Ep. 51: Defining ‘Habitat’ — and the Future of Conservation

Welcome to The Undark Podcast, which will deliver — once a month from September to May — a feature-length exploration of a single topic at the intersection of science and society. In this episode, join science and environmental journalist James Dinneen and podcast host Lydia Chain as they take a look behind the curtain at the Fish and Wildlife Service’s latest move — to formally define ‘habitat’ for the first time in U.S. history.

Below is the full transcript of the podcast, lightly edited for clarity. You can also subscribe to The Undark Podcast at Apple Podcasts, TuneIn, or Spotify.

James Dinneen: In 1965, a biologist named Francis Rose was wandering around a tree farm in Louisiana when he heard something like this:

[Mississippi frog sound]

It was the croak of what was then called the Mississippi gopher frog.

And he couldn’t have known it then, but that was one of the last times anyone ever heard the frog in Louisiana.


Fifty years later, the Mississippi gopher frog — now known as the dusky gopher frog — became semi-famous when a legal dispute over what constituted its habitat figured at the center of a case in the United States Supreme Court

Justice John Roberts: We’ll hear argument first this morning in Case 17-71, Weyerhaeuser Company versus the United States Fish and Wildlife Service. Mr. Bishop.

Timothy S. Bishop: Mr. Chief Justice, and may it please the Court. Congress amended the Endangered Species Act in 1978.

James Dinneen: The arguments in the case focused on what happened with the dusky gopher frog, but the question at the heart of the case was about much more than the frog. It was about all endangered species, and what the law is able to do to prevent their extinction and speed their recovery.

John G. Roberts: Thank you, counsel. The case is submitted.

James Dinneen: The question was: What is habitat?

[Undark podcast music]

Lydia Chain: This is the Undark Podcast. I’m Lydia Chain.

Since 2018, the Trump administration has introduced a number of changes to the rules that govern how the Endangered Species Act is applied. In general, the changes have weakened protections for endangered species under the law.

The latest change was just finalized on Dec. 16, after the U.S. Fish and Wildlife Service proposed for the first time a legal definition of “habitat” in response to the dusky gopher frog Supreme Court case.

The proposal sparked more than 160,000 comments in the Federal Register, an unusual flood of public opinion for an obscure regulatory definition.

Some comments were in favor of the definition, many were against it. All had thoughts on why something that seems as straightforward as the definition of “habitat” has far-reaching implications for endangered species.

James Dinneen has the story.

Just a quick note: In a previous version of this episode, Center for Biological Diversity attorney Collette Adkins described Louisiana landowner Edward Poitevent as a Tea Party activist. He vigorously disputed this, and the reference has been removed from the following audio and in the transcript online. We’ve also added a clarification that while most of the land designated as critical habitat was owned by Poitevent, some of it was owned by the Weyerhaeuser timber company and others.

James Dinneen: So the Fish and Wildlife Service proposed two alternative definitions of habitat in August, but they’re substantially similar, so I’ll just give you the first one. Here it is. It’s two sentences long:

Sentence 1: “The physical places that individuals of a species depend upon to carry out one or more life processes.

Sentence 2: Habitat includes areas with existing attributes that have the capacity to support individuals of the species.”

Now that might seem pretty sensible, but what some conservationists hear in that definition is that the government is not allowed to protect areas for an endangered species unless it contains habitat which is perfect right now.


Jason Rylander: Under the proposed regulation, basically, habitat has got to be move-in ready. And, you know, that’s great if you can find it, but it’s, it’s increasingly unrealistic.

James Dinneen: That’s Jason Rylander, the senior endangered species counsel with the conservation advocacy group Defenders of Wildlife. He says that’s a problem for lots of endangered species who don’t have much move-in ready habitat left. That’s part of the reason they’re endangered.

James Dinneen: On the other side though, some landowners, developers, and industry groups see the definition as an important limitation to the Endangered Species Act, arguing a broader definition of habitat could lead to unpredictable regulations and impose economic burdens without benefitting conservation all that much.

John Anderson: We have to put some bounds as a society around the regulations. So that there’s clear consistent guidelines.

