James Gorman

It has been a big year for leeches. A new species was discovered near Washington and announced in August by Anna Phillips, who may have the world’s best job title: curator of parasitic worms at the Smithsonian National Museum of Natural History.

The new leech, Macrobdella mimicus, has three jaws and 59 teeth, and is quite literally a creature of the Washington swamp: It drinks your blood and drops off when it’s full. This particular parasite is not registered as a foreign lobbyist.

And there’s more leech news: In May, a man was charged in what may be the first case of leech smuggling in Canadian history. He had flown into Toronto with almost 5,000 leeches in a grocery bag — for personal use. At least, that’s what he said.

What kind of personal use could that be? Well, leeches are good for bait, although fake ones are cheaper. There is do-it-yourself bloodletting. And you can keep them as pets. (They are not cheap, though: If you buy them online, you could pay $18 for a jumbo leech.)

Still, 5,000 is a lot of personal leeches. Suspicious officials called in Sebastian Kvist, curator of invertebrates at the Royal Ontario Museum, to identify the smuggled contraband. He said that dried leeches can be ground into a powder that is reputed in Chinese traditional medicine to have a variety of benefits. It is a leech-intensive process.

Kvist, who also helped identify Macrobdella mimicus, is a designer of a new museum exhibit called “Bloodsuckers: Legends to Leeches,” a celebration of the sucking, sipping, drinking and lapping of the blood of mammals, birds, reptiles, fish and amphibians in real life as well as the imagination.

The exhibit opens Nov. 16 at the Royal Ontario Museum, in case Halloween is just too short for you. Kvist said that although the smuggling incident did not prompt the exhibit, some of the leeches seized at the airport will be on display — live.

He and Doug Currie, senior curator of entomology at the museum, have been plotting such an exhibit for some years, because they both research blood-feeders and wanted to open up the world of hematophagy to the public.

Although insects are big in the blood-feeding world, leeches occupy a special place in the human imagination — somewhere between vampire bats and that tiny fish that was once reputed to swim up the human urethra.

To those who love them, leeches are just incredibly cool. Mark Siddall, a curator and professor at New York’s American Museum of Natural History known far and wide as “the leech guy,” bows to no one in his admiration.

Hirudin, an anticoagulant derived from leeches, was essential in early human dialysis, he pointed out. Leeches are now used in certain kinds of surgery, such as the reattachment of a body part, to drain excess blood. They have even been approved by the Food and Drug Administration as a medical device.

“They’re beautiful,” Siddall noted. If you can bear to look at the next one that gets attached to you in a pond or stream, you will see “it’s got orange polka dots running down its back.”

“A lot of the marine leeches are fantastically beautiful,” he added.

Currie, on the other hand, specializes in bloodsucking black flies. Although smaller than leeches and perhaps not as feared, they are vastly more numerous and arguably more hated.

Both scientists hope that the upcoming exhibit might leave visitors, if not more inclined to love blood-feeders, perhaps more able to tolerate sharing the planet with them.

Dracula is included in the exhibit, by the way, along with fantasies of vampires from many cultures. The Royal Ontario is a science and culture museum, and imaginary creatures are welcome. There are a lot of them to keep Dracula company, like the ancient utukku of Mesopotamia, the Icelandic draugr and the recent (1995) chupacabra, first sighted in Puerto Rico.

What are they like? Awful, all of them, and bloodthirsty, of course. The Penanggal of Malaysian folklore is at the top of the list of the most disgusting. It’s a floating head with dangling entrails. Happy Halloween.

The bloodsuckers of reality may be less horrific, or not. But they are certainly far more numerous. There are 30,000 animal species that feed on blood. You may ask: Why so many? Kvist’s question is: Why so few?

If blood is so plentiful and energy-rich, and it is, why didn’t more of the 1.3 million known species get in on this diet choice during the course of evolution?

The answer is that drinking the blood of other creatures while they are alive, and might possibly swat you, is not as easy at it looks.

Some difficulties are obvious (see: swatting). And although blood often flows close to the surface of the body, you have to get through the skin to draw it out. Thus, the many drills, biting parts and teeth of blood-feeders.

But like bank robbers, blood-feeders need to be stealthy. And there’s the clotting problem: you have to keep the blood flowing if you want to suck it.

Then there are nutritional obstacles. Blood lacks enough B vitamins, and even insects need them. Although blood transports B vitamins, it’s always dropping the nutrients off where they are needed. Siddall said red meat has roughly 1,000 times as much B12 as blood, ounce for ounce.

That’s not all: Iron can be toxic, and blood has so much that, as a plasma-diner, it’s dangerous to have a lot of somebody else’s in your digestive system.

Leeches have solutions for all these problems. Their saliva is a complex mixture of many, many compounds, including anticoagulants and anesthetics, which has left them in great demand among medical researchers.

Leeches solve the vitamin problem by playing host to bacteria in their stomachs that create B vitamins. (So do ticks and lice and other blood-loving creatures). And leeches have several adaptations to protect themselves from iron, including a type of tissue that binds iron to proteins to make it less toxic.

“If you think of evolution as beautiful, this is one of the more beautiful systems,” Kvist said.

He also has advice for when you get bitten. Do not pull the leech off, or shake salt or lemon juice on it, or burn it with a cigarette. All of these things are profoundly disturbing to the leech, which may then vomit up the contents of its stomach while still plugged into your bloodstream. That could cause an infection.

