Progress 01/01/23 to 12/31/23
Outputs
Target Audience:Our target audiences were: The scientific community: we presented our work at one international and one national conference. Tanzanian wildlife officials: throughout 2023we continued to engage with Tanzanian stakeholders, including TAWIRI (Tanzanian Wildlife Research Institute) and TANAPA (Tanzanian National Parks) personnel. Livestock producers: beginning in late in 2021 and continuing through 2022 and 2023, we collected fecal samples from livestock and wildbeest in areas of overlap between the two outside Serengeti. Project personnel continued to interact with livestock herders to explain the rationale for the project. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The project continues to support postdoctoral Associate Jason Donaldson, who has led the publication of two manuscripts and given several presentations on the project at national and international meetings. Two Tanzania post-baccalaureate students (Basil Senso and Aidan Trentinus) continued to serve as research technicians on the project, and Basil will be joining the project as a graduate student beginning in the next reporting period.Jeremia Serakikya works as a project field assistant and has received ongoing tyraining in data managament. Houssein Kimaro continues to pursue his PhD at the University of Glasgow. How have the results been disseminated to communities of interest?We have presented project fidnings at one national(CRWAD) and one international (Savanna Science Network Meeting) meeting, and have published twopapers resulting from work on the project. What do you plan to do during the next reporting period to accomplish the goals?In 2024, we will wrap up our data collection for Objective 1 and for Experiment 2 (Objective 2). We expect to prepare publications related to both of these project components, and will complete an additional experiment designed to understand the effects of the grass sward microlcimatre on larval survival. We also expect to generate our first datasets from the DNA barcoding component to evaluate the extent of the transport effect between migratory and resident ungulate species, and between migrants and livestock. Finally, we expect to have a large dataset on species occupancy data from our camera trap array available, now that suitable AI tools for image analysis are finally in place. This will put us in a position to complete many of our remaining analyses for objective 1.
Impacts
What was accomplished under these goals?
Objective 1- To quantify the effect of animal movement on gastrointestinal nematodes (GIN) in resident wild herbivores and the external environment. a) Major activities Our work during this reporting period largely tracks the long-term monitoring conducted in 2022. We continue to hold monthly team meetings to discuss field and laboratory work, data analysis and project coordination. b) Data collected We have continued data collection (camera trap data, pasture and fecal samples, environmental data) for: i) our long-term longitudinal data set, and ii) pre- and post-migration periods of the study. We collected and processed monthly fecal samples from one migratory (wildebeest) and four resident (topi, hartebeest, Grant's gazelle and buffalo) herbivore species within our camera trap network. In addition, we have collected and analyzed nematode larvae from pasture samples on 10 permanent camera-trap locations. Our sampling effort doubles during pre-migration and post-migration months (May-Jun and Oct-Nov). In addition, we have collected hourly environmental data (soil moisture and temperature) from 20 permanent sensor nodes located within our camera-trap sampling sites. We have also collected herbivore distribution data from a network of > 100 camera traps distributed across our study area. c) Summary statistics and discussion of results First, we asked whether wildebeest dung deposition (a proxy for wildebeest occurrence at a site) affect GIN density in the environment. Accounting for seasonal variation in wildebeest movement strategy, we found that wildebeest dung density was strongly associated with positive deviations in environmental GIN density at the site level during the short rainy season (~Nov-Dec), but not other seasons. Rainfall and grass height also affected GIN density in the environment, but these factors were independent of the effect of wildebeest density. This result suggests that during some phases of the migration cycle, wildebeest can transport gastrointestinal worms into habitats occupied by resident species potentially elevating exposure risk to these species. Second, we asked whether higher GIN densities in pasture represent a risk factor for resident infection. Accounting for various environmental factors, including seasonality, we found that GIN density at a site is positively associated with the probability that a resident species sampled near that site is infected with GIN. This result suggests that GIN densities in the environment translate to higher risk of infection in resident species. Finally, we