James Dinneen: This is John Anderson, executive director of the Energy and Wildlife Action Coalition, a group of electric utilities and renewable energy companies in favor of the definition.

John Anderson: We can’t turn the entire country into a nature preserve. I mean, it’s just not possible.

James Dinneen: But before getting too far into the debate, it’s worth taking a step back to understand why it is that 50 years after the Endangered Species Act became law, the definition of something so basic as “habitat” is coming up now.

And to do that, you have to talk about the dusky gopher frog. Latin name: Rana sevosa.

[Recording of dusky gopher frog in Mississippi]

Steve Reichling: Their species name sevosa means cloudy dark or you could translate it and call them dusky.

This is Steve Reichling, the director of conservation and research at the Memphis Zoo, where he oversees the zoo’s dusky gopher frog reintroduction program.

Steve Reichling: It’s an endearing little creature. They’re very shy and very gentle. One of the things that they do if they’re in the human hand and are a little frightened, which would probably be most of the time, is they’ll often duck their heads down low and put their two forelegs up over their eyes as if to say “Just make it go away. I don’t want to see this.” They’re very, very shy little creatures.

James Dinneen: Reichling shared this recording of the dusky gopher frog’s snoring croak from a pond in Mississippi where thousands of captive-bred frogs have been reintroduced in the past few years.

[Recording of frogs in Mississippi]

The higher-pitched chirps are spring peeper frogs. And the honks are leopard frogs.

Today there are a number of dusky gopher frog populations like this in several ponds around Mississippi, but when the frog was listed as endangered 20 years ago, things were different.

Steve Reichling: The only known wild population was living in and around a little ephemeral pond. Most of the time it’s not even a pond — called Glen’s Pond. There was probably only about 100 frogs living in this habitat. So there were 100 dusky gopher frogs left in the world.

James Dinneen: The major culprit behind the frog’s decline was the loss of more than 98 percent of the longleaf pine forests which once covered much of the south — cleared for agriculture, commercial tree farming, and urban development.

The frog was particularly vulnerable to these changes because of its reliance on longleaf pine forest for its very particular habitat needs. It’s picky.


For one, the dusky gopher frog requires what are called ephemeral ponds in order to reproduce.

Steve Reichling: These are ponds that are dry, just depressions in the ground. And they fill with rainwater at specific periods of time, hold water just long enough for the frogs to come in and breed, reproduce, and the tadpoles to finish the metamorphosis and leave. And then the ponds dry out, thereby killing any fish that might have gotten in there or predatory insects.

James Dinneen: To survive in those sandy areas when the ponds are dried up, the frog requires lots of cool, moist holes in which to burrow. Because the frog is too delicate to dig its own holes, it relies on holes created by the gopher tortoise, which is itself threatened.

The frog can also live in burnt-out stumps when there are no tortoise holes around, though that requires frequent burning, which is also necessary to maintain the open-canopy longleaf pine savannas on which this whole, intricate web relies.

Across the frog’s historical range — which includes southeastern Louisiana and western Alabama, as well as Mississippi — these features of its habitat became exceedingly rare through the 20th century as longleaf pine forests were cleared and ephemeral ponds were filled-in.

And so by 2001, the 100 or so frogs in Glen’s Pond, Mississippi were the only ones left.

[Recording of dusky gopher frog in Mississippi]

James Dinneen: Once a species is listed as endangered, the Endangered Species Act requires the federal government to take certain steps to protect the species and help them recover. One of these steps is to designate what’s called “critical habitat” for the species.

Collette Adkins: What critical habitat is, it’s the areas that the Fish and Wildlife Service has determined are essential for the conservation of the species.

James Dinneen: This is Collette Adkins, a senior attorney at the conservation advocacy group Center for Biological Diversity, which has been closely involved with the dusky gopher frog litigation since it sued the Fish and Wildlife Service to list the species as endangered in 2001.

Collette Adkins: And critical habitat, once designated, requires that anytime there’s a federal action, like the granting of a federal permit under the Clean Water Act, for example, that there needs to be a consultation with the U.S. Fish and Wildlife Service.

James Dinneen: Basically, when you need permission from a federal agency to build something in an area considered to be “critical habitat,” that agency has to make sure it’s okay for the species before giving you permission.

