ZeFrank on Merlin Tuttle

March 23, 2021 • 2:45 pm

I must have my constitutional, but I’ll leave you with this video about the life and work of a great naturalist and biologist, Merlin Tuttle. Tuttle (born 1941) devoted his career to studying and saving bats. His various efforts are shown in the film, and have occurred worldwide.

Donate to his foundation, which you can do here. Bats are wonderful creatures and good for the planet.

h/t: Mark

John Muir gets canceled

September 1, 2020 • 9:30 am

This article on the cancellation of John Muir, outdoor lover and founder of the Sierra Club, appeared in the Pittsburgh Post-Gazette (click on screenshot below), but I also found the same piece in the National Review. (The author, John Fund, is the National Review‘s national-affairs reporter.) Yes, the National Review is a conservative magazine, but investigate the facts for yourself if you’re dubious.


The pieces begin with the revelation that Muir was not immune to the bigotry of white people of his time—he made racist statements. But he’s also being tarred for his association with other bigots AND, according to a statement on the Sierra Club website by Michael Brune, Muir even recanted many of his bigoted views. But that doesn’t matter, for the Sierra Club is intent on flagellating itself.


The most monumental figure in the Sierra Club’s past is John Muir. Beloved by many of our members, his writings taught generations of people to see the sacredness of nature. But Muir maintained friendships with people like Henry Fairfield Osborn, who worked for both the conservation of nature and the conservation of the white race. Head of the New York Zoological Society and the board of trustees of the American Museum of Natural History, Osborn also helped found the American Eugenics Society in the years after Muir’s death.

And Muir was not immune to the racism peddled by many in the early conservation movement. He made derogatory comments about Black people and Indigenous peoples that drew on deeply harmful racist stereotypes, though his views evolved later in his life. As the most iconic figure in Sierra Club history, Muir’s words and actions carry an especially heavy weight. They continue to hurt and alienate Indigenous people and people of color who come into contact with the Sierra Club.

But is that the case.  If Muir changed his mind—and the article at the top shows how he came to recognize that white people committed genocide on Native Americans. So why do his words continue to “hurt and alienate” people? Do people even know about Muir’s earlier attitudes, what his words were, or how he changed? I doubt it.

It’s even more unfair to tar Muir for being friends with Henry Fairfield Osborn (an famous paleontologist, which isn’t mentioned above), who helped found the American Eugenics Society after Muir’s death. If you’re to be canceled not just because of your own words, but because of your association with someone who had racist attitudes in the late nineteenth centuries, then virtually all white men from that era are guilty and complicit.

But wait! There’s more. No environmentalist organization is free from these taints. I’ve added a link to Nelson’s article in the excerpt below (also from the paper’s piece):

The debate over John Muir is only the beginning of a purge sweeping the environmental community. In Crosscut magazine, Glenn Nelson wrote a piece last month headlined “Toppling John Muir from Sierra Club Is Not Enough.

Mr. Nelson called for dramatic efforts to “overcome a violent history of exclusion” by environmental groups. He said the next focus should be on the National Audubon Society, whose namesake, artist John James Audubon, “was an enslaver who opposed the intermingling of races.” The fact that Audubon may have himself been born to a black Creole woman in Haiti is less important than the fact the Audubon Society “has not reconciled its association with a man who, like Muir, embraced racist ideas and activities.”

If we are to expunge from their place of honor all the historical figures who changed their views later in life or who held views that were common in their time, where will it stop?

The rest of the piece is a series of whataboutery citations of others who weren’t canceled. For example, Fund notes that Martin Luther King, Jr., who wrote an advice column for Ebony magazine, once told a gay teenager to get rid of his “culturally acquired” gayness. Of course he didn’t get canceled. But King wasn’t a bigot, either. Still, that part of the article is largely irrelevant, though it does call out a certain hypocrisy in the Cancel Culture.