Kvist suggests letting the leech fill up and fall off on its own, but even he doesn’t believe anyone will follow this advice. A less disturbing alternative is to slowly and methodically pry off the leech’s mouth with something like a credit card, sort of the way you try to get an old registration sticker off a windshield.

Kvist is a treasury of information on leeches. They are descended from earthworms, and the ancestral wormy parasite from which they all came, 250-300 million years ago, was a blood-feeder. There are now 700 species of leeches, and 200 of them no longer feed on blood. They eat insects and other little creatures.

What about the other 29,500 species of blood-feeders? There is the famous vampire bat, which nicks the ankles of cattle and other animals and laps the trickling blood. Its anticoagulant is called draculin.

But how about vampire finches, one of the many finches in the Galápagos? They peck the tails of boobies until they bleed. This may not sound like the best way to make a living, but one report said there are more vampire finches than any other kind of finch in the Galápagos, and they sometimes swarm their food sources.

There are also blood-loving snails, fish and moths. But insects and ticks are by far the most numerous blood-feeders. They make up 25,000 of those 30,000 species, including bedbugs, fleas, lice, tse tse and other flies, and the ubiquitous mosquito.

The black flies that Currie studies have reputedly killed large mammals when swarming them (perhaps by shock rather than what is delicately referred to as exsanguination).

The flies are herculean processors of organic material in streams and rivers — “ecosystem engineers,” Currie said. The larvae, which live in the water, attach themselves to rocks by one end, and use feathery appendages at the other end as a kind of net to catch the tiniest bits of edible detritus — motes that are too small for fish and other insects.

The larvae clean the appendages with their mouths, eating all the little bits they collect. But they only extract about 20% of the nutritional value of the catch. Black fly larvae feces, nice little compact pellets, still have 80% of the original goodness.

And here’s the great news: Those pellets are big enough to feed other creatures. Millions and millions and millions of black fly larvae make tons and tons and tons of delicious edible poop, keeping ecosystems healthy and thriving so you and your children can enjoy swimming in mountain streams.

Black flies don’t transmit disease in North America, but in Africa and Latin America, they carry a parasite that causes river blindness. Other blood-feeding insects — such as mosquitoes and ticks — spread a host of devastating diseases: malaria, sleeping sickness, Lyme, babesiosis, Zika, dengue, encephalitis and others.

Black flies are now spreading north, as climate change affects ecosystems. This could be bad news for some birds, like the red knot, which nests in the Arctic, Currie said. Chicks have no real defense against the insects.

Looking at the toll insects take when they drink blood kind of makes leeches look like humanity’s friend. True, some land varieties will drop down on you from trees as you are walking through a rainforest. But they don’t spread human diseases.

And if you keep them as pets and you forget to buy leech food — Kvist buys cattle blood and sausage casing from the butcher, and makes tasty little blood balloons — you can always feed them your own blood. Kvist does so, on occasion, as do other leechologists.

One of the current uses of leeches is to assist in wildlife surveys. Scientists can recover the DNA of the last four animals a leech has fed on from its stomach. This provides a nice snapshot of what’s running around the environs, and scientists don’t have to tramp through the jungle chasing animals or setting up camera traps — or worse, real traps.

“Leeches blow camera traps away,” Siddall said.

He and Kvist are off to Madagascar in November to collect leeches in an area that is being eyed for its conservation potential. Knowing what inhabits the potential park is essential.

Fortunately, “there is a horde of leeches in this park,” Siddall said, so the researchers won’t need to track down actual animals that live there, just the leeches.

And that is easy: “They find us.

This article originally appeared in

(Science Times)

Meet the Bloodsuckers

It will come as no surprise to squirrel lovers — and haters, for that matter — that the twitchy, resourceful rodents are exquisitely attuned to the world around them.

Researchers at Oberlin College reported Wednesday in the scientific journal PLoS One that squirrels pay attention not only to alarm calls, as many animals do, but also to the background chatter of birds, and that they relax a bit when the birds sound relaxed.

Of course they do. They’re squirrels. They pay attention to everything. I’d be willing to bet that they can tell the difference between an irate bird lover banging on a window in pajamas (no problem) and one with her snow boots on (better get ready to skitter away).

Still, that kind of unproven certainty can lead one astray. For instance, goatsuckers, a group of birds that includes the whippoorwill, do not milk goats, Aristotle’s declaration to the contrary notwithstanding. If Aristotle had done a bit more research, he might have saved goats ages of anxiety.

Keith Tarvin is not repeating the philosopher’s mistake. He’s a biologist at Oberlin who studies what kind of information animals derive from the many sounds around them. He and his students set out to get some hard data on what squirrels listen to.

“I’ve been interested in alarm calls for a while,” he said. In a recent scientific paper, for instance, he reported that gray squirrels pay special attention to the alarm calls of robins. This kind of eavesdropping is widespread in nature. “Even some lizards that don’t make their own vocal sounds eavesdrop on some other animals like birds,” he said.

As he and his students discussed the soundscape squirrels live in, he said, “that led us into chatter,” the general background noise of nature — in particular the calls that birds make when nothing big is going on. Their question was not what one sparrow might be saying to another but whether squirrels took note of the birds’ conversations when they weren’t shouting about hawks.

