Richard Conniff's Blog, page 46

Rude Houseguests This Weekend? These Guys Are Worse.

Care to babysit for my maggot? (Photo: Craig Rotermund)

They aren’t as sexy as vampires, but roughly 40 percent of species on Earth live on the flesh, blood, and brains of other species. They’re parasites, and where vampires have a monotonous penchant for making their victims wander around with hollow eyes and prominent canines, parasites are highly imaginative in the ways they turn their hosts into instruments of their will.

The classic example is a parasitic fluke that infects a land snail, causing the snail to cough up slime balls, which deliver the fluke to an ant. But the ant is a way station en route to the fluke’s ultimate destination inside a sheep. So the fluke induces the ant to climb up on the tip of a blade of grass—the opposite of its normal instinct for self-preservation—and wait till a grazing sheep comes along to gobble it up along with the grass. The parasite then reaches its adult life as a fluke in the sheep’s liver. After it mates there, its eggs find their way back to other snails by way of the sheep’s droppings.

This is the strange circle of life, and since the discovery of that bizarre strategy in the 1950s, researchers have documented hundreds of other such parasite-host associations, in every animal phylum. For instance, a South American ant, normally black, sometimes develops a bulbous, bright red abdomen and then climbs up to assume the position, abdomen skyward, among the similarly colored fruit on a berry bush. The ant is mimicking a berry under orders from a nematode parasite, which is intent on achieving its destiny in the gut of a berry-eating bird.

Biologists are of course fascinated and regularly reveal intricate new parasite career plans. Thus a new study in Animal Behaviour describes a solitary fly in Virginia that ambushes a worker bumblebee as it forages among the flowers. Both fall to the ground. The fly (a conopid fly also known as “the thick-headed fly”) then uses can opener–like extrusions on its abdomen to shove apart the segments of the bee’s carapace and fire an egg into its abdomen. The bee soon recovers and goes on about its work gathering nectar for another week or two—while a tiny, wriggling maggot develops in its gut. Then, just before the maggot becomes a pupa, the thick-headed-fly-to-be somehow causes the bumblebee to dig its own grave and bury itself alive.

As is common with parasites, the fly larva may be triggering a mechanism that already exists in the host species, according to the study, by the University of Virginia’s Rosemary L. Malfi and her coauthors. Young bumblebee queens, having mated, normally dig an underground hibernaculum to wait out the winter, and they emerge again in the spring to start a nest. But worker bees aren’t supposed to dig, and they never get to emerge.

Instead, the fly pupa hibernates through the winter inside the shelter of its dead host’s corpse and emerges fatter and healthier than it might have if it had endured the aboveground hazards of extreme weather, dehydration, and predators—not to mention parasites that parasitize other parasites. The strategy is so effective that in one of the three bumblebee species Malfi looked at, 45 percent of individuals carried the parasite.

We’re unlikely to experience a vampire attack, but we humans are the playground of numerous parasites, including hookworms, roundworms, pinworms, and tapeworms. We have blood flukes, which, like sheep flukes, spend part of their lives in snails and—in the disease called schistosomiasis—cause severe damage in humans. By way of mosquito bites, we also sicken and sometimes die at the hands of the parasites malaria and filariasis (which can lead to elephantiasis). But most of these old friends can seem thankfully remote in the developed world.

The parasite Toxoplasma gondii, on the other hand, infects 1.1 million people in the United States every year, and they generally stay infected for life. According to the Centers for Disease Control and Prevention, about 60 million Americans now carry it; it disproportionately afflicts African Americans, Latinos, and the poor. The parasite develops in cats, and because there are millions of cats in this country, it’s all around us. It spreads to humans through cat feces, in litter boxes, sandboxes, and gardens, or from improperly cooked meat of infected livestock. Because it often occurs without symptoms, there’s a tendency to treat it as if it were trivial. But toxoplasmosis ranks as the second-leading cause of death and the fourth-leading cause of hospitalizations among food-borne illnesses. It can cause blindness or severe developmental defects in children.

