This Tiny Bird Scored a Win for Science

Commentary: A California bird is breathing a little easier this month after the U.S. Fish and Wildlife Service made a decision in late August not to remove it from the federal Endangered Species list. The coastal California gnatcatcher, a tiny gray bird that lives in one of California’s most threatened ecosystems has thus survived a second attempt by Southern California real estate developers to remove it from protection.

By the decision to keep the gnatcatcher protected, the USFWS shows that there are still some limits to how far moneyed interests can take advantage of legitimate scientific disputes to advance their own potential profit.

The coastal California gnatcatcher is one of three subspecies of California gnatcatcher, and it’s possibly the most imperiled. The other two subspecies are found south of Ensenada on the Baja Peninsula, where – at least for the time being – the birds’ preferred shrub-land habitat isn’t under significant development pressure.

The California gnatcatcher species, to which all three subspecies belong, isn’t protected on its own under the Endangered Species Act. But the coastal subspecies, a denizen of coastal  California from Ensenada north to Ventura County, lives in one of the most-endangered habitats on the West Coast: coastal sage scrub. Most coastal sage scrub habitat has long since been converted to urban and suburban sprawl. As a result of the destruction of its habitat, USFWS listed the coastal California gnatcatcher as Threatened under the U.S. Endangered Species Act in 1993.

That was 23 years ago, and the coastal California gnatcatcher has been a target of real estate developers ever since. That’s because the Feds declared more than 197,000 acres of coastal Southern California as critical habitat for the gnatcatcher. That's an area slightly smaller than San Diego, much of it on land that real estate developers would dearly love to fill with upscale tract homes and shopping centers.

If you’re even a minor speedbump between developers and their imagined profit, you can get Public Enemy Number One status pretty quickly. The coastal California gnatcatcher is no exception. Ever since it was listed, the gnatcatcher has been the target of attempts to strip it from protection by developers and their allies.

This most recent attempt, launched in 2014 by the conservative Pacific Legal Foundation on behalf of a handful of property owners’ associations, building industry trade groups, and conservative thinktanks, charged that the coastal California gnatcatcher should be delisted because it failed to meet the basic definition of a distinct subspecies of gnatcatcher.

What’s a subspecies?

In order to discuss that assertion, we’ll need to define what a subspecies is. If you’re wondering just what that definition is, you have a lot of company. Part of the problem is that a subspecies is defined as a subgroup of a species – just like it says on the tin – and biologists aren’t really able to agree on what a species is.

There’s the canonical Biological Species Definition, which holds that a species is a group of related organisms that can interbreed and produce offspring that are themselves capable of reproduction. That definition works okay, in many cases, for many large animals. But exceptions to the rule are as close at hand as the dog sleeping on your couch. (Dogs and coyotes are different species, but can and do mate, and can and do produce fertile progeny.) Birds of some species hybridize and produce fertile offspring; gulls are a good example along the West Coast. Plants make fertile hybrids across not just species boundaries but across genera, the next taxonomic level up. Many organisms, especially the micro- kind, don’t reproduce sexually at all so they can’t make fertile hybrid offspring by definition.

In short, many biologists find the Biological Species Concept less than helpful for their work. They may turn to other Species Concepts. In 2006, the philosopher of science John Wilkinslisted 26 such concepts. A definition of “species” is necessarily going to be at least partly subjective.

A subspecies, then, is a distinct grouping of individuals belonging to a species, which share more traits with each other than they do with other members of their species, but which can still produce fertile offspring with those others. Subspecies are assumed to be genetically distinct from the rest of their species, and are usually but not always geographically isolated.

If you hew to the Biological Species Concept, the notion of a subspecies makes a lot of intrinsic sense: it can describe a group within a Biological Species that’s distinctly different, but whose members can still breed with others in the species and produce fertile offspring. In fact, the Biological Species Concept makes the idea of Subspecies pretty much necessary. But if the Biological Species Concept proves to have holes in it, and some species can produce fertile offspring with some other species, then the definition of subspecies gets murkier.

On the other hand, nature rarely fits itself willingly into our tidy categories. The concept of subspecies does offer a pretty handy way to acknowledge that species, whatever they are, aren't uniform. Populations within species are always evolving, and a subspecies may very well be a new species in the process of being born. As long as there are species with different traits shared in local populations, a term like "subspecies" will likely be used to describe and categorize those differences. 

It’s thus unsurprising that scientists will often disagree over whether a group of organisms is a “good” subspecies or not; it’s hard enough to figure out what a subspecies is. In general, biologists will often call a group of individuals a subspecies if that group shares distinct anatomical, behavioral, or genetic differences from the rest of the species. And other biologists will disagree.

The gnatcatcher battle

There are even biologists, for instance, who will argue that birds don’t have subspecies. In 2004, ornithologist Robert Zink — then at the University of Minnesota, though he’s since moved to the University of Nebraska — published a paper in which he challenged the very notion of bird subspecies, at least as currently defined.

In that paper, entitled “The Role Of Subspecies in Obscuring Avian Biological Diversity and Misleading Conservation Policy,” Zink suggested that 97 percent of all named subspecies of continental birds the world over don’t stand up to genetic scrutiny, and specifically mentions the coastal California gnatcatcher as a subspecies he calls problematic.