The researchers hypothesized that the squirrels were paying attention, and over the course of a couple of years Tarvin and two undergraduates, Mary Lilly and Emma Lucore, designed and conducted an experiment to test that idea. They played a recorded screech of a red-tailed hawk, which put the squirrels on alert and caused them to act vigilant.

Then they played recordings of desultory bird chatter, or of background noise without birds. They made all the recordings at one bird feeder at different times. Then Lilly, who did the fieldwork (Lucore had graduated after helping to design of the experiment), had to find squirrels around Oberlin, in the winter, on her bicycle. It was cold, she said, but squirrels are easier to observe in the winter, with no leaves to obscure their actions.

She carried with her a sound system in a repurposed cat litter box. “I looked pretty ridiculous,” she said. Once she found a squirrel, she set up the sound system and played the different recordings: the hawk followed by bird chatter, and the hawk followed by birdless background noise. She kept track of what the squirrels were doing by entering data into a customized app on her phone.

She tracked six “behavioral states” and how long each squirrel was in that state: foraging, preening, resting, standing, freezing and fleeing. Standing, freezing and fleeing were the vigilance states.

The results were that when the squirrels heard the relaxed birds, they, too, relaxed. And they did so more quickly than when they heard background noise without bird chatter.

The squirrels were probably responding to the gestalt of a calm-sounding neighborhood, Tarvin said, or as Lilly put it, “the sound of no danger.” But it’s possible there are specific signals they are picking up that the researchers have not identified.

The finding is significant not just to add to the reputation of squirrels as wary and clever. Tarvin said the research also supported the idea that there may be “public information networks that exist in ecological communities.”

Human-generated sound, or sound pollution, could interrupt those networks in ways we don’t yet understand, Lilly said.

“We really can’t know the impact of the sounds that we’re creating unless we know more about the sound information that’s part of the ecosystem,” she said.

Squirrels Relax When They Hear Birds Relaxing

(Trilobites)

LEPENSKI VIR, Serbia — The faces are haunting. About 8,000 years ago, over a period of perhaps 200 years, artists who lived in this settlement on the banks of the Danube carved about 100 sandstone boulders with faces and abstract designs. The faces are simple, with wide round eyes, a stylized nose and downturned open mouths. They do not look happy.

I imagine these stone heads posing an existential question something like the one my son startled us with when we told him that he had to go to play group even if he didn’t want to. He was 3, and as the loss of freedom struck him, he had a tantrum. “How did this happen to me?” he wailed.

Archaeologists say the heads seem to be a mixture of human and fish features, accounting for their strangeness. Some designs look like fish skeletons. The gorges and pools in this part of the Danube were long a home to sturgeon and other large fish that sustained human life. Perhaps a fishing people imagined their souls migrating into fish after death.

And many of these sculptures were kept in strange trapezoidal dwellings, with hard limestone floors. In some cases the dead lay buried under the homes. So the sculptures might have represented ancestors. I take this as consistent with my interpretation. You die and suddenly you’re a sturgeon: What’s your first question?

Lepenski Vir — Vir means whirlpool in Serbian — was first inhabited more than 12,000 years ago and off and on over thousands of years. Archaeologists excavated it from 1965-70, when most of the site was flooded during the building of the first of two dams on the Danube.

But I first came upon the museum and reconstruction of the site in Serbia only a few months ago as a tourist. I was stunned by the sculptures and the mystery of the site’s past. It sits across the river from a mountain cliff on the Romanian side of the river, and its trapezoidal homes echo the shape of the cliff. There are other sites of similar age, a few of them with boulder sculptures, on either side of the Danube in this area, now known as the Iron Gates. But only Lepenski Vir has boulders with faces.

I called Dusan Boric, an archaeologist who has studied the site extensively, to find out more. Boric, a fellow at Columbia University’s Italian Academy for Advanced Studies, said Lepenski Vir is more important than ever for research. Studies of ancient DNA that trace patterns of human migration into Europe, chemical analyses of bones and pottery, and continuing archaeological studies of burial practices place the site at the very moment when farmers from the Near East began to migrate into southeastern Europe and met the hunters and gatherers who lived there at the time.

Researchers still debate the precise dating of different settlements at Lepenski Vir and nearby sites but agree on the essential fact that the sites capture a record of the meeting and mixing of two cultures and peoples.

It took a few thousand years for agriculture to spread to all of Europe. Permanent settlements were created, and the population changed with this migration and others that followed. This transition from a hunting and gathering culture to a farming culture marks the change from the Mesolithic to the Neolithic for archaeologists.

Lepenski Vir offers a snapshot of that process at its very beginning. David Reich, a Harvard expert in ancient human DNA and human migration, has drawn DNA from bones at Lepenski Vir. “It is a mother lode of material,” Reich said.

In a recent paper, he and other scientists reported new findings about the “genomic history of southeastern Europe.” As part of that study they drew DNA from four individuals at Lepenski Vir. Two were identifiable as Near Eastern farmers. And studies of the chemistry of their bones show that they had not grown up at Lepenski Vir but were migrants from elsewhere. Another had a mixed hunter-gatherer/farmer heritage and had eaten a diet of fish. Another had hunter-gatherer heritage.

The dating of the skeletons showed a range. The one with mixed heritage was from 6070 B.C., or about 8,000 years ago. The farmers were dated as 6200-5600 B.C. And the hunter-gatherer probably earlier than the others.

The DNA of this ancient population of hunter-gatherers contributes only a small fraction of European ancestry today, Reich said. Europeans now represent a mixture of genetic contributions from waves of migrants. The site, he said, is a key landmark in the “lost landscape of human variation.”

