Richard Conniff's Blog, page 48

Take 10 Doses of Hope for Earth Day

Feeling much better today, thank you. (Photo: Mike Blake/Reuters)

In the thick of the struggle to achieve any progress on environmental issues, it’s easy to despair. The political world can seem to be dominated by preening nimrods who value wildlife only as targets. Plutocrats with bottomless bank accounts call the shots. And nothing seems to change.

In retrospect, though, amazing changes have happened, and it’s worth bringing some of these past success stories to mind, as a source of strength in the day-to-day struggle:

1. Peregrine falcons now routinely do their 200-mile-an-hour headfirst dive off skyscrapers from Fifth Avenue in New York, to Third Avenue in Seattle. But just 40 years ago they were almost extinct. They came back—as did ospreys, cormorants, and a host of other bird species—because Rachel Carson’s 1962 book Silent Spring led to a ban on DDT. This broadly destructive pesticide had been causing a fatal thinning of eggshells in many bird species, among other unintended effects. Carson’s book put an end to an era of indiscriminate and unexamined use of pesticides and herbicides.

2. The bald eagle, our national bird, was down to just 417 nesting pairs in the 1970s—and

DDT was once again a culprit. Passage of the Endangered Species Act in 1973 contributed significantly to recovery, and by the time bald eagles were removed from the endangered species list in 2007, the population had rebounded to more than 11,000 nesting pairs.

3. Black-footed ferrets were thought to be extinct until a dog brought home a freshly-killed specimen one day in 1981 in Meeteetse, Wyo. That led to the discovery of a remnant population of several dozen individual. Working under the umbrella of the Endangered Species Act, the U.S. Fish and Wildlife Service launched a captive breeding program. More than 1,000 black-footed ferrets now survive in 18 wild populations around the Mountain States.

4. Just 20 years ago, remote islands around the world seemed to be permanently infested with rats, goats, pigs, cats, and other species introduced by early colonial navigators. These pests often consigned native species to extinction. But in recent years, the island rewilding movement has recaptured island after island for its original inhabitants. Rat Island in the Alaska Maritime National Wildlife Refuge is the latest such victory, having recently become free of rats for the first time since 1780. This year, Hawadax Island, as it’s now known, is a raucous jubilation of nesting sea birds.

5. In the 1960s, dark, stinking clouds of smokestack pollution were commonplace in American cities, and vehicles added leaded gasoline and other emissions to this toxic brew. That began to change with the Clean Air Act, which became law in 1963 and has been steadily improved with amendments over the years. The 1990 amendments alone now prevent 160,000 deaths from fine particle pollution and 4,000 from ozone pollution in a single year. To get a sense of what life would be like without that law, try breathing the air in modern Beijing.

6. In the 1960s, it was routine for businesses to dump 55-gallon drums of toxic chemicals into rivers—I witnessed it—on top of the daily load of floating sewage from huge municipal waste pipes. Massive fish kills were common. A few rivers even went up in flames. Because of cleanups mandated under the Clean Water Act of 1972 that all began to change. One result: A recent study of California rivers noted a 100-fold decrease in lead and a 400-fold drop in copper and cadmium.  Also as a result of that law, fish and bird species are now flocking back to old habitats, and people are no longer horrified at the idea of swimming in urban waterways.

7. Researchers first reported in the 1970s that the refrigerants and aerosol propellants known as CFCs, or chlorofluorocarbons, were causing serious damage to the ozone layer high in the atmosphere. Skeptics, many of them from industry, attacked the evidence and delayed action. But in 1985, a huge hole appeared in the ozone layer over Antarctica, with CFCs clearly to blame. The resulting alarm led to an international agreement to end CFC production by 1994.

8. At about the same time, the United States was struggling to find a solution to the acid rain problem that was killing forests and streams. Republicans in the George H.W. Bush Administration, together with the Environmental Defense Fund, devised an ingenious solution called cap-and-trade, which set a steadily decreasing cap on the power plant emissions that mainly caused the problem.  But instead of imposing government rules, cap-and-trade allowed the power companies to figure out how to meet that cap, often by buying or selling pollution rights. That reduced acid rain emissions by half, at dramatically lower cost than anyone had believed possible. Cap-and-trade could now provide a model for dealing with climate change—if Republicans would just reclaim bragging rights to their own free market innovation.

9. It may seem odd to mention this in the middle of a brutal war for rhino horn, but one of conservation’s earliest success stories was the recovery of white rhinos from a single small breeding population of just a few hundred individuals at the end of the nineteenth century to more than 20,000 animals in the wild today.  Saving the rhinos was the purpose of Africa’s first protected conservation area—Hluhluwe-iMfolozi Park in South Africa—and it provided the seed stock for repopulating white rhinos around southern Africa. If early conservationists could stop the killing back then, surely we can now.

10. Europe was the first continent to wipe out its megafauna, and it is now so crowded and overdeveloped that it’s hard to conceive of a wildlife recovery there. But a study by the group Rewilding Europe recently reported that many species are now coming back, as farmers abandon marginal land all over the continent. Even wolves have begun to return to Germany, France, and into the border country of Belgium and the Netherlands.

This is of course only a very incomplete list of environmental success stories. I welcome readers to suggest their own favorites.

More important, readers should take heart from past successes and make them the model for winning the new battles we face today.

 

Love on Rogers Lake: A Tale of Two Alewives

(Illustration: Eric Nyquist)

My latest, for the op-ed page of today’s New York Times   (I had to edit that version down. This is a slightly longer version.):

We would see amazing things if we could learn to be travelers in our own neighborhoods, Henry David Thoreau once suggested. Lately, I have come to think that this is more true than I had imagined.

Most mornings in warm weather, when I am home in coastal Connecticut, I head out before dawn to row on a 260-acre dogleg of a lake, backed up behind a rickety old dam. And I see plenty of wonderful things as I do my laps: An osprey cruising with a freshly-caught fish carried underneath, like a seaplane pontoon. A kingfisher looping along the shoreline. A newly emerged damselfly riding on my deck for a lap-and-a-half till its wings harden enough for flight. And once, at a distance of 50 feet, a bald eagle scavenging the carcass of a cormorant. But I did not realize until recently that a grand evolutionary experiment was taking place beneath my hull.

Along with other members of my rowing club, The Blood Street Sculls, I spent an inordinate amount of time last year moaning about a project to rebuild the dam where Rogers Lake in Old Lyme, Conn., spills down to become Mill Brook, on route to Long Island Sound and the sea. Construction required dropping the lake level by more than two feet, and that increased the risk for rowers of tearing off a skeg, or ripping out the bottom of a boat, or just spilling ignominiously while running across an unexpectedly low patch.

