Richard Conniff's Blog, page 49

Readers Respond To “The Evil of Outdoor Cats”

(Illustration: Christelle Enault )

These letters appeared today in the NY Times, in response to my article “The Evil of the Outdoor Cat.”

The letter from the Humane Society executive is the most interesting.  It says that neither the Humane Society nor other groups can sell euthanasia of feral cats to the public, and therefore we should leave feral cats free to kill wildlife, as we have known them to do for almost a century.

This is a highly selective, even perverse, notion of “animal welfare,” for an outfit that describes itself as “the nation’s largest animal protection organization” dedicated to preventing “cruelty before it occurs” and seeking “a humane and sustainable world for all animals.”

Maybe they mean they are for preventing cruelty, “except when we can’t sell it to the public.”

To the Editor:

Re “The Evil of the Outdoor Cat,” by Richard Conniff (Sunday Review, March 23):

Thank you for addressing a portion of the litany of problems with allowing cats to roam outdoors. There is a new trend by “no kill” “rescue” groups, which oppose all euthanasia, to release even tame cats into the not-so-great outdoors to take their chances as part of trap-neuter-release programs. In addition to killing wildlife and running afoul of it, these cats succumb to freezing winter weather, traffic, infections and infestations, human beings with evil intentions, and other perils.

As a humane officer for many years, I’ve seen it all and can attest to the fact that cats’ predation on other animals aside, it is not kind to allow them to come to such harsh and painful ends. Trap-neuter-return is illegal in most states because it constitutes abandonment of an animal, and should be in all.

INGRID E. NEWKIRK

President, People for the Ethical

Treatment of Animals

Washington, March 24, 2014

To the Editor:

Richard Conniff sensitively explores an issue that is an impossible dilemma for cat owners. Keeping a cat indoors amounts to caging an animal that was meant to run and roam, and it can make life miserable for both cat and owner. Yet being responsible for the death of small animals, birds especially, is also unacceptable.

I do take issue with Mr. Conniff’s offhand comment that he put a bell on his cat and “she shed it in some bush,” apparently the end of his efforts. Seven years ago we adopted a male rescue cat who loves the outdoors. We were dismayed when, the first week we had him, he made multiple deliveries of dead birds to our front door daily.

We put a collar with a bell on him (an elastic collar with a quick-release clip is the only safe collar for a cat, by the way). Our avian deliveries stopped immediately. In the seven years since, we’ve seen only two dead birds in the yard.

Yes, he routinely loses his collar in the bushes, but having an extra supply on hand is the answer. For us, with this particular freedom-loving cat, it is a compromise we have chosen to accept.

LYNN McBRIDE

Charleston, S.C., March 24, 2014

To the Editor:

The outcry over cats and their predation hasn’t been this feverish since a Massachusetts ornithologist, Edward Forbush, published “The Domestic Cat: Bird Killer, Mouser and Destroyer of Wild Life” (1916). That this issue has gone unresolved for a century testifies to its complexity.

In recent years, humane organizations have pressed the idea of keeping pet cats indoors with great success; the percentage of indoor cats has risen from 52 percent to 64 percent in the past 15 years. It’s unfortunate that some have chosen to campaign against these trap-neuter-return programs, one component in the broader solution to the outdoor cat challenge.

Local animal care societies and agencies appreciate what Richard Conniff doesn’t: Americans support nonlethal reduction approaches that save cats and wildlife, not cat extermination programs that governments and private agencies cannot manage, afford or sell to the public.

BERNIE UNTI

Washington, March 24, 2014

The writer is a senior policy adviser and special assistant to the president for the Humane Society of the United States.

To the Editor:

Richard Conniff sets up false dichotomies. There is a middle ground between free-roaming diseased cats and those confined indoors for their whole lives — for example, well-cared-for, vaccinated cats allowed some supervised time outdoors. Cat lovers and bird lovers are not necessarily enemies or even mutually exclusive. I am a naturalist who has cultivated bird habitat, and I share my life and home with cats.

Yes, free-roaming and feral cats are part of the problem, but as Mr. Conniff acknowledges, humans are as well. For example, the precipitous mid-20th-century decline of bluebirds was largely attributable to habitat destruction, pesticides and the invasive house sparrow. Nothing is harder on birds than rampant sprawl, sanitized suburbs full of nonnative trees and plants, and killer skylines. A 2005 Forest Service report estimated that between 500 million and 1 billion birds die nationwide from collisions with buildings, communication towers, power lines and other structures.

Today my heart broke to find on the side of the street, killed by a car, a cedar waxwing. Two years ago a fledgling hawk perished on a neighbor’s wire fence. If outdoor cats are “evil,” then so are we.

LAURA GREENLEAF

Richmond, Va., March 25, 2014

The Unnatural World of Killer House Cats

Adorable but deadly (Photo: Richard Conniff)

My latest for Takepart:

Earlier this week, I published an article in the New York Times remembering a cat I once owned and loved named Lucky. She was my last outdoor cat, partly because her own death was a bloody reminder of just how dangerous the outdoor life can be for the cats themselves: She died one night, torn to pieces by a bobcat, after 10 years of wandering freely around the neighborhood.

But she was also my last outdoor cat because I realized, after the fact, how deadly outdoor cats can be for wildlife: By letting Lucky wander freely, I had made it possible for her to kill hundreds of birds, mammals, reptiles, and amphibians over the years. While writing about wildlife and maintaining my own yard with wildlife in mind, I had unintentionally been stripping wildlife from the entire neighborhood.

Other cat owners are increasingly coming to the same grim realization—in part because of a federal study last year that added up the billions of animals killed by cats every year in the Lower 48 States. I argued in my article that outdoor cats will soon be as socially unacceptable as smoking in the office, or leaving dog poop on the sidewalk. The editors headlined it “The Evil of Outdoor Cats,” and it attracted widespread attention on the web, some of it angry. One reader commented that a better headline would have been “The Evil of Humans.”

