California Biodiversity Day

Celebrate with us: September 7th – 15th, 2024

Discover the nature of California

What makes California so special? An expansive coastline dotted with estuaries, tidepools, sandy beaches, dunes, and islands. Thousands of miles of rivers connecting the sea to landscapes of redwoods, oak woodlands, grasslands, and chaparral. The highest mountain peaks and lowest desert valleys in the nation. Within these iconic and diverse California landscapes are millions of living organisms, including thousands of unique plant and animal species – more than any other US state! This extraordinary biodiversity is at the core of California’s remarkable nature, sustaining our livelihood, culture, and well-being.  

September 7th is California Biodiversity Day, a chance to inspire discovery of the nature of California through weeklong activities. Established in 2018 by Governor Jerry Brown, California Biodiversity Day became a part of the state’s first California Biodiversity Initiative to safeguard the state’s natural heritage in response to the growing loss of biodiversity and ecosystem function across the state. In 2020, Governor Newsom signed a groundbreaking Executive Order to protect 30% of California’s lands and waters by 2030, known as California 30×30. Together, these initiatives aim to protect biodiversity, build resilience to climate change, and ensure equitable access to nature for all Californians. By participating in California Biodiversity Day, you can connect to and learn more about the nature around you while also contributing to these important conservation targets!

Find an event near you!

Use the map below to find virtual and in-person events such as educational webinars, nature walks, art and games, and biodiversity “bioblitz” explorations.


California Biodiversity Challenge: Find 30 Species!

Can you find at least 30 wild species in California during California Biodiversity Week?! Whether you participate in a hosted event or discover nature on your own time, join the 30 Species Challenge on the nature tracking app, iNaturalist, and post your observations! Your observations in California will help better understand biodiversity in California and contribute to the California 30×30 initiative, to conserve 30% of California’s lands and coastal waters by 2030. Go out and explore your neighborhood or local park, take a hike or explore the coast, or join in one of the many CA Biodiversity Week events being held across the state!

Participating is easy!

  1. Download the app on your phone and sign up for free. Start here:
  2. Visit the  inaturalist project: CA Biodiversity Week Challenge 2024: Find 30 Species
  3. Click “Join” to sign up!
  4. Submit your nature observations between September 7th – 15th! 

Check out this video for a quick guide on How to Make an Observation on iNaturalist. For more information, checkout Getting Started with iNaturalist

2024 Biodiversity Goals

The 2024 California Biodiversity Week is celebrated from Saturday September 7th to Sunday September 15th! Organizations across California host in-person and virtual events throughout the week to connect people with their local biodiversity while encouraging actions to protect and steward it.

Please join us by hosting or attending a nature discovery event and participating in the “Find 30 Species” Challenge (see below!). With your help we can meet our goal to increase public participation in biodiversity events throughout the state and connect people of all ages and backgrounds to the nature of California. 

We encourage the use of community science apps such as iNaturalist and eBird during your events. Observations of California nature in these platforms are used globally to understand biodiversity, track its changes overtime, and make conservation decisions to steward and protect it.

2024 Goals: In honor of the California 30×30 movement, our goals come in 30s!

  1. 130 in-person events hosted by individuals and organizations across the state that foster connection with the nature of California
  2. 300 participants in the Find 30 Species Challenge! Find and submit 30 species observations to iNaturalist! Let’s collectively identify 3030 species across California!
  3. 30 birding activities submitted to eBird and shared with the username “CaliforniaBiodiversityDay”. You can see your observations and others shared on the California Biodiversity Week eBird Trip Report

Biodiversity Resources

Media Toolkit

Biodiversity Factsheets


For Educators

Take Action

There are infinite ways in which people can promote biodiversity in their neighborhoods through small everyday actions. Here are some tips!