That dynamic can make “critical habitat” designations controversial.

Collette Adkins: Yeah it’s complicated. The Fish and Wildlife Service is supposed to make decisions about listing solely based on the best available science, but unfortunately, they are pulled in a lot of directions. There’s often a lot of resistance to giving endangered species protections.

James Dinneen: There are also differing views on whether “critical habitat” designations are always effective protections for species.

Jake Li: I think in the conservation community, there’s oftentimes a very strong sort of urge to defend critical habitat to say that it always benefits species. And if you look at the data, I don’t think that theory bears out.

James Dinneen: This is Jake Li, director of biodiversity at the Environmental Policy Innovation Center, a conservation nonprofit.

Jake Li: So far, about 60 species have been fully recovered under the Endangered Species Act, and delisted, and approximately 50 of those species have never had critical habitat designated. So it’s a little hard to make the argument that critical habitat was essential to the recovery of those species, if they never had it.

James Dinneen: For both these reasons, the Fish and Wildlife Service doesn’t always rush to designate “critical habitat” though it is required by the Endangered Species Act. More than half of currently listed endangered species lack any “critical habitat” designations.

Collette Adkins: I don’t want to minimize the importance of critical habitat. It does good in the world, but it’s not this oppressive tool, because the Fish and Wildlife Service just never has used it that way. They almost always need to be forced to do the right thing.

James Dinneen: In the case of the dusky gopher frog, the Fish and Wildlife Service didn’t designate “critical habitat” for the frog until years after the frog was listed, and only after it was sued twice to do so by the Center for Biological Diversity.

And when the Fish and Wildlife Service eventually did propose “critical habitat” for the frog, there was another issue.

Though the frog had historically lived in parts of Alabama and Louisiana, the proposal only included sites in Mississippi.

Collette Adkins: And there was huge outcry from the scientific community. Gopher frog experts explained that you can’t recover the frog if you only protect the areas where it lives now in Mississippi.

James Dinneen: The thinking was that the frogs would be susceptible to extinction caused by random disasters like drought, or a hurricane, or disease if they only lived in Mississippi. In fact, in 2003, a nasty disease had nearly wiped out all the eggs of the remaining frog population in Glen’s Pond.

So Fish and Wildlife biologists went on a search for habitat outside Mississippi. In Alabama, where the frog was last seen in 1922, they were unable to find anything they considered to be suitable. But in Louisiana, after a few leads on possible ephemeral ponds led to dead ends, they visited a pine plantation in St. Tammany Parish, where in 1965, a biologist named Francis Rose had reported the presence of dusky gopher frogs.

Collette Adkins: There was this one complex of ponds in St. Tammany Parish where there were five of these ephemeral ponds all within, you know, frog hoppin’ distance apart, and the Fish and Wildlife Service designated that. But unfortunately, it turned out to be on lands where the private landowners just were absolutely unwilling to cooperate.


James Dinneen: From your perspective, how might the Weyerhaeuser dispute have been approached differently?

Collette Adkins: Yeah. Boy … I think that …

It’s difficult. I mean, to look back at that with hindsight.

I mean there’s part of me that would have liked that case to have never happened.

James Dinneen: Though the ponds had appeared to be on land owned entirely by the Weyerhaeuser commercial forestry company — which at the time was considered to be sympathetic to frog conservation — Weyerhaeuser actually owned only a small portion of the land and was leasing the rest. Most of the land at issue was owned by a man named Edward Poitevent.

Collette Adkins: Edward Poitevent was the primary landowner of the area at issue in the Weyerhaeuser case. And, you know, he was a real private property rights guy, a lawyer, and he took it up as a personal cause to challenge this critical habitat designation.

James Dinneen: Poitevent declined to be interviewed for this story.

Tony Francois: Okay, there may be some background noise here just let me know if you need me to go try to squelch it.

James Dinneen: But I spoke with his lawyer and an attorney on the Weyerhaeuser case, Tony Francois, who is a senior attorney at the Pacific Legal Foundation, a nonprofit libertarian law firm.