asked whether given our observations of seasonally-varying effects of wildebeest on GIN densities in the environment and associations between GIN densities and resident infection risk, wildebeest presence affects GIN infection rates in resident herbivores.Notably, while we found positive associations between wildebeest density and GIN intensity for hartebeest and buffalo in the short and long rainy seasons, respectively, suggesting a transport effect of wildebeest on GIN parasitism in this context, we found negative effects of wildebeest on GIN intensity for hartebeest, topi, and Grant's gazelle in both the long rainy season and during the dry seasons. These negative associations suggest that during some parts of the migratory cycle wildebeest may exert strong trophic effects on GIN reducing infection risk to resident herbivores. Objective 2- To evaluate if and how mobile host movement intensity and duration modulate trophic and transport effects. a) Major activities We completed our first proposed field experiment (simulation of transport and trophic effects of varying intensity and duration) in the last reporting period. In addition, we designed and performed a second experiment aimed at examining the short- and long-term effects of fire on parasite larvae in forage. This work consisted of a targeted experiment design to quantify larval mortality and persistence following fire, followed by observational longitudinal studies of larval abundance and its drivers in blocks of paired burned vs. control plots. b) Data collected Pasture larvae were collected from 25 plots (5 treatments x 5 replicates) at three time points over the course of the experiment. Microclimate data (temperature and soil moisture) were collected simultaneously. We conducted six monthly surveys of pasture height, herbivore visitation, fecal abundance, pasture larval abundance and environmental conditions in burned vs. control plots. c) Summary statistics and discussion of results The data analysis on experiment 1 is complete, with results showing strong effects of simulated migration intensity on larval abundance. The publication of this work is still in the preparation stage. Data analysis on the fire study show that fire effectively "cleanses" forage patches of nematode larvae, and that herbivores reinforce a state of low pasture biomass in previously-burned plots. This work has now been published. Objective 3- To develop a general model of infection risk as a function of transient host movement dynamics. a) Major activities We have produced a mathematical model of the system based on existing data. Our goal is to refine the model with field-derived parameters over the course of the project. b) Data collected We have collected no new data for this project, but continue to use existing data from Objectives 1 and 2 to refine model parameters. c) Summary statistics and discussion of results The model results suggest that migration has the potential to either enhance or reduce infection rates in residents, depending on the relative magnitude of transport or trophic (parasite removal) effects. Increases in migration intensity and/or duration magnify these baseline effects. Objective 4- To use insights from wild mobile herbivores to predict patterns of GIN spillover to livestock. a) Major activities Our team continues to collect fecal samples from areas within Serengeti National Park and paired adjacent livestock-dominated areas. b) Data collected This work is being led by our collaborators at the University of Galsgow. There is ongoing collection of fecal samples and culturing of larval samples for DNA analysis. c) Summary statistics and discussion of results Strongyle nematodes were detected in > 70% of cattle, > 95 of goats and > 90% of sheep.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Donaldson, J. E., Holdo, R. M., Anderson, T. M., Morrison, T. A., Hopcraft, J. G. C., McIntyre, J., Devaney, E., Hempson, G., Senso, B., Trentinus, A., & Ezenwa, V. O. (2023). Direct and indirect effects of fire on parasites in an African savanna. Journal of Animal Ecology, 92, 23232332. https://doi.org/10.1111/1365-2656.14013
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2024
Citation:
Donaldson, J.E., Ezenwa, V.O., Morrison, T.A., Holdo, R.M.
Effects of migratory animals on resident parasite dynamics.
Trends in Ecology & Evolution, 2024. doi.org/10.1016/j.tree.2024.01.005
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
CRWAD January 2024 meeting
The role of animal migration in spreading environmentally transmitted parasites
Vanessa Ezenwa, Jason Donaldson, Houssein Kimaro, Basil Senso, Aiden Trentinus, T. Michael Anderson, Eileen Devaney, Gareth Hempson, J. Grant C. Hopcraft, Jennifer McIntyre, Thomas Morrison, Ricardo Holdo
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Savanna Science Network Meeting, Skukuza, South Africa, 2023
Fire and macroparasites: quantifying the benefits of seasonal fires for wild ungulates
Donaldson, J. E., Ezenwa, V. O., Anderson, T. M., Senso, B., Trentinus, A. and Holdo, R.M.