We have two issues here. First, how hard do we come down on people like Muir and Audubon who expressed views common in white men of their time but are now seen as odious? In my view, not as hard as people are doing. For, as Steve PInker has amply demonstrated, morality has evolved and improved over the past several centuries. While it’s historically salient to recognize that men like Muir and Audubon did express a common white bigotry, it doesn’t seem fair to single them out—as opposed to everyone else—and then cancel every aspect of their legacy. It’s unfair to expect people brought up in a certain culture to overcome it by becoming super-moral. (Animals named after Audubon will be the next to go.)

This is especially true when Audubon, uncharacteristically, recognized his errors later in life and corrected them.  The claim that the bigotry of these men still hurts people seems to me exaggerated and, as usual, is undocumented and unevidenced. The assertion alone is taken as the evidence. 

The other issue, largely unconnected, is whether conservation organizations are either excluding people of color or have created an atmosphere that makes them unwelcome. If that is the case, it would seem to have little with John Muir’s bigotry. Nelson’s article makes a case worth hearing that yes, there has been both deliberate and unwitting exclusion of minorities from outdoor groups. And this article in Orion Magazine argues that Native Americans have been treated pretty shabbily by the National Park Service.

So, the eagerness of organizations like the Sierra Club to flagellate themselves for century-old words or attitudes of their founders is unseemly: a form of au courant virtue signaling. But if those organizations could do meaningful outreach to those who don’t often get opportunities to get into the wilderness, they should. After all, we’re all evolved humans, and, if E. O. Wilson be right, we all have a degree of “biophilia.” Surely those who don’t get the opportunity to exercise it should be exposed to the great outdoors, and although the main object of the Sierra Club is to appreciate and preserve wilderness, everyone should be given that opportunity.

Readers’ wildlife photos

August 24, 2020 • 7:45 am

The tank is a bit lower than I like, so I importune readers with good wildlife photos to send them in.

On July 10, reader Mark Jones recounted conservationists’ success in breeding white storks (Ciconia ciconia) to release in the wild, and sent some photos. Today he adds a verbal and photographic update (his pictures). Mark’s caption and quotes are indented:

An update on the white stork chicks at the Knepp Estate in West Sussex; the four surviving chicks (out of six I think) have now all fledged their nests and have been seen out and about. Fingers crossed that the re-wilding continues its current success. The quote from the White Stork Project:

“24TH JULY 2020: “Our fourth and final chick from 2020 took its first flight and fledged the nest today. This is the single chick from nest 2 who has been growing well.  After losing the other two chicks, the parents put all of their energy into raising this chick. It has been seen flying in the fields near the nest and has also been seen with the adults in the nearby enclosure where we have our static population.  It is great to see it integrating with the rest of the flock.”

As mentioned before, Knepp is doing an extensive back-to nature experiment in farming, with free roaming herbivores (cattle, ponies, pigs and deer) and a ‘hands-off’ approach to the land. This has resulted in an explosion of biodiversity in this corner of Sussex, apart from the storks. This all seems highly sustainable ecologically, but I’m not sure how sustainable financially it is; it is partly paid for by glamping and safari trips . Anyway, it’s lovely to see properly diverse meadows for a change, so I hope it’s not idealistic to think a lot more land can be farmed this way.

There have been three nests (all built by the storks themselves, not manmade as I may have indicated before) this year and two have produced chicks. Apparently the eldest chick in the nest photographed has already flown with the parents at least once, but the others are still to fledge the nest.

The photos:

The nest in the top of the tree, with the three chicks standing up.

One of the parents arrives with food.

A sequence showing the mum (or dad, perhaps someone can tell?!) flying into the nest delivering something to eat, judging by the chicks’ reaction, although I couldn’t see what.

The three chicks side by side.

The oak tree (spot the nest) with some of the free roaming Exmoor ponies grazing below.

A fly-by from one of the adult storks.

Readers’ wildlife photos

July 10, 2020 • 7:45 am

Today we have installment #2 of Mark Jones’s photographs (#1 was yesterday). The photos document the return of the stork to England. You can read about their comeback in this article, which notes that the species hasn’t bred in England for hundreds of years: the last documented breeding was in fact in 1416! Yet everyone loves storks, and the conservationists’ goal is to get thirty pair breeding in nature by 2030.