Now, though, the dam is finished, and starting this month, alewives, also known as river herring, are climbing the new fish ladder there and returning to Rogers Lake from their feeding grounds at sea. The work is part of a coast-wide effort to remove dams, build fish ladders, and improve habitat in the hope of returning the river herring to their former glory.

Alewives are anadromous fish: Born in freshwater, they spend their lives in the ocean, returning annually to their birthplaces to spawn. Until colonial era dams cut off the migration, hundreds of thousands of alewives would have come pouring into Rogers Lake every spring—and into other lakes like it along much of the Atlantic seaboard. Farmers used to apply them to their fields as fertilizer, at a rate of up to 1400 fish per acre. In towns all along the coast, river herring festivals celebrated their arrival.

What’s particularly intriguing about Rogers Lake, though, is that the first dam built on Mill Brook in 1672 inadvertently drew a pre-Darwinian dividing line across a species. On one side, the anadromous alewives continued their old seagoing life. But on the other side, in Rogers Lake, other members of the same species became landlocked.

Over the past 17 years, local conservationists have added fish ladders to the dams lower down on Mill Brook, and about 10,000 anadromous alewives a year have been recovering at least a part of their old migration. But the new fish ladder means they can finally complete the journey–and come face to face with their landlocked cousins, after a separation of 342 years.

Evolution has wrought strange changes in the intervening 100 or so generations, most notably in size. The landlocked fish are now just a third the length of their foot-long seagoing cousins. Somewhere beneath the hull of my rowing shell, it’s as if mastiffs are returning to discover that their distant kinfolk, and potential mates, have become Chihuahuas.

 

At his laboratory at Yale University, ecologist David Post clambered over obstacles in what would be a walk-in freezer, if it weren’t so full, and eventually pulled out plastic bags containing frozen landlocked and anadromous alewives. “They look like something you’d get out of a pickled herring jar, because that’s basically what they are,” he said. “They’re not nearly as sexy as Atlantic salmon, or as funky as eels. They’re silvery and nondescript, and that’s both the joy and the curse of working with these fish.” (On the sexiness question, one theory holds that the name “alewife” derives from their big-bellied resemblance to a female tavern keeper.)

The joy, for an ecologist, is that alewives are a keystone species. As predators, said Post, they “drive the ecosystem” of every coastal lake and stream from the Carolinas to Maine—or at least the ones to which they can still gain access. As prey, alewives, together with menhaden, Atlantic herring, and other forage fish, are the basic food stock for the entire Atlantic fishery, as well as for seabirds, whales, dolphins, and other species.

Part of the curse is that even biologists have a hard time telling alewives from bluebacks, another species of river herring. At sea, alewives, bluebacks, and Atlantic herring all school together, and to fishermen trawling huge nets for the Atlantic herring, they look the same. As a result, an estimated 3.8 million river herring disappear every year as bycatch, and that may be an important reason the overall river herring population has plummeted by more than half since the 1960s.

Post has been studying alewives in Connecticut lakes for the past decade and now has a National Science Foundation grant to track the outcome of the reunion at Rogers Lake. Before the dams cut them off, he said, the alewives arrived each spring as “slash and burn” predators on the planktonic life in the lake. They picked off everything they could find—mostly fly larvae and feathery little crustaceans like copepods and water fleas—and then headed back out again, leaving what was left of the plankton to recover for another harvest the following spring. “It’s a pretty good lifestyle, if you’re anadromous,” said Post. “You eat everything in sight and go elsewhere.”

But once the alewives became landlocked, they had to get by on the smaller plankton left behind, leading to an almost complete disappearance of large plankton. To human eyes, this effect is almost invisible: Post held up a small jar of water containing thousands of larger plankton from a lake without landlocked alewives, and it looked like a faintly yellow broth. A jar from Rogers Lake, on the other hand, could have passed for clear water. The change in the prey base forced the alewives not just to become significantly smaller but also to develop more closely-spaced gill rakers, apparently so they could strain food from the water, rather than picking it off one particle at a time.

So what will happen when the two forms of alewife come together? The difference in size may not matter for mating, since alewives don’t practice internal fertilization. Instead, they broadcast sperm and eggs into the water simultaneously. But the anadromous alewives begin breeding in April, several weeks ahead of their landlocked cousins. So the two forms may just pass each other with a glance, curious but puzzled.

Or there may just be enough of an overlap for romance. If so, what happens to the young of the year? Will they turn seaward at the end of the summer, as did their anadromous forebears more or less forever? Or will the landlocked lifestyle keep its hold on them?

It is an evolutionary family drama, and it makes me think that Thoreau was right: With every stroke of my oars, I am skimming across the surface of unsuspected mysteries.

 

When Should Scientists Kill?

Lost but now is found: A Holdridge’s toad. (Photo: Juan G. Abarca Alvarado)

In May 2006, in the Himalayan foothills of northern India, an astronomer and ecologist named Ramana Athreya caught two of an elusive bird species in a mist net. He‘d first spotted these birds and recognized them as something unfamiliar in 1995. Now, after more than 10 years, he held the prize in his hand. It was unmistakably a new species, the sort of thing most ornithologists can only dream of discovering.

The usual procedure would have been to kill those specimens as mercifully as possible and carefully preserve them for science. That’s been the usual procedure for the past 250 years of species discovery and identification. Having the bird literally in hand has been the essential means of defining a species, both for the original scientific description and as source material for later researchers.

Instead, to the chagrin of many scientists, Athreya set the birds free. “We thought the bird was just too rare for one to be killed,” he said at the time. “With today’s modern technology, we could gather all the information we needed to confirm it as a new species. We took feathers and photographs, and recorded the bird’s song.” Even without a complete bird, that was enough to publish a scientific description of the species, now known as Bugun liochichla.

An article out today in the journal Science argues, in essence, that more scientists should follow Athreya’s example. That is, they should think twice before taking specimens, particularly when rediscovering species that had been presumed extinct. Those kinds of rediscoveries have happened more than 350 times over the past century or so, and for an excited naturalist, the instinct is to bring home proof in the form of a specimen.  But such collecting risks consigning the species to “re-extinction,” as the headline of the new article puts it.

“This is the only article I have ever written out of rage,” coauthor and herpetologist Robert Puschendorf said, in an interview. A few years ago, in Costa Rica’s Monteverde Cloud Forest Reserve, he was present when two colleagues spotted a stream-dwelling frog species that had until then been considered extinct–and collected it for one of their museums. He acknowledged that he had once done the same thing, adding, “In my defense, I’ll say that there were tons of them, the night we rediscovered the species. I’m not proud of what I did, but at least I did not collect the only individual of a species.”

The new article describes one species, the great auk on Eldey Island in Iceland, where “centuries of exploitation for food and feathers” severely reduced populations, “but overzealous museum collectors also played a role in its extinction.” The last breeding pair were collected in the 1850s by a fisherman, to be preserved for science, their internal organs ultimately deposited at the Zoological Museum in Copenhagen. The article also links professional and amateur collecting to the decline of Mexico’s elf owl.

