and will use this information to guide management recommendations to minimize habitat for pest and vector species, and provide habitat for beneficial species. Over the next several months, we also anticipate completing laboratory analyses to characterize bird diets and vector status. Additionally, we plan to transcribe interview recordings in the next year, and then code our findings with NVivo qualitative data analysis software for key themes. These data will be used to illuminate farmer motivations and experiences regarding bird management. Much of the work over the next year will focus on data analysis and interpretation, and manuscript preparation. We have designed and will prepare the following manuscripts from our ecological data over the next year: Net effects of birds services and disservices in strawberry systems (data from: exclosure analyses, transect surveys) Linking bird traits to functional role in strawberry systems to predict which species provide ecosystem services and disservices (data from: point count surveys, mist net data, fecal analyses). Assessment of how ecological network structure (bird-insect and bird-plant interactions) shifts in response to local and landscape diversification gradients (data from: mist net data and fecal analyses) Bird community analysis focused on the influence of diversification practices on bird diversity, richness, abundance, and functional community shifts in beneficial, pest, and vector species (data from: point count surveys and fecal analyses).
Impacts
What was accomplished under these goals?
In the spring of 2018, we visited all of the growers in our network to update them on the results of past research projects, and presented our upcoming research plan as we asked for continued engagement in our socioecological research. We selected farms that cover a gradient of local and landscape practices, and used a combination of farm surveys and aerial imagery to quantify diversification. We began our field season by setting up our bird exclosure experiment on 15 farms. We ran the exclosure experiment for two one-month periods (April - May, June - July), sampled insects from each plot, and visited exclosures weekly to harvest and score berries for bird and insect damage. We also conducted berry damage and fecal density transect surveys in strawberry fields to assess bird disservices. We found that birds have a net neutral effect on strawberry yield, and that the greatest impact of birds on strawberries is mediated through insects, and not direct bird damage. At field edges, birds increased strawberry damage by acting as intraguild predators who consume beneficial insects; however, further from edges, birds decreased strawberry damage by providing pest control. Birds had the most positive effect on strawberries in intensive agricultural landscapes with little natural habitat. Not all farms experienced direct strawberry damage from birds, but farms that had more fencing and wires were more likely to have problems with birds eating strawberries, and damage was more likely to occur near field edges. Similarly, we found that fecal density in crop fields also increased on farms with more fencing and wires, although only 0.04% of berries had fecal contamination. From our transect surveys, we found that bird flick damage (evidence of birds consuming strawberry fruit or seeds) increased on farms that had more fencing and wires, and farms that were surrounded by more crop diversity (500 m radius). Bird damage to strawberries decreased with the use of more bird deterrent practices, and on farms that were surrounded by a higher density of semi-natural habitat. We expect to submit a manuscript on the net effects of bird services and disservices in strawberry systems in the spring of 2019. During the summer of 2018, we used avian point count surveys and mist-netting efforts to characterize and obtain samples from bird communities. We conducted point count surveys (1 - 6 point counts per farm, depending on farm size) at 20 farms, and repeated these counts for three days. After a planned second year of sampling, we will use occupancy models to determine how diversification influences avian community composition. We obtained 1,168 fecal samples (from 1,303 bird mist-net captures) that will be used to create dietary profiles and screen for pathogen presence. Co-PI Rankin's lab has extracted DNA from all samples, and expects to finish sequencing samples by the summer of 2019. Co-PI Snyder's lab has developed pathogen screening protocols (for Salmonella, Campylobactor, and pathogenic E. coli) and will have results by the summer of 2019. These data will be used to identify beneficial, pest, and vector bird species, and will eventually be paired with point count data to understand how diversification practices shift the functional role of avian communities. We developed an interview guide to address how grower values and identities correlate with attitudes toward birds, and how external constraints shape both attitudes and practices. Co-PI De Master then conducted in-depth, qualitative semi-structured interviews with 17 growers, and themes that emerged from these interviews were leveraged to design a quantitative survey. Co-Investigator Echeverri surveyed 52 growers to understand how and why farmers manage birds. We plan to combine these results with prior surveys and interviews conducted in the region to write an invited review on the socio-ecological effects of food-safety scares in the California Central Coast for the journal Frontiers in Sustainable Food Systems. Early results from the survey suggest that farmers diverge sharply in their attitudes towards birds and that different species are perceived differently. Critically, we observed remarkably little variation among growers in the underlying values and identities that we hypothesized would influence decision making. This surprising result has caused us to re-evaluate our stated hypotheses and design a new work-plan for leveraging our sociological data (see below). The 2018 field season also presented an opportunity to partner with an agroecology class at UC Santa Cruz. We worked with a participating grower to coordinate a bird banding demonstration, taught students basic banding techniques, and informed students of our research design and questions (26 students, 1 faculty, 1 staff). We have also shared our research results through a series of invited talks and workshops. In December 2018, PD Karp traveled to Washington D.C. to present our project and results at the annual project director's meeting. In January 2019, the project postdoc presented results from our bird exclosure experiment during a tour of High Ground Organics Farms as part of the EcoFarm conference (150 participants, 2 growers). In February 2019, the project postdoc was invited to present research results at two different venues: 1) as part of a workshop hosted in partnership between Live Earth Farm, the Agriculture and Land-based Training Association (ALBA), Hedgerows Unlimited, and the Resource Conservation District of Santa Cruz County; and 2) a public talk on bird conservation science hosted by the San Francisco Bay Bird Observatory (40 attendees). Additional workshops are planned for the spring of 2019 in partnership with the Wild Farm Alliance (a member of the project's advisory board).
