Our Team

Theresa Crimmins is the Director for the USA National Phenology Network and has been a part of the organization since 2007. Hailing from Ohio and Michigan, she received a B.S. and M.A at Western Michigan University and a Ph.D. from the University of Arizona. In her role with the Network, Theresa supports an amazing team of individuals and works enthusiastically to support the growth and use of phenology data and resources curated by the USA-NPN, involvement in Nature’s Notebook, and a broader appreciation of phenology among scientists and non-scientists alike.

Theresa is also an Associate Professor in the School of Natural Resources and the Environment at the University of Arizona and has published over 70 peer-reviewed articles and book chapters in journals including Nature, Geophysical Research Letters, Global Change Biology, and Journal of Ecology. Her writing has  appeared in Scientific American, The Hill, and the Arizona Daily Star, and she has appeared in the PBS productions SciGirls and American Spring Live as well as on NPR and The Weather Channel. In 2022, she was recognized by the University of Arizona as a Woman of Impact.

Nathan Acosta works on development, enhancement, and maintenance of the USA-NPN's web platforms. His duties mostly involve working on USA-NPN's websites making sure they function smoothly and are able to meet researcher's and observer's needs. He works closely with the rest of the team to make sure all aspects of the IT infrastructure work as intended and efficiently as possible.

Nathan graduated from The University of Arizona and got a B.S. in Computer Science with an Informatics minor and an Undergraduate Certificate in Cyber Security. He grew up in Arizona's neighboring state of Sonora, Mexico and he is passionate about researching and preserving the immense biodiversity of the Sonoran Desert. When he's away from the keyboard he likes to learn new cooking recipes, play the piano, and spend time with his family and dogs.

Samantha Brewer communicates with new and existing Nature’s Notebook observers and organizations through engaging activities, newsletters, campaigns, and training materials. She coordinates with Local Phenology Leaders to strengthen their programs and assist in volunteer recruitment and retention strategies. She also works to identify communities that are underrepresented in the scientific field and offers guidance for them to develop their own Local Phenology Programs that fit the needs of their organizations and produce quality data. Samantha leads the Local Phenology Leader Certification Course, and supports the Local Phenology Leader Community of Practice.

Samantha earned her Bachelor’s and Master’s degrees in biology at Northern Arizona University. She has worked across the state of Arizona studying avian ecology, with her Master’s thesis focusing on Gray Hawk population changes along the San Pedro River. She also has a background in Education - teaching biology and ecology at both the college level and K-12 settings. Prior to working for the USA-NPN, she worked as an Educator and Certified Local Phenology Leader for the Reid Park Zoo in Tucson. In her free time, she loves cross-stitching, gaming, and running along The Loop trail. 

Ellen Denny coordinates the development of the USA-NPN protocols for the collection of standardized ground-based plant and animal phenology observations across the nation.  She also serves as a scientific data manager for the National Phenology Database, and as a global liason, helping to advise developing national phenology networks around the world, and working towards global integration of phenology data.
 
Ellen has a B.S. in Aquatic Biology from Brown University, and an M.F.S. (Forest Science) from the Yale School of the Environment (formerly Yale School of Forestry & Environmental Studies). Her professional interests began in marine invertebrate ecology, shifted to ecological restoration, and eventually landed in terrestrial ecosystem ecology. She spent a decade working as a field ecologist and data manager in the forests of New England before coming to the USA-NPN in 2008. Ellen lives in Kittery, Maine, and participates remotely in the Tucson-based National Coordinating Office.

Erin Posthumus manages USA-NPN projects that inform decisions and advance science. She serves as the USA-NPN lead for key partnerships including USFS, USFWS, NPS, and Audubon; coordinates activities to support the creation of new data products; and implements and oversees data collection campaigns at local to national scales. Erin oversees communications and works to establish new partnerships for the USA-NPN.

Erin received a B.A. in Environmental Biology from the University of Colorado at Boulder and a M.S. from the University of Arizona's School of Natural Resources and the Environment. With a background in wildlife conservation and management, she spent several years working as a wildlife field technician in locations across the country before serving in the Peace Corps in Vanuatu from 2007-09. Erin has been with the USA-NPN since 2010. Erin enjoys hiking, baking, and tending her small urban farm.

Jeff Switzer will be using his programming skills to enhance and debug all aspects of the USA-NPN's IT infrastructure. His duties range from solving problems with the mobile apps to creating features for the website to optimizing the database. He assists the USA-NPN team in making processes and functionalities more efficient and more adept to handling observer’s needs.  

Jeff graduated from the University of Wyoming with B.S. degrees in computer science and mathematics. As a graduate student, he researched resource-bounded dimension and joined a startup where he developed an electronic medical records system. He then spent two years teaching in Africa before joining the NPN team. When he's not coding you can find him camping, mountain biking, making music, and drinking tea.