Puschendorf acknowledged that collecting specimens and preserving them in a museum can provide essential information for scientists. He began his own career examining museum specimens of frogs to see when and where the deadly chytrid fungus first appeared. That kind of information can help to save species from extinction. “I’m definitely not saying, ‘Do not collect,’ ” said Puschendorf. “What I’m saying is ‘Think about when you’re to going to collect.’ ”

As an alternative to collecting, the article notes that “most smartphones have a camera and a voice recorder sufficient to gather high resolution images as well as an organism’s call” and that combining this data with genetic information from skin swabs or other sources “can be just as accurate as the collection of a voucher specimen.” It suggests that this information should be stored in digital repositories for access by other scientists.

If Puschendorf’s article was written out of rage, it is likely to elicit rage from other scientists. “This guilt-driven paper is as bad as I was afraid it would be,” said Piotr Naskrecki, associate director of the E.O. Wilson Biodiversity Laboratory at Harvard, in an email. The examples it cites of negative impacts from collecting “are rare exceptions” rather than the rule, and the article “offers naive, mostly impractical recommendations that apply to a tiny handful of potential cases. Try to document a new ant species using your phone and a recorder, or a new fungus using molecular markers in a group where no species has ever been sequenced.” Naskrecki worried that publication in a high-profile journal such as Science “will reinforce many readers’ belief that collecting and natural history collections are outdated relicts of Victorian science that can and should be phased out. Very disappointing.”

To put the putative threat from collecting in perspective, mammalogist Kristofer Helgen noted, also by email, that the mammal collection at the Smithsonian Institution, where he works, “reflects almost 200 years of targeted collecting, representing many hundreds, if not thousands, of expeditions. It is the single most important resource globally for understanding the biology of mammals. However, this collection amounts, in total number of specimens, to only about one-half of the total number of animals estimated to be road-killed in the U.S. per day.”

Helgen added, “I do agree that lethal collecting of truly endangered taxa is a very important ethical issue and for mammals where it might threaten survival of populations, is certainly to be avoided, and this is already reflected in the permissions required and normal ethical standards currently in operation in professional field biology and collections-based science.” But within those community standards, collecting “provides arguably the most rigorous source of data not just for definitive identifications but also for understanding variation in nature, geographic distributions, conservation prioritization, ecology of health and disease, environmental change through time, and many other very important and practical aspects of our world.”

Debate along these lines is likely to be loud and passionate, and that’s a good thing, says Ben Minteer, a coauthor of the new article. He also points out that it is an old story. The debate about using lethal methods dates back at least a century, to another article published in Science, by the pioneering vertebrate biologist Joseph Grinnell.

“The type of field observer who depends solely on long-range identification is becoming more and more prevalent,” Grinnell wrote. “But the opera-glass student, even if experienced, can not be depended upon to take the place of the collector. Accuracy in identification of species and especially subspecies rests for final appeal upon the actual capture and comparison of specimens.” Grinnell thought that the prejudice against collectors was the work of “extreme sentimentalists.” Minteer and Puschendorf noted that precedent in their original draft for the new Science article and also quibbled that Grinnell didn’t know about genetics or the perils of species rediscovery.

Perhaps in the interest of stirring up the debate, and simplifying the story, the editors of modern-day Science cut out that reference.

A Cold Death in South America

View of Tierra del Fuego painted by Alexander Buchan four days before he joined the fatal expedition into the interior

In putting together The Wall of the Dead:  A Memorial to Lost Naturalists, I have been continually aware that local collectors and other underlings often get left out of history.  So I was intrigued to come across an account of two explorers lost in January 1769 on Capt. Cook’s first circumnavigation of the globe.  Both Richmond and Dorlton were servants–and specimen collectors–for the great botanist Joseph Banks.  Cook’s journal noted them both as negro servants.

Banks writing afterward in his journal:

 The weather had all this time been vastly fine much like a sunshiny day in May, so that neither heat nor cold was troublesome to us nor were there any insects to molest us, which made me think the traveling much better than what I had before met with in Newfoundland.

We passd about half way very well when the cold seemd to have at once an effect infinitely beyond what I have ever experienced. Dr Solander was the first who felt it, he said he could not go any fa[r]ther but must lay down, tho the ground was coverd with snow, and down he laid notwisthstanding all I could say to the contrary. Richmond a black Servant now began also to lag and was much in the same way as the dr: at this Juncture I dispatchd 5 forwards of whom Mr Buchan was one to make ready a fire at the very first convenient place they could find, while myself with 4 more staid behind to persuade if possible the dr and Richmond to come on. With much persuasion and intreaty we got through much the largest part of the Birch when they both gave out; Richmond said that he could not go any further and when told that if he did not he must be Froze to death only answerd that there he would lay and dye; the Dr on the contrary said that he must sleep a little before he could go on and actualy did full a quarter of an hour, at which time we had the welcome news of a fire being lit about a quarter of a mile ahead. I then undertook to make the Dr Proceed to it; finding it impossible to make Richmond stir left two hands with him who seemd the least affected with Cold, promising to send two to releive them as soon as I should reach the fire. With much difficulty I got the Dr to it and as soon as two people were sufficiently warmd sent them out in hopes that they would bring Richmond and the rest; after staying about half an hour they returnd bringing word that they had been all round the place shouting and hallowing but could not get any answer. We now guess’d the cause of the mischeif, a bottle of rum the whole of our stock was missing, and we soon concluded that it was in one of their Knapsacks and that the two who were left in health had drank immoderately of it and had slept like the other.

For two hours now it had snowd almost incessantly so we had little hopes of seeing any of the three alive: about 12 however to our great Joy we heard a shouting, on which myself and 4 more went out immediately and found it to be the Seaman who had wakd almost starvd to death and come a little way from where he lay. Him I sent back to the fire and proceeded by his direction to find the other two, Richmond was upon his leggs but not able to walk the other lay on the ground as insensible as a stone. We immediately calld all hands from the fire and attempted by all the means we could contrive to bring them down but finding it absolutely impossible, the road was so bad and the night so dark that we could scarcely ourselves get on nor did we without many Falls. We would then have lit a fire upon the spot but the snow on the ground as well as that which continualy fell renderd that as impracticable as the other, and to bring fire from the other place was also impossible from the quantity of snow which fell every moment from the branches of the trees; so we were forc’d to content ourselves with laying out our unfortunate companions upon a bed of boughs and covering them over with boughs also as thick as we were able, and thus we left them hopeless of ever seeing them again alive which indeed we never did.

In these employments we had spent an hour and a half expos’d to the most penetrating cold I ever felt as well as continual snow. Peter Briscoe, another servant of mine, began now to complain and before we came to the fire became very ill but got there at last almost dead with cold.