In some other areas, archaeologists and ancient DNA experts have not always seen eye to eye, but here, Boric said, the new techniques have been a great boon. With ancient DNA analysis, he said, “What we are getting is an incredibly powerful tool for understanding what went on in the past.”

I asked Reich if he experienced the same emotional jolt from DNA findings that I get from the sculptures. “I do,” he said. “It’s a little bit like being a trained musician. You’re able to hear things the untrained person wouldn’t.”

When he sees the results of complicated and statistical DNA analyses pinpointing a moment when different groups of people were beginning to trade cultures and intermarry, he said, it hits him in a visceral way. “These little hints,” he said, “bits of genetic data, mean profound things.”

Another indication of the merging of two cultures is a change in burial practices. Throughout Europe, the Mesolithic foragers laid a body down stretched out. The migrant farmers from the Near East brought another way of treating death, setting the body in a crouched or fetal position.

Both practices are found at Lepenski Vir. And when the burial practices are combined with DNA profiles, the picture is richer still. Some of the dead of Near Eastern heritage are buried in the way of the foragers. And others of foraging heritage are buried in the way of the farmers.

The farmers also brought their animals. There are bones from at least one dog, which may someday help illuminate the muddled picture of dog domestication, which now seems to have occurred separately in Asia and Europe.

Laurent Frantz of Queen Mary University of London, Greger Larson of the University of Oxford and other researchers this month published an exhaustive study of the introduction of Near Eastern pigs, originally domesticated in Anatolia, into Europe. They looked at ancient and modern DNA of wild and domestic pigs, including specimens from the Iron Gates sites.

What they found was that the farmers brought their pigs with them, but that over 3,000 years, those pigs interbred with European wild boar. Today, the DNA of those original pigs is lost. The farmers from the Near East brought the cultural practice of keeping and breeding pigs, which survived, although the original pig genome did not.

Frantz said, “The first 2,000 years of domestication that takes place in Anatolia left almost no trace in the modern genome of domestic pigs.”

As to the faces, fishing was important on the Danube before farmers came and continued long afterward. Pottery that was used for cooking grains elsewhere in Europe was used for preparation of fish at Lepenski Vir. And the strange faces appear nowhere else. There are about 100 such sculptures at Lepenski Vir. In neighboring settlements, also of fishing people, also where farmers came and met and married foragers, there are some sculptures with designs like those found on the Lepenski Vir stone heads, but none of the nearby sculptures have faces.

The farmers did not bring them with them. The hunter-gatherers did not make them before the farmers came. They did not spread to the rest of Europe.

I have on my desk now replicas of two of the heads that I picked up when I visited the museum at Lepenski Vir. I look at them and I feel a muddled kinship to the artists, the departed souls, the sturgeon. I too would like to know the answer to what I believe is their question.

But I tell them what I told my son. I have absolutely no idea.

This article originally appeared in <a href="https://www.nytimes.com/2019/08/19/science/archaeology-europe-migration.html" id="f3e8a143-e7af-360f-adf9-5a1292578624">The New York Times</a>.

A Puzzling Cultural Mixer on the Danube

CHINCHINIM, Goa, India — Seven young men sprinted down paths, darting behind houses and vaulting low walls. Each one carried a long-handled net.

From yards, alleys and streets the din of canine outrage filled the air, announcing the invasion of the neighborhood. Some dogs hid; others retreated a bit before resuming their chorus of barking. The most wary fled long before the catchers got near.

Too bad. Getting caught could be the best thing that ever happened to them. T-shirts emblazoned with a paw print logo are the uniform worn by the dogcatchers who work for Mission Rabies, and the team carries the canine rabies vaccine. Once given a shot, a dog should be safe for at least a year.

Goa is India’s smallest state. Originally colonized by the Portuguese, it’s a popular tourist destination set between the Arabian Sea and the mountain range of the Western Ghats. Although its churches and the importance of Roman Catholicism set it apart from the rest of India, Goa shares with other states the same abundance of street dogs. In town centers, in middle-class neighborhoods with fenced yards and around palm-thatched huts where women cook over open fires, dogs — black and white, dusty brown, friendly and furtive — are everywhere.

As is rabies. Worldwide, about 59,000 people a year die from rabies, most in Africa and Asia, 99% of them because they were bitten by a rabid dog. About 40% of the victims are children, according to the World Health Organization, which has announced a campaign to reduce human deaths from dog-transmitted rabies across the globe to zero by 2030. The WHO estimates the death toll in India at about 20,000 a year.

Mission Rabies, which is part of Worldwide Veterinary Service and supported partly by Dogs Trust Worldwide, both nonprofits, has targeted Goa as a place to demonstrate the viability of its program to stop the spread of canine rabies. It spends about $300,000 a year and has vaccinated 100,000 dogs a year since 2017, about 50,000 a year before that. Deaths of people from rabies in Goa fell to zero last year from 15 in 2014, when the campaign started. There are none so far in 2019.

The program has gained the full support of the state government, which now contributes about $70,000 per year. And its work is widely recognized as effective. Ryan M. Wallace, a veterinarian who heads the rabies epidemiology unit at the Centers for Disease Control and Prevention in Atlanta and who has collaborated with Mission Rabies in Haiti, said its effort in Goa was “one of the most successful programs in lower/middle income countries that I have seen in a decade.”