A lot of readers misunderstood a central point I was trying to make about the dramatic decline in bird populations in this country, and about the loss of habitat. Readers commented correctly that the real menace to wildlife comes from suburban sprawl, agricultural intensification, logging, mining, industrial pollution, and climate change. But a lot of cat-owners seemed to think that was an argument for continuing to let their cats go outside to kill. “Whatever damage cats are doing,” a reader in Seattle commented, “it can only be a small fraction of the many human-caused threats to wildlife, in particular habitat destruction.” It was like arguing that, because there are wars going on out there, my little murders shouldn’t count.

In fact, killings by outdoor cats matter far more than they might in a healthier world. My basic argument was that there’s hardly any place left for birds and other wildlife to live, and what habitat remains is often heavily fragmented. That makes animals far more vulnerable to predation by cats. Several readers who are scientists pointed out factors that actually make the effect of cat predation far worse than I had suspected.

The first is what biologists call “mesopredator release.” When humans remove wolves, coyotes, and other large predators from a habitat, the mid-size (or meso) predators they would otherwise kill or out-compete suddenly flourish. It’s boom time for skunks, raccoons, and especially house cats—which then go on to kill birds and other small animals in huge numbers.

Creating protected habitat, as that same Seattle reader suggested, doesn’t fix this problem. A 1999 study of mesopredator release looked at what happened when coyote populations declined and habitat became fragmented in southern California. The most important effect was indirect: The 46 percent of cat owners who sometimes kept their cats indoors because they didn’t want them to be eaten by coyotes no longer had to worry about that.

Around one habitat fragment in San Diego, 77 percent of neighboring cat owners let their cats wander outdoors—and almost all of those cats were killers. The math was devastating for wildlife: 35 cats from 100 nearby houses hunted in a 49-acre parcel of land. Some bird species hung on in that habitat with a few as 10 individuals. But the cats were bringing home 525 dead birds a year, and probably leaving many more tattered remains in the bush. Local extinctions were inevitable.

The other factor I failed to recognize was something biologists call “hyperpredation.” In a natural habitat, the predators tend to live by boom and bust. One year the foxes get fat because there are so many chipmunks to eat. The next year, there are too many foxes and too few chipmunks, and the foxes starve.   But pet cats, and colonies of feral cats, don’t live like that. We feed them, and we maintain them at densities many times higher than what’s normal for foxes or all other similarly-sized natural predators combined. When the chipmunks or sparrows go bust, the cats just go home for dinner. Then they come out again next day to hunt some more. It’s a miracle anything else manages to survive.

In the light of what I have learned from readers, I am beginning to think it’s time to re-name the popular practice of trying to control feral cat populations with TNR—that is, by trapping them, neutering them, and then releasing them again into the wild. A better name might be TNRH, for “Trap, Neuter, Release, and Hyperpredate.”

But let’s save that hot topic for another column.

A New Science Revamps Our Ideas About Domestication

White leghorn rooster.

My latest column for Takepart:

One of the most startling developments in recent science has been the realization that DNA and environment—or nature and nurture—do not by themselves tell the whole story. If we want to understand who we are and how we live, we need to look beyond genetics to epigenetics. That’s the science of how all the information coded in our DNA gets translated and expressed in our bodies and our behaviors.

And here’s the real stunner: This new science suggests that you can inherit the after-effects of things that happened to your grandparents and perhaps even your great-grandparents.  That is, you can inherit their acquired traits: Did they experience high levels of prenatal stress? Were they neglected as children? Were they exposed to toxic chemicals? Did they smoke? The effects can show up in how their DNA—and yours—get expressed. By extension, the things we experience in our own lives may shape genetic expression in generations to come.

Epigenetics may also provide a new paradigm for understanding one of the central mysteries about the animals in our lives: domestication. A study in the journal Applied Animal Behaviour Science argues that epigenetics may offer better answers to old questions: Why do dogs have the most varied shape and size of any species on the planet? How did chickens adapt so quickly to living with humans? How do pigs raised in crowded industrial facilities handle the stress of their increasingly unnatural lives? And how can we recognize when stress is occurring and deal with it more intelligently?

If you remember high school biology, the idea of inheriting acquired traits might just make you say, “Hey, wait a minute.”  You may even be recalling the French naturalist Jean-Baptiste Lamarck, best known as the author of the utterly discredited 19th-century idea that inheritance of acquired traits might be the driving force behind evolution. That notion fell out of favor as scientists instead came to accept evolution by natural selection—that is, evolution produced by the winnowing force of disease, predation, reproductive success, and other factors. Lamarckism became an object of ridicule.

Twentieth-century biology added the idea that DNA was the sole repository of all genetic information. And the dogma was that acquired traits could have no effect on DNA. But studies over the past 10 years have modified that idea. In experiments with rats, exposure to bug spray, jet fuel, BPA in plastics, and the agricultural fungicide vinclozolin (a potent disruptor of endocrine function) have all produced characteristic patterns of distortion in gene expression persisting over generations. Suddenly Lamarck doesn’t look so ridiculous anymore.

Discoveries about epigenetics caught the attention of Per Jensen, an evolutionary biologist at Sweden’s Linköping University and the author of the new study. His research focuses on how domestication of dogs, chickens, and other species has achieved such “stunning” variation in morphology, physiology, and behavior in just 10,000 years—especially when the genetic differences between domestic animals and their wild counterparts are often trivial.

Could epigenetics be the answer? In one study, Jensen took domestic white leghorn chickens and their wild ancestors, red junglefowl, and reared both on an unpredictable-light schedule. Because these birds don’t eat in the dark, that made it difficult for them to predict when to feed. The chronic stress also made them less adept at figuring out how to find food in a simple maze. The effects of that stress showed up in their brains postmortem. It also showed up epigenetically in future generations of white leghorns—but not in red junglefowl.