Now might our situation truely be calld terrible: of twelve our original number 2 were already past all hopes, one more was so ill that tho he was with us I had little hopes of his being able to walk in the morning, and another very likely to relapse into his fitts either before we set out or in the course of our journey: we were distant from the ship we did not know how far, we knew only that we had been the greatest past of a day in walking it through pathless woods: provision we had none but one vulture which had been shot while we were out, and at the shortest allowance could not furnish half a meal: and to compleat our misfortunes we were caught in a snow storm in a climate we were utterly unaquainted with but which we had reason to beleive was as inhospitable as any in the world, not only from all the accounts we had heard or read but from the Quantity of snow which we saw falling, tho it was very little after midsummer: a circumstance unheard of in Europe for even in Norway or Lapland snow is never known to fall in the summer.”

17 January 1769

17. The Morning now dawnd and shewd us the earth coverd with snow as well as all the tops of the trees, nor were the snow squalls at all less Frequent for seldom many minutes were fair together; we had no hopes now but of staying here as long as the snow lasted and how long that would be God alone knew.

About 6 O’Clock the sun came out a little and we immediately thought of sending to see whether the poor wretches we had been so anzious about last night were yet alive, three of our people went but soon returnd with the melancholy news of their being both dead. The snow continued to fall tho not quite so thick as it had done; about 8 a small breeze of wind sprung up and with the additional power of the sun began (to our great Joy) to clear the air, and soon after we saw the snow begin to fall from the tops of the trees, a sure sign of an aproaching thaw. Peter continued very ill but said he thought himself able to walk. Mr Buchan thank god was much better than I could have expected, so we agreed to dress our vulture and prepare ourselves to set out for the ship as soon as the snow should be a little more gone off: so he was skinnd and cut into ten equal shares, every man cooking his own share which furnishd about 3 mouthfulls of hot meat, all the refreshment we had had since our cold dinner yesterday and all we were to expect till we should come to the ship.

About ten we set out and after a march of about 3 hours arrivd at the beach,, fortunate in having met with much better roads in our return than we did in going out, as well as in being nearer to the ship than we had any reason to hope; for on reviewing our track as well as we could from the ship we found that we had made a half circle round the hills, instead of penetrating as we thought we had done into the inner part of the cuntrey. With what pleasure then did we contratulate each other on our safety no one can tell who has not been in such circumstances.”

Cook in his journal seems to be confused about who had the rum, blaming it on the two black servants.

Parkinson does not mention the deaths at all, and says that Banks and Solander ” returned to the ship much pleased with their adventure.”  And Hawkesworth noted that, after the catching and dissecting of a shark on January 11, “Nothing remarkable happened till the 30th.”

In early December the Endeavour continued south, heading for the Horn and then on to the Pacific Ocean. Although Cook had to resist Banks many requests to make landfall for the purpose of further study, he nonetheless took an increasing interest in the collections of his ‘Gentlemen Passengers’. It was early in January of 1769 when the Endeavour first reached Tierra del Fuego in preperation for rounding the Horn. When Captain Cook realized the strength of the current through Straight le Marie, he knew he would have to bide his time until conditions were favourable. This afforded Joseph Banks and Daniel Solander a chance to make landfall and to investigate the local wildlife, while Cook and his crew restocked the ship’s wood and water supplies.

The Sub-Antarctic summer is a fickle thing, and can prove fatal for the inexperienced explorer. Banks had decided that since ‘The weather was vastly fine, like a sunshiny day in May, so that neither heat nor cold was troublesome to us’ it was a perfect day for a short excursion inland. He wanted to reach higher ground to get a sense of the lay of the land, and look for any interesting alpine plants. His entire retinue joined him that day: Daniel Solander[image error], the botanist; Herman Spöring, Solander’s assistant; Charles Green, the astronomer; William Monkhouse, the surgeon; and Alexander Buchan, the artist; as well as four servants and two seamen to help transport the equipment and carry back the collections. Not all would return alive.

The terrain proved more difficult going that it first appeared, since what had looked like tundra proved to be a bog populated by extremely dense, waist-high trees. They pressed forward through the strange little forest when Buchan was struck with an epileptic fit. They built a fire and tended to the stricken artist, and seeing that he appeared to be recovering, Banks and Solander continued on. The two botanists did find some alpine plants, and were collecting specimens when Solander first noticed the sudden bitter cold. The sun disappeared behind thick clouds and snow began to fall heavily.

They were able to return to the main group where they found that Buchan had fully recovered. With the snow coming down hard it was difficult to see their way clearly, but Banks knew that the only option was to head back to the ship. After some distance Solander and one of the servants, Tom Richmond, were feeling the early stages of hypothermia and grew tired and lethargic. Banks tried to keep them moving, but was unsuccessful. On Banks’s orders the others had moved ahead and established another fire in a clearing. Eventually Banks was able to rouse Solander and assist him through the dark to the makeshift camp while leaving another servant, George Dorlton, and a sailor to watch over Richmond. The sailor arrived at the camp around midnight, too drunk to make much sense. Banks took four of the hardiest men in his party and returned to where Richmond and Dorlton remained. Unable to get them back to the camp, Banks had his men fashion a crude shelter out of branches, and left his two grey hounds with the men to help keep them warm.

When they returned the next morning, Richmond and Dorlton were both dead. The dogs, however, were alive but reluctant to leave their friends.

As so often happens in a blizzard, they were much closer to their goal than they had realized, and were able to return to the ship, with the dogs, by just after noon.

A shipmate noted in his private journal that “this was a heavy loss to Mr. Banks, as they were both very useful.”

Help for Farmers When Honeybees Fail

Right now in Washington and Oregon, 380,000 honeybee hives are at work pollinating cherry, pear, and apple orchards. Last month, a million hives—three-quarters of the nation’s entire stock of commercial honeybees—were pollinating almonds in the Central Valley of California. Pollination by insects is an essential service, necessary for71 percent of the top 100 crops worldwide. But it has also become alarmingly expensive and uncertain, as colony collapse disorder and other problems have doubled or tripled the cost of renting honeybee hives.

Why not let native pollinators do the same work for free?

That might be a good idea, except that populations of wild pollinators have also collapsed, largely because intensive agriculture has eaten up huge swaths of former habitat, with no end in sight. When researchers in Utah and Illinois recently looked at four North American bumblebee species, they found that their geographic range had shrunk by as much as 87 percent, and population by as much as 96 percent, with a significant share of the loss having occurred just within the past 20 years.

The developing concern over a different kind of national security—pollinator security—recently led the White House for the first time to include a pollinator garden in its plantings, with the aim of supporting bees and monarch butterflies and drawing attention to their crucial role in food production. A group called Make Way For Monarchs is lobbying for large-scale federal action ahead of National Pollinator Week in June. (It has also called on Americans to “join us in a day of action and contemplation for imperiled pollinators” today, April 14.)