Erin Zylstra is a quantitative ecologist who specializes in the development and application of analytical tools to better understand ecological processes and inform conservation efforts. She has developed hierarchical modeling frameworks to characterize demography and population dynamics of wildlife species and helped to design and evaluate monitoring programs for species of conservation concern. Erin joined NPN as a Research Scientist in 2024 and is interested in assessing the effects of climate and land use change on plant and wildlife populations and optimizing sampling methods to obtain high-quality data to inform these assessments.

Erin received a B.S. in Biology from the University of Michigan and then an M.S. in Statistics and an M.S. and Ph.D. in Wildlife Conservation and Management at the University of Arizona. She was a postdoctoral research associate at Michigan State University for several years, and more recently, was a Quantitative Ecologist with the Tucson Audubon Society. Erin has worked with a wide variety of species, including desert tortoises, amphibians, and monarch butterflies, but has a particular fondness for plants and animals in the Sonoran Desert of southern Arizona.

Hi, I'm Abhiram Rao Arshanapally, a junior at the University of Arizona majoring in Management Information Systems and Operations Supply Chain Management. I’m passionate about data analysis, sustainability, and entrepreneurship, and I founded Tree Organization, an environmental initiative in India focused on promoting sustainable practices. I’ve gained valuable experience as a Data Analyst Intern and grader for MIS courses, as well as leadership skills as the Vice President of the Worldwide Wildcats Club. I’m very excited to be working as a Student Data Assistant with the USA-NPN, where I can apply my skills to meaningful projects. I look forward to contributing to impactful work while continuing to grow in this role!

Monica Brody-D'Urso is a junior at the University of Arizona, where she is pursuing a major in Medicine and a minor in Biochemistry. She aims to become a primary care physician in her community, exploring the integration of herbal and allopathic medicine in clinical practice. Monica is actively involved in various clubs, including Mycocats, a mushroom foraging group; the CEASA hydroponics club; Flying Sams, which offers clinics in Mexico; the Mobile Health Unit; and Humane Borders. In her free time, she enjoys gardening, painting, and cooking. She is thrilled to work with USA-NPN, as it allows an outlet for her love of plant sciences.

Ram Dheeraj is a graduate student at the University of Arizona majoring in Data Science. He is originally from Hyderabad, India, working with USA-NPN as a Web Analyst Assistant. He assists the USA-NPN team to enhance its Google Analytics platform. He usually likes to play chess and cricket in his free time.

Chi is currently pursuing a Master's degree in Management Information Systems at the University of Arizona. With a background in outreach, data analysis, and program and product management within the climate tech sector, Chi will be contributing to various upcoming projects at USA-NPN. These projects will involve tasks such as project management, streamlining data visualization, and assisting with Figma mockups. In her free time, she enjoys visiting national parks and spending time on the pottery wheel.

Mano Tainatongo is an undergraduate student at the University of Arizona majoring in Natural Resources. Mano is from Tucson, Arizona and is working as student administrative assistant for the USA-NPN. Outside of school Mano enjoys hiking and camping all across Arizona.

Hello! My name is McKinsey, and I'm a sophomore at the University of Arizona studying Natural Resources with an emphasis in Conservation Biology in hopes of becoming a Wildlife Biologist. I've been using Nature's Notebook for my studies since I began at UofA, and I'm ecstatic to be working with USA-NPN to help share their awesome projects!

I’m originally from Goldsboro, North Carolina and moved to Tucson in May of 2019. I’m currently waiting for my application to the U of A to be approved but hope to study Ecology and Environmental Biology in the fall, I enjoy hiking and learning about animals as well as their ecosystems. I also enjoy learning about plants and at one point and time grew various types of cactus. 

Jeremy Clark is helping USA-NPN to develop a multiyear strategy to ensure that it thrives well into the future. Jeremy is a strategy advisor and business builder with experience at many successful research and innovation-centric companies including Xerox PARC and Comcast. He earned an MBA from the University of Chicago, and his functional experience covers technology research and innovation, strategy development, business model transformation, and product development.

Jeremy has recently been working to apply this experience to the sustainable development challenge for business. He took a career break in 2022 to study for an MSc in Sustainable Development from the University of Surrey in England, which definitely changed his frame of reference for what should be considered good growth! He enjoys hiking, biking, and any interactions with dogs, and he is increasingly fascinated by phenology and its amazing potential for informing climate change response.

Alison M. Meadow is an Associate Research Professor based in the University of Arizona’s Office of Societal Impact. She has a background in environmental anthropology, Indigenous studies, and urban planning. She received her PhD in Anthropology from the Resilience and Adaptation Program at the University of Alaska Fairbanks. Alison’s research focuses on the process of linking research with decision making to improve the usability of science with an emphasis on evaluating the societal impacts of research. She is a co-investigator with the NOAA-funded Climate Assessment for the Southwest (CLIMAS). Alison works with research programs to help them move research into use by communities, practitioners, and policymakers. Outside of work, Alison can usually be found swimming and hiking – or at home with a stack of good books.