Recent research also connects infection with a variety of psychiatric disorders, including schizophrenia, bipolar illness, and self-directed violence and suicide, as well as memory loss in the elderly. In one study, women infected with toxoplasmosis were 54 percent more likely to attempt suicide. All of this makes preventing the disease, by keeping cats indoors and other measures, an increasingly urgent issue in public health.

Beyond that, evidence suggests that the parasite manipulates the neurology of rodents to make them less fearful and more likely to be caught and eaten by cats. The chilling implication is that it has similar effects in the human brain. That is, parasites are manipulating the minds not just of ants or bumblebees or mice—but of people too.

Vengeful Taxonomy (And Other Joys of Scientific Naming)

The Black-tailed Godwit’s name seems to mean ‘good to eat’ in Old English, though they are not typically eaten. (Photo: Steve Round/RSPB)

This is a book review I wrote for The Wall Street Journal:

Latin for Bird Lovers

By Roger Lederer and Carol Burr

Timber Press, 223 pages, $24.95

Early this year, a Rutgers University entomologist who had discovered a new species of South American cockroach announced a contest to give it a scientific name: The genus Xestoblatta already existed, but the species name was up for grabs. “Most people have negative feelings about cockroaches, so why not name one out of spite, scorn, or revenge?” Dominic Evangelista wrote. “Got a cheating ex-boyfriend? Hate your boss? Maybe you’re just tired of hearing news about certain celebrities—Xestoblatta justinbieberii, perhaps? You get the idea.” For a bid of about $4,000 (funds that would go to support Mr. Evangelista’s next collecting expedition), anyone could consign an enemy to the seventh circle of scientific immortality. He called it “vengeful taxonomy.”

The incident was a reminder that scientific names, those sometimes cumbersome binomial identifiers, can be more entertaining than we may imagine—a point driven home by “Latin for Bird Lovers,” a book by the husband-and-wife team of Roger Lederer, an ornithologist, and Carol Burr, an artist and former English professor. Their handsomely illustrated account of about 3,000 bird names tells us, among many other things, that the quail genus name Excalfactoria means roughly “source of heat” and derives from the Chinese practice of using these tiny birds as hand-warmers. Almost as oddly, turkey vultures travel under the genus name Cathartes, from the Greek katharsis meaning “cleansing” or “purifying.” The name honors their work clearing away the dead. There’s a genus of flycatchers named Attila, “because of their aggressive nature, as in Attila the Hun.” And such is the richness of avian biodiversity, there’s also a bird genus named after Bleda the Hun, the brother Attila is said to have murdered en route to power.

Birdwatching is hugely popular in the United States: A 2006 study estimated that 48 million Americans participate in some fashion, and spend $36 billion a year at it. But most birders nervously avoid scientific names, because, as the co-authors concede, “it’s nice to be able to speak of the Coppersmith Barbet instead of the tongue-twisting Megalaima haemacephala.” On the other hand, paying attention to scientific names “opens up a whole new way of looking at and understanding birds,” they write. It reveals relationships that might otherwise go unnoticed, and reminds us that similar-sounding common names—American robin and European robin, or meadowlark and lark—can give us false ideas about taxonomic connections. Though Mr. Lederer and Ms. Burr don’t make this point, scientific naming also gives us the opportunity to utter the inexplicably delightful words Upupa epops, the name given to the common hoopoe, in imitation of its call.

The best part of this book, for a beginning birder, will be the sidebars on biology and behavior that are liberally sprinkled among the dictionary-like name entries. For instance, I had not previously encountered the word “zygodactyl,” meaning two toes forward, two back. This trait is what allows birds to sleep perched on a branch without falling off, because a tendon down the backs of the legs pulls these opposite toes together in a curled position around the branch, where they remain until the bird uncurls them to take flight. [Update: See comment below.]