Jensen theorizes that humans may have unwittingly selected individual animals for domestication based in part on how prone they were to epigenetic effects—that is, based on their ability to respond to challenges more rapidly over generations, allowing them to adapt more quickly to the changing conditions of domestication. So far, that’s just an interesting theory. Jensen has yet to show epigenetic inheritance of beneficial or adaptive traits.

But the work on domestic animals has already attracted the interest of animal welfare groups because it suggests that epigenetics may soon provide a better way to tell if animals are experiencing stress. Right now, researchers wanting to understand stress generally measure levels of the stress hormone cortisol. But cortisol only reveals an animal’s stress levels over the past few hours. In the livestock industry, where that kind of testing often occurs at the slaughterhouse, that’s not terribly revealing. Instead, says Jensen, epigenetic testing could be available within the next five years to determine whether an animal experienced stress months earlier. That could make it easier to set standards for more humane practices in the livestock industry.

Epigenetics also raises troubling ethical questions, Jensen writes. For instance, stress may be bad for an animal in its own lifetime. But in some circumstances it might lead epigenetically to future generations that are better equipped to handle stress. Conversely, “protecting animals from stressful experiences could sometimes perhaps have more negative welfare consequences in the long run.” Jensen remains hopeful that it will be possible to shape animal welfare across the generations “by both positive and negative stimulation in different life phases, mediated by epigenetic mechanisms.”

For our domestic animals, the real bottom line may be that even stranger changes lie ahead, through the newly discovered power of epigenetics.

Finding Species Before They Disappear Forever

The Anguilla Bank skink, a Caribbean species discovered along with 23 others in 2012, is vulnerable to extinction. (Photo: Karl Questel)

My latest, for Smithsonian magazine:

One night in June, 2012, entomologist Piotr Naskrecki was exploring a forest on Mt. Gorongosa in Mozambique, when he spotted a new species out of the corner of one eye. He’ll publish the first scientific description of his find, a katydid, later this month in the journal Zootaxa.  But its debut will almost certainly also serve as its death notice: When Naskrecki went back in 2013, hungry farmers had already turned that stretch of forest into corn fields.

We live in the middle of what scientists say is the Earth’s sixth great extinction event.   Number five was the one that got the dinosaurs.  Number six started back about 10,000 years ago, when human hunters and climate change wiped out mammoths and other megafauna.  It has lately accelerated as humans have pushed into the farthest corners of the planet.  Biologists must now sometimes race to discover species even as the chainsaws are cutting down the forest around them. Speed is the new priority, to make discovery happen ahead of extinction—even perhaps in time to prevent extinction.

Scientists have so far described almost two million species.   But it has taken them 250 years to get there.  They now describe about 18,000 new species every year, and conservationists say that’s not nearly fast enough. A 2011 study in the journal PLoS Biology conservatively estimated that there are 8.75 million species on Earth, with more than 85 percent of them unknown to science.  The authors calculated that, at the current rate of species discovery, it could take hundreds of years and $364 billion to describe them all.   But long before then–in fact, sometime in the next century–75 percent of them will have gone extinct without being described.  But that just makes “attempts to discover and conserve biodiversity appear hopeless,”according to the authors of a more recent study in Science.  They authors figured that, by ramping up the rate of discovery tenfold, scientists could complete the catalogue of life on Earth in just 50 years.

Quentin Wheeler, director of the International Institute for Species Discovery, argues for a “NASA-scale mission to map the biosphere once and for all.”  It could boost the rate of new species to 200,000 a year, he says, by funding 2000 existing taxonomic specialists, each supported by a staff of three, to devote themselves full-time to producing 100 species descriptions a year. That’s roughly the model the National Science Foundation used for its short-lived Planetary Biodiversity Inventory. It might cost $1 billion a year, he says, “but the United States spends $150 billion just responding to invasive species.”

Genetic techniques are already speeding up the process of discovery.  In Madagascar, for instance, ant specialist Brian Fisher takes an assembly line approach to collecting and analyzing a study site, sending off batches of undescribed insects for DNA “barcoding,” to get a sense of how many unknown species may live there.  In Southeast Asia, the intrepid pioneers of a new technique called iDNA (for invertebrate DNA) go a step further, barcoding the DNA in the blood of land leeches picked off their own bodies, to see what other mammals and birds the leeches have been feeding on.

Digital technology has also begun to democratize taxonomy, bringing experts and amateurs together through Internet sites like Fisher’s Antweb.org and even Facebook, to crowdsource the preliminary sorting of specimens. The literature of species discovery is also becoming more widely available via web sites like the Encyclopedia of Life.  And later this year, researchers from anywhere in the world will be able to go online and examine the defining “type” specimens of a species without ever leaving home.  Instead, they’ll use remotely-operated digital microscopes now being installed at the Smithsonian’s National Museum of Natural History and sister museums in London and Paris.

The actual description of a potential new species still requires tedious and time-consuming comparisons with known species, and a lot of specialized taxonomic expertise.  But trained taxonomists increasingly come from the tropical nations where much of the discovery is now happening, and in Europe amateurs taxonomists now contribute 40 percent of the species descriptions.

A more complete catalog of life on earth would create a baseline for recognizing changes in our environment, and it would provide an enormous boon to biomimicry—the highly profitable human knack for devising everything from medicines to gadgets based on models from the natural world.

A catalog of all the life on earth would help us respond to environmental changes, such as invasions of nonnative species, and would boost the quest for medicines and other materials extracted from or inspired by living things. To drive home the need for speed, biologists tell the story of a chemical found in an ancient swamp forest tree in Borneo. It stopped HIV cold, but when rsearchers raced back for more samples, a stump remained where the tree had stood. If a few surviving specimens had not turned up in a botanical park, the experimental drug Calanolide A might not exist today.