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Progress 01/01/22 to 12/31/22
Outputs
Target Audience:Our target audiences were: The scientific community: we presented our work at two international conferences, with a focus on the modeling aspects of the project. Tanzanian wildlife officials: throughout 2022 we continued to engage withTAWIRI (Tanzanian Wildlife Research Institute) and TANAPA (Tanzanian National Parks) personnel, both inArusha, Tanzania, and at the Serengeti Wildlife Research Institute in Serengeti National Park. Livestock producers: beginning in late in 2021 and continuing through 2022,wecollectedfecal samples from livestock and wildbeest in areas of overlap between the two outside Serengeti. Project personnel continued to interactwith livestock herders to explain the rationale for the project. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Postdoctoral Associate Jason Donaldson submitted a manuscript based on project work, and developed a new study focused on the role of fire in the system. In addition, he had the opportunity to co-teach two undergraduate courses in 2022, including a field course. Two Tanzania post-baccalaureate students (Basil Senso and Aidan Trentinus) were recruited to serve as research technicians on the project. As part of this role, both students were trained in parasitological techniques (nematode egg and identification quantification from ruminant feces, nematode larvae culture, isolation and preservation, and nematode larvae isolation and quantification from pasture). In addition, Basil and Aidan received training on aspects of data entry and basic analysis. Basil is currently developing an independent project focused on lungworms in the study system and Aidan is developing an independent project focused on protozoa (coccidia). Basil has applied to the MS program in Ecology at UGA, and will join the program as a graduate student in 2024. Jeremia Serakikya, who is responsible for field work, continues to gain new field skills, most recently with the addition of tick sampling in the project plots. Houssein Kimaro is a Tanzanian PhD student who matriculated at University of Glasgow in October 2021, was trained in field and lab methods related to parasite sampling, and led the execution of the first project experiment in 2022. How have the results been disseminated to communities of interest?Project results have been shared with the Tananzia Wildlife Research Institute (TAWIRI) and the Tanzania Commission on Science and Technology (COSTECH). In addition, Dr. Donaldson has presented project results at two international scientific meetings. What do you plan to do during the next reporting period to accomplish the goals?We have now set up the second of our two main experiments, and expect to complete its first iteration by the end of the reporting period (Objective 2). We also expect to submit a manuscript based on the results of our first field experiment. We have finally completed the image analysis pipeline for our camera trap data. We expect to continue to collect fecal and pasture samples for analysis and to complete the first data analysis and manuscript for the main component of the project (Objective 1). We also expect to submit a second manuscript on the modeling component of the stuyd, parameterized from project field data (Objective 3). Finally, ourUK collaborators will be in a position to conduct analyses of fecal samples collected at the wildlife-livestock interface (Objective 4).
Impacts
What was accomplished under these goals?
Impact This research is quantifying how multiple potentially opposing processes act to diminish or enhance the level of threat that parasites carried by mobile or migratory animals pose to resident animals, including livestock. This effort is significant because animal movement has been implicated in the spread of a number of infectious diseases of human and animal health importance, yet the rules that govern when or where such outcomes are to be expected are almost entirely unknown. We spent our first year setting up the tools (lab, field, computational) needed to complete the work, and in this second reporting period are well into our long-term data collection and experimental work. PI Holdo worked with the project postdoc (Donaldson) on the environmental sensor network, experimental design, and modeling. Co-PI Ezenwa developed protocols for parasite sampling, trained lab personnel, oversaw the expansion of data collection to include the sampling of additional parasite and commensal taxa (e.g., respiratory nematodes, protozoa, gut microbiota, ticks), while co-PI Anderson deployed the camera trap network and developed image analysis algorithms. Postdoc Donaldson worked on all aspects of field data collection, including both the observational and experimental components of the study, coordinated field and lab personnel, and led model development. Field assistant Norbert Munuo maintained the Snapshot Serengeti camera trap network and downloaded imagery from SD cards every month. We anticipate that our results will impact management decisions in both natural ecosystems and rangeland, because we ultimately propose to provide tools to help us understand what the net effect of allowing animals to move over large areas will have on parasite intensity and prevalence. Accomplishments Objective 1- To quantify the effect of animal movement on gastrointestinal nematodes (GIN) in resident wild herbivores and the external environment. a) Major activities During the reporting period, we collected and processed monthly fecal samples from one migratory (wildebeest) and four resident (topi, hartebeest, Grant's gazelle and buffalo) herbivore species within our camera trap network. In addition, we have collected and analyzed nematode larvae from pasture samples on 10 permanent camera-trap locations. Our sampling