Surprisingly, the actual name explanations that the authors offer are often less satisfying. It’s useful to learn that bald eagles, which are of course not actually bald, get their common name from the word “piebald,” meaning a patch of white. And I had not realized that robins are called “red-breast” because “orange was not a known color until the sixteenth century.” Not all the entries have that much to do with Latin, you will note, and most run for little more than a sentence, with the co-authors explaining that they have been able to make room for further detail “only when we think the reader’s curiosity might be piqued.” So when they tells us that the scientific name Limosa comes from the Latin for “full of mud” while the common name “Black-tailed Godwit” seems to derive “from Old English, meaning good to eat,” they offer no explanation of this apparent culinary contradiction. Likewise, we learn that the genus name of the ostrich, Struthio, “does not quite fit,” because in classical Greek it means “camel sparrow”—but not how it got that name.

One delightful exception to this parsimonious approach has to do with the naming not of a species, but of a spy. The writer Ian Fleming was living in Jamaica and birdwatching with the help of the field guide “Birds of the West Indies,” when he decided that the author’s name—James Bond—had the right strength and simplicity for the hero of his novels. When the real Bond, a Philadelphia ornithologist, discovered this identity theft years later, Fleming joked that he could retaliate by putting Fleming’s name in an insulting fashion on “some particularly horrible species of bird.”

It never happened. In fact, no instances of “vengeful taxonomy” turn up in this book, because it is in truth a coveted honor to be immortalized in the scientific name of one of the 10,000 or so bird species on Earth. New bird discoveries are now exceedingly uncommon, and the chance of getting your name on one is infinitesimally tiny.

But cockroaches? Days after Dominic Evangelista announced his naming contest, another entomologist named May Berenbaum swooped in with a $4,250 bid. The species in question has a pronounced fondness for traps baited with beer, and the male has what Mr. Evangelista described as an “extremely vile” practice of excreting uric acid on the female as a nuptial gift. But Ms. Berenbaum ignored the rich vindictive possibilities, declaring it an honor and a bargain to have her name on “this beer-swilling, uric-acid-excreting cockroach,” which will now enter the annals of science as Xestoblatta berenbaumae.

Mr. Evangelista is currently planning his next expedition, so patrons of science—and people who merely delight in scientific names—might want to start saving now.

 

“Mission Impossible” Techniques To Save The World’s Wildlife

Scientists are using a microphone array to study Cory’s shearwaters on an island in the Azores, 900 miles west of Portugal in the North Atlantic. (Photo: Marevision/Getty Images)

My latest for Takepart:

Sometimes the best way to understand nature is to get as far away from it as possible. The 19th-century popularization of binoculars was a step in that direction, allowing people to back off and observe wild animals without disturbing them. Camera traps, left unattended in the field for weeks at a time, have more recently also minimized the intrusion while revealing unexpected worlds of animal behavior.

Scientists have lately begun to deploy a host of new remote sensing techniques to solve some of the most challenging problems in wildlife conservation. I’ve written here before about iDNA, a novel technique for finding out what birds and mammals live in a habitat by sequencing the DNA from their latest blood meals eaten by leeches and mosquitoes. Even better, eDNA does the same thing for aquatic species by sequencing DNA from a water sample.

But let’s say you don’t have a DNA sequencer at hand and must rely instead on sound. Here is your mission, if you choose to accept it: Count how many seabirds are nesting on a sheer cliff face, on a remote island, with raging seas crashing on the rocks just below. Bear in mind that ornithologists have demonstrated an alarming penchant over the past few centuries for plunging to their deaths while studying such birds. Naturally, you want to know if you could—please, please, please—just use binoculars to do a visual count from a boat. But the birds often nest out of sight, in burrows or under rocks, and some species take flight only under cover of darkness.