Part of that effectiveness depends on men in yellow shirts whom I’ve been trailing as they sprint after dogs, between houses, in 90-degree weather.

“They’re so fit,” said Julie Corfmat, who manages the Goa project. “They do this every single day all year round, during the monsoon, in the heavy rains.” Actually, she said, the downpours help. “The dogs are taking shelter; they hesitate before they run out because of the heavy rain; that makes it easier to catch them.”

I missed several captures, as the teams split up and I followed the wrong group. The next time there was a shout I followed two catchers down a dirt path on the right side of a house. One catcher, net high, was positioned perfectly when a medium-size dog sprinted off the top of a thigh-high wall. As its forefeet touched ground, the catcher slapped down the net, trapping the dog, then lifted and twisted the net so the dog was quickly immobilized and stopped trying to escape.

Within moments a team member arrived with a small cooler containing syringes and doses of the vaccine. He pinched some skin below the nape of the dog’s neck and gave it a shot. Another team member marked the dog’s forehead with paint so follow-up crews would know it had been vaccinated. Freed, the dog raced away.

Attaining global eradication is the goal of anti-rabies organizations, but most see it as an aspiration, not a likely achievement. Not because the science is difficult, or the practical methods are unproven. Medically, rabies is easy to prevent, in dogs and people. Organizationally, the path to stopping rabies is well understood.

But, like all public health problems, rabies control depends on large and continuing government action. Eradication of canine rabies in a dog population, which is how human deaths drop to zero, requires a long-term commitment. To reach zero human deaths, the 120 countries in which the disease is endemic would need to find the money and act efficiently, now.

Even in India, with a powerful central government, Maneka Gandhi, a member of parliament and widow of Indira Gandhi’s son Sanjay, as well as a former government minister and animal welfare activist, said rabies “is not really a priority issue with the government, unfortunately.”

Goa is an exception that Mission Rabies hopes can lead the way, if not for the globe, then for India, and if not for India, then for other countries. The state government is fully behind the program of Mission Rabies, which has published data that not only shows it is remarkably effective, at reasonable cost, but also offers lessons on what needs to be done to stage effective anti-rabies campaigns: vaccinating dogs.

Most Lethal Disease

Case by case, rabies is the most lethal disease known. The virus enters the body at the time of a bite. It then begins to travel up nerves toward the brain. In humans, once it reaches the brain stem, usually after about two weeks, but perhaps months later, it starts to cause excessive salivation, convulsions, impaired movement, sensitivity to light and noise, and sometimes avoidance of water.

Once symptoms appear, it is nearly 100% fatal. But it can be prevented even if a person is infected with the virus. A series of shots, given before symptoms appear, can stop the virus in its tracks.

About 15 patients are known to have survived the disease once symptoms have appeared, according to the WHO, but all of them except one had at least one dose of vaccine before symptoms appeared. And many of them had permanent neurological damage.

In most cases, and in most parts of the world, rabies is a death sentence. The patient is kept isolated and tied to a bed in a dark room. Death is often preceded by seizures, pain and hallucinations.

As if the deadliness of the virus weren’t terrifying enough, rabies is spread by humanity’s oldest animal friend. For 15,000 years or more we have lived with dogs, loved them, buried them alongside us, written poetry and songs to them. And for 4,000 years at least, and probably much longer, some of them have wagged their tails and licked our faces one day only to infect us the next.

The disease is described in texts from Greek and Roman antiquity, and in an ancient Ayurvedic text, the Sushruta Samhita. Some of the old records suggest an understanding that it was the saliva that transmitted the disease. But it wasn’t until Louis Pasteur developed his vaccine more than a century ago that anything could be done. Since then, the rabies virus, which looks like a bullet in images made with an electron microscope, has been exhaustively studied.

Neuroscientists have even adapted a disabled version of the virus to study how the brain works because the virus predictably travels through nerve and brain cells, synapse by synapse.

Control and Eradication

Rabies perfectly illustrates the concept of “one health,” the idea that the health of human and animal populations are inextricably tied together. If cattle have tuberculosis, it can spread to people. An ebola reservoir in apes or bats can spread to humans.

For rabies, the link is direct. Wherever there are people, there are dogs. If dogs are suffering and dying from rabies, humans will also suffer and die. In essence, if you save dogs, you save humans.

The consensus among rabies experts is that if the level of vaccination in the dog population can be kept at 70% over a period of seven years, the variant of the rabies virus that thrives in dog populations will disappear.

Effective vaccination depends not only on technical tools but also on an understanding of dog-human relations. Who owns or cares for dogs in any given community? And how much control do the humans have over the dog population?

In countries where dogs have become leash-bound pets, like the United States and Western European nations, canine rabies has been eliminated. The result is that there are one to three deaths a year caused by rare contact with bats, dog bites outside the country or bites from other animals, like raccoons. In most of the Americas, North and South, national governments have devoted the money and political will to vaccinate the vast majority of dogs every year, so even in countries where the disease is not eliminated, deaths are rare.

In Africa, where tens of thousands of people die from rabies each year, most dogs, even if they run free, are owned by families, as in the Americas, and vaccination drives can concentrate on the owners, who will bring them to vaccination locations.

India is different. Street dogs and people in India often have a kind of understanding. The dogs aren’t wild, but they aren’t owned either. Free-roaming dogs are often supported by the community, but nobody decides when and where they live, eat or mate.

