Therein lies the problem.

In California, the vast majority of the population lives near the coast, and those people need houses to live in, along with other urban developments to sustain them. As the people move in, the scrubland moves out, and it has nowhere else to go. The range of scrubland has been reduced by 85-90% of its historic range along the California and Baja California coastline, and most predictions expect that number to only increase as development continues and climate change threatens the coastal ecosystem further.

When the scrub goes, so do the creatures that live in it. Perhaps the most emblematic and divisive of these is the coastal California gnatcatcher, one of the species I've been spending the most time on with my work in the Effects Pathway Manager (see my previous blog for more info on that!). This tiny grey bird lives exclusively in coastal sage scrub communities, where it spends its time hunting for insects (spiders are a delicacy!) and flitting from one bush to the next. While some might regard the bird as cute and charismatic, it has been the bane of residential and commercial developers in Southern California since it was listed under the Endangered Species Act (ESA) by the US Fish and Wildlife Service in 1993.

A male coastal California gnatcatcher. Picture by Ian Davies.

Gnatcatchers are a non-migratory, territorial species, meaning just one pair occupies a certain area of scrubland and will generally push out any competitors who try to intrude. This life history trait makes them extremely dependent on large patches of uninterrupted coastal sage scrub. The ESA protections for the species extend to its habitat – what is called a Critical Habitat Designation, allowing for the Service to protect not only the gnatcatcher itself, but the habitat it relies on.

The most recent attempt to delist the species was dismissed by a federal court in July 2019, but it’s unlikely that this was the last battle. California is, after all, the most populous state in the country, and that population is growing every year. There is also the argument that the gnatcatcher shouldn’t be protected in the first place because some don’t consider it to be a valid species – a claim that has been shot down several times in the past.

Despite all of that, there is some good news. The Critical Habitat Designation protections given by the ESA have preserved thousands of acres of coastal sage scrub. And, when construction projects do occur in these areas, there are often conservation measures employed that involve setting aside an area as protected habitat or even planting new shrubs in another area to compensate for the developed space. And it is possible for gnatcatcher and humans to coexist. I was lucky enough to see some gnatcatchers a few weeks back on a hike within some coastal sage scrub habitat that was adjacent to an established housing development. My work in EPM, as well as all of the great work of fellow biologists working on the gnatcatcher with ESA Section 7 consultations, will help to preserve not only the species itself, but achieve a managable equilibrium between both the people and the animals that call Southern California home.

Agency: U.S. Fish and Wildlife Service

Program: US Fish & Wildlife Service - DFP

Location: Carlsbad Fish and Wildlife Office