The solution? To figure out how populations of Cory’s shearwaters are surviving, despite the introduction of cats and rats, on an island in the Azores, 900 miles west of Portugal in the North Atlantic, European scientists recently turned to a microphone array. First, they set out microphones in lower elevation areas where they could count all nests within recording distance. That gave them a baseline figure for how much noise a given number of nests produces in breeding season.

Then came the climbing—though a lot less than would be required to count individual nests on the cliffs, some of them almost 2,000 feet high. The roped-up researchers placed a series of recording devices on the cliff faces. Then they left the birds alone for the five-month breeding season.

Anybody who has ever visited a nesting colony will spot the apparent flaw in this technique: Colonies of nesting birds can make a hellacious, Hitchcockian racket. To break down five months of noise into analyzable chunks, the researchers pulled out brief samples from nighttime periods when the phase of the moon and weather conditions were uniform. Then big data technology came to the rescue, with an automated call recognition algorithm. The researchers say the technique needs further tinkering to achieve the necessary precision, but they estimate that the test island of Corvo is home to more than 6,000 nesting pairs of Cory’s shearwaters.

Other forms of eavesdropping have lately proved useful in creatures as disparate as dolphins and honeybees. A team led by Elena Papale of the University of Torino didn’t know at first if it could make sense of how different dolphin populations and species whistle underwater. The whistling varies according to a population’s genetic characteristics and adaptations to a particular environment, but these differences are small and they may also shift over time.

The researchers studied three dolphin species in the Atlantic and the Mediterranean, recording the whistling of different groups as they observed them visually. When they later analyzed recordings by their acoustic structure alone, they found they were able to assign 82 percent of the calls to the correct dolphin species. With further refinement, Papale believes, scientists will be able to employ underwater microphone arrays for “constant and continuous monitoring” of dolphin populations.

Finally, a study being published today in the journal Current Biology used honeybees to answer a complicated question: Over the past two decades, the European Union has spent $56 billion on schemes to make farms more hospitable to birds, butterflies, and other wildlife. Was it money well spent?

The new study relied on one of the most astonishing behaviors in the insect world: Honeybees returning to the hive give “waggle dances” to map out the route to a particularly appealing patch of flowers. So researchers at the University of Sussex recorded 5,484 such dances over two years. Then they deciphered them to see where honeybees were foraging in a 36-square-mile mixed rural and urban area on the southeast coast of England.

“Imagine the time, manpower, and cost to survey such an area on foot,” said lead author Margaret Couvillon, “to monitor nectar sources for quality and quantity of production, to count the number of other flower-visiting insects to account for competition, and then to do this over and over for two foraging years. Instead, we have let the honeybees do the hard work of surveying the landscape and integrating all relevant costs and then providing, through their dance communication, this biologically relevant information about landscape quality.”

It turned out the honeybees liked the environmentally friendly areas created under EU agri-environment schemes, and because bees are good indicators of habitat for other wildlife, that suggests these schemes are working as intended. (On the other hand, the bees avoided areas created under organic farming schemes, possibly because of mowing or other management practices.)

Altogether these three studies bring to mind an adage of the celebrated war photographer Robert Capa. “If your photographs aren’t good enough,” he once said, “you’re not close enough. ” But with wildlife, the opposite seems to be true: If your science isn’t good enough, maybe you need to get farther away.

Chemical Warfare in the Garden

Colorado potato beetle Photo: Nigel Cattlin/Getty Images

I love cabbage and wish I could grow it in my garden. But every time I try, the leaves end up peppered with holes. Flea beetles—little leaping insects, less than a 10th of an inch in length—are the culprits. Meanwhile, their larvae are doing terrible things to the roots. I am, however, both too organically inclined to attack them with pesticides and too lazy or distracted to do it with organic methods.