Mark’s words are indented:

It is over 600 years since we have had white storks (Ciconia ciconia) in England, so imagine my excitement when, as I was photographing one of my favourite trees near my home, three of them flew down and landed on it! We just don’t see birds this size in Sussex, so it came as a bit of a shock. A complete stroke of luck, and I was also testing a new 300mm lens at the time.

These storks come from a rewilding project at Knepp Castle (www.whitestorkproject.org), which is having a bit of success at the moment with some chicks being raised and drawing the sightseers. But this is the first time I’ve seen them in Rudgwick (about 10 miles from Knepp as the stork flies). If you look closely you can see that all the storks are ringed, with a GB ‘number plate’.

Anyway the lens performed reasonably so I hope you like this selection.

Incidentally, for more context this is the tree that I was making a long exposure photo of; now with added storks.


Trump administration weakens Endangered Species Act

August 13, 2019 • 10:00 am

Everything the Trump administration does seems aimed in the wrong direction, but as a biologist, I’m really pissed off at this latest bit of stupidity. Read the NPR or NYT articles below (click on screenshots) to see the latest debacle:


Here are some of the changes. The new regulations:

  • weaken protections for species listed as “threatened”: one step below “endangered”;
  • allow future listings to be based partly on economic assessments (the NYT says, “for instance, lost revenue from a prohibition on logging a critical habitat”) rather than on science alone. This is a first, and something the original Act aimed to avoid.
  • make it easier to remove species from the “endangered” list;
  • limit the nature and amount of habitats are considered when deciding whether a species is listed as “endangered”. Environmental groups claim that this will make it harder to protect species at risk from warming climates, which alters where they live and how much space they occupy; and
  • give the government a lot more discretion about interpreting the phrase “foreseeable future” when deciding whether to list species. This would allow the government to largely ignore impending threats to species’ existence, one of them being climate change. In other words, what could happen in the future can be ignored when deciding which species to save.

The Trump administration claims that this will “help conservation efforts” (Interior Secretary David Bernhardt) and “ease the regulatory burden on the American public, without sacrificing our species’ protection and recovery goals” (Commerce Secretary Wilbur Ross). Those are, of course, lies. This is not about conserving species, but about making it easier for ranchers, oil drillers, and developers to take over land at the expense of its animal and plant inhabitants. Not a single change increases protection for species.

The motivations for this change are transparent, and become even more transparent when you see that, as NPR reports, “Republican lawmakers and industry groups celebrated the revisions. . . .”  Frankly, the government’s defense of these changes, which are a pack of lies, and its refusal to even acknowledgethe real motivations, sicken me. This is just one more REM bout in the continuing nightmare that is Trump.

But not everyone is going gentle into this bad plight. According to the Associated Press, both Maine and Massachusetts, along with several conservation groups, said they’ll sue the government over these latest changes. Should we sign petitions? See the next post.

h/t: Ken

Giant stick insects to be re-introduced to Lord Howe island

June 6, 2019 • 12:00 pm

Seven years ago (that long???!), I wrote about the giant stick insects (phasmids) found on a pinnacle of rock (“Ball’s Pyramid”) near Lord Howe Island, which lies between New Zealand and Australia. (See the posts here, here, and here.) Lord Howe is an oceanic island—the remnants of an ancient volcano—and home to many endemic species of plants and animals.  As I wrote earlier:

I’ve written twice before about Drycoceocelus australis, the giant stick insect of Lord Howe, an isolated volcanic island in the South Pacific (see here and here). The beast was once thought to be extinct, but climbers found 24 on Ball’s Pyramid, a jutting vertical spire of rock about 8 km from Lord Howe. They’re “YUUUJE,” as Philomena would say: up to six inches long and weighing nearly an ounce. They look like this, showing why their nickname is “tree lobsters”:

Male Lord Howe Island Stick Insect

Here’s Ball’s Pyramid, where the insects were found by explorers in 1964. As the Pyramid was  part of the volcano that created Lord Howe Island, and only 23 km away, the stick insect was once numerous on Lord Howe, too, though it was wiped out by 1920 by a combination of fishing (they were used for bait) and rodent invasion.


