San Antonio passes Austin in the 2023 City Nature Challenge

The River Authority
May 17, 2023

Estimated Read Time: 4 Minutes

What is the City Nature Challenge?

The iNaturalist City Nature Challenge (CNC) is a four-day annual global Bio-blitz organized by the Natural History Museum of Los Angeles County and the California Academy of Sciences. It is one of the largest community science events in the world and is held annually at the end of April. During the Bio-blitz, citizen scientists worldwide participate in this challenge to observe and document the wildlife in their cities. The main goals of the CNC are 1) helping species of greatest conservation need (SGCN), 2) monitoring changes in the range of native species, and 3) possibly identifying new species. This family-friendly challenge encourages all ages to go outside , observe nature, and contribute to valuable citizen science data while learning to identify some of the native species that inhabit our local riparian habitats as well!

This year's challenge was held from April 28 to May 1, 2023. The San Antonio Metro Area boundary for this challenge includes 12 counties, including Bexar, Wilson, Karnes, and Goliad counties. These counties comprise the four-county jurisdiction of the San Antonio River Authority (River Authority). This challenge is vital to our San Antonio River Watershed for several reasons. First, the CNC is essential in educating the community about the vast biodiversity of species that rely on the creeks and rivers of our watershed. Second, it sheds light on the current health of our watershed, including the status of SCGN that live within it. Third, it helps with the Texas Parks and Wildlife Department's research and conservation efforts by contributing valuable data to the Texas Nature Trackers.

Preparing for the City Nature Challenge

City Nature Challenge

In preparation for the 2023 iNaturalist City Nature Challenge, the River Authority and the San Antonio River Foundation held immersive nature walks in the winter and spring of 2023 to help the community discover unique flora and fauna of the riparian areas in the southern basin of San Antonio River. Community members were also trained to record their observations using the iNaturalist app.

Master Naturalists gather under pavilion for observation event.
Volunteer and Engagement Coordinator Minna Paul leads event.

Walk on the Wild Side at Branch River Park in Goliad County.

Volunteers gather around horned toad statue at Escondido Creek Parkway.
Observers gather to admire plants.

Walk on the Wild Side at Escondido Creek Parkway in Karnes County.

Bird watching groups observes avians at Helton Nature Park

Walk on the Wild Side at Helton Nature Park in Wilson County.

How many observations were made in the san antonio river watershed? 

A map depicting the amount of observations recorded across the San Antonio River Basin.

A map of observations made in the San Antonio Metro Area during the 2023 CNC. See the whole map.

This year 19,967 observations of 2564 different species by 858 citizen scientists were made in the 12 counties of the San Antonio Metro Area, which includes the River Authority's four-county jurisdiction. This was an increase of over 3000 observations from last year's challenge! The San Antonio Metro Area also ranked 3rd Place in the Texas City Nature Challenge, passing the Greater Austin Area for the first time in CNC history!

Winners of the Local Intra-Nature Challenges

  • Campus Nature Challenge: St. Mary's University with 1373 observations of 581 species
  • Corporate Nature Challenge: Toyota- San Antonio with 807 observations of 259 species
  • Texas Master Naturalist (TMN) Chapter Challenge: TMN-Alamo Area with 4843 observations of 1175 species
  • Community Nature Challenge: River Authority's River Warriors with 2590 observations of 900 species

Check out some of the wildlife observed during the 2023 CNC!

Grid image of multiple nature observations. top row left: purple martin, top right Oblique Longhorn. Bottom row left: White-eyed Vireo, bottom right: Red admiral

Photo Credit: (c) Ken Butler (CC-BY-NC) | Photo Credit: (c) Marley Diehl (CC-BY-NC) | Photo Credit: (c)dnvarga (CC-BY-NC) | Photo Credit: (c) Laura Keene (CC-BY-NC)

Over 64% of the observations made in the 2023 CNC are now research-grade. Expert naturalists and scientists will continue identifying the documented species in this challenge to contribute further research-grade data. Visit the CNC 2023: San Antonio Metro Area page to learn more about this year's observations!

A group of people gather for a selfie after a successful nature observation event.
Two men take a photograph of a plant.
Observers take photos of nature using cameras and their phones.

CNC participants attended Bioblitz events at Cibolo Creek Ranch, Friederich Wilderness Park, and many other locations to add their observations to the challenge.

Decorative banner saying "Thank You"


Many thanks to those who attended the River Authority nature walks and contributed to the success of this year's City Nature Challenge. Our collective support helps raise awareness and contribute to stewardship and sustainability for our local creeks and the San Antonio River!  

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