This Week’s Green News Roundup

This week’s green news roundup from the The Nature Conservancy’s Cool Green Science blog:

Biodiversity

If biodiversity is so important for human well-being, why isn’t Europe languishing? (Conservation Bytes)

Character displacement as the driver of evolution: new doubts, and doubts about the new doubts. (Wired)

And you thought The Birds was scary? Kelenken is Wired’s absurd creature of the week. (Wired)

Wildlife

Frog creates “chemical invisbility cloak” to confuse aggressive ants. (Mongabay)

Bats bouncing back: there are signs that the bats who survived die-offs from white-nose syndrome can resist infection. (Strange Behaviors)

Snowy owl mania continues: 9 photos to celebrate the ongoing irruption. (Huffington Post)

New Research

Basin-level data on forest disturbance is consistent with an Amazon carbon sink – and points to small-scale disturbance as the big player. (Nature Communications)

What is the most sustainable way to harvest rainwater? A new study looks at ancient systems to answer this modern question. (Environmental Science and Technology)

How do fireflies glow? Study in PNAS found that it started with an enzyme that makes fat. (Ars Technica)

A new way to cry wolf: is the latest questioning of the role of large predators and trophic cascades good science, or just tilting at windmills? (Mary Ellen Hannibal)

Climate Change

Up to 30 more dry days per year for the Mediterranean, Central America and Indonesia by century’s end, says new research. (Nature)

What we know: AAAS surprises the internet by releasing its own report to help the American people understand the science of climate change. (AAAS)

Can we have green energy and save birds? The answer is blowing in the wind. Maybe. (Audubon)

Nature News

Another victim of the polar vortex in North America: honeybees. (Compound Eye/Scientific American)

Cows, crops and timber: an ambitious agroforestry program in Colombia improves incomes, restores degraded land and makes farms more resilient to climate change. (Yale E360)

“There is no sector in American business that wouldn’t like to have better environmental information,” says NOAA CIO Joseph Klimacivz. Ocean Agency working to make data more accessible. (America Geophysical Union, EOS Transactions)

Science Communications

The anti-tweet. Longform digital journalism is a great medium for science communication. The Tow Center at Columbia University is exploring how all the pieces fit together. (National Association of Science Writers)

The secret life of Science Guy Bill Nye, in video on NOVA. (PsiVid/Scientific American)

To open access, or not to open access? Excellent review of the landscape and its pitfalls by Gary C. White. (The Wildlife Society News; HT Sharon Baruch-Mordo)

Science comprehension is a “culturally random variable.” (Translation: All cultural groups — including conservatives — have equal levels of science literacy.) (Dan Kahan/Cultural Cognition Project)

This & That

The return of the science patron. Solutions-focused environmental science benefits in a big way from the growth in science philanthropy – but is there a downside? (New York Times)

Did you miss taxonomy appreciation day? (Small Pond Science)

- See more at: http://blog.nature.org/science/2014/03/21/best-nature-science-web-resilient-invisible-frogs-resilient-bats/#sthash.DerJQu5u.dpuf

Saving Wildlife By Going to the Source of the Problem

Coop member Miguel Arce with a hand-caught sand bass (Photo: Carlos Aguilera-SmartFish)

It may seem counterintuitive and even downright risky. But protecting habitat often involves working closely with the people doing the damage. It can mean supplying efficient sawmills to rainforest loggers who might otherwise hack the timber they harvest into planks with chain saws. It can mean helping communities in Africa manage trophy-hunting concessions more profitably so they don’t need to kill as many animals. And it can mean introducing better fishing practices to fishermen who are inadvertently killing thousands of endangered loggerhead turtles every year.

The object isn’t to make exploiting the environment easier, faster, more destructive. Instead, says Hoyt Peckham, it’s about setting up a framework to help people focus on resources that can withstand the pressure—and then get the full value from whatever they harvest. Helping them earn more while harvesting less gets their buy-in, because they’re building better lives for their families.

That’s the delicate balancing act Peckham, a visiting scholar at Stanford University’s Center for Ocean Solutions, has been working ever since he showed up in Baja California as a doctoral student doing marine biology research more than 10 years ago.

One day not long after he arrived, Peckham discovered 17 dead loggerhead turtles and two live ones caught on 200-hook long-lines. He watched a fisherman on one boat slit the throat of a turtle to get it off the hook while the skipper complained that the turtles were a nuisance, distracting them from the marketable fish they were really after. People in the small fishing community of Santa Rosa had no idea that the turtles were rare, much less endangered. It turned out the nearby waters were a hot spot for juvenile turtles that had migrated from spawning grounds in northern Japan. Baja California’s small fleet of open skiffs, or pangas, was responsible for one of the deadliest sea turtle bycatches in the world.

Because Mexico lacks the necessary resources to enforce its natural resource laws, Peckham turned to working with the fishermen instead. With the help of government agencies and nonprofits, including Grupo Tortuguero de las Californias, northwestern Mexico’s regional sea turtle conservation network, he brought in sociologists, anthropologists, market researchers, and fisheries experts to help the fishing community figure out a way forward.

Maybe more important, he arranged for Efrain de la Paz Regalado, the leader of the Santa Rosa fishing community, to meet his counterparts from Hawaii and Japan. Those fleets, operating on an industrial scale, were spending millions to avoid killing a single loggerhead. The 100-boat Hawaiian fishing fleet faced an annual shutdown if it had a bycatch of more than 17 loggerheads in a year—an amount the Santa Rosa boats were killing in a single day. When de la Paz heard the Hawaiians describe their efforts at that meeting in 2007, he was clearly shaken, and immediately volunteered that the Santa Rosa fleet would give up on its long-line fishing gear. According to Peckham, that decision to switch to turtle-safe fishing gear has saved 900 to 2,200 loggerhead turtles every year since.