Tony Francois: It’s not at all clear to us or to Mr. Poitevent, even after all these years, what led the Fish and Wildlife Service to pick their property to designate.

James Dinneen: In 2016, Poitevent, along with Weyerhaeuser and a few other landowners in the area, sued the Fish and Wildlife Service, arguing that the critical habitat designation was unlawful and imposed significant economic costs that outweighed the benefits to the frog.

Tony Francois: It’s basically not worth most developer’s effort to try to develop a property that’s been designated as critical habitat. You go from having a pretty valuable asset to having, once the timber leases expired, nothing.

James Dinneen: It’s worth adding here that in general, the economic impact of critical habitat is a point of contention, and some studies suggest that the impact is often exaggerated. Either way, the official analysis in the frog case found there would be anywhere from no impact at all to a $34 million impact depending on what the owners decided to do with the land.

But aside from the money issue, the landowners’ central argument was that the federal government had exceeded its authority by designating “critical habitat” in a place where the frog probably couldn’t survive without modifying what was there.

Namely, Mr. Poitevent’s ponds, though properly ephemeral, were no longer surrounded by the longleaf pine savannahs the frogs need. They were surrounded by the dense loblolly pine trees of the Weyerhaeuser plantation. If any dusky gopher frogs were ever going to survive long-term there, some of Weyerhaeuser’s trees would have to be replaced. There might even have to be some controlled burning to keep things the way the frogs like it.

Tony Francois: So our argument was that this can’t be designated as critical habitat, because it’s not habitat.

James Dinneen: Of course, that leads to the key question here. What is habitat?

That question would take the case all the way to the Supreme Court.

Justice Elena Kagan: Mr. Bishop, may — may I offer you a hypothetical just to understand the scope of your argument, which is a bit unclear to me?

James Dinneen: Here’s Justice Elena Kagan questioning Weyerhaeuser’s lawyer during oral arguments in October of 2018.

Justice Elena Kagan: So, in my hypothetical, there is a species which, like this one, is in only a single habitat, and for whatever reason, that habitat is no longer going to support the species. Disease has come, a predator has come, it’s gotten too hot, it’s gotten too cold, whatever it is … And there is no habitat that at the present moment — there is no other habitat that at the present moment is capable of conserving the species over the long term. But there is a habitat that, with only slight improvements, what the government calls reasonable efforts, can support the species. Okay? … Can the government designate that area as unoccupied, critical habitat?

Timothy S. Bishop: No, it has to be habitat.

James Dinneen: The lower courts had said something else. They had agreed with the Fish and Wildlife Service that an area could be considered essential to the conservation of a species even if the species couldn’t live there right away. That is it could be critical habitat even if it wasn’t habitat. How you defined habitat itself was beside the point.

Justice John Roberts: I have the opinion of the Court today in case 17-71 …

James Dinneen: But the Supreme Court, in a unanimous decision, saw it differently.

Justice John Roberts: We disagree.

James Dinneen: Here’s Chief Justice John Roberts.

Justice John Roberts: According to the ordinary understanding of how adjectives work, critical habitat must also be habitat. Adjectives modify nouns. They pick out a subset of a category that possesses a certain quality. It follows that critical habitat is the subset of habitat that is critical to the conservation of an endangered species.

James Dinneen: But after all that, the Court did not say what habitat actually is, leaving that to the lower courts. A few months later, before the lower court ruled on a definition, the Fish and Wildlife Service settled with Poitevent and the other landowners by removing the Louisiana habitat designation.

Collette Adkins: It was actually very, just very clean and clever of them, because we had gone into that session with such contention after the Kavanaugh hearings. … But they came up with this really wonderful way of reaching consensus, that was very narrow.

And we could have had a substantive ruling that would have really constrained the Endangered Species Act, but we escaped without any damage to the Act at all. And we knew that at the end of the day, the real battle was going to be on the ultimate definition.


James Dinneen: The Supreme Court says, okay, we need a definition of habitat. Why can’t we just use the dictionary definition? Or is there is there a clear definition from science?

Jason Rylander: Well, there isn’t, as it turns out.

James Dinneen: This is Jason Rylander again from Defenders of Wildlife.