Flea beetle

It turns out that flea beetles are even trickier than I knew, according to a new study in Proceedings of the National Academy of Sciences. Cabbages have devised what ought to be a perfectly adequate defense. Their tissues contain compounds called glucosinolates, which leak out when the plant is damaged—for instance, by an insect bite. The leaking fluid comes into contact with a plant enzyme called myrosinase, normally stored separately. The combination of the two components triggers the “mustard oil bomb.” For us, that’s just part of the taste of cabbage. For beetles, it’s

a toxic and foul-smelling chemical defense.

Yet when the beetles should by all rights be fleeing in horror or falling down dead, they say, in effect, “Really? Is that all you got?” Then they resume eating. In fact, the mustard oil bomb causes male flea beetles to release a pheromone that attracts other flea beetles to the scene. The cabbage’s primary means of defense instead becomes a dinner bell for insect pests: “Yes, we’ll take mustard with that!”

It gets worse, according to a research team led by Franziska Bera at the Max Planck Institute for Chemical Ecology. Just in case the plant doesn’t release glucosinolates, the beetles have sequestered their own supply within their bodies. They also carry a stash of myrosinase, a bit like suicide bombers belted up for self-immolation. One possibility is that the beetles have adapted the mustard oil bomb as a defense against their own enemies, as some aphids do. But the researchers suggest that it may also amplify the male beetles’ “come and get it” signal. Either way, the beetles avoid what the new study calls “auto-intoxication.” Nothing dies except my cabbages.

This sort of chemical warfare arms race is common in the natural world, and apparently also in my garden. Tomatoes, for instance, have their own form of chemical defense. But when hungry larvae of Colorado potato beetles light into the leaves of a tomato plant, they inoculate the plant with bacterial pathogens, according to a study published last year. That tricks the tomato into thinking it’s been attacked by a pathogen rather than an herbivore. The poor confused tomato suppresses its chemical warfare against leaf eaters and ramps up its antibacterial defenses instead. Thus the beetle grows fat, the study reports, by “hijacking the defensive machinery of the host plant for its own benefit.”

I shouldn’t make it sound as though the plants are always on the losing side of this relationship. They’ve evolved a host of mechanical defenses, including thicker leaves, hairs, thorns, spines, and even sticky extrusions that can trap and hold insects, along with an arsenal of chemical weapons, including terpenoids, alkaloids, anthocyanins, phenols, and quinones, to kill or slow the growth of their leaf-eating tormentors. In fact, plants and insects have been living together, quarrelling, and one-upping one another’s weaponry for 350 million years.

Even if I were the oldest gardener on Earth, I would still be a newcomer in the garden. That should probably fill me with a sense of awe before the wonder and complexity of nature.

Mainly, though, I’m wondering if there will be anything left for me to eat.

Disco Leopards

This is not the “Leopard Party” video from Sexy Leo Girl, or Leopard Playboy Party (episodes one to five), or Leopard Lounge UK Candy Girls Makeover Party.

It’s the one from the Wildlife Conservation Society.  But watch it anyway:

Chimp Study Suggests Behavioral Differences Between Sexes Are Innate

(Photo: Herwig Prammer/Reuters)

One of the perennially raging debates in modern society has to do with the origin of male and female behavioral differences: Why are girls more verbal or more attentive to facial expressions? Why do boys like to compete in larger social groups and do risky things? Or as a parent might put it: Why is my daughter playing with dolls when she could be studying toddler astrophysics? And did my son really just chew his peanut butter sandwich into the shape of a gun?

On one side of the debate is the “men are from Mars; women are from Venus” argument that biology frog-marches us into our stereotypical gender roles. On the other is the “gender similarities hypothesis,” arguing that most of our supposed gender differences are small and show up only on average. In a phrase, “Men are from Minneapolis; women are from St. Paul.”

A recent study on chimpanzees, published in the journal Animal Behaviour under the title “Boys Will Be Boys,” comes down on the side of biology (but hold the frog-marching). Elizabeth V. Lonsdorf and her coauthors, including the celebrated primatologist Jane Goodall, looked at young male and female chimps in Tanzania’s Gombe National Park.