But what’s probably more important is that some farmers have begun to ask whether introducing flower strips, hedgerows, and other forms of habitat in the margins of their farms might bring back wild pollinators—and ensure that their crops will get the pollen they need to bear fruit. A new study in the Journal of Applied Ecology adds to the growing evidence that it can work.

Michigan State University entomologists Brett Blaauw and Rufus Isaacs looked at blueberry farms over a four-year period. Planting a one-acre patch of perennial wildflowers cost about $700, with a state program picking up much of the tab. The wildflowers, grown on unused land next to 10-acre patches of blueberries, didn’t seem to make much difference in the first three years, as the plantings became established.  But by year four, farms with flower patches had a 33 percent higher pollination rate than farms that relied solely on honeybee colonies. The payback timetable was also attractive, even setting aside the state subsidy. The increased value of the crop in year four was sufficient to pay for the initial cost of planting, with the likelihood that benefits would continue indefinitely thereafter.

The fourth-year results in the new study were particularly revealing, according to Blaauw, because that year happened to be a terrible one for pollination. Nonetheless, the farms that relied on a diversity of wild pollinators suffered much less than farms that relied on trucked-in honeybees. The wild pollinators served as a sort of insurance policy, he says.

Beneficial insects also took up residence in the new plantings and, though the new study doesn’t try to quantify the benefit, these newcomers seem to have gone to work picking off crop pests. One farmer in the study, Richard Rant, of West Olive, Mich., liked the results well enough to add wildflowers throughout his farm. He reported that he was able to cut back from 10 or 12 insecticide applications on his blueberries each year, to just two or three in some years, at a savings of up to $6,000 a year.

Up to now, conventional agriculture has been headed in exactly the opposite direction. Over the past 15 years, development of herbicide-tolerant crops has led to a massive increase in spraying of Roundup, wiping out all other plant life—that is, habitat for wild pollinators—on more than 100 million acres of row crops in the Midwestern grain belt alone. At the same time, the federal mandate for corn-based ethanol has resulted in the planting of crops, just since 2008, on 23.6 million acres of marginally-productive land formerly set aside for conservation—more lost pollinator habitat. That change has had exactly the opposite effect of insurance: Taxpayers had to pay $8.3 billion for crop failures on that marginal land in the 294 counties with the highest rates of conversion, according to a 2012 study by the Environmental Working Group.

Experiments like the one in Michigan have increasingly demonstrated the value of taking a step back—for instance, by planting hedgerows for pollinators alongside almond fields in California, or flower strips among the mango trees in Africa. The U.S. Department of Agriculture now works with the Xerces Society, an entomological group, to help farmers figure out which wildflowers or other pollinator habitat are likely to work best on a given terrain, or with a particular crop. Many states also have programs to help farmers pay for wild pollinator habitat. Michigan, for instance, has so far subsidized 2,000 acres of wildflower plantings, in theory supporting 20,000 acres of crops.

But the scale of agricultural intensification so far dwarfs all these efforts. Until that changes, the fate of wild pollinators—and of the food on our tables—remains at risk.

There’s Something Fishy About These Bats

The long-fingered bat. (Photo: Antton Alberdi, UPV/EHU)

For researchers on the Mediterranean coast of Spain, near Valencia, the mystery began when bat excrement on the floor of a cave turned out to be loaded with scales, suggesting that an insect-eating bat species had instead turned to fishing.

It wasn’t a complete surprise. Bats are amazingly diverse, with 1,240 species (that’s 20 percent of all mammals), and they’ve had 50 million years to develop a multitude of quirky behaviors. Different bat species are known to eat almost anything—insects, of course, but also fruit, leaves, flowers, nectar, pollen, and, yes, blood. It might be genuinely surprising if somebody said bats catch and eat songbirds, except that researchers caught bats doing just that in 2007.

Frogs too. Early this year, researchers in Central and South America reported on how the male túngara frog’s love song produces a widening pattern of ripples on the surface of the water. Bats have learned to use that pattern as a flight path to cruise in and pluck up the unfortunate Lothario for dinner.

Still, Ostaizka Aizpurua-Arrieta and her coauthors on a new study in the journal PLOS One wanted to find out how Spain’s long-fingered bat learned to fish. “It was a special challenge for me because we didn’t think fishing was among the habits of the long-fingered bat,” says Aizpurua-Arrieta. These bats use echolocation to hunt down their main food source, immature midges, at the surface of the water. But the sonic pulses the bats emit for echolocation can’t penetrate below the surface, to where fish live. The long-fingered bat also weighs no more than a third of an ounce, which is “why it is difficult to imagine it fishing.”

And yet,

as the study progressed, researchers discovered one bat that had, in a single hunting bout, gobbled down 15 fish. Even more odd, the bats were preying on a species that is a newcomer to their neighborhood. Public health officials introduced Gambusia holbrooki around the Mediterranean in the 1920s for mosquito control. The mosquitofish, as they are known, went on to displace native fish species in eastern Spain, including two that are now critically endangered—a pattern that’s been repeated often enough for mosquitofish to rank among the 100 most invasive species in the world.

Deciphering how the long-fingered bats learned to fish was a bit of a detective caper. The researchers first trapped 15 bats as they were returning from their first feeding of the night to their roost at a limestone cave in Montgó Nature Reserve. They held these bats long enough to examine their droppings with a field microscope and identify the four bats with the highest concentration of fish scales in their diet. Then they attached tiny tracking transmitters to those four bats, and set them free. When the target bats went out to forage again, the researchers tagged along by car and on foot, ending up at two artificial ponds on a nearby golf course. There, they were able to set up high-speed cameras and record the behavior.

Both ponds turned out to be loaded with mosquitofish, which constantly broke the surface to catch their prey. Much as in the study of bats catching Túngara frogs, the bats were able to use their echolocation to lock onto the resulting ripples. They instantly swooped down and snatched up the fish with their elongated legs. Even the largest fish was only a little over an inch in length and only 4 percent of the bat’s own weight—well within its carrying capacity, even after pigging out on multiple fish.

The study raises two interesting possibilities. Because intensive agricultural development has damaged many of the water bodies on which it depends, the long-fingered bat is now categorized as a vulnerable species. The new findings could provide a means to rebuild populations. But the study suggests that the bats themselves may already be adapting. “We cannot rule out a learning process being involved in the intensity of fishing,” the researchers write.

They don’t say if this fishing behavior “is definitely new for the species from an evolutionary point of view,” or merely an adaptation of occasional past fishing on native species, to take advantage of the opportunity to feed on more densely populated mosquitofish.