Rob Guralnick is a Curator and Professor at the Florida Museum of Natural History.  His research work focuses on global change and much of his work centers of understanding how species respond to disturbance.  He has a special interest in phenology, both in terms of how species respond phenologically to change and how to develop phenology data and knowledge resources for the community.  He is a current PI on Phenobase, which is focused on integrating data on phenology globally and is a collaborative PI on new funding to support the National Phenology Network.  His work with NPN will be focused on  integration with other global biodiversity resources.  Dr. Guralnick has a PhD in Integrative Biology from the University of California at Berkeley. 

Erin Grady is botany master’s student at the University of Florida and a graduate research assistant on the Nature's Notebook mobile app project. Her thesis focuses on the dynamics of iNaturalist user activity and their role in filling spatial data gaps. She is passionate about connecting individuals to their local natural environments and is working towards an Environmental Education and Communication graduate certificate alongside her degree. Other interests include urban forestry and equitable access to recreation and green space. She holds a Bachelor of Science in Biology from California Polytechnic State University, San Luis Obispo.

Janet Prevéy is a global change ecologist with the United States Geological Survey at the Fort Collins Science Center in Colorado. Her research synthesizes information from reciprocal transplant studies, manipulative experiments, community scientist observations, satellite imagery, and long-term monitoring plots to explore how environmental changes influence phenology and vegetation dynamics across different spatial and temporal scales. Learn more about Janet's research. 

Janet is working with the USA-NPN to explore the value of USA-NPN data and identify species and phenophases that are highest priority to science and management applications to emphasize for continued monitoring. 

Kerissa is a research ecologist and strategic advisor whose work is focused on catalyzing community science research and building capacity for organizations in the field of science and education. She has worked as a collaborator with the USA-NPN since 2010 and manages the New York Phenology Project. She is currently working with the USA-NPN team as a multi-agency strategic project manager for the Northeast Climate Adaptation Center funded project titled “Thermal Calendars for a Changing Climate.”  She lives in the Catskill Mountains of New York and loves to grow things. 

Jane Breckinridge is the director of the Euchee Butterfly Farm located in Leonard, Oklahoma. She is also the co-director of the Tribal Alliance for Pollinators, which unites traditional ecological knowledge with cutting edge technical resources to create an innovative model for conservation and restoration of tribal lands. Jane leads the Oklahoma efforts for Time to Restore. 

David Gwin is the Texas State Coordinator for USA-NPN’s Time to Restore.  In this capacity, he works with stakeholders across the Lone Star State to identify, setup and monitor sites that generate better information about nectar availability and fruit production to ultimately help inform those working on pollinator restoration to know what to plant and when to harvest seed. 

David earned his Bachelor of Arts and Master of Science degrees from Oklahoma State University in Stillwater, Oklahoma.  After completing his formal education, he spent over three decades in professional public service with six Texas communities in developing, administering, and refining their local economies.  Since leaving municipal service, David has wholly devoted himself to his lifelong passion, which is better understanding, actively appreciating, and enthusiastically conserving our diverse natural resources.  He was certified as a Texas Master Naturalist in 2005 and has been an active participant in that statewide volunteer service effort in four different ecoregions of the state.  In his free time, David loves hiking, camping, and almost anything else that keeps him out in the wilder parts of Texas. 

Gina Lloyd has been working with citizen science programs in both a volunteer and professional capacity for over three years. She has trained volunteers for FrogWatch USA data collection walks since 2019 and regularly leads these walks with a large local network of citizen science volunteers and academics. Since beginning work at the Jean Lafitte Barataria Preserve, she has also helped develop volunteer training workshops and led data collection hikes for the Nature’s Notebook program. As the Louisiana State Coordinator for Time to Restore, Gina is working to establish several new Nature’s Notebook monitoring sites across the state in partnership with communities interested in tracking phenological changes.

Rachel Goland is excited to collaborate with USA-NPN and the US Forest Service on the Shifting Seasons project to better understand and support Forest Service needs for phenological information. Rachel received her B.S. in Environmental Science from Cornell University in 2020. She now lives in New York’s Adirondack Park where she works as a land manager for New York State. Outside of work, she enjoys exploring the wilderness on foot or by boat, foraging for fungi, and reading books of all genres. 

Georgia Murray is a Staff Scientist with the Appalachian Mountain Club. Previously she has conducted biogeochemical research for the Marine Biological Laboratory’s Ecosystem Center at Toolik, Alaska a Long-term Ecological Research site and worked at the University of Washington maintaining a long-term small watershed monitoring site within Olympic National Park. Georgia currently oversees Appalachian Mountain Club’s ambient air pollution program in cooperation with the U.S. Forest Service including mountain-based monitoring of cloud, rain, and stream water chemistry in Wilderness areas in the White Mountain National Forest. She also leads AMC’s plant phenology monitoring work using Nature’s Notebook, which incorporates community science, and conducts mountain climate research. Back in 2010, Georgia suggested "Nature's Notebook" as the name for the USA-NPN's data collection program - thank you, Georgia!