California Naturalist
California Naturalist
California Naturalist
University of California
California Naturalist

Northern CA PPSR Projects 1

Welcome to our ongoing effort to catalog citizen science and other public participation in scientific research (PPSR) projects for UC California Naturalists and other citizen scientists.  We invite you to browse the listed projects or enter key words (like birds, youth, invasive, coast, Alameda, etc.) in the search box above to find projects in your area. It's a great way to stay involved and keep developing your skills as a natural scientist!

A vast majority of the information in the database was gathered from project websites and may be out of date. We encourage you to contact projects directly to get involved and learn about most recent opportunities. If you work with a listed project and would like to add to, update, or correct the information we have, please email Also, please consider filling out the "PPSR perspectives" survey. Click here to access the survey, which will help guide this project in the coming year.

If you know of a project not on our list, please go to the "tell us about a project" link on the left so we can list the project here. Thanks for your help!

Special thanks goes to the National Science Foundation Informal Science Education program and the Stephen J. Bechtel, Jr. Foundation for supporting this database of projects.

Western Monarch Thanksgiving Count

Organization Name
Xerces Society
Organization Website
Cal Poly; National Parks Service; California Monarch Campaign
Contact Name
Mía Monroe
Contact Email
Contact Phone
Project Purpose (taken from project materials)

Census Western Monarch colonies at a number of locations along the California coast and help address questions about natal grounds for the migratory generation in the west and other factors relevant to monarch butterfly migration

Participant Activities

Collect data on the status of monarch populations overwintering along the California coast. The survey is conducted over a two-week period around the (American) Thanksgiving weekend in November, as well as around New Years.

Volunteers visit colonies near them during the early morning while monarchs are non-mobile. They can use binoculars to view clusters and estimate the number of monarchs per cluster, then extrapolate that to the remainder of the colony to derive an estimate of colony size.

Volunteers record the following survey data at each site using the standardized data form: date, site, observers, time spent searching for clusters, count time start and end, presence of nectar and water sources, and observations of tagged or mating monarch butterflies.

Data Entry
  • Data Sheets
Other Participant Activities
System Studied
  • Invertebrates
Geographic Scope
All (see 'geographic scope')
Western Monarch wintering sites along the California Coast
Location - Map
Time Commitment
  • Once a year
Volunteer Qualifications

Binoculars and minimal monitoring equipment

Volunteer Training
Cost to Participant
How will the findings be used?

Data, reports and resulting scientific publications are available on the website

Other Information

Surveys should be conducted at least once per season, although twice or more is preferred. If you can conduct only one survey this winter, it should be done during the week of Thanksgiving. If you can complete additional surveys, the next priority date is the week of January first (a New Years count). If you want to conduct more than these two surveys, feel free to establish weekly, bi-weekly or monthly schedules throughout the Monarch overwintering season (November through the first week of March). Even if you conduct surveys throughout the season, it is important to include counts at Thanksgiving and around New Years so we can compare population sizes among the sites.
Surveys should be conducted by at least two observers in the mornings while temperatures are low (usually below 13C or 55F) and monarch butterflies are still clustered.

last update:

If you work with this project and would like to add to or update the information below, please email

If you know of a project not on our list, please go to the "tell us about a project" link on the left so we can list the project here. Thanks for your help!

This database is focused on projects in California focused on the environment. For opportunities outside California, as well as national projects that don't have a California-specific components, check

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