The other tragedy of commercial fishing in the area was that fishermen were often stuck selling their catch to a single buyer on the beach, who was paying them less per pound than they would’ve earned recycling soda bottles they picked up on the street. The fishermen were caught in a vicious circle where low quality and low prices drove them to catch more and more fish, for less profit.    “It’s a kind of reverse alchemy,” says Peckham. “They were taking fish that could be worth gold and inadvertently turning them into trash.” Meanwhile, chefs in the nearby resorts of Cabo San Lucas were paying a premium to import the very same seafood.

Even if these chefs had arrived in Baja California expecting the seafood paradise of the world, they usually abandoned the idea of buying local because the quality of the fish was so poor. The fishermen used gill nets in which the fish drowned overnight and then stewed for hours, as enzymes turned the quality of the flesh bloodier, fishier, and with a shorter shelf life. When they hauled in their nets, they tossed the fish into the bilges and left them to rot in the sun. A visiting Japanese fisherman actually wept at the sight, a spectacle that finally caught the attention of the Santa Rosa fishermen.

On their own initiative, and with help from outside experts, many fishermen in the area are now abandoning gill nets. Instead, they hand-haul fish on individual lines, immediately bleed their catch, and store it in ice water, to deliver a near-sashimi-grade product suitable for sale to the restaurants in Cabo San Lucas. Peckham and his collaborators go around knocking on doors to persuade chefs that the local product is is good enough and reliable enough for their restaurants.

Peckham is at heart still a marine biologist. “It’s daunting for me becoming a fishmonger,” he says, but none of the existing distributors could meet his standards for sustainability and social responsibility. “I feel that the fishermen should be owning that part of the supply chain.”

The resulting social and commercial initiative, called SmartFish, is now “working well at a boutique level,” says Peckham. The Pew Charitable Trusts recently acknowledged Peckham’s work with a $150,000 fellowship in marine conservation; he hopes to use that money to scale up SmartFish to the international level. But every fishery is different, and it’s not easy to find what he calls “the sweet spot between sustainability and quality.” For the SmartFish idea, these are still the early days.

The Evil of the Outdoor House Cat

(Illustration: Ginette Lapalme)

My latest for The New York Times:

Once upon a time I had a cat named Lucky, and the name fit. She turned up on our doorstep as a stray and stayed with us for 10 years, until her rather gruesome demise. (More about that later.) I liked her because she was a free spirit, and a survivor, going out for two, three, even five days, in all seasons. She’d show up when it suited her, waiting in the dark before dawn till I came downstairs and turned on my desk lamp. Then she’d make her presence known by rising up on her hind legs and gently scratching with her forepaws on my window.

Sometimes, without stopping to say hello, she’d leave us tattered offerings, with little starbursts of coagulated blood, on the front walk. The birds were disturbing, the moles and deer mice not so much.

Jane, the older woman who lived two doors down, mentioned that Lucky sometimes lurked near her bird feeder, but she didn’t seem to think much of it, and neither did we. We put a bell on Lucky, but it didn’t last a week before she shed it in some bush.

If all this sounds lackadaisical, particularly in someone who writes about wildlife, I should note that Lucky, who died in 2008, was our last outdoor cat.

We were about to become early adopters in the trend that is beginning to make outdoor cats as socially unacceptable as smoking cigarettes in the office, or leaving dog droppings on the sidewalk.

What’s driving this trend is a growing sense of alarm about the dramatic decline in wildlife, and especially bird, populations, combined with a new awareness that cats bear a significant share of the blame.

The National Audubon Society tracks 20 common North American bird species — Eastern meadowlarks, field sparrows and the like — that are now in decline. Their numbers have dropped by 68 percent on average since 1967, because of a variety of factors.

In Britain, likewise, farmland bird populations have plummeted just since 1995, with turtle doves, for instance, down by 85 percent, cuckoos by 50 percent, and lapwings by 41 percent.

If these were stock market numbers, people would be leaping from buildings. But the peculiar thing about what biologists have called “the second Silent Spring” is that people tend not to hear it.

Like a lot of other cat owners, I used to think that when Lucky went outside and, now and then, killed an animal, she was “just doing what’s natural” for a cat. I was aware that cats have caused or contributed to the extinction of 33 species. But all of those species were living on islands and many had likely never seen a predator before early navigators introduced cats. The mainland nature around me was savvier than that, I figured, and had the scale to handle incidental killings by a few house cats.

But that is no longer true, if it ever was. Intensification of agriculture is eliminating millions of acres of habitat from the countryside. The relentless development of cities and suburbs has also squeezed out wildlife, and will squeeze harder over the next few decades. Urbanized land area in the Lower 48 states is on track to more than triple between 1990 and 2050, according to the United States Forest Service. In four Northeastern states, more than 60 percent of the total land area will be urban by midcentury, up from about 35 percent in 2000.

Wildlife increasingly hangs on in the margins, in parks and on forgotten scraps of land, which function, as it happens, a lot like islands.

And wildlife in the United States must share this land with a growing population of about 84 million owned cats, and anywhere from 30 to 80 million feral or stray cats. When all of them do “what’s natural” in a fragmented natural world, it adds up.

Using deliberately conservative assumptions, federal researchers recently estimated that free-ranging cats killed about 2.4 billion birds annually in the Lower 48 states, a substantial bite out of the total bird population. Outdoor cats also kill about 12.3 billion small mammals a year — not just the proverbial rats and mice but also chipmunks, rabbits and squirrels — and about 650 million reptiles and amphibians. In some cases, they are pushing endangered species toward extinction.

But here is the number that sticks in my mind: Letting my own cat, Lucky, outdoors may have consigned as many as 33 birds and dozens of mammals to death every year. If you have ever seen a cat toy with its victim, you know these are not quick, or pretty, or painless deaths. So you might expect animal welfare groups to be ardently campaigning against outdoor cats, and particularly against the care and feeding of feral or stray cats, which do most of the killing.