Publications
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Progress 03/15/17 to 03/14/18
Outputs
Target Audience:Over the last reporting period, we focused our efforts on relationship building with growers to maintain positive relationships and to expand our research network to include new stakeholders. Grower participation is an essential component of our research, and we will continue to nurture these relationships as we conduct socio-ecological research and ultimately deliver research results to growers. To that end, during our pilot field season in July of 2017, we coordinated a short research demonstration with local growers and farmworkers. We demonstrated bird mist-netting techniques, explained our research approach, and discussed how birds can both provide pest control and cause damage to strawberry crops. Throughout the reporting period, we have also maintained relationships with key stakeholders who will eventually receive results (e.g., staff at the Nature Conservancy [TNC] and the Agriculture and Land-based Training Association [ALBA]) and began cultivating new relationships (e.g., scientists at University of California Cooperative Extension [UCCE]). Thus, while our project is still nascent, we are well poised to reach a variety of stakeholders as our project develops and we generate new findings. Changes/Problems:Because we received funds in March 2017, we decided to conduct a pilot field season in the July 2017 rather than a full field season. Thus, we hired our project postdoc in Fall 2017 and will be conducting fieldwork starting in April 2018. This slight delay allowed us to solidfy our methods and will result in a more thorough and carefully executed project. We decided to make this change shortly after receiving our funds and after consulting with the program manager (M. Bowers). What opportunities for training and professional development has the project provided?The project has provided training for growers and farm workers through a mist-netting demonstration that we offered in July of 2017. Our ecological team has also gained experience in bird processing techniques. We spent a day in the field training with other researchers at UC Davis to learn how to take blood samples from birds. We also learned how to prepare and process blood samples to ask questions about bird health and condition as we plan an extension project building on our goal of developing strategies for co-managing birds for conservation and strawberry production. Currently, we are in the midst of recruiting students to train in ecological field methods as part of our research team this summer. We have commitments from one recent graduate of UC Davis and one undergraduate student to participate in our summer field season. Both of these students are interested in conducting independent research extension projects, and will be offered hands on mentorship and support in developing their research projects. Our project postdoc began in the fall of 2017 and has already gained skills in leadership, data management, and networking. She gained leadership experience by organizing weekly conference calls with our co-investigators across institutions and by setting up a shared Google Drive for our research team. The postdoc and PI-Karp created and implemented a data sharing and management plan to streamline access to documents and collaboration for the research team. She also arranged a field workshop with colleagues at UC Davis who have expertise in our proposed field methods to ensure the success of our research. Additionally, the postdoc gave an invited talk on her doctoral research as part of a UC Davis seminar series, and has received professional development training in granstmanship, working with PD Karp to submit two additional postdoctoral fellowship applications. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?We are now contacting growers to gauge interest in our research and will begin conducting site visits and qualitative interviews. We will then use interviews to develop surveys to learn about farmers' experiences with birds. During April through July, we will conduct ecological research, including: 1) bird exclosure experiments to measure pest control by birds and bird damage to berries. 2) mist-netting of birds to collect fecal samples for pathogen and diet analyses; 3) surveys of pest damage and fecal deposits in strawberry fields; 4) bird point counts to quantify how many and which types of birds are visiting farms. Following the end of the summer field season, we will process fecal samples to characterize bird diet profiles, identify insects from vacuum samples, and begin quantitative analyses. We will also perform qualitative analyses on survey data.
Impacts
What was accomplished under these goals?
Because we received funds in April 2017, we decided to conduct a short pilot field season in the summer of July 2017 and recruit the project postdoc in fall of 2017. Thus, in the first few months of the project, we focused on solidifying field methods, recruiting project staff, and on maintaining relationships with growers. In Fall of 2018, the project postdoc- Elissa Olimpi- joined our project. Since then, we have focused on coordinating the social, ecological, quantitative, and qualitative aspects of this project through several, regular electronic meetings of project members. We have been working on recruitment of growers interested in hosting our research on their farms. As many growers in our network have been involved in past research projects, we are conducting site visits and updating growers with results of prior research, and presenting our upcoming research plan as we ask for continued engagement in our socioecological research. We will soon be able to deliver research results on bird diets from our pilot season to growers. In addition to recruiting our project postdoc, we have also been focused on recruiting students from underserved communities to engage with our research. We have partnered with coordinators of various program designed to increase diversity in STEM fields at UC Davis, UC Berkeley, and UC Santa Cruz, and have advertised a research position for an undergraduate student through colleges and community colleges within our study system (California State University Monterey Bay, Monterey Peninsula College). Now, we are now gearing up to begin ecological and social fieldwork this spring. We have updated and resubmitted our state and federal banding permits, as well as our IACUC protocol, and all of these permits have been approved. We have ordered most of the supplies that we will need for our field season, set up a new lab for insect identification and PCR, and have arranged the rental of field vehicles and housing. Our team has created detailed protocols and datasheets for each of our proposed ecological field methods. Our social science team has completed background research investigating farmer values, has developed and tested an interview guide, and is coordinating survey efforts with other projects and organizations (e.g. The Nature Conservancy, USDA-funded Avian biodiversity: impacts, risks and descriptive survey (A-BIRDS) project at Washington State University). By coordinating with other regional social science projects, we will avoid research fatigue among participating growers and potentially open the up the possibility of distributing our surveys to broader networks.
Publications
- Type:
Journal Articles
Status:
Under Review
Year Published:
2018
Citation:
Gonthier, D., A. Sciligo, D.S. Karp, A. Lu, K. Garcia, G. Juarez, T. Chiba, and C. Kremen (In Review) Managing the services and disservices of birds in California farmlands. Journal of Applied Ecology.
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