What determines when flowers bloom? When butterflies emerge from their chrysalises? When trees drop their leaves? Or when birds migrate? Answers to these and other questions about plant and animal lifecycle events can be found in the science of phenology. Nature’s clock is guided by three main factors: sunlight, temperature, and precipitation. The health of species and ecosystems depends on lifecycle events happening at the right time. Imagine if flowers bloomed before their pollinators emerged. Or if birds migrated to feeding grounds that lacked the fruits they were intending to forage on. The Fern Glen Phenology Trail builds on the Cary Institute’s commitment to environmental monitoring, with the goal of managing healthy ecosystems. In this project, citizen scientists make and record observations of plants along the Fern Glen Phenology Trail (located on the Cary Institute campus), according to protocols established by the National Phenology Network. Participants submit data to the Network’s database, where they can be accessed by scientists, teachers, and citizens interested in studying how plant lifecycle events are changing over time. The task: After attending a training session and setting up a 'Nature's Notebook' observer account on the National Phenology Network (NPN) website, participants will visit the Fern Glen Phenology Trail and answer questions about the development of the marked plants on the trail. Observers collect data either using datasheets that can be downloaded from the NPN website or the NPN mobile phone app. If you use datasheets, the data must be entered into the NPN website. Data collected using the mobile phone app are automatically uploaded to the NPN database. That’s it! This program is a collaborative effort with the New York Phenology Project (NYPP) and the Environmental Monitoring & Management Alliance (EMMA).