Rahul Sehgal, India-Asia director for the Humane Society International, who is based in Ahmadabad, said, “In other places people don’t feed dogs.” But, he said, “I haven’t seen a single place in India where dogs are not fed by individuals or community.”

For example, a family living by the side of the road in Vadodara, where the Humane Society was conducting a sterilization campaign, shared their life and what food they could earn, or were given, with a few dogs. They said quite definitely that they did not own the dogs, but they did want to know when the black dog taken away to be neutered would be returned.

Not everyone in India loves dogs, of course. Packs of dogs have attacked people. And occasionally communities erupt with violence against dogs. In Kerala in 2016 when several people died from being mauled by dogs vigilantes engaged in widely publicized killings of street dogs.

There are about 35 million dogs in India, Sehgal estimated, compared with 90 million dogs in the United States. India is only a third the size of the United States, geographically but three times the size in population, so the number of dogs per suburban acre, or city block, is about the same, and the number of dogs per person far less. But any visitor walking through a neighborhood in India could be forgiven for thinking that the country has a much denser dog population. The difference is that in India, the dogs are mostly outside; in the United States, they’re mostly indoors.

Rabies campaigns in other countries often involve getting owners to bring dogs to central vaccination points, but that poses problems in India, because of the lack of individual ownership. The answer, according to Mission Rabies, is to send out teams to find and vaccinate street dogs, using various techniques, with about 40% requiring capture by nets.

The vaccination workers in Goa first cover neighborhoods in pairs, traveling by foot or on a scooter, calling to friendly dogs who will approach and allow themselves to be held and vaccinated and talking to people who own or feed dogs. All vaccinated dogs get a paint marking that will last for a week or so. When I went along during this phase, we picked up puppies to vaccinate, were invited in for tea by one devoted dog lover and encountered none of the frantic barking that accompanies the net catchers.

The parkourlike athleticism of the net catchers comes with the second pass through a neighborhood. And finally another team makes a third pass, looking for any dog that hasn’t been marked.

On one of those cleanup passes, an adult dog wouldn’t move from her spot by a low stone wall until the team got really close. She was hiding puppies, five fur bundles about 1 week old.

As a veterinarian handled the pups and the mother watched from a distance, a neighbor politely asked if we could take the puppies away.

Beyond Goa

Andy Gibson, a veterinarian from Sussex, England, oversees the Goa project for Mission Rabies and frequently visits India. He joined Mission Rabies not long after he found himself doing an MRI on a cat and wondering whether a life spent caring for the pets of the rich was what he wanted.

Gowri Yale, a veterinarian from Bangalore, who works in Panjiim for Mission Rabies, took a similar turn. She was working with livestock but felt the industry was cruel.

“I’m a vegan now,” she said. “And when I thought about becoming a small animal vet — cats and dogs — I felt I was helping rich people keep fancy pets, so I thought I want to do something with more impact.”

In a small Mission Rabies office in Panjim, the two vets discussed the central importance of data gathering to the project in Goa. “If you don’t measure it, you can’t prove it,” Gibson said. And if you can’t prove it, you can’t get political support.

The Mission Rabies program has three aspects: vaccination, education and data gathering.

At the heart of the plan is a smartphone app that allows the vaccination teams to track their GPS-monitored progress through a neighborhood on a map as they move from street to street. Team leaders can easily see each day’s progress. And the accumulated data helps set the next day’s plan and provide information for analysis. The CDC, which advises the Haitian government, used the app there and achieved an increase in dogs vaccinated to 76% from 40%.

Mission Rabies estimates the vaccination cost per dog, including salaries and other costs, at $2.50, far lower than the cost of treating humans, which involves not only a more expensive vaccine but also potential hospital stays. By that accounting, every dog in India could theoretically be vaccinated for under $90 million. India now spends $490 million a year on post-bite treatment, Gibson estimated.

Gibson has heard criticism that Goa’s project is too small a model to be replicated at a large scale.

Applying the Goa project’s methods on a larger scale would require at least one technical piece that is missing — an oral vaccine. Western Europe eradicated rabies in foxes by dropping baits with oral vaccines, beginning in 1990 when rabies was widespread and lasting more than 20 years.

The oral vaccine has also been tested in dogs in Haiti and other countries with success. And Gibson has run tests to show how the oral vaccine can reduce the number of people needed to reach hard-to-vaccinate dogs. Many dogs now caught in nets might approach hand-tossed bait.

The End of Street Dogs?

While international experts, like Wallace, are insistent that mass vaccination is the way to stop rabies and that Mission Rabies’ work in Goa has been successful, the response to such efforts in India is mixed.

“In India it will never be possible to do it in a disciplined and effective manner because that costs too much and it needs an army with cameras, data gathering, computer recording etc.,” Maneka Gandhi said in an email.

In addition, she said, dogs that are vaccinated but not sterilized “will have 12 puppies in the coming year and then the process starts again.”

Instead she supports population control. “The sterilization of dogs is a must,” she wrote. “There is no other way.”

The parent organization of Mission Rabies does include programs that train vets and sterilize dogs. And population control of dogs, through sterilization (with vaccination), is the approach preferred by Humane Society International.

But that approach poses its own challenges for the future. In North America and Western Europe, increasing wealth has led to a change in the status of dogs, which has certainly made rabies control by vaccination much easier. As Wallace put it, they move off the streets, “into our yards, then our houses, then our beds.”