effort doubles during pre-migration and post-migration months (May-Jun and Oct-Nov). In addition, we have collected hourly environmental data (soil moisture and temperature) from 20 permanent sensor nodes located within our camera-trap sampling sites. We have also collected herbivore distribution data from a network of > 100 camera traps distributed across our study area. b) Data collected We have continued data collection (camera trap data, pasture and fecal samples, environmental data) for: i) our long-term longitudinal data set, and ii) pre- and post-migration periods of the study. Over the course of the reporting period (2022), we have collected 2244 fecal samples from 507 wildebeest, 452buffalo, 429hartebeest, 431 Grant's gazelle and 425 topi. We performed nematode fecal egg counts on all samples and cultured a subset of 400 samples. Over 10000 individual larvae were preserved for molecular barcoding in the US. We have also carried out monthly pasture larvae sampling at 10-20 focal sites, for a total of 186 pasture samples. In 2022, we also began to sample ticks within our focal pasture plots. We also started quantifying respiratory nematodes (lungworms) from fecal samples focusing on the Alcelaphines (hartebeest, topi, wildebeest),and preserving feces from all focal herbivores for gut microbiome analysis. c) Summary statistics and discussion of results Strongyle nematodes were detected in 75.7% of wildebeest (384/507), 50.4% of buffalo (228/452), 93.5% of hartebeest (401/429), 97.9% of Grant's gazelle (422/431) and 93.9% of topi (399/425) samples. These data show an expected pattern of variation among herbivore species in levels of parasite infection, including high prevalence and intensity in Grant's gazelle and relatively low prevalence and intensity in buffalo. We also saw variation in the number of different nematode taxa present different herbivores. We exported the first batch of nematode larvae collected between October 2021 and December 2022 to Yale U. for molecular barcoding. This work will commence in mid-2023 and will provide us with more fine-scale information of the degree of parasite sharing across herbivores. Given the observed variation in parasite prevalence, intensity, and species composition across resident herbivores, we are well-positioned to examine the differential impacts of wildebeest migration on parasitism in these species. Objective 2- To evaluate if and how mobile host movement intensity and duration modulate trophic and transport effects. a) Major activities We have now completed our first proposed field experiment (simulation of transport and trophic effects of varying intensity and duration). In addition, we designed and performed a second experiment aimed at examining the short- and long-term effects of fire on parasite larvae in forage. This work consisted of a targeted experiment design to quantify larval mortality and persistence following fire, followed by observational longitudinal studies of larval abundance and its drivers in blocks of paired burned vs. control plots. b) Data collected Pasture larvae were collected from 25 plots (5 treatments x 5 replicates) at three time points over the course of the experiment. Microclimate data (temperature and soil moisture) were collected simultaneously. We conducted six monthly surveys of pasture height, herbivore visitation, fecal abundance, pasture larval abundance and environmental conditions in burned vs. control plots. c) Summary statistics and discussion of results The data analysis on experiment 1 is not yet complete, but preliminary results suggest strong effects of simulated migration intensity on larval abundance. Data analysis on the fire study show that fire effectively "cleanses" forage patches of nematode larvae, and that herbivores reinforce a state of low pasture biomass in previously-burned plots. Preliminary results suggest that this low biomass state may expose larvae to harsher environmental conditions and higher mortality. We expect to complete data analysis and publication submission for this study in 2023. Objective 3- To develop a general model of infection risk as a function of transient host movement dynamics. a) Major activities We have produced a mathematical model of the system based on existing data. Our goal is to refine the model with field-derived parameters over the course of the project. b) Data collected The first version of the model is based on parameters collected from published studies. c) Summary statistics and discussion of results The model results suggest that migration has the potential to either enhance or reduce infection rates in residents, depending on the relative magnitude of transport or trophic (parasite removal) effects. Increases in migration intensity and/or duration magnify these baseline effects. Objective 4- To use insights from wild mobile herbivores to predict patterns of GIN spillover to livestock. a) Major activities Our team continues to collect fecal samples from areas within Serengeti National Park and paired adjacent livestock-dominated areas. b) Data collected Over the reporting period we have collected 688 fecal samples to date from 228 cattle, 231 sheep and 229 goats. Fecal egg counts were performed on all samples. A subset of samples (31 goats, 31 cattle and 30 sheep) were cultured; 7615 individual total larvae were preserved for DNA analysis and exported to UK partners at the University of Glasgow. c) Summary statistics and discussion of results Strongyle nematodes were detected in 70.6% (159/228) of cattle, 95.1% (218/229) of goats and 91.8% (212/231) of sheep.
Publications
- Type:
Journal Articles
Status:
Under Review
Year Published:
2023
Citation:
Donaldson J.E., Ezenwa, V.O., Morrison, T., and Holdo, R.M. Animal migration and parasitism: the key roles of migration intensity and duration. Ecology Letters, in review.