Although the insects were thought to be extinct after 1964 on Ball’s Pyramid as well, climbers in 2001 found a small population—only 24 stick insects. These were recovered and brought to Melbourne to expand the population for possible re-introduction on Lord Howe, as described in this post and the video below:

But reintroduction wouldn’t work on Lord Howe so long as there were rodent predators there. So, hand in hand with the captive breeding program, a process of rodent extirpation is now planned to begin this year, as described in this news piece in Science (click on the screenshot):


From the article:

. . . the Lord Howe project, years in the making, “will be the largest rodent eradication undertaken on a permanently inhabited island anywhere in the world,” says Andrew Walsh of the Lord Howe Island Rodent Eradication Project, who is overseeing the effort to spread 42 tons of poisoned cereal pellets across the island. Some 28,000 bait stations were filled across farmed and residential areas starting 22 May, and helicopters will scatter baits over more forested and mountainous parts of the island as soon as weather permits.

Walsh and his colleagues hope to undo some of the damage from the voracious rodents, which have wiped out five endemic birds, two plants, and 13 insects, including the 15-centimeter-long, black, waxy-looking Lord Howe Island stick insect, also called the phasmid or tree lobster (Dryococelus australis). Some lost species, including the phasmid, have subsequently been rediscovered on surrounding islets. Eliminating the estimated 360,000 rodents—including house mice, which arrived in the 1860s—could allow the native animals to return to the main island, and will also protect another 70 or more threatened species, such as the little shearwater, masked booby, and several endemic palms that grow in the island’s cloud forest.

I don’t know if this will work, for they have to get every single last rodent off the island (unless the last one is a male or non-pregnant female), and that would be hard. But they’re going ahead with the project, which will cost $ 7.3 million U.S. ($10.5 million Aus). Not everybody is in board with this, though, as some residents think the baits “might harm children, pets, cattle, and other wildlife or damage the lucrative tourist trade.” And the article adds:

People weren’t the only complication. Research in 2007 had revealed that the poison, a rodenticide called brodifacoum, might endanger two endemic birds, the Lord Howe Island woodhen and the Lord Howe Island currawong. Since April, a team from Sydney’s Taronga Zoo has been involved in rounding them up, housing the roughly 200 woodhens and 125 currawongs captured so far—more than half the wild populations—in aviaries and pens. The birds have “settled in beautifully,” says Leanne Elliott, wildlife conservation officer at the zoo. Once the poison has broken down, they’ll be released into the wild again, likely in stages toward the end of the year.

This is a massive conservation effort, and I hope it will work. The reintroduction of the stick insect is only speculative now, but will likely occur, since they plan a trial release of the Aussie-bred phasmids in 2021 on an islet in Lord Howe’s lagoon.

Here’s a prize-winning animation about the phasmids: “Sticky”.

THAT’S a bee!

February 22, 2019 • 7:30 am

JAC: In lieu of Reader’s Wildlife Photos today, I’ll take a break and importune you to keep sending me photos (I have a reasonable backlog, but I get nervous. . . .). In its place Greg has contributed a short piece about an enormous bee just rediscovered after several decades.

by Greg Mayer

There are many rare species, especially among invertebrates, that would not be encountered very often, even if they were not in decline. It is thus hard to know some species’ conservation status. Wallace’s Giant Bee (Megachile pluto) has not been seen since 1981, but the New York Times reported on Thursday that it has been rediscovered on one of the islands in its Northern Moluccas range. [Be sure to click on the photo, to get the full effect.]

Wallace’s Giant bee, with a honeybee for scale. Photo by Clay Bolt from The New York Times.

Note the insect in the upper left of the picture. “That’s not a bee.” The insect below it– “THAT’S a bee.”