They focused on chimps two-and-a-half to three years old, when they are still infants but just starting to be weaned and a little less dependent on their mothers. (Both male and female chimps continue to travel and socialize with their mothers until they are at least eight years old, and they begin to spend the majority of their time away from her only at around age 10.)

Previous research on chimpanzees has found that adult females are less gregarious than adult males. The exception may be when they are sexually receptive. But they become less social again when pregnant and, as mothers, often spend much of their time accompanied only by their dependent offspring. Even one-on-one friendships—generally considered a female strength—seem to be relatively unimportant.

Adult males, meanwhile, spend much of their lives forming alliances, competing for status, and hunting in intensely hierarchical groups.

So how soon do these differences begin to show up?

Gender differences in socializing showed up beginning with the chimps’ “first independent forays into their social group,” the researchers write, with young females having fewer social interactions and particularly avoiding adult males, while young males sought out social interactions with adult males. Because mothers do almost all the child rearing and seem to show little difference in how they rear males or females, the implication is that these differences are innate.

More promisingly, for those who prefer an expansive view of female propensities, juvenile females tend to be better than males at tool use. In previous research at Gombe, Lonsdorf found that they pay more attention, for instance, when Mom is “termite fishing”—that is, dipping a stick into a termite mound and drawing it back up with edible insects attached. But they also pay close attention when she is making a nest, and they cradle sticks like baby dolls. Meanwhile, males are off roughhousing and acting foolish.

These gender differences make ecological sense, Lonsdorf explained in an interview. Young females need to pay attention to termite fishing and other forms of tool use. “It’s a less stressful way to get animal protein, because you can just plop down.” An adult mother carrying her baby for years at a time is not going to swing through the trees with male hunting parties in search of meat.

The new study looked at data recorded over 34 years of study and focused on 21 individual chimps. For each chimp, observers had spent at least 10 hours making notes once every five minutes on every detail of social interactions, mainly physical contact, grooming, and play. The study not only concludes that male and female social tendencies appear quite early in chimpanzees but also extrapolates these results to humans, close kin to chimps. “These data suggest,” the coauthors write, “that the behavioural sex differences of human children are fundamentally rooted in our biological and evolutionary heritage.”

The counterpart of young female chimps learning to use tools, said Lonsdorf, is that human girls tend to excel at an early age at fine motor skills like writing and drawing. Human boys, like male chimps, tend to excel at gross motor skills like running and throwing. Lonsdorf said that when she first started working at Gombe she was interested in tool use mainly to find out how chimpanzees learn. “But the sex differences kind of popped out.”

Since then Lonsdorf, a psychologist at Franklin and Marshall College, has become a mother of a daughter, now eight, and a son, age four. “I see them as chimps,” she admitted. “There are a lot of parallels to draw and not a lot of differences.” Her son “was born into a girl’s house, with girl toys, and Barbie dolls, and no trucks, no weapons.” When he first picked up a Barbie doll, she watched curiously to see how he would play. “He immediately started to beat the dog with it. He turned Barbie into a weapon.” Lonsdorf sat back, eyes wide, and thought, “Oh, this is a boy.” (Then she taught him not to hit the dog.)

“I frankly think it’s OK that male and female are built differently to be good at different things,” said Lonsdorf. “I think it should be celebrated.” The danger, she added, is that “people will latch on to it and say, ‘See, women should only have babies,’ ” or otherwise use it to excuse traditionalist prejudices or to exclude people from certain careers.

The opposite danger, among more progressive parents, may be to pretend that propensities don’t exist. Or worse, parents may want to train or punish them out of existence, banning dolls or weapons (or dolls as weapons) from the house. The new research suggests that a better approach is to understand where boys and girls are coming from and then use those propensities, without disparaging them, as a means of helping children achieve whatever their potential happens to be.

