West LA Times

UCLA biologists have presented mixed findings regarding urban wildlife in Los Angeles. While unexpected pockets of biodiversity exist within the city, increasing overall biodiversity remains a challenge. Of all major taxonomic groups studied, only snails and slugs are commonly found, likely due to abundant landscaping and irrigation.

The study suggests methods for making cities more hospitable to both urban-tolerant species like coyotes and those that typically avoid urban areas, such as wrentits. "Los Angeles should rightly pat itself on the back for attracting and supporting mountain lions, most notably, the late, great P-22," said Joseph Curti, a doctoral candidate in ecology and evolutionary biology and lead author of the study published in PLOS One. "Our study highlights additional native species that are present within even the most urbanized areas of the city."

Conducted as part of the LA City Biodiversity Index—a tool designed to monitor progress toward L.A.’s Green New Deal goal of no net loss of native biodiversity by 2050—the research assesses habitat conditions and connectivity. It also evaluates community engagement in biodiversity efforts and protection plans for endangered species.

The city's LA Biodiversity Index Baseline Report awarded Los Angeles 37 out of 110 possible points. Generally, higher urban intensity correlates with fewer native wild species. This metric will be reevaluated every three years to track efforts aimed at enhancing urban biodiversity.

"This work provides the foundational data and maps needed for the city and Angelenos to proactively create habitat for biodiversity," said co-author Michelle Barton, an environmental manager for Los Angeles. "Over time, we hope to see that initiatives that create new habitat support not just urban tolerant species but also our urban avoider species."

Using public observations logged on iNaturalist, UCLA researchers evaluated responses from 510 native species within a 124-mile radius of Los Angeles to factors like noise, light, and impervious surfaces. The greatest diversity was found near hills or affluent neighborhoods with ample green spaces; however, isolated refuges were also discovered within the city center.

For instance, twenty-spotted lady beetles thrive in Dodger Stadium's parking lot while Pershing Square supports mourning doves and Vaux’s swifts among other species. Researchers focused on twelve taxonomic groups accurately detected by community scientists on iNaturalist:

- Amphibians and reptiles

- Bees and wasps

- Birds

- Butterflies and moths

- Dragonflies and damselflies

- Grasshoppers, locusts, crickets

- Hoverflies

- Lady beetles

- Leafhoppers

- Mammals

- Snails and slugs

- Spiders

Observations were mapped across a quarter-mile grid throughout Los Angeles to assess how well each species fared relative to others under varying levels of urban intensity.

Previous research indicated that some raptors like Cooper’s hawks thrive in urban settings while others like American kestrels do not. By evaluating responses along a continuum of urban tolerance—from most tolerant to least avoidant—researchers gained nuanced insights into each species' relationship with their environment.

"Now we have a sense of not only urban tolerant/urban avoidant but the degree to which each species is responding to our measures of urban intensity," Curti explained.

To promote neighborhood biodiversity, residents are encouraged to plant native flora (specific areas can be found at Calscape), create habitats by avoiding excessive pruning or removing artificial light sources at night, refrain from using herbicides/pesticides around homes, retain tree snags/deadwood for habitats—and keep cats indoors due to their predatory impact on birds/small animals.