Jason Rylander: The dictionary definition of habitat is not particularly nuanced. And if you look at the scientific literature, there’s quite a few articles and discussions about what habitat means in that context as well, and no universal definition of the term.

James Dinneen: Like other commenters from the conservation community, Rylander argues that the definitions proposed by the Service in August are too restrictive, especially for species like the dusky gopher frog whose recovery will require restoring lost habitat.

Jason Rylander: There may be a species where, you know, all you need to do is make some changes to vegetation, or you need to, you know, restore a marsh area. Or you may, you know, anticipate that because of climate change, you can already see that a species range is moving, say, moving northward. And these are areas that are going to be necessary for its recovery.

So I think it’s increasingly likely that there are going to be species in the dusky gopher frog situation, where much of its habitat has already been wiped out. And just finding areas that are meaningfully restorable is going to be hard going forward.

James Dinneen: I asked Rylander to read an alternative definition of habitat he and Defenders of Wildlife proposed to the Fish and Wildlife Service:

Jason Rylander: “Habitat is the area or type of site where a species naturally occurs, or that it depends on directly or indirectly to carry out its life processes, or where a species formerly occurred, or has the potential to occur and carry out its life processes in the foreseeable future.”

So it includes this sort of temporal idea of both where the species has been and where it’s likely to be.

James Dinneen: While that definition is much broader than the proposed Fish and Wildlife definitions, Rylander says that this would not mean the Fish and Wildlife Service could designate critical habitat anywhere it wanted. Designations would still be limited by the requirement in the Endangered Species Act that the areas be “essential to the conservation of the species.”

Others though are basically satisfied with the definitions proposed by the Fish and Wildlife Service.

John Anderson: We thought that the definition that was proposed by the Fish and Wildlife Service was good and sensible.

James Dinneen: This is John Anderson again from the Energy and Wildlife Action Coalition.

John Anderson: It really is essential, not just from my members’ perspective, but also property owners and the rest of the regulated community, that when we are designating critical habitat and habitat, that those speak to the needs of the species at that time of listing.

James Dinneen: According to Anderson, a broader definition like the one proposed by Rylander would risk raising too many boundaries to development without enough benefits for conservation. For instance, he described a situation where renewable energy development is hampered by critical habitat designations that are not, as he puts it, “right-sized.”

John Anderson: The Service has the ability to revise critical habitat designations. So if it is determined in the future, that a species is shifting their population outside of their historic range, by all means, let’s talk about increasing or changing that. But if they cannot exist there today, I just don’t think that there’s a legal grounds for the Service to be able to say that those areas should have the same protections as areas that can be occupied today.

James Dinneen: Jake Li at the Environmental Policy Innovation Center sees the issue a bit differently. While he agrees the new definition would limit critical habitat, he thinks it would only impact areas where species don’t currently live, which only accounts for a small percentage of critical habitat designations.

Jake Li: According to the Fish and Wildlife Service’s own data, in the last roughly 10 years, the amount of unoccupied habitat designated is somewhere in the neighborhood of 1 percent. Right? So we’re really talking about a reduction in this 1 percent, not necessarily a reduction in the remaining 99 percent.

James Dinneen: He thinks the real significance of the new habitat rule will largely depend on how the Biden administration uses critical habitat.


Jake Li: If in a Biden administration, they decide they really want to lean in on using critical habitat as a tool to protect, you know, ecosystems, to address resiliency, to help species adapt to climate change. Right? These are all the things that really need to be done to conserve America’s biodiversity. If that’s the direction that the agency wants to take, then I think this new definition would actually have a much more significant impact on the amount of critical habitat designated. So we basically are at a fork in the road, right, at this point.

James Dinneen: On Dec. 16, the Fish and Wildlife Service finalized the definition after considering those 160,000 comments and making some adjustments, though it maintained the controversial part that implies habitat has to be move-in-ready. In other words, with this definition, places like the Louisiana ponds probably could not be protected under the Endangered Species Act.

The final definition reads:

“For the purposes of designating critical habitat only, habitat is the abiotic and biotic setting that currently or periodically contains the resources and conditions necessary to support one or more life processes of a species.”