Instead, these groups have mainly addressed the feral cat problem with a strategy called T.N.R., which involves trapping cats, neutering and immunizing them, and then releasing them again. Scientific studies have generally found that T.N.R. is not particularly effective at reducing feral cat colonies. The practice has also come under attack from one animal welfare group: PETA has described T.N.R. as a way for shelters to look good to donors, because they don’t have to euthanize as many unwanted cats. But given the number of birds and small mammals the released cats go on to kill, I question whether the Humane Society and other T.N.R. backers should call themselves “animal welfare” groups anymore.

None of this may sound as if outdoor cats are on the way to becoming socially unacceptable, although when birders and cat lovers start shouting at each other about outdoor cats, it can seem as if we are en route to open warfare. But the change in attitudes toward smoking didn’t come easy, either. The smoking analogy is also more apt than may at first appear because outdoor cats, like secondhand smoke, also threaten the health of innocent human bystanders.

Cats are three to four times more likely than dogs to carry rabies, according to the Centers for Disease Control and Prevention. They also share dozens of other parasites or infectious microbes with humans, including roundworms, hookworms, giardia and campylobacter. When cats live outdoors it is almost impossible to predict what they will bring home next. In Massachusetts and New York, for instance, cats recently turned up infected with a worm normally found in raccoons. One owner pulled four of them, about six inches long, through her cat’s skin, “which isn’t the best idea,” says one of the Cornell University scientists who reported the cases.

Most insidiously, outdoor cats are the primary hosts of toxoplasmosis, which is estimated to infect almost 30 percent of all humans worldwide. Toxoplasmosis produces lifelong parasitic cysts in the brain, and though it is generally asymptomatic it has been linked to neurological impairments, depression, blindness and birth defects. Even in asymptomatic individuals, the infection is associated with significant loss of memory in later life, according to a study last month in the journal Brain, Behavior, and Immunity. But I’m not really arguing that outdoor cats will become socially unacceptable because they are bad for humans. Rather, I think ardent cat lovers will eventually see that the multiple hazards of outdoor living are also terrible for cats.

And that brings me back to Lucky, and the night that her good name failed her. We never really found out what happened. But the other outdoor cat in the neighborhood, also a longtime survivor, died that same night. And the next morning a bobcat crossed right in front of my car and stopped in the middle of the road to fix me with a brazen I’m-walking-here-and-what-are-you-looking-at glower.

Most of Lucky turned up in the yard next door. Another piece was served up on the picnic table. A third, with a starburst of coagulated blood, appeared on the sidewalk, right where Lucky used to leave her offerings. I suppose it was a fitting end, in a live-by-the-sword sort of way, and for once, wildlife triumphed.

But I also know that I will never own an outdoor cat again.

 

Nature as a Conspiracy of Con Artists

Jumping spider that lives as stealth ant (Photo: Robert Jackson)

My latest for Takepart:

When we grow tired of the lies and fakery of human life, we often turn to the natural world for all that is honest and true. “What strength belongs to every plant and animal in nature,” Ralph Waldo Emerson once exulted. “The tree or the brook has no duplicity, no pretentiousness, no show. It is, with all its might and main, what it is.”

A lovely sentiment to be sure, but the natural world is in fact overrun with fakes, liars, imitators, and con artists, of almost every color and description. There are beetles that pretend to be wasps, aardwolves that pretend to be hyenas, caterpillars that pretend to be bird poop (the better not to be eaten by birds), and a night-flying bird, the pootoo, which pretends to be a broken tree branch by day, so it can sleep in peace.

The natural world can seem at times like a grand charade, and with apologies to Mr. Emerson, there might just as well be a blinking neon sign at the entrance saying “Duplicity “R” Us.” For a naturalist, this is a large part of the fun—and as two new studies demonstrate this week, an enduring subject of fascination. For the animals themselves, it is a matter of life and death.

The first study, published in Behavioral Ecology and Sociobiology looks at timid jumping spiders in the Philippines, which like to make their nests near Asian weaver ants. These ants are fierce predators of, among other things, jumping spiders. So why hang out in their neighborhood? According to co-authors Ximena J. Nelson and Robert R. Jackson of New Zealand’s University of Canterbury, it’s because the jumping spiders have a much nastier hobgoblin to fret about.

The predatory spitting spider also likes to eat jumping spiders. It catches them, as its name suggests, by spitting sticky gum from its fangs and gluing its victim to the nearest surface. Then, with the leisurely deliberation of the television serial killer Dexter, it wraps its victim in silk and injects it with venom.

It turns out, though, that predatory spitting spiders hate the smell of Asian weaver ants. So the jumping spiders gain a measure of protection not just by making their homes near these ants, but by taking on their smell and pretending to be one of them. Yes, they still have to deal with the annoying problem of living surrounded by killer ants—so the jumping spiders build their nests out of a dense, tough weave, to make them ant-proof. At the entrance holes, they rig hinged flaps of silk, like swinging doors, to slap shut again when a spider darts in or out, so no ants can enter.

The idea of deception and mimicry in nature got started in the 1860s, when Henry Walter Bates, a British naturalist in South America, noticed something peculiar. He was puzzled to observe that certain butterfly species show off with bright colors and yet somehow manage not to get eaten by birds or other predators. Eventually, Bates figured out that they were mimicking the colors of another nearby butterfly species, which predators leave alone because they taste so bad.

The bright coloration of the model species is an honest signal, which benefits both the potential prey by keeping it unmolested, and the would-be predator, by sparing it from digestive woe. But the copycat strategy—harmless species borrowing the color or smell and thus the protected status of more dangerous or repulsive species—works too, and this form of dishonest signaling is widespread in the animal world. It’s now called Batesian mimicry.

The second study, published in the journal PLOS One, asks how these little miracles of deception could have evolved in the first place. If the starting strategy for a species is to hide itself from predators as much as possible, how does it make the leap to life in full, flaming color? “How did these imitators get past that tricky middle ground, where they can be easily seen, but they don’t quite resemble colorful toxic prey? And why take the risk?” asks lead author Kenna D. S. Lehmann, a graduate student at Michigan State University.