Either way, it’s a reminder: Never underestimate a bat.

The Crank Who Made Cities Livable

British social reformer Edwin Chadwick. (Photo: The Print Collector/Print Collector/Getty Images)

Visiting a city in a tropical nation a few years ago, I was puzzled to see that the trees opposite a makeshift slum were all plastered in a thick, almost congealed, layer of shopping bags.

“Why doesn’t the government just ban plastic bags?” I asked my taxi driver stupidly.

“People would be angry,” he explained and then grew vague. It turned out that in makeshift slums without plumbing, those bags were the closest thing a lot of people had to a toilet. And because there was no proper way to dispose of them afterward, the nearby trees and bushes had become a waste disposal system.

That spectacle clung to me after I retreated to my hotel room, with its polished chrome hardware and its sanitized porcelain throne. And it made me think that what the world needs now is a terrible crank—sorry, I mean, a brilliant social reformer—named Sir Edwin Chadwick, Knight Commander of the Order of Bath.

Chadwick is, admittedly, an unlikely hero for our day. He was so arrogant and self-righteous in his campaigns on behalf of the poor that he managed, despite ample competition, to make himself one of the most hated men in 19th-century Britain. He was also a terrible bore, in the fashion of

people obsessed with a great idea—but even more so because he insisted on talking to polite Victorian society about a problem it preferred to pretend didn’t exist: how to live in crowded cities without being buried or drowned in human waste.

This cause made Chadwick a relentless explorer into East London and other British slums, which suddenly teemed with newcomers working in the factories of the Industrial Revolution. Their world was as foreign to politicians and bureaucrats as Calcutta, but Chadwick went out to see firsthand how the working poor lived. He described what he found in merciless detail: cellars three feet deep in human waste and houses where “every article of food and drink must be covered” lest swarms of houseflies attack it and render it unfit for use, “from the strong taste of the dunghill left by the flies.” In the process, he contracted a case of typhus that nearly killed him.

Chadwick went on to launch a sanitary movement that would make life better in the slums and far beyond. Even if he was an intolerable intrusion on the complacency of the London establishment of the 1850s, Chadwick and his counterparts, among them Max Joseph Pettenkofer in Germany and Lemuel Shattuck in the United States, made city living tolerable for the rest of us, introducing services city dwellers in the developed world now take for granted, including street cleaning, garbage collection, public water supply and sewerage systems, and urban planning of open spaces for better air circulation.

The sanitary movement even changed the way houses looked: The airy open hallways, large windows, and screen porches of upper-middle-class houses of the late 19th century are one minor vestige of the sanitary movement’s salubrious work. Through his key ally Florence Nightingale, Chadwick also helped make hospital sanitation and infection control accepted practice.

There is a tendency now to dismiss Chadwick and his ilk, because they were proponents of “filth theory,” the old idea that diseases resulted from filth, bad air, and even “morbific effluvia.” Thanks to Louis Pasteur and development of the “germ theory” of disease, we know that microbes, not filth, are really to blame. But the truth is that filth theory and the sanitary movement worked: Deaths from epidemic diseases, notably cholera and typhoid fever, began to decline long before medical researchers understood what caused these diseases or how to treat them. The sanitary movement had removed many of the conditions in which germs could thrive.

Why should all this matter to the modern world? Because the squalid conditions of London in the 1830s now flourish in the impromptu slums that have sprung up around cities all over the developing world. And the issues that obsessed Chadwick and his fellow sanitarians are the same ones that will shape our increasingly urban future. So-called megacities are the ones with a population of 10 million plus, and by 2025—that’s closer to us than the year 2000—650 million people will live in 37 megacities around the world. By 2040, when babies being born now reach their 20s, 5.7 billion people will live in cities.

People often talk about this urban future with New York or Tokyo in mind. But the reality is São Paulo, Kolkata, Lagos. The unplanned neighborhoods in these new megacities typically have no toilets. They lack sewers or sanitation. The winding, narrow alleyways often make it impossible to bring in trucks for water supply or waste disposal. So people who flee rural poverty to inhabit these cities will die as they did in Dickensian London, of epidemics, pollution, crime, and misery. They will die of cholera, as they died in Chadwick’s time.

That’s why we need an Edwin Chadwick, or a hundred Chadwicks, today. However unheroic, or boring, or bad-mannered it may seem, we need relentless campaigners for access to sanitation. Bored civil servants and lazy politicians will no doubt prefer to look elsewhere, as they did in Chadwick’s day. But we need a new sanitary movement to remind them that the slums of the megacities are not beyond hope or caring, any more than were the slums of London in the Industrial Revolution.

 

Hidden Superheroes of the Forest Underworld

A black-chinned red salamander in Georgia. (Photo: Todd W. Pierson/University of Georgia)

My latest for the New York Times:

If someone asked you to name the top predator in North American forests, you might think of bears, or maybe great horned owls. But here’s another answer to think about: woodland salamanders.

These skittish, slippery amphibians literally live under a rock, or a log, or any convenient dark and damp forest habitat. As apex predators go, they are mainly small, a few inches long and weighing well under an ounce.

But they are hugely abundant — and very hungry. On an average day, a salamander eats 20 ants of all sizes, two fly or beetle larvae, one adult beetle and half of an insect called the springtail. And in doing so, they collectively affect the entire course of life in the forest — and perhaps far beyond.

According to a new study in the journal Ecosphere, salamanders play a significant role in the global carbon cycle. If flatulent cattle are among the black hats of climate change (the livestock industry emits 14.5 percent of human-associated greenhouse gases), then salamanders may just be the white hats, helping to stave off climate disaster. If no one has noticed this before, well, this is how it goes when you live under a rock.

A painted ensatina in northern California. (Photo:
Todd W. Pierson/University of Georgia)

The study — by Hartwell H. Welsh Jr., a herpetologist at the United States Forest Service’s research station in Arcata, Calif., and Michael L. Best, now at the College of the Redwoods in Eureka, Calif. — notes that salamanders’ prey consists almost entirely of “shredding invertebrates,” bugs that spend their lives ripping leaves to little bits and eating them.

Leaf litter from deciduous trees is on average 47.5 percent carbon, which tends to be released into the atmosphere, along with methane, when the shredding invertebrates shred and eat them.

If there aren’t as many shredders at work and the leaves remain in place, uneaten, they are covered by other leaves, “like being trapped under a wet blanket,” as Dr. Welsh put it. The anaerobic environment under those layers preserves the carbon until it can be captured by the soil, a process called humification.

At least in theory, having more salamanders in a forest should mean fewer shredding invertebrates and more carbon safely locked underground. The researchers tested this theory in a forest in northwestern California, laying out a series of 16-square-foot enclosures, like containers for raised-bed gardens.