In India, a big reduction in street dog populations would mark a significant cultural change, which, Sehgal said, is already beginning. As India becomes more urban and standards of living increase, he said, “Suddenly people are intolerant of dogs.” People travel to other countries, he said, and “they don’t see dogs in the street.” Over time, street dogs may disappear in the cities. “There will be apartments; there will be malls; there will be gated communities that will not tolerate the survival of these dogs.”

If so, that would be a very different India. Despite noise, feces, bites and the always present chance of rabies, the attitude of many Indians toward free-roaming dogs is still extraordinary tolerance.

At a community meeting in Vadodara, run by the Humane Society, people complained about dogs stealing shoes. But when I asked if they wanted fewer than the 20 or so dogs that lived in their neighborhood, there was not the outcry I expected.

No, several people said. They didn’t want the dogs taken away. And they didn’t want fewer dogs. But if the dogs could bark less, that would be much appreciated.

This article originally appeared in <a href="https://www.nytimes.com/2019/07/22/science/rabies-dogs-india.html" id="bdc93f9c-c9c7-3754-a0b0-67b71a7a438b">The New York Times</a>.

Corralling Rabies, One Street Dog at a Time

It is too soon to know the extent of Dorian’s impact, and really too soon to ask. Ecological post-mortems are nowhere near the first order of business. But interviews with scientists and the findings in a paper published Monday by Ecology Letters suggest that many birds are resilient, and that when a hurricane does push a species over the brink, it is almost always a species that we have put there in the first place.

If what we’re worried about is extinction, “we’re the driving force,” said David Steadman, curator of ornithology at the Florida Museum of Science, who has done a vast amount of research on Caribbean birds.

By destroying the environments where birds live, introducing alien predators and damaging the environment in other ways, humans gradually put birds — and of course other species — at risk. A hurricane or another disaster may deliver a final punch, but it is not the underlying cause of extinction. Christopher Elphick, an ornithologist at the University of Connecticut and one of the authors of the new paper, said development and sea level rise, both caused by humans, are the slow and sure killers.

He compared it to heart disease: “Eating just a little too much fat in your diet is what causes the heart attack. But shoveling snow is what pushes you over the edge.”

Birds do die in hurricanes, of course, and suffer other indignities. Dorian blew some to Nova Scotia. And some were spotted hiding out in the hurricane’s eye. Who knows where they ended up? Fortunately, Hurricane Humberto, which had people in the Bahamas worried about a second hit, took another path over the weekend.

Scientists concentrate on species and subspecies. In terms of the Bahamas, only speculation is possible at the moment. One species on the extreme edge, the Bahama nuthatch, only one or two of which were known to be living before Dorian, may well have been pushed to extinction. Others that are in trouble, like the Bahama parrot, may have suffered little impact.

Diana Bell of the University of East Anglia said that researchers from her lab found a Bahama nuthatch last year. That’s one single bird. She said another team reported finding two.

The Bahama nuthatch was already thought to be extinct before Dorian nailed Grand Bahama, where one or two nuthatches may have still been alive.

“This could have been the coup de grâce for the nuthatch,” Steadman said.

Steadman, who has been researching birds in the Caribbean and elsewhere for many years, said that in contrast the Bahama parrot — which is in trouble, but not as severely — may have done just fine.

Much of the parrot population dwells on the south of the island, which was hit but not devastated. And the parrots nest in cavities in the island’s limestone, and no doubt would have hunkered down during the storm. “I would doubt if there’s so much negative impact on that parrot population at all,” he said.

Other birds that are struggling there are the Bahama swallow and the Bahama oriole.

Past hurricanes have hit certain bird populations very hard, but selectively. Hurricane Hugo in 1989 brought Category 5 winds to the Francis Marion National Forest in South Carolina that knocked down the old growth nesting trees of the red-cockaded woodpecker. The bird nests in tree cavities in old-growth forests, and the storm snapped old trees in two; 87% of the forest’s 1,765 cavities were destroyed.

Joseph M. Wunderle Jr. of the U.S. Forest Service, who is based in Puerto Rico, said the managers of the forest responded with artificial cavities to help save the woodpeckers that remained.

Wunderle has studied and written about Caribbean birds and hurricanes for decades. Hurricane Maria, he said may have knocked out a group of Puerto Rican parrots that live at a high elevation. “The official count now is two birds in the Luquillo Mountains,” he said. The power of the hurricane played a role. Colleagues of his told him that when Maria struck as a strong Category 4 hurricane in September 2017, it killed 17 of 20 parrots wearing tracking devices. “They found them dead under fallen trees and tree branches,” he said.

The St. Kitts bullfinch also fell victim to hurricanes in the late 19th century, Wunderle said. The bird survived for a while and disappeared, he said. It had lived in a mountain forest on St. Kitts, feeding on fruits and seeds, and the plants took a long time to recover. Why didn’t it move to the lowlands? At lower elevations wild areas had been replaced with fields of sugar cane. By humans.

Insect eaters do a lot better, Wunderle said. Even if adult insects are lost in a hurricane, there are eggs, pupae, larvae. And there is a lot of dead wood, which many insects love.

The Cozumel thrasher is another example. The island was hit by Hurricane Gilbert in 1988 and Hurricane Roxanne in 1995. The introduction of alien predators to the island may have contributed to its disappearance.

When bird populations are reasonably widespread, they can, however, be quite resilient in the long term.