She and her co-authors started from scratch, building a digital world in which each of their sim-species had to develop its own way of life, learning how to prey and how to avoid predators. Then they introduced a species that was poisonous and said so with an honest signal. Other studies in the real world have shown that a powerful poison can support the development of multiple copycat species. But they don’t all get it right from the start. The new PLOS One study showed that a powerful poison in the model species can be enough of a deterrent to make predators take notice and steer clear of these imperfect mimics. “Even if they managed to look like a poisonous prey just 25% of the time, they still got protection,” says Lehmann. That means making small, incremental steps from camouflaged wallflower to colorful con artist could have been a workable evolutionary strategy.

It was like witnessing the birth of fraud.

Why Ecological Restorations Fail (And A Way To Fix)

Qiaoyuan Wetland Park in Tianjin, China, has terraced ponds that incorporate designed experiments to monitor benefits.

My latest for Yale Environment 360:

Restoring degraded ecosystems — or creating new ones — has become a huge global business. China, for instance, is planting 90 million acres of forest in a swath across its northern provinces. And in North America, just in the past two decades, restoration projects costing $70 billion have attempted to restore or re-create 7.4 million acres of marsh, peatland, floodplain, mangrove, and other wetlands.

This patchwork movement to rebuild the natural world ought to be good news. Such projects are, moreover, likely to become far more common as the world rapidly urbanizes and as cities, new and old, turn to green infrastructure to address problems like climate change, flood control, and pollution of nearby waterways. But hardly anyone does a proper job of measuring the results, and when they do, it generally turns out that ecological restorations seldom function as intended.

A 2012 study in PLOS Biology, for instance, looked at 621 wetland projects and found most had failed to deliver promised results, or match the performance of natural systems, even decades after completion. Likewise, an upcoming study by Margaret A. Palmer at the University of Maryland reports that more than 75 percent of river and stream restorations failed to meet their own minimal performance targets. “They may be pretty projects,” says Palmer, “but they don’t provide ecological benefits.”

Hence the increasing interest in what Alexander Felson, an urban ecologist and landscape architect at the Yale School of Forestry and Environmental Studies, calls “designed experiments” — that is, experiments designed by ecologists and incorporated into development and landscape restoration projects to test which alternative approaches work best — or whether a particular approach works at all. The idea is both to improve the project at hand, says Felson, and also to provide a scientific basis for making subsequent projects more successful.

At first glance, the designed experiment idea might seem to echo practices that already exist. Environmental consultants have been a part of most development projects for decades. But they almost never do long-term research on a project, says Felson. “Adaptive management,” the idea of continually monitoring environmental projects and making steady improvements over time — or “learning by doing” — has also been around in ecological circles since the 1970s. But a recent survey in Biological Conservation found “surprisingly few practical, on-ground examples of adaptive management.” In part, that’s because “long-term investigations are notoriously difficult to establish and maintain.”

To deal with that challenge, Felson proposes incorporating ecologists into the design team, so that designers and ecologists build a relationship and complement each other’s strengths from the start. As part of its Million Tree Initiative, for instance, New York City was proposing in 2007 to plant almost 2000 acres of new and restored forest over a ten-year period. The project fit the city’s sustainability agenda to reduce air pollution, sequester carbon dioxide, control stormwater run-off, and provide wildlife habitat.

But planners didn’t have much basis for determining which species were more likely to achieve those goals, or where to plant them. The usual feedback about whether an urban tree planting project is successful boils down to a single question: “Are they alive or are they dead?” Nor could science provide much guidance. A literature search turned up only a single long-term study of new urban forests planted with native tree species.

So Felson and a team of scientists and designers proposed designed experiments for New York’s planned forests — plantings with different species, in varying configurations, some with compost or other amendments, some without — to learn what worked best.

The proposal represented a compromise between two sensible but contradictory ideas. On the one hand, it is widely accepted that the best time to plant a tree is 50 years ago — or, failing that, right now. On the other hand, Felson writes, you “would not build a wastewater treatment plant if it did not achieve water-quality standards, so why plant an urban forest without knowing that it performs the intended function?”

Because experimental plots are not typically scenic, the ecologists worked with park managers to disguise the test plots within a more natural-looking forest. The first test forest went in at Kissena Corridor Park in Queens in 2010, and a second at Willow Lake in 2011, on the site of the 1964 World’s Fair.

The ambition is to study traits like carbon sequestration and how species patterns change over decades. But the study is already producing results that may be useful within the context of the Million Tree Initiative, according to Felson and Yale co-authors Mark Bradford and Emily Oldfield: If the goal is to get trees to canopy height as quickly as possible, for instance, competition from shrubs will actually make them grow faster, not slower. Some trees, like basswood, do better in more diverse plantings; others, like oaks, prefer less diversity. Compost doesn’t seem to make much difference for the first two years but kicks in during year three.

The designed experiment idea has begun to turn up in restoration projects around the world, notably in China. The northeastern city of Tianjin, for instance, was struggling in 2003 to deal with a 54-acre former shooting range that had become an illegal dumping ground and was also heavily polluted by urban runoff. It hired Kongjian Yu, founder of the Beijing design firm Turenscape, who had trained at Harvard with Richard T.T. Forman, a leading thinker in urban landscape ecology.

The result, Qiaoyuan Wetland Park, opened in 2008, with none of the great lawns and formal plantings seen in conventional Chinese parks. Instead, Yu’s design features a naturalized landscape of ponds, grasses, and reeds, with walkways and viewing platforms for local residents.

Traditional landscape design in China is “based on art and form,” says Yu. “My practice is to find a scientific basis.” The park features a terraced system of 21 ponds, designed to filter urban runoff as it moves through the site. Yu calls it “peasant” landscaping, based on traditional rice farms. But the ponds are of different sizes and depths, with the aim of monitoring how each microhabitat affects water quality, PH values, and the character of the evolving plant community.