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Progress 01/01/21 to 12/31/21
Outputs
Target Audience:Our target audiences for this reporting period were the following: Tanzanian wildlife officials: much of the first year of the project was spent on permitting and project setup activities. A key goal was to reach out to Tanzanian stakeholders to gain support for our proposed research activities. Our main approach in this regard consistet of meetings with TAWIRI (Tanzanian Wildlife Research Institute) personnel, both in the main office in Arusha, Tanzania, and at the Serengeti Wildlife Research Institute in Serengeti National Park. Livestock producers: second, late in 2021 we began the process of collecting fecal samples from livestock and wildbeest in areas of overlap between the two outside Serengeti. Project personnel interacted with livestock herders to explain the rationale for the project. Changes/Problems:COVID-19 delayed our ability to begin field work in Serengeti until mid-2021. As a result, we have had to shift our experimental timeline around. We had originally intended to conduct experiments 1 and 2 in years 1 and 2, respectively. We will now conduct these experiments in years 2 and 3, respectively. Other aspects of our project are proceeding as planned or ahead of schedule. To compensate for our inability to beging field work until July 2021, we prioritized model development in year 1. This work was originally slated to begin in year 2. What opportunities for training and professional development has the project provided?Postdoctoral Associate Jason Donaldson has developed mathematical modeling skills, a key addition to his scientific toolkit. In addition, he has been honing his grant-writing skills and submitted a research grant proposal in 2021. Two Tanzania post-baccalaureate students (Basil Senso and Aidan Trentinus) were recruited to serve as research technicians on the project. As part of this role, both students were trained in parasitological techniques (nematode egg and identification quantification from ruminant feces, nematode larvae culture, isolation and preservation, and nematode larvae isolation and quantification from pasture). In addition, Basil and Aidan received training on aspects of data entry and basic analysis. Basil and Aidan are responsible for the processing of fecal and pasture samples. Jeremia Serakikya and Meritho Katei, who are responsible for field work, added to their existing field skills through training on nematode pasture sampling techniques. Finally, Houssein Kimaro is a Tanzanian PhD student who matriculated at University of Glasgow in October 2021 and was trained in field and lab methods related to parasite sampling. 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?In 2022 we plan to collect field data (pre- and post-migration) for two migration events (May-Jun and Nov-Dec). In addition, we will conduct Experiment 1 in Feb-Mar 2022. We will have completed a first version of our modeling study and submitted it for publication. In addition, we continue to collect livestock fecal samples and conduct our first analyses (including genotyping) of pasture and fecal sample data collected in 2021 and 2022.
Impacts
What was accomplished under these goals?
Impact This research will quantify how multiple potentially opposing processes play in diminishing or enhancing the level of threat that mobile animals pose to resident animals, including livestock. This effort is significant because animal movement has been implicated in the spread of a number of infectious diseases of human and animal health importance, yet the rules that govern when or where such outcomes are to be expected are almost entirely unknown. We spent our first year setting up the tools (lab, field, computational) needed to complete the work, and have begun the data collection phase. PI Holdo worked with the project postdoc (Donaldson) on the environmental sensor network, archived camera trap data and modeling. Co-PI Ezenwa worked with the postdoc on lab setu , developed protocols for parasite sampling, and trained lab personnel, while co-PI Anderson deployed the camera trap network and developed image analysis algorithms. Postdoc Donaldson worked on all aspects of field logistics, including site selection, laboratory setup and coordination of field and lab personnel, and led model development. No Field assistant Norbert Munuo maintained the Snapshot Serengeti camera trap network and downloaded imagery from SD cards every month. We anticipate that our results will impact management decisions in both natural ecosystems and rangeland, because we ultimately propose to provide tools to help us understand what the net effect of allowing animals to move over large areas will have on parasite prevalence. Accomplishments Objective 1- To quantify the effect of animal movement on gastrointestinal nematodes (GIN) in resident wild herbivores and the external environment. a) Major activities During the reporting period, we: -Purchased/acquired all necessary project equipment (laboratory equipment and supplies, camera traps, environmental sensor components, etc.). -Secured project housing, permits, necessary lab space, internet service and project vehicles. -Set up a laboratory for processing of pasture and fecal samples in Serengeti. This included installing a solar system for powering lab equipment (centrifuges, microscopes, fridge/freezer). -We hired and trained a lab and field team. -Used pre-existing data on animal distribution patterns