The species had also not been seen between its discovery by Alfred Russel Wallace in 1859 and 1981, so it is perhaps not surprising that it was some time until a third encounter. Simon Robson, of the University of Sydney, reports that only a single individual was found, and photographed and filmed by Clay Bolt. They were part of a team that was part of an effort to search for other species that have not been seen for sometime. A previously unreported specimen of the Giant Bee was sold last year for $9100 on eBay, so there is concern that a market could develop that might make this apparently naturally rare species artificially rarer. That, combined with ongoing deforestation in Indonesia, creates concern for the species’ future.

JAC: I’ve added one photograph (with credits) that I found on another site:

Photograph of a specimen of Wallace’s Giant Bee © NJ Vereecken In Wildlife

Cheetah urine may help save the species

February 15, 2019 • 2:30 pm

The song at the beginning of this cheetah video shows what it would sound like if Barry White got involved in saving wildlife. Here’s a cool video from VICE about breeding cheetahs (Acinonyx jubata), and I hope they’re breeding them for release. I still get queasy about saving a species by keeping it permanently in captivity—especially a species in which individuals are evolved to lope and run.

What they do here is determine which male a female likes by exposing her to urine samples from diverse males. That will facilitate pairings that produce cubs.  Note that they collect the urine by putting a cologne—Calvin Klein’s “Obsession” (LOL)—on a urine-catching receptacle. Also note the female’s flehmen response, which you may have seen in your own cat.

The YouTube video:

The global cheetah population has plummeted over the last century. While zoo programs have made captive breeding a focus of their conservation efforts for endangered species, successful mating is a tricky dance. But inventive research has found that it may only take a few sterile gauzes soaked in urine to find that special someone to share the dance floor with.

h/t: Amy

The Crest-tailed mulgara is alive!!

February 10, 2019 • 12:45 pm

Yes, today we have a species long thought to be extinct, that, like Lazarus, has returned from the dead. It’s the Crest-tailed Mulgara (Dasycercus cristicauda), a small carnivorous marsupial that was thought for more than a century to be extinct, and whose existence was based on bone fragments. As Roaring Earth and the University of New South Wales report, recently one female was found in the desert of central Australia. And where there’s one, there’s more:

From the UNSW report:

A crest-tailed mulgara — thought to be extinct for more than 100 years — was recently found burrowing through the sand dunes of New South Wales.

Known previously only through fossilized remnants, the animal is one of two species of mulgara found throughout Central Australia. These marsupials have crested bushy tails, measure up to a foot in length, and boast sandy-blonde fur.

. . . A team from the UNSW Sydney’s Wild Deserts project made the unexpected discovery during recent scientific monitoring.

UNSW scientist and Wild Deserts ecologist Dr Rebecca West says it is particularly exciting to find a Crest-tailed Mulgara alive for the first time in NSW.

“The Crest-tailed Mulgara was once widely distributed across sandy desert environments in inland Australia, but declined due to the effects of rabbits, cats and foxes,” West says.

“The species weighs around 150 grams and has pale blonde fur and a thick tail with a distinctive black crest.”

The discovery comes at a great time, according to UNSW scientist and Wild Deserts project co-ordinator Reece Pedler.

“Next year we are due to begin introduced predator and rabbit eradication from a large area, which will no doubt help the Mulgara,” Pedler says.

From Roaring Earth, which makes a mistake in the first line (they mean “near extinction”):

The mulgaras were originally driven to extinction due to the introduction of invasive species including cats, foxes, and rabbits, all of which have European origins. Their return to existence in this specific area could be indicative of a natural decline in rabbit and invasive predator populations.

The recently spotted mulgara was found by researchers from the Wild Deserts project on a scientific monitoring trip in Sturt National Park, located just north-west of Tibooburra. Researchers identified the animal as a young female before releasing it back into the wild, hopeful for its reproduction.

Wild Deserts aims to reintroduce locally extinct mammal species back into their native habitats, which also involves removing some invasive species like rabbits, feral cats, and foxes. The greater bilby, burrowing betong, Western quoll, and Western barred bandicoot are the project’s primary focus, but they will now keep their eyes peeled for mulgara tracks as well.