That’s a bold claim, and it was based on previous work by Zink, in the form of a paper published in the journal Conservation Biology in 2000 in which Zink and his colleagues reported no differences in the mitochondrial DNA of coastal California gnatcatchers that were distinct enough to merit considering the coastal birds as a subspecies.

If other scientists agreed with that claim, it would have huge consequences. In order to merit protection under the U.S. Endangered Species Act, the coastal California gnatcatcher would have to be either a full species, a subspecies, or a smaller taxonomic category called a Distinct Population Segment, a rarely used category used to describe geographical populations of a species. If the coastal gnatcatcher were to be stripped of its subspecies status, the U.S. Fish and Wildlife Service would have to delist it, removing the federal speed bump on potential development of those 197,000 acres of gnatcatcher Critical Habitat.

And that would mean even bigger profits for developers, who saw the potential value in Zink’s 2000 paper in Conservation Biology. In 2010, The Pacific Legal Foundation petitioned USFWS to delist the gnatcatcher based on Zink’s research. They filed the petition on behalf of the Coalition of Labor Agriculture, and Business, Property Owners Association of Riverside County, and M. Lou Marsh, M.D., a San Diego-area property owner who’d been denied a permit from the California Coastal Commission to subdivide her ocean-front property due to the presence of gnatcatchers there.

In 2011 USFWS declined to delist the coastal gnatcatcher, saying that Zink’s mitochondrial DNA study wasn’t enough proof of the coastal gnatcatchers' lack of genetic distinctiveness. The agency said it’d need a study of the birds' nuclear DNA to make that decision. Genes in mitochondria mutate very slowly, while their counterparts in cell nuclei change frequently enough that they better reflect evolutionary changes occurring on shorter time scales of tens of thousands of years.

Zink published another paper that did just that, in 2013, in the journal The Auk. That study compared eight nuclear DNA “loci” in coastal and other gnatcatchers, and reported that even with the nuclear DNA comparison, Zink didn’t find enough difference between gnatcatchers to declare the coastal one a good subspecies.

That study was the basis for the Pacific Legal Foundation’s most recent petition in 2014. It also prompted a fairly devastating rebuttal in the pages of The Auk in 2015, based on further research done by John McCormack and James Maley of Occidental College’s Moore Laboratory of Zoology. McCormack and Maley pointed out that Zink’s study examined parts of the birds’ nuclear genome that were relatively slow to change, and that other genetic markers — as well as the macroscopic differences in appearance and song noted over a century of observation — showed significant differences between coastal and other gnatcatchers.

In a brief conversation with KCET last week, McCormack pointed out the relevance of his findings to the broader context of the Southern California environment, saying “It's small but important differences like those among the gnatcatchers that drive evolution and allow species to adapt to our changing climate.”

(I discussed McCormack and Maley's criticism of Zink's work at some length in 2014, in case you want a deeper dive into the science.)

It’s neither new nor particularly noteworthy when biologists disagree over taxonomy. And every once in a while, a scientist is going to make a discovery that inconveniences defenders of the world’s endangered habitats. Protecting the coastal California gnatcatcher means protecting other rare species that rely on the coastal sage scrub habitat; if a valid and thorough scientific study results in delisting the gnatcatcher for whatever reason, it’s an impediment to helping those other species. In a better world, we would shrug our shoulders, feel grateful that we understood the living world a bit better, and find some other way to protect the gnatcatchers’ neighbors.

But in a world in which protecting species runs counter to rich people getting richer, there’s always the possibility that even science done in good faith will be turned to ends other than learning more about the world.

Zink’s work prompted muttering of undue influence as soon as the second Pacific Legal Foundation petition was filed, much of it spurred by a report in the Los Angeles Times that developers’ trade organizations had funded his gnatcatcher work. McCormack and Maley even referred to the developer funding issue in their paper (as did I in my 2014 article.) Zink responded in a way that didn’t particularly help his case, by clarifying that developers had actually funded his earlier work, and that his 2013 paper had actually been funded by the Transportation Corridor Agency (TCA), a public body charged with building toll roads through gnatcatcher habitat in Orange County. TCA funds had been made available to Zink by Robert Thornton, an attorney active in fighting the gnatcatcher’s listing in 1993, as well as in subsequent efforts to delist.

Zink maintained that the sources of funding made no difference in his studies’ design, or in their results. There's no particular reason to think he's not sincere in that claim. And it may be that Zink’s role as adviser to the Center for Environmental Science, Accuracy & Reliability (CESAR), a think-tank with close ties to the Westlands Water District that was one of the 2014 petitioners to delist the gnatcatcher, is a mere good-faith association based on that organization’s finding him a useful and relevant expert. (Zink advises CESAR on the Endangered southwest willow flycatcher; the group was one of several petitioners in August 2015 asking USFWS to delist the bird, claiming — this will sound familiar — that it's not a valid subspecies.)