Some of the enclosures had salamanders, others didn’t. Each enclosure was joined to its neighbors by low, screened openings, so invertebrates could move freely back and forth, but the salamanders had to remain in their enclosures.

The presence of salamanders resulted in a significant decrease in shredders: fly and beetle larvae, adult beetles and springtails. In the plots with no salamanders there were more shredders, and they consumed about 13 percent more of the leaf litter. Almost half of that lost weight was carbon, released into the atmosphere.

“It’s more than just a curious phenomenon,” Dr. Welsh said. “It’s real.”

The authors calculate that woodland salamanders at the density in their study would send 179 pounds of carbon per acre of forest down into the soil, rather than up into the atmosphere. Extrapolated to the huge numbers of woodland salamanders and other predators working in the leaf litter of forests around the world, that is enough to affect global climate.

Another factor is that many salamanders have no lungs. About 70 percent of all salamanders belong to a single family, the Plethodontidae, which in effect breathe through their skin. (A pulsing flap of skin under their throats, called the gular fold, lets in just enough air for a sense of smell.)

The process requires much less energy than breathing with lungs, enabling salamanders to “be really small and exploit really tiny things that are not calorically sufficient for birds or mammals,” said John C. Maerz, a salamander specialist at the University of Georgia who was not involved in the Ecosphere study. While humans, with their relentless metabolism, burn off most of what they eat, salamanders store large amounts of carbon, nitrogen and other nutrients in their own bodies, or in the form of abundant offspring.

This low-key lifestyle makes them the hidden masters of the forest — “the vacuum cleaners of the forest floor,” as Dr. Maerz put it.

But he and the Ecosphere authors do not entirely agree about what that means for the larger significance of salamanders.

Dr. Maerz thinks the effect on the carbon cycle may apply in wet conditions, but not when the weather is too dry for humification. He also worries about trying to apply what happens “in these little square meters” on a larger scale.

His own studies have demonstrated that stable isotopes of carbon and nitrogen in leaves end up, via shredding invertebrates, stored away in the flesh of salamanders — like “a standing crop of nutrients,” he said. But climate heroes? Dr. Maerz prefers to think of them simply as a dominant driver of the forest energy cycle.

Shahid Naeem, an ecologist and climate scientist at Columbia University, agreed that “temperature, rain and other nonbiological factors probably explain more about the carbon cycle than salamanders.”

But he added:  “What’s nice about the study is the elegant quantification of how a change in a food web has consequences — something a lot of people know when it comes to the big, visible species, but not when it comes to the smaller, less visible, ones.  Lose the salamanders, and there are effects that ripple through the system.”

The notion of losing something as abundant as salamanders is not all that far-fetched. Another new study, in the journal Global Change Biology, compares present-day salamanders with some of the180,000 specimens collected across the United States by the herpetologist Richard Highton, now retired from the University of Maryland. Dr. Highton, who began collecting in 1957, thought he saw a decrease in salamander size and abundance beginning about 1980.

When Karen R. Lips, an amphibian specialist, came to the University of Maryland a few years ago, she decided to follow up that hunch. She and colleagues revisited many of Dr. Highton’s research sites, concentrating on relatively unchanged habitat in national parks and forests from Tennessee to Maryland. Their results showed that salamanders had shrunk in size by 8 percent in 55 years — about 1 percent per generation.

That is “one of the largest and fastest rates of change ever recorded in any animal,” Dr. Lips said. Worse, salamanders were disappearing; even the abundant and widely distributed red-backed salamander was often absent.

Dr. Lips, who had done pioneering research on the chytrid fungus pandemic devastating frog species, thought at first that it might be spreading to salamanders. But her team found almost no trace of chytrid in the salamanders they collected, nor could they attribute the changes to logging, acid rain or overcollecting by biologists.

Instead, the study concludes that salamanders, which were mostly small to start with, are becoming even smaller as a way to adapt to warmer weather and reduced rainfall. If so, they may well rank as both heroes and victims in the fight against climate change — with unknown consequences for the fate of the forests themselves.

Are Fences The Only Way to Save Africa’s Lions?

(Photo: Marvin E. Newman/Getty Images)

Is building fences the best way to protect wildlife from people, and people from wildlife? For a lot of wildlife enthusiasts, the question conjures up memories of zebra and wildebeest carcasses piled high in the 1980s, when cattle fences cut off ancient migration routes in Botswana’s Kalahari Desert. But this time, some biologists think that fences might just be the only way to save Africa’s rapidly disappearing lions, which have lost half their population just since 2000.

And while Africa is the focus of the argument, the debate has extended to the idea of building fences to separate wildlife from people and livestock even around habitats as remote and sacrosanct as Yellowstone National Park.

The argument this time got started in March 2013 when lion biologist Craig Packer and more than 50 coauthors published an article in the journal Ecology Letters noting that Africa’s lions have already lost 75 percent of their original habitat. It predicted that almost half of the remaining unfenced lion populations “may decline to near extinction over the next 20-40 years.” On the other hand, “every fenced population is expected to remain close to its carrying capacity for the next century,” largely because fences reduce habitat loss, poaching, illegal grazing, and other problems caused by the rapidly increasing human population.  According to Packer and his coauthors, fences also make it possible to conserve lions for an annual cost of just $500 a square kilometer, versus $2,000 for unfenced lions.

That article provoked a response in the same journal from predator biologist Scott Creel and an equally large team of co-authors, pointing out that 10 of the 17 fenced reserves in Packer’s study had a population of five or fewer lions and yet were counted as success stories. Meanwhile, Tanzania’s Selous Game Reserve, with 640 lions, “would be considered a failure.” The fenced reserves were also less than a tenth the size of the unfenced ones, and in unfenced reserves, each management dollar conserved many more lions.

Elephant breakout

A new article appearing today in the leading journal Science takes the fence argument to a broader audience. Sarah Durant from the Zoological Society of London and two co-authors argue that fenced reserves inevitably cause dramatic changes in vegetation and marked declines in wild herbivores. The antelopes are hammered from the top-down by lions and other predators, and from the bottom-up, because they can no longer find enough vegetation to eat. Fences also frequently fail to deliver the promised results. In South India, for instance, a study of 37 fences found that elephants broke through almost half of them.

When I spoke to Packer at his research station in Tanzania’s Serengeti National Park, he argued that it might ultimately be necessary to fence in even the Selous, a Switzerland-sized area, which has been the source of most of the 1,000 lion attacks in Tanzania on humans over a recent 15-year period. But in other cases, it might be more practical to fence in villages within protected areas, as in Mozambique’s Niassa National Reserve. Or it might pay to fence in certain remote pastures to reduce conflicts with wolves outside Yellowstone National Park.

Packer also had one fence more immediately in mind. A largely agricultural population of 600,000 people now farms and grazes along the western border of the Serengeti, he said, and that population is doubling every 20 years. In a paper to be published soon, one of his graduate students has found that bushmeat hunting there consumes 100,000 wildebeests a year. About 250,000 head of cattle also graze illegally in the park.