Ecologists on staff at Turenscape and Yu’s students at Beijing University do the monitoring. Among other results, they recently reported that three families of Siberian weasel now call the park home, a remarkable development in a city of 7.5 million people. Yu acknowledges that the experimental results don’t hold much interest for city officials, who have sometimes tried to replace “messy” reeds with playgrounds and formal plantings. But Yu has employed the results from Tianjin to improve his subsequent projects, which also incorporate designed experiments.

The pell mell pace of urban development in China, combined with the often catastrophic environmental after-effects, together create a demand for landscape designs that do more than look pretty, according to Yu. The usual engineering solutions — for instance, “larger pipes, more powerful pumps, or stronger dikes” to handle monsoon flooding — often just aggravate other problems, like the water shortages and falling groundwater levels that now afflict 400 Chinese cities. Yu sees naturalized landscapes as urban “green sponges” to retain and filter water, with designed experiments to show whether or not they deliver the promised services.

The goal of incorporating designed experiments more broadly in restoration and development projects is likely to meet resistance on both sides. Developers may regard ecologists as natural adversaries, and research as a costly nuisance. The idea of working within the agenda of developers and government agencies may also strike some ecologists as a fatal compromise.

But China is no means the only place with rapidly worsening environmental issues. As urban crowding increases worldwide and the effects of climate change become more evident, cities may require every new development or restoration project to deliver multiple ecosystem services. The stricter financial standards of the green marketplace will also oblige project managers to demonstrate that those services are real and quantifiable.

“There are certainly problems with what we’ve been doing in restoration projects, but it doesn’t mean we should stop,” says Franco Montalto, a Drexel University environmental engineer who has written about the designed experiment idea. “We should be trying to figure out what doesn’t work and stop doing that, and figure out what does work and do more of it. That’s what you learn from experiments.”

Signs of Recovery in the White-Nose Scourge

The first time white-nose syndrome really hit Aeolus Cave, on the side of a mountain in Dorset, Vt., the carcasses littered the entrance like a carpet. “You couldn’t step on the ground without stepping on dead bats,” says Scott Darling, a biologist with the Vermont Fish and Wildlife Department. “Nowhere else have people seen that level of mortality in a cave.”

Bats afflicted with the fungus during their hibernation usually “fly out and die on the landscape,” unnoticed. But “in Aeolus Cave, for whatever reason, many, many died right there in Guano Hall,” the steeply sloped tunnel-like cave entrance. Statewide, Vermont lost 90 percent of its bats during the first few years of the epidemic, from 2008 to 2010. The other 19 states and five Canadian provinces where white-nose occurs have suffered a similar rate of loss. It may be the most precipitous decline in any animal group ever, with an astonishing 5.7 million bats now thought to have died. But Aeolus, the site of decades of pioneering research on bats, became the poster child of the epidemic.

Now, Darling sees the first tentative signs of a possible recovery there.

In an experiment at Aeolus Cave in April 2012, researchers placed identifying bands on bats emerging from hibernation. When they went back to count them last April, 50 percent had survived. According to Darling, some other banded bats have been known to survive as long as six years in white-nose areas.

“We don’t know if it’s something genetic or something behavioral,” says Darling. But these survivors of the great die-off seem to have a kind of resistance or resilience. “Immunity” may be too strong a word. Somehow, though, they manage to live normal lives despite hibernating in a cave heavily infected with white-nose syndrome. “There’s hope here in the Northeast that we’ve seen the worst of it,” says Darling. But he adds that there is still “a lot of uncertainty. Are we still losing 20, 30, 40 percent?”

White-nose fungus originated in Europe, where it does not appear to harm the bats. But in North America, where it first appeared in 2006, it has caused devastating losses to seven species. The disease causes hibernating bats to wake up in the middle of winter, and it is a disturbing sight. I visited Aeolus in the 1990s, long before white-nose appeared. Biologists conducting bat counts in winter then were careful to whisper, to avoid waking the hibernating bats that covered the ceilings and walls.

A bat in deep hibernation drops its heart rate from as many as 1,300 beats a minute to as few as eight. Once disturbed, the bats seem to sway visibly, as they shiver toward wakefulness. They warm themselves up at a rate of about one degree a minute. Some shift their forelimbs, making the slow, dreamy, ineffectual movements of a person trying to fend off a nightmare.

Because there are no insects to feed on in winter, bats must get through hibernation with stored body fat. It makes up 30 percent of their body weight at the start and drops down to as little as 5 percent by spring. The trouble with white-nose fungus isn’t just that it wakes up bats in midwinter; the effect is to send them out looking for food that’s not there. A single day of waking can burn 10 to 30 days’ worth of stored fat, meaning death.

Even if a recovery occurs at Aeolus and spreads to other states, Darling warns that the bats are “not rebounding yet.” Any recovery will inevitably be slow.  Despite their small, somewhat mousy appearance, bats do not breed like mice.  They are remarkably long-lived. Researchers have recovered bats at Aeolus 30 years after they were originally banded. Each female also produces only a single offspring a year.

So the devastating consequences of the white-nose epidemic are likely to be evident for decades to come, in the form of mosquitoes and agricultural pests not eaten. (In one study at Aeolus, a single bat caught and ate 175 mosquitoes in a 15-minute period.) A 2011 study in Science magazine estimated that the loss of bats from white-nose syndrome and other factors is now costing North American farmers more than $3.7 billion a year.

Whether this will begin to change anytime soon depends on another experiment in progress at Aeolus. At the beginning of winter, researchers glued tiny radio tags to the backs of 450 bats there. A big, hoop-shaped receiver antenna, positioned in a passageway leading to the cave entrance, will register every time those bats go in or out.

Roughly a month from now, Darling and other researchers will make the climb back up to Aeolus. They hope to confirm last year’s promising results. If it’s good news, church bells will ring out across New England and perhaps beyond, even if the bell towers themselves remain, for now, empty of bats.