What birds reveal about California’s 30×30 conservation efforts

California has committed to the 30×30 conservation initiative, which aims to conserve 30% of its lands and waters by 2030. The fundamental question remains whether those conservation investments actually help maintain or increase biodiversity. UC Santa Barbara Bren School of Environmental Science & Management graduate students investigated this by examining one of California’s most visible indicators of ecosystem health: birds.

On May 29, graduate students Nathalie Bonnet, Isabella Segarra and Peter Vitale presented their project, “Mind the GAP: Avian responses to conservation investments in California,” for the Bren School’s 2026 Master of Environmental Data Science (MEDS) Capstone Project presentations. 

The project involved partnership with Point Blue Conservation Science and the students’ faculty advisor Naomi Tague. They worked to evaluate if protected lands in California support more biodiversity than less-protected and unprotected areas do. 

“Global biodiversity loss is threatening over 1 million known species,” Bonnet said during the presentation. “However, large-scale efforts toward biodiversity conservation are happening around the world and here in California.”

The researchers turned to birds as a bioindicators to determine if conservation investments are truly producing measurable ecological benefits. Birds are often used in ecological monitoring because they are widely observed and often respond to habitat changes. They are also relatively well documented over long periods of time. 

The team used bird observation records from Point Blue’s Avian Knowledge Network. This large database contains bird monitoring information collected by scientists and conservation organizations.

The researchers used those observations to calculate a biodiversity index that measured both the number of bird species that are present as well as the distribution of the species in an area. They then compared biodiversity in different habitat types and land protection categories all across California.

The analysis revealed that protected areas largely supported higher bird biodiversity than unprotected lands.

The researchers found that protected sites consistently exhibited higher biodiversity on average. However, the relationship was not uniform across all habitats.

“Protected areas saw higher biodiversity across our habitats,” Vitale said. “However, it’s not the case over all of them.”

In some habitat types, such as working lands and shrub habitats, the team observed patterns that differed from the main trend. The researchers said these differences might reflect ecological factors or sampling differences but the underlying causes remain uncertain.

The findings suggest that while protected lands often provide important biodiversity benefits, conservation outcomes may depend heavily on local habitat conditions and management approaches. In a follow-up interview with the Daily Nexus, the researchers said the species-level findings highlighted additional complexities beyond the broader biodiversity patterns.

The researchers also analyzed population trends for several focal bird species selected for their conservation relevance and strong habitat associations to understand how individual species respond to conservation investments.

The team focused on the western meadowlark, the song sparrow and the red-winged blackbird, selected for their conservation relevance and strong habitat associations, during the presentation.

The results for the western meadowlarks suggested that populations grew in some unprotected areas that were actively managed through stewardship practices. On the other hand, song sparrows exhibited declines in both protected and unprotected lands, but these declines were more pronounced in unprotected areas.

Red-winged blackbirds showed a different pattern. Populations stayed relatively stable in protected areas and declined in unprotected lands — a trend the researchers suggested may be linked to wetland loss on working landscapes.

The species analyses revealed that protection alone does not guarantee positive outcomes for every bird. Biodiversity was generally higher in protected areas but individual species responded differently depending on habitat conditions and management practices. As Isabella Segarra noted, the species-level results showed there were “many other mechanisms driving these patterns.”

“Protection alone isn’t sufficient for some of these species,” Segarra said.

Additional analyses suggested that active stewardship practices on some unprotected lands may also contribute to positive biodiversity outcomes. Bonnet said some of these patterns suggest that “stewardship is the driver of biodiversity rather than just the protection alone.” 

The project also highlighted important limitations in California’s biodiversity monitoring efforts.

The researchers found that bird observations were heavily concentrated in northern California and there were substantially fewer observations available in many southern regions. Data gaps were particularly noticeable in some of the state’s most highly protected areas, where access limitations and data-sharing restrictions reduce available information.

The team developed an interactive dashboard allowing users to explore bird observations and biodiversity patterns, as well as data gaps throughout California in order to address these challenges. They also provided Point Blue with resources that can help guide future biodiversity research.

As California approaches its 2030 conservation deadline, the researchers emphasized that measuring success requires more than simply counting acres placed under protection. Bonnet said California is already “very close to that 30% conservation goal” and emphasized “ensuring that we continue to invest resources in that active stewardship” while “developing… more data driven evidence.” Their findings suggest that protected lands generally benefit biodiversity, but that stewardship practices and habitat-specific management will also play important roles in determining whether California ultimately achieves its conservation goals.

There are four years left before the state’s 30×30 target year. The team argued that continued investment in both conservation and biodiversity monitoring will be essential for understanding whether California is truly on track to create this more biodiverse future. As Vitale put it, based on the team’s statewide analysis, “it seems to be working.”