Here are some photos of the rediscovered one:


Photo: Reece Pedler
Photo: Katherine Moseby

And a video:

Now what confuses me here is that there’s a Wikipedia page on the species, not mentioning its rediscovery, giving a range map, implying that there are a fair number of these things, and showing the picture below. They do say that there are two species in the genus, the other being the brush-tailed mulgara, but this one is clearly identified as the “crest-tailed mulgara”. Nor is the brush-tailed mulgara described as having nearly gone extinct.

Photo credit: Bobby Tamayo, Simpson Desert, QLD.

Perhaps Wikipedia has gone badly wrong here, in which case we have another examples for Greg Mayer’s long-promised “What’s the matter with Wikipedia?” post.

Readers are welcome to clarify this conundrum.

h/t: Kiera

A new paper confirms six subspecies of tigers, promoting conservation of the species (with some curmudgeonly comments on conservation genetics by Professor Ceiling Cat)

October 29, 2018 • 10:30 am

It’s a sad situation that the tiger (Panthera tigris), the world’s largest and arguably most magnificent wild cat, is heading towards extinction in nature. Fewer than 4,000 of them remain in the wild, and there are more in captivity than are roaming free in nature. Their current range is only 7% of the territory they occupied before humans killed them and destroyed their territory. Here, from Wikipedia, is a map of their present versus historical ranges. Sad, isn’t it?

One strategy for saving the tiger is to recognize subspecies, which are populations of the species that are recognizably different, either genetically (usually through inspection of DNA sequences) or through morphology (morphological differences, of course, often reflect genetic differences). Subspecies used to be called “races,” and still are by some people, but the term “race” is now in bad odor because of its past misapplication to our own species.

The designating-subspecies strategy here is two-pronged, with one prong scientific and the other political. The scientific rationale is that because populations differ genetically, saving different populations that are genetically diverse is a way to conserve overall genetic diversity in that species. Why? It’s sometimes not clear, but reasons given are to enable the species to recover if populations go extinct from inbreeding (a loss of genetic diversity), to conserve populations that look different and thus could be considered to have diverse appeal, and to save rare alleles that might prove adaptive under environmental change. I consider this strategy ill-conceived for reasons I’ll mention below.

The political reason is simply because some conservation laws, like the U.S.’s Endangered Species Act of 1973, allow a population to be listed as threatened or endangered if it’s not an entire species but simply a subspecies: a genetically different population. If you want to save a species, then, one way is to help save its constituent subspecies, regardless of the genetic rationale above. All that’s required is that a population be designated a subspecies because it is genetically different from other populations, and then that subspecies cannot be touched. Exactly how different a population must be to be regarded as a subspecies is not clear, and is subject to discussion and argument by biologists.

The use of the “subspecies” category thus gives conservationists a way to save species by saving their populations, even if the genetic rationale supporting it is weak. But because most conservationists and many biologists, including me, see saving species as an intrinsic good, regardless of genetic differentiation, we can use the “genetic differences” regulations as a way to do what we really want to do: save species as wholes regardless of how genetically different their populations are. And that surely holds for the vanishing tiger.

In other words, it’s in the interests of species-loving biologists to designate as many subspecies as possible as a way to save species, regardless of whether we agree with the “saving genetic diversity” argument. (As I said, I don’t really buy into that argument.) Thus you can use even tiny genetic differences, perhaps as little as a single gene causing change in, say, color—or even a diagnostic difference in DNA sequence of unknown function—as a way to designate subspecies and thus save species.

Now some biologists do think that we need to conserve genetic diversity within a species, and sometimes they might be right. But more often I think it’s a tactic to enable them to do what they feel impelled to do: stave off the destruction of threatened species by any means possible.

I hasten to add, though, that investigating population differences is of interest in its own right. For instance, we can get an idea whether those populations might be reproductively isolated (no gene exchange because of biological differences), and thus true species rather than subspecies. Or the genetic differences might give us some idea of the history of the species and the evolutionary relationships among populations. Or you might be able to identify illegal wildlife traffickers by looking at the DNA of material they’re selling.