A Biden administration could let the new definition stand or begin the long process of changing the rules once again.

Jake Li: My guess is that the Biden administration will at minimum very, very seriously consider rescinding this rule. Essentially, just hit a reset on this rule and figure out how to define habitat in a way that’s more helpful for conservation.

[Music and Mississippi frog sound]

James Dinneen: I asked Tony Francois what had happened with the ephemeral ponds in Louisiana since the dusky gopher frog case was settled. Francois didn’t know, so I emailed Edward Poitevent.

He emailed back to say nothing has changed. The land is still used for logging and will be until Weyerhaeuser’s lease runs out in 2043. He maintains the Fish and Wildlife Service never proved the ephemeral ponds existed on his land at all.

[Music break]

Lydia Chain: James, thank you for joining us on the show.

James Dinneen: Thanks for having me. It’s good to be here.

Lydia Chain: So, habitat designations are often controversial. Are there particular concerns that the people that you talked to are thinking about in terms of how it might affect development?

James Dinneen: Yeah, I think one common misconception about critical habitat designations is it’s the same thing as making some area a wildlife preserve. Nothing can happen in that area anymore. Once it’s critical habitat you can’t build anything. That’s not what it means. It means that if you’re doing anything on a property that requires permission from the federal government — which, a lot of stuff requires permission from the federal government — then agencies have to check with the Fish and Wildlife Service to make sure that any actions that you were to take wouldn’t impact whatever endangered species the area is designated as critical habitat for.

There are ways that the designation can limit development, either because there are delays or it could be that certain kinds of development actually do harm whatever elements of critical habitat are there in a space and you don’t get permission to build what you wanted to build. And so that’s why critical habitat designations can be controversial and can limit development.

One of the more interesting places that, specifically John Anderson, who is the executive director of the Energy and Wildlife Action Coalition, the scenario that he laid out for me is one where critical habitat designations — if the definition of habitat were to be so broad that the Fish and Wildlife Service designated wide swaths of territory as critical habitat — that with massive investment in renewable energy development and infrastructure development that the incoming Biden administration has announced, those critical habitat designations would really impede that development. So you could sort of foresee looming legal battles where there’s one group that’s trying to build a wind farm and another group that’s saying you can’t build a wind farm because it’s on critical habitat of an endangered species like the sage grouse or something. It’s kind of an interesting conflict between two major environmental problems. On one hand, biodiversity loss and habitat loss, and on the other hand, transitioning the grid to be less reliant on fossil fuels.

Lydia Chain: Rylander, from the conservation advocacy group, he proposes a different definition of habitat that includes the phrase “foreseeable future.” Can you expand a bit on that?

James Dinneen: Yeah, I think Rylander adding foreseeable future is really thinking about climate change and how endangered species might be impacted by a changing climate and how a changing climate will impact ecosystems and potentially make new areas occupiable by a particular species that without the climate changing would not have been occupiable. He’s also probably thinking about ecosystem restoration efforts. People doing things, modifying areas to make them habitable for a species. But there is a debate among conservationists and among developers and different groups about whether the Endangered Species Act and critical habitat in particular are really the best tools to help endangered species deal with climate change — whether the tools are out of date and sort of have to be stretched to do the sorts of things that might be necessary to protect species dealing with climate change. So there is some discussion about whether we might need new legislation to afford endangered species the necessary protections to help them deal with a changing climate.

[Undark podcast music]

Lydia Chain: James Dinneen is a science and environmental journalist from Colorado based in New York. He also produced the additional music on today’s episode. Our theme music is by the Undark team and I’m your host, Lydia Chain. See you next month.

UPDATE: In a previous version of this podcast, a Center for Biological Diversity attorney, Collette Adkins, described Louisiana landowner Edward Poitevent as a Tea Party activist. Poitevent vigorously disputed this characterization and it has been removed from both the audio and the accompanying transcript. The podcast has been further updated to clarify that while most of the land designated as habitat was owned by Poitevent, a small portion was owned by the Weyerhaeuser timber company and others. Finally, Poitevent’s name was also misspelled as Pointevent in an earlier version of the podcast transcript. It has been corrected.