You are here

Spring desert near one of the Tucson Phenology Trail sites, the Santa Rita Experimental Range in Green Valley, Arizona.

Image credit:
LoriAnne Barnett

Tucson Phenology Trail

The Tucson Phenology Trail seeks to link the University of Arizona to the community, encourages people to engage in active, outdoor education, ask and answer local science, management, and climate questions, and connects like-minded organizations together through a shared community project.   

Instagram Follow us on Instagram!    Check us out on Facebook! 
Contact us by email:

Our Partners

Covering almost 75 miles in the greater Tucson, Arizona area, the Tucson Phenology Trail consists of walks at our wonderful partnering organization sites. You will find a sample of the species we are tracking below. Participate in Nature's Notebook and add your favorite Tucson group to your account—you can make observations there when you visit. Want to partner with us? Find details on how to do that below.

Partner locations

Species of Local Interest

The Plants 

Velvet mesquite Yellow and Blue paloverde Netleaf hackberry
Desert willow Goodding's willow Fremont cottonwood
Buffelgrass (invasive) Texas barometer bush Buckhorn cholla
Penstemmon Cloned and common lilac* Jojoba
Creosote bush Saguaro Ocotillo
Catclaw acacia Desert Ironwood Candy barrelcactus
Scarlet globemallow Coues' cassia (Desert senna) Butterfly milkweed
Bloodflower (milkweed) Rush milkweed Horsetail milkweed

Local Campaigns

Tracking Flowers for Bats in Southern Arizona

The US Fish & Wildlife Service, in partnership with the USA National Phenology Network, is seeking to better understand where and when nectar sources are available for bats while they are in Southern Arizona raising their young.

Nectar Connectors

We are seeking observers to learn about the flowering timing of nectar sources for monarchs and other pollinators! Pollinators are an essential part of our environment - they ensure the reproduction of 85% of the world's flowering plants, and over two-thirds of our crop species. Many threats, including habitat loss and use of pesticides, threaten these pollinators.

Southwest Season Trackers

Southwest Season Trackers is a partnership between researchers and volunteers to improve models that predict how plants in the southwest U.S. will respond to changing climate and also to enhance the efficiency of landscape restoration and management efforts in the region. For example, phenology can tell us when to harvest fruits of native plants, when to apply herbicides to unwanted shrubs, and when allergy season will begin.

Greenwave Southwest

We invite you to join us in tracking the “green wave”—the flush of green that accompanies leaf-out–-over the course of the spring season, as well as the spread of seasonal color across the country in the autumn.

We can only answer these campaign questions if we have enough consistent data available to make meaningful comparisons, so help us by making year-round observations! Read about the importance of having year-round observations on our plants and animals in this helpful article:

The Ocotillo and the Hummingbird: Year-round observations tell the best story.

Explore the data report created for the Tucson Dataset.


Adventure Awaits - Become a Nature's Notebook Observer! by Parker Liu

Phenology: Observe more about the natural world by Elena Acoba



If you live in Tucson or are just visiting, you can help us build a long-term dataset for the plants and animals we've tagged in Nature's Notebook

Follow these three steps:

  1. Register for a Nature's Notebook account
  2. Join the Tucson Phenology Trail Partner Group when you register by finding the group in the list. Click on the + to expand the list of participating sites and place a checkmark next to those you wish to visit. 
  3. Save your work at the bottom of the page to create your account. 

If you already have an account for Nature's Notebook:

  1. On the Edit My Account page, find the Tucson Phenology Trail Partner Group
  2. Click on the + sign to expand the list of participating sites and place a checkmark next to those you wish to visit. 
  3. Save your updated information and return to your Observation Deck to start observing. You can access your group sites from the site selection drop-down menu in the left column.

Partner your organization or group

Want to join our Tucson Phenology Trail? We are looking for like-minded organizations to use phenology as a science and outreach tool in their existing programs.  If your group:

  1. Provides outdoor education opportunities, teaches about ecology, science and climate literacy, and encourages spending time in nature
  2. Is a school or program looking to connect with a long-term scientific research project
  3. Has a site that is staffed by volunteers or paid staff members interested in leading programs related to phenology, who can be a site "phenology champion"
  4. Can commit to facilitating repeated phenology observation through time for our national phenology database 

Then we invite you to join us!  Contact our Education Coordinator for more details on how to participate and partner your organization.  


Share this content.