Elphick, his colleague Chris Field and other researchers from the University of Connecticut were inspired to look at the effects of catastrophic storms on marsh birds because they were in the midst of surveying bird populations in Eastern coastal marshes when Hurricane Sandy struck in 2012.

They were surprised to see that the effect on bird populations was not that great. Individual birds certainly suffered, and that often prompts an immediate reaction from both the public and scientists. “People see dead birds and say, oh my God,” Elphick said. But individual deaths don’t necessarily mean trouble for the species.

Their team wanted to understand the long-term prospects for bird species over 20 years after a disaster. They created a computer model and after putting in data on the size of a population, its pattern of reproduction and other factors, they ran simulations to see how bad a species would have to be hit by a disaster for it to have an effect on its long-term prospects.

They looked at four birds: the clapper rail, willet, saltmarsh sparrow and seaside sparrow. For saltmarsh sparrows and clapper rails, almost all adults had to be killed for there to be a change in the long-term prospects of the population. The seaside sparrows and willets weren’t quite as robust, but they still needed to experience reproductive failures of more than 75 percent for their long-term survival to be threatened.

In general the team found that the coastal birds they studied are highly resilient to individual storms. They believe their simplified model — which concentrates on deaths and reproductive failures, not the strength of storms — could be useful for projecting what is likely to happen to other species facing disasters.

Of course, Elphick said, “there are two big caveats to our general result.” The species they studied are very small, or very localized. And that is exactly the situation for island birds, particularly where humans have changed the environment.

Climate change may bring an increase in frequency and strength of hurricanes that could change their calculations somewhat, Elphick said. But the biggest threats to the birds he studied are the gradual erosion of habitats by human development and, for marsh birds, development of the marshes where they live, and rising sea levels, which make average tides and storms more dangerous during nesting periods.

Development and rising sea levels are, of course, caused by us. As Bell put it: “Birds evolved to withstand hurricanes. They didn’t evolve to withstand destruction by humans.”

Hurricanes May Kill Some Birds, but Humans Are the Real Threat

In a catastrophic hurricane like Dorian, the loss of lives and homes can be overwhelming. But even in the midst of devastating sadness and disbelief, a far less urgent but perennial question can tug at the back of the mind. What is the impact of these storms on wild creatures, like birds?

In a catastrophic hurricane like Dorian, the loss of lives and homes can be overwhelming. But even in the midst of devastating sadness and disbelief, a far less urgent but perennial question can tug at the back of the mind. What is the impact of these storms on wild creatures, like birds?

It is too soon to know the extent of Dorian’s impact, and really too soon to ask. Ecological post-mortems are nowhere near the first order of business. But interviews with scientists and the findings in a paper published last week by Ecology Letters suggest that many birds are resilient, and that when a hurricane does push a species over the brink, it is almost always a species that we have put there in the first place.

By destroying the environments where birds live, introducing alien predators and damaging the environment in other ways, humans gradually put birds, and of course other species, at risk. A group of scientists reported last week that there were 2.9 billion fewer birds in the United States and Canada then there were in 1970, a drop of 29%. The most significant causes, they said, were habitat loss and wider use of pesticides.

A hurricane or another disaster may deliver a final punch, but it is not the underlying cause of extinction. Christopher Elphick, an ornithologist at the University of Connecticut and one of the authors of the new paper, said development and sea level rise, both caused by humans, were the slow and sure killers.

Steadman, who has been researching birds in the Caribbean and elsewhere for many years, said that in contrast the Bahama parrot — which is in trouble, but not as severely — might have done just fine.

They were surprised to see that the effect on bird populations was not that great. Individual birds certainly suffered, and that often prompts an immediate reaction from both the public and scientists. “People see dead birds and say, ‘Oh my God,’” Elphick said. But individual deaths don’t necessarily mean trouble for the species.

They looked at four birds: the clapper rail, willet, saltmarsh sparrow and seaside sparrow. For saltmarsh sparrows and clapper rails, almost all adults had to be killed for there to be a change in the long-term prospects of the population. The seaside sparrows and willets weren’t quite as robust, but they still needed to experience reproductive failures of more than 75% for their long-term survival to be threatened.

In general the team found that the coastal birds they studied were highly resilient to individual storms. They believe their simplified model — which concentrates on deaths and reproductive failures, not the strength of storms — could be useful for projecting what is likely to happen to other species facing disasters.

Birds' Top Danger? Humans

The bulls — 50 or so — come for the opening event in the Professional Bull Riders circuit, which this year runs Jan. 4-6. Cowboys on horses herd them up the ramps. The bulls soon emerge into a kind of animal-athlete locker room.

Bull riding is a big business, and a big-time sport. For the riders, it’s astonishingly dangerous; in 2018 one rider died at a Professional Bull Riders event in Brazil, and two others died at non-PBR events. The list of injuries on the organization’s site is long and disturbing, dominated by concussions, with the occasional fractured sternum, joint separation or severe facial laceration.

For the past 15 years or so, bucking bulls have been intensively bred like racehorses to make them harder to ride. Breeders use high-tech reproductive techniques and a detailed, computerized registry of 180,000 bulls and cows. Cowboys have continued to be bred the old-fashioned way.

NEW YORK — Each year, when the bucking bulls arrive at Madison Square Garden, livestock trailers pull into 33rd Street and back up to ramps that lead five floors up to the arena.

James Gorman

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