Sarah Durant, a long-time cheetah researcher in the Serengeti, acknowledged the problem on the western border there. But while a fence might seem like the simplest solution, she said, “to me, it’s a bit of a regression to ‘fortress conservation,’ where you had protected areas and kept people out.” The more recent trend in conservation has been to give people a stake in protected areas and develop mutually beneficial ways for local humans to co-exist with wildlife.

A fence on the western side of the Serengeti would ultimately need to run more than 300 kilometers, at a cost of $3,000 per kilometer. Apart from the question of who pays that bill, local communities would almost certainly oppose it, not least, said Durant, because they have come to depend on the park for bushmeat. Nor would a fence necessarily change things all that much. At other parks, people have simply cut through the fences—and used the wire to make new snares.

If money were spent instead on developing ecotourism and other community benefits, said Durant, “you might end up with a community that’s more tolerant of wildlife and more engaged” with the park. She also warned that once protected areas choose to fence out neighboring communities, “there’s no going back.” People lose their coping skills for living with wildlife and their connection to the landscape.

It’s a measure of just how complex and divisive the fence issue can be that wildlife officials from Kenya and Tanzania appear on opposite sides of the debate. Also lining up against one another are biologists working on the same species, in the same habitat, and even for the same for the same organizations, including the Wildlife Conservation Society and Panthera.

“We all acknowledge that there’s a line where fencing may be the last resort,” said Durant. “But we differ in where we draw that line.” The Science paper says fences can sometimes be valuable in “last-ditch attempts to preserve wildlife areas already isolated by human development.” Fences have served successfully in Kenya, for instance, to separate critically endangered hirola antelope from predators, and in Australia to protect native marsupials from invasive species.  But fences should remain just that, said Durant—a last resort.

Packer countered that the population of Africa is on track to quadruple to four billion people over the remainder of this century. That could just mean that the last resort is already here.

Sorry, Cat Lovers, TNR Simply Doesn’t Work

My latest for Takepart, on the feral cat fight:

Various estimates say that anywhere from 20 to 100 million feral cats roam the United States. Together with pet cats that are allowed to wander free, they kill billions of birds, mammals, and other animals every year.

Every time I write about the need to deal with this rapidly worsening problem, certain readers argue for a method called TNR, which stands for “trap, neuter, and release,” or sometimes “trap, neuter, and return.” So let’s take a look at how it might work.

TNR is an idea with enormous appeal for many animal welfare organizations, because it means cat shelters no longer have to euthanize unwanted cats: They just neuter and immunize them, then ship them back out into the world. It’s a way to avoid the deeply dispiriting business of putting animals down, not to mention the expense of feeding and caring for the animals during the usual waiting period for a possible adoption. And it enables animal shelters to put on a happier face for donors: “We’re a shelter, not a slaughterhouse.”

TNR advocates generally cite a handful of studies as evidence that this method works. The pick of the litter is a 2003 study that supporters say shows TNR enabled the University of Central Florida to reduce the feral cat population on its Orlando campus by 66 percent. On closer examination, though, what that study showed was that 47 percent of the cat population was removed through an intensive adoption program, another 11 percent was euthanized, and at least another six percent was killed by automobiles or moved off campus to nearby woods. TNR itself appears to have accomplished almost nothing—and took 11 years to do it.

By email, the lead author of that study, Julie K. Levy, told me that adoption is a common component of TNR programs. She added, “I’d hate to speculate about what the outcome would have been without some cat removal, as that introduces a lot of uncountable variables.” But Levy, who remains a TNR advocate, was part of a team that subsequently examined just that question in two large-scale TNR programs in San Diego County, Calif., and Alachua County, Fla. She and her co-authors found that “any population-level effects” from TNR alone “were minimal.”

The programs might have been effective, the co-authors suggested, if they had neutered 71 to 94 percent of all feral cats, but that rate is “far greater than what was actually achieved.” It is, in fact, far greater than almost any TNR program ever achieves, because, as Levy has written more recently, “capturing free-roaming cats, transporting them to a central facility for sterilization, and returning them to the trapping site are resource-intensive activities,” and “challenging to sustain.”

TNR advocates also frequently cite a large-scale program on 103 cat colonies in Rome. Trapping and neutering decreased the populations of 55 cat colonies there, while the other 48 colonies either gained population or stayed the same. The authors of that study concluded that, in the absence of a public education campaign to stop people from abandoning cats, “all these efforts” are “a waste of money, time and energy.”

And yet TNR proponents just go on touting the same evidence, with an almost magical faith that it will somehow turn out to support their almost religious beliefs. They do this, I think, because anyone who has seen a pet dies knows how emotionally devastating it can be. Twice in my life, I’ve been the person who delivered a pet to the veterinarian to be, as the euphemism has it, “put to sleep.” They rank among the worst days of my life. But both deaths were quick and painless, a matter of falling asleep on my lap, and in both those cases it was infinitely better for the animal than to go on living with disease and impairment.

That’s the choice TNR advocates refuse to make. They see only the individual cat saved from euthanasia and willfully blind themselves to the consequences for the cat itself and for everyone else. When they cite the Rome study as a success story, for instance, they neglect to note that Italy doesn’t have rabies. In this country, on the other hand, rabies prevention efforts cost $300 million a year, and 40,000 people must receive treatment after being bitten or scratched.

Cats are three to four times more likely than dogs to have rabies, and yet TNR programs inevitably leave a significant percentage of feral cats on the street, untreated, for years at a time, aggravating the rabies problem and numerous other diseases of both cats and humans. Because of the threat to public health, most communities have laws preventing individuals from hoarding animals even in the privacy of their homes. But as the authors of one recent article on cat-borne diseases put it, TNR “is essentially cat hoarding without walls.”

The cats in TNR programs also go on killing. Let’s say each cat kills 30 birds a year, and the local TNR program has a population of 100 cats. Over a 10-year period, that program has made itself an accessory to 30,000 unnecessary deaths. (Yes, I’m assuming that the population stays the same. That’s because a lot of TNR programs explicitly aim “to maintain stable cat populations.”) TNR advocates see the cat deaths as individual tragedies. But birds somehow just die as populations, or species. Because the cats do their killing out of our sight, and without our direct intervention, people fail to see that those other deaths are equally individual, and—because cats like to have their fun—far more cruel.

Despite all this, TNR continues to gain popularity. It could well show up next in your community. Politicians like how it sounds to be against killing, so they are easy targets for TNR advocates driven by an extremely narrow definition of “animal welfare.” Be prepared to stand up and remind community leaders that if they are genuinely against killing animals—and if they believe in protecting public health—they need to be against TNR.