were used to identify focal monitoring sites at 100 camera-trap locations. -Refurbished our camera trap network, installing 150 new cameras. -Fabricated and installed 75 of our projected 100 environmental sensor nodes. -Conducted monthly group meetings for project coordination. -Have deployed 8 new GPS collars on wildebeest to track their movement patterns through the study sites. This is supplemented by an additional 15 GPS collars from a related ongoing study. -Refurbished 5 of our automatic weather stations within our camera trap network. -Developed field protocols for animal and pasture parasite sampling and initiated parasite data collection. We initiated 'baseline' and 'migration' parasite sampling in October 2021. This involved developing and implementing a sampling scheme for collecting 20 fecal samples per host species (buffalo, grant's gazelle, hartebeest, topi, wildebeest) in months designated as 'baseline' and 40 samples per host species in months designated as 'migration'. Sample collection is distributed across the target camera sites described above. We also developed a protocol for isolating and archiving third-stage nematode larvae collected from 'migration' month fecal samples. Finally, we developed a protocol for quantifying nematode larvae in pasture at select camera sites, including 10 sites that are sampled in 'baseline' months and 20 sampled in 'migration' months. -Created a secure shared folder to store all project data (fecal sample egg counts, pasture larval density). -Developed a first iteration of a mathematical model of the system (to be submitted for publication in 2022). b) Data collected We began data collection (camera trap data, pasture and fecal samples, environmental data) for: i) our long-term longitudinal data set, and ii) the first pre- and post-migration period of the study. To date we have collected 535 fecal samples from 103 wildebeest, 109 buffalo, 105 hartebeest, 111 Grant's gazelle and 107 topi. We performed nematode fecal egg counts on all samples and cultured a subset of 200 samples. Over 10000 individual larvae were preserved for molecular barcoding in the US. We have also carried out monthly pasture larvae sampling at 10-20 focal sites. Importantly, we have completed parasite sampling for one of six proposed 'pre-migration' periods. c) Summary statistics and discussion of results Strongyle nematodes were detected in 68% of wildebeest (70/103), 46% of buffalo (50/109), 94% of hartebeest (99/105), 97% of Grant's gazelle and 90% of topi (96/107) samples. These data show an expected pattern of variation among herbivore species in levels of parasite infection, including high prevalence and intensity in Grant's gazelle and relatively low prevalence and intensity in buffalo. We also saw variation in the number of different nematode taxa present different herbivores. For example, lungworms were commonly observed among the Alcelaphines (hartebeest, topi, wildebeest). Future molecular barcoding of larval samples will provide us with more fine-scale information of the degree of parasite sharing across herbivores. Given the observed variation in parasite prevalence, intensity, and species composition across resident herbivores, we are well-positioned to examine the differential impacts of wildebeest migration on parasitism in these species. Objective 2- To evaluate if and how mobile host movement intensity and duration modulate trophic and transport effects. a) Major activities We set up our first field experiment (simulation of transport and trophic effects of varying intensity and duration) and recruited a Tanzanian graduate student to run the experiment (supervised by collaborator Morrison, UK PI). b) Data collected None to date c) Summary statistics and discussion of results We have no results to discuss at present. Objective 3- To develop a general model of infection risk as a function of transient host movement dynamics. a) Major activities We have generated a first draft of a mathematical model designed to explore the effect of introducing migratory animals into resident grazer system. b) Data collected The first version of the model, intended to be general, is based on parameters collected from published studies. c) Summary statistics and discussion of results Preliminary model results suggest that introducing migrants into a grazing system leads to major changes in parasite intensity in resident species. Objective 4- To use insights from wild mobile herbivores to predict patterns of GIN spillover to livestock. a) Major activities We have recruited project personnel to conduct this component of the project, and have begun data collection on livestock fecal samples in areas of domestic/wild ungulate contact. b) Data collected We have collected 160 fecal samples to date from 53 cattle, 53 sheep and 54 goats. Fecal egg counts were performed on all samples. A subset of samples (11 goats, 11 cattle and 9 sheep) were cultured; 1819 individual total larvae were preserved for DNA analysis and exported to UK partners at the University of Glasgow. c) Summary statistics and discussion of results Strongyle nematodes were detected in 75.4% (40/53) of cattle, 88.9% (48/54) of goats and 88.7% (47/53) of sheep.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Holdo, R.M., Donaldson, J.E, Anderson, T.M, and Ezenwa, V.O. 2021. Transport and trophic effects of animal movement on gastrointestinal nematode infection. CRWAD Annual Meeting virtual poster presentation.
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