An increase in tiger subspecies—or rather, a genetic confirmation of traditional subspecies— comes from a new genetic survey of the world’s tigers by by Yue-Chen Liu et al., just published in Current Biology (paper here, pdf here; reference below; ask if you can’t get it). There’s also a summary of the study in this week’s New York Times (click on screenshot below).

The upshot of the paper:

  • Tigers are genetically depauperate, probably because of a reduction in species size to around 50,000 during Pleistocene glaciation.
  • Nevertheless, sequencing of mitochondrial and nuclear DNA of tigers shows clear genetic differentiation among populations, and the well-demarcated populations (genetically, not morphologically) correspond to the six subspecies already recognized: the Bengal tiger, the Amur tiger, the South China tiger (only one specimen used), the Sumatran tiger, the Indochinese tiger, and the Malayan tiger.

Here’s a phylogeny of the tigers based on 11,600,055 autosomal variants, showing that they fall into six neat groups (consult the paper for caption and methodology) corresponding to the different subspecies already recognized (colors). Mitonchondrial and X-chromosomal analyses give similar phylogenies, and the numbers at the branches show that these are significantly demarcated using bootstrapping methods:


Below is a cluster analysis of tiger genomes using the “ADMIXTURE” program. The data are based on nearly two million variants on the autosomes. The different colors recognize units that the program can distinguish under assumptions of different numbers of clusters, with the number of clusters to look for set from 4 to 6. As you see, under the assumption of 5 clusters you get five subspecies, and with 6 clusters you get six subspecies. (This is not a trick, but a way to recognize hierarchically differentiated populations.)

  • Gene flow among populations was extant but low, reflecting the fact that they’re geographically isolated and have been so for some time. They aren’t considered different species because there is some gene flow and because hybrids, at least in captivity, are readily formed and are fertile.
  • These differences aren’t so readily discerned using morphology, since tiger subspecies generally lack diagnostic physical traits, though there are some average differences in size, shape and color (see here for a summary). That is, you can’t unambiguously put a single tiger into one of the six subspecies using morphology alone, but you can do it using just a few genes.
  • These findings, while confirming traditional classification, go against the suggestion of some biologists that there are only two subspecies of tigers. Those biologists say that having only two subspecies is better than having more, because the recognition of some very small subspecies, like the South China tiger, would make them “face extinction”. (This baffles me unless those researchers don’t think we should make an effort to save this population.)
  • Some of the DNA data give evidence that population differences arose by natural selection (this comes from the pattern of the variation associated with these regions). As the paper notes, “We identified multiple genomic regions that are candidates for identifying the adaptive divergence of subspecies. The body-size-related gene ADH7 appears to have been strongly selected in the Sumatran tiger, perhaps in association with adaptation to the tropical Sunda Islands.”

But genetics does confirm the populations previously recognized by average trait differences. That’s not a novel finding, but the genetically diagnostic differences, say the authors, will help us conserve the species. As they say in the paper (my emphasis):

Because many of the conservation policies and measurements regarding the tiger, including coordinated captive breeding programs and legislations in several tiger range countries, are based on “subspecies taxonomy,” an appropriate description of subspecies is vitally important.

Considering the subspecies concepts presented above, the genome-wide signatures of phylogeographic partitioning and evidence for long-term restriction of gene flow and adaptive divergence jointly allow us to elucidate tiger evolution and corroborate six phylogeographic units. These findings provide the strongest genetic evidence for subspecies delineation in tigers to date, evidence stronger than that used to define subspecies in nearly any felid reported thus far. These population units correspond precisely with the geographic subspecies named much earlier. . .

Understanding the tiger’s natural history from a genomic perspective provides a data-driven foundation for subspecies recognition, conservation strategic planning, and management actions. Our general goals are to reverse the species’ decline by maximizing the efforts to preserve the genetic diversity, evolutionary uniqueness, and potential of the species Panthera tigris.