Scientists often stake out principled positions on disagreements over finer points in their field and defend those positions vociferously. While it's always good to acknowledge the valid arguments against your position, there's nothing inherently wrong in having a viewpoint and arguing for it. But there’s an old saw about it being just as important to avoid the appearance of impropriety as it is to avoid impropriety itself.

Flitting birds and jumping mice

Zink’s not alone, incidentally, in finding support for his subspecies-busting from CESAR. The group’s chief scientific advisor, Rob Roy Ramey, was involved in a similar delisting petition over the Preble’s meadow jumping mouse, a Rocky Mountains rodent listed as a Threatened species since 1998.  The similarities between efforts to delist the Preble’s meadow jumping mouse and the coastal gnatcatcher are striking. Ramey published genetic studies indicating that the Preble’s wasn’t a valid subspecies of the jumping mouse, and thus didn’t merit Endangered Species Act protection. That would mean fewer restrictions on developers wanting to build out the riparian grasslands along the Front Range of the Rocky Mountains, where the Preble’s lives. In its examination of the petition, USFWS asked U.S. Geological Survey biologists to reexamine Preble’s jumping mouse genetic work; those biologists announced that Ramey hadn’t examined enough genetic loci to make his case, and that looking at more loci provided enough evidence that the Preble’s mouse was a valid subspecies. The USFWS declined to delist the Preble’s meadow jumping mouse as a result.

And as with Zink’s work, Ramey’s work found avid support among developers and allied industry, as well as with anti-environmental ideological activists.

CESAR was also involved in the effort to delist the Preble’s meadow jumping mouse, as well as similar efforts focusing on the Southern Resident orca population, the endangered Stephens kangaroo rat, and the southwestern willow flycatcher, as well as opposing listing the sage grouse. (CESAR has staked out seemingly greener positions on a few issues, including an unsuccessful attempt to get the Atlantic eel listed as Threatened.)

Fish And Wildlife takes a stand

In that better world I mention a few paragraphs back, it wouldn’t be who a scientist hangs out with that determined the validity of his or her work: it would be the work itself. Affiliation with a seemingly ideologically driven group like CESAR, or support from anti-environmental activists, or for that matter support from wildlife protection organizations, does not necessarily erode the credibility of a scientist’s work. Scientists don’t give up their right to have opinions when they get their doctorates. But every scientist, whether in academia, or on the payroll of a corporation or a non-profit advocacy group, has a professional responsibility to guard against error in his or her work. And personal bias is a very well known source of potential error, one which all scientists continually have to guard against. In that light, affiliating with a group that’s staked out a political position against listing subspecies sure looks a little iffy. And when that position is backed by groups with money riding on the outcome, a scientist’s “potential error” alarms ought to be going off like mad.

On August 31, USFWS made its call about which scientists' work it found more persuasive: based largely on the work of McCormack and Maley, the coastal California gnatcatcher would continue to be treated as a valid subspecies, and it would keep the protection of the Endangered Species Act. In the jargon of the Endangered Species Act, USFWS had found delisting the coastal California gnatcatcher "not warranted."

“Science worked,” McCormack told me. “We were able to rebut the case against the gnatcatcher, and then a scientific panel weighed the evidence, all while U.S. Fish and Wildlife was making its decision. If only it could work like that in every case.”

But of course, it doesn’t. Even just within the USFWS, there are significant recent examples of apparent disregard for science in favor of preserving the economic status quo, from decisions to delist gray wolves in parts of their range, to deciding not to pursue listing the wolverine,  to proposing to issue 30-year eagle take permits for wind power companies. (In the case of the wolf the flawed genetic study relying on too little data that was used to argue for delisting was actually performed by USFWS scientists, and published in an internal agency journal.)

Disagreements over points of science like that over the coastal California gnatcatcher are good for science. We learn by challenging unspoken assumptions and pushing at the weak points in others’ arguments. But that process only works well when it takes place among scientists. Adding the profit motive to one side of the debate can only distort things. 

It’s not just USFWS that’s affected by politically-driven science. At a recent hearing before the San Bernardino County Board of Supervisors held to determine the fate of the proposed Soda Mountain Solar Project, representatives of project owner Regenerate Power misrepresented easily documentable facts about whether desert bighorn sheep used the site. Water users in the Central Valley offer spurious studies purporting to prove that the biggest threats to Delta smelt and Sacramento River salmon are pollution and predation by striped bass, rather than the effective dewatering of rivers due to diversions for agriculture. A speculative water company claims its scientists have proven that it can pump enough water to green suburban lawns from the Mojave Desert for decades without damaging the local desert ecosystem. Struggling biologists with staggering student debt are told that they’re finding too many species of concern on the developer’s project site, and that the developer might find another consulting firm if that continues.

It’s no wonder that there’s chronic mistrust of scientists among a cynical public. If a few scientists are perceived as offering pay-to-play scientific studies — whether or not they actually are — it helps sow public mistrust of all scientists.  And that helps only those who benefit from others’ ignorance.

But for now, the coastal California gnatcatcher still enjoys a little bit of legal protection, and there's still a small speedbump in the way of those who'd pave every last remaining unprotected inch of Southern California with terra cotta and stucco.