  • Take small actions to stop the spread of invasive species. Landscape with native plants, properly clean and dry watercraft when recreating in bodies of water, and do not release pets into the wild. If you’re going camping, buy firewood at your destination to help reduce the spread of harmful insects and fungi. Biodiversity decline in California is driven in large part by invasive species and pests spread by humans. Learn more here.
  • Discover the native plants in your area by searching Calscape, California’s hub for California native plants and native plant gardening, created by the California Native Plant Society (CNPS).
  • Keep feline friends indoors. This is for your cat’s own health and safety. Outdoor cats also spread diseases and are a major threat to biodiversity, driving the disappearance of birds and small mammals everywhere they are left free to roam. Read more about what you can do to help biodiversity, here.
  • Participate in local stewardship activities aimed to restore the land and wildlife around you. 
  • Learn about Indigenous stewardship practices from the Inter-Tribal Council of California and the Tribal Marine Stewards Network.
  • Create habitat in your yard or neighborhood for everything from healthy soil microbes to bees and butterflies to birds! How? Avoid excessive pruning and mowing in the spring, leave leaves on the ground in the fall, retain tree snags and other deadwood where safe, and garden with native plants.
  • Reduce wildlife collisions around your home.  Bright lights attract and confuse wildlife at night: Consider swapping out your bulbs for yellow-toned lights and/or motion sensors. Birds collide with clear clean windows: Apply small decals to large windows in your home or business. Both of these actions are highly effective at preventing wildlife deaths around your home!
  • Continue to discover the nature around you. Sign up for iNaturalist and use it to help you ID your nature sightings everytime you’re outdoors! Submit them on the platform and contribute to the global community of biodiversity champions like you!

Website Resources

Calscape | California’s Native Plant Gardening Destination

Nature for All – Nature for All in Los Angeles (

Life in the City (


(We will include imagery from the Atlas of California Biodiversity)

California Biodiversity Facts:

Biodiversity comes from the words “biological diversity” and refers to the variety of life on earth. Think of our varied iconic landscapes in California – like a coastal redwood forest – then imagine all the living world that lives with it, from everything as small as bacteria and fungus to as big as the redwood tree and the ecosystem that surrounds it. This is the biodiversity of California.

California is one of the most biodiverse regions in the world and one of 36 Global Biodiversity Hotspots. These are areas containing exceptional concentrations of endemic plant and animal species found nowhere else on the planet, but also experiencing high rates of habitat loss.

Of any state in the U.S., California has both the highest total number of species and the highest number of endemic species (i.e., those that occur nowhere else). 

California has the most rare and imperiled species of any state with more than 30% of California’s species threatened with extinction!

Contributions of Native American Tribes to Biodiversity:

California Native American tribes have played a central role in stewarding nature and safeguarding biodiversity since time immemorial. These tribes and tribal communities, having persisted from the state-sanctioned historical wrongs committed against them, have maintained relationships with, and knowledges of, California’s lands, coastal waters, and freshwater systems. 

Tribal connection, ownership, stewardship, and uses of ancestral and traditional areas— including living, fishing, hunting, gathering, and ceremony—are central not only to tribal identity and sovereignty, but also biodiversity protection and ecosystem function. Biocultural significance, which accounts for the interconnected nature of people and places, is a critical component of biodiversity and particularly important for ensuring that conservation initiatives include the needs and priorities of California Native American tribes and traditional cultural practitioners. 

By the Numbers in California

Check out these fun facts about California’s amazing biodiversity:

  • Over 30% of all plant & vertebrate species in the U.S. occur in California.
  • 1000+ species of vertebrates (65% occur only in California): 650 birds, 220 mammals, 100 reptiles, 75 amphibians, 70 freshwater fish, 100 marine fish and mammals 
  • 6,500+ types of plants (2000+ endemic to California)
  • 30,000+ species of insects including 1,600 species of native bees
  • 52 types of conifers, with 14 that grow here and nowhere else (i.e., endemic). (By comparison, the next highest is Oregon with only 32.)

Other Resources:

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Report: Hidden in Plain Sight California’s Native Habitats are Important Carbon Sinks (