The New York Times article echoes the conservation importance emphasized by the study’s authors.  But, as I implied above, recognizing six subspecies rather than two is important mainly because it gives biologists a legal handle to save tigers in general. The genetic differences between populations, as diagnostic as they are, are in my view not sufficient reason by themselves to save all populations. Sufficient reason to save the populations, though it won’t fly with governments and laws, is simply because we need to save as many tiger populations as we can, because they add to our world, because they were here before us, and because we have no right to wipe out a dwindling species for our own selfish needs. Despite their fierceness, tigers can’t fight human development. Most nature-loving biologists simply want any way to save tigers, and genetics (again, this is my opinion) gives them an excuse—but not a good population-genetic reason. Any one population of tigers surely contains enough genetic variation to replenish all the other populations, whether that variation be common or rare. And, of course, new mutations occur.

Here’s what one of the authors say in the NYT piece:

A system recently proposed by some scientists that would classify the world’s tigers into two subspecies would harm the world’s remaining tigers rather than benefit them, said Shu-Jin Luo, a geneticist at Peking University who led the study. Preserving what is left of tigers’ genetic diversity will require ensuring that all remaining subspecies are taken into account, she and her co-authors argue.

“If you think that all tigers are genetically homogeneous, you might say if you lose the Amur tiger, you still have the Bengal tiger — and that’s O.K. because they’re very similar,” Dr. Luo said. “But that’s not O.K., because now we know that tigers are not all alike.”

No, tigers are not all alike; they differ on average in appearance, and in DNA sequence, some of those differences probably being the result of geographically varying natural selection. But what do we gain by saving subspecies because they have genetic differences. What, indeed, are the genetic differences we’re trying to conserve? Genes for morphology? Those differences are inherent within in any one subspecies, so you could constitute any extinct population simply by either selecting variants within another subpopulation, or transplanting members of extant populations to areas of extinction, where selection will act eventually to create a new subspecies (it may be different from the old one). Are we trying to save variants that might be adaptive in the whole species, enabling it to respond to new selective pressures? If so, those variants are probably latent in several populations, so you don’t need to conserve them all. Are we trying to prevent inbreeding? Well, there’s no evidence that extinction is caused by inbreeding in this species, and to save them that way requires crossing members of different subspecies, which wipes out the differences we’re trying to conserve in the first place.

What I’m not saying here is that because the rationale for conserving genetic variation in tigers is weak, we shouldn’t try to save every subspecies. No, what I’m saying is that the genetic-variation excuse is a way that some biologists, chafing under legal restrictions, try to save every member of a species, no matter how many subspecies there are. Having six rather than two subspecies of tigers makes it easier to save them all, but what if the genetic variation analysis had shown just two, or four, distinct subspecies? Would it be less pressing to save tiger populations? I doubt that even conservationists would agree. And that shows that we’re using political rather than sound genetic rationales to save endangered species.

My message here is just this: we should save all the tigers because tigers are an inherent good. If we have to do that by recognizing subspecies, well, that’s the way we have to do it. But we shouldn’t pretend that we need to save subspecies to “conserve genetic variation in tigers”. That rationale is very weak, and makes conservation dependent on subjective criteria like the frequency of DNA variants that may not even play a role in adaptation—now or in the future. I think it’s time for conservation geneticists to tell us exactly what kind of genetic variation they want to save, and why. (There’s very little written about this.) And it’s time for biologists to admit that for many of us, our interest is not in conserving genetic variation, but in saving every tiger possible. The subspecies ploy is one way to do that, but it’s still a ploy.

We should save all tigers because of they are dwindling but magnificent; because of this:

(From the NYT): Tigers in a park in Hailin, northeast China. A century ago, about 100,000 tigers roamed Asia’s habitats. There remain only about 4,000 in the wild worldwide.CreditVisual China Group/Getty Images

The way to save tigers is not to designate subspecies and then use various schemes to conserve genetic variation, but to save the habitat in which tigers live and to keep people from poaching them.


Liu, Y.-C., X. Sun, C. Driscoll, D. G. Miquelle, X. Xu, P. Martelli, O. Uphyrkina, J. L. D. Smith, S. J. O’Brien, and S.-J. Luo. Genome-wide evolutionary analysis of natural history and adaptation in the world’s tigers. Current Biology, online. DOI: https://doi.org/10.1016/j.cub.2018.09.019