“I think one of the great things about humans,” said Lonsdorf, “is our capacity to recognize those differences but also realize that propensity does not determine ultimate capability. Yes, we’re built different, but we can all catch up if we want to.  It’s a matter of education and will.”

 

Unlocking the Secrets of the Polar Bear’s Amazing Evolution

(Photo: Ariadne Van Zandbergen/Getty Images)

We are a self-centered species, and what follows will seem at first like a particularly blatant example of it: Take polar bears, a species we seem to be pushing rapidly toward extinction, and study them—quick, before it’s too late—to learn how their biological adaptations can help us cope with our own deep-fried, high-fat modern diet.

“For polar bears, profound obesity is a benign state,” said one researcher, in the press release for a new study being published today in the journal Cell. “We wanted to understand how they are able to cope with that,” added another. “If we learn a bit about the genes that allow them to deal with that, perhaps that will give us tools to modulate human physiology down the line.”

Wow, and could I please have a side of bacon with that?

OK, I think the press release was pandering (starting with the headline “Humans May Benefit …”). The scientists, possibly nudged along by the news office, were just succumbing to the myth that most people will care about the study of other species only to the extent that it might somehow make their own lives more comfortable. Let’s be honest, though, polar bears are amazing all by themselves, and that’s what this new research is really all about.

What interested the scientists was the chance to learn how polar bears have adapted to live all winter in some of the coldest and least hospitable conditions on Earth, without access to drinking water, subsisting almost entirely on a heart-attack diet of seal blubber, and yet also swimming ultramarathon distances in summer.

“How is that even possible?” said Eline Lorenzen in an interview.

She’s a molecular ecologist at the University of California at Berkeley, and part of a team of researchers extending from Denmark to China that used detailed genetic analysis to understand not only the how, but the why, and the when of polar bear evolution.

Polar bears, it turns out, are a remarkably new species. Other large mammals typically separate into new species at most once every million or two million years, said Lorenzen. Forest and savannah elephants, for instance, went their separate ways three million years ago. Humans and chimpanzees last shared a common ancestor perhaps seven million years ago. But according to two separate genetic techniques used for the new study, polar bears evolved from brown bears just 479,000 to 343,000 years ago.

Moreover, they seem, based on analysis of an ancient polar bear jawbone, to have completed the shift to their present form and behavior by 110,000 years ago.  Assuming a generation time of just over 11 years, that represents a radical change in appearance, behavior, and physiology in as little as 20,500 generations. In evolutionary terms, that’s basically overnight.

How did they come to live like that? The timing of polar bear evolution coincided, according to the study, with a long period of unusually warm weather, which “could have enabled brown bears to colonize northern latitudes that were previously uninhabitable for the species.” But when the climate switched back to colder conditions, isolated populations either died or rapidly adapted to “some of the world’s harshest climates and most inhospitable conditions.”

The most obvious change was the shift to white coloration, for camouflage against snow and ice. But some of the most important adaptations were the invisible ones, according to the new study, mainly involving genes for coping with high fatty acid intake and cardiovascular function.

Because they prey mainly on the thick blubber of ringed seals, polar bears typically have a total blood cholesterol level of about 381 milliliters per deciliter and a fatty triglyceride level of 292. For a human, that would spell atherosclerosis and a heart attack. But polar bears don’t suffer any known problems from this diet, apparently thanks to mutations to a gene known as APOB. In humans, mutations to APOB are associated with cardiovascular calamity. But the mutation in polar bears leads to production of a protein that seems to help clear lipids and cholesterol harmlessly from the blood. In the single sentence in the study relating to human beings, the co-authors note that this finding should encourage researchers to study a broader range of species “in our search for the underlying genetic causes of human cardiovascular diseases.”

And for the bears? Nothing in the new study can help with the main cause of their current decline: Loss of Arctic sea ice due to climate change. There are currently an estimated 20,000 to 25,000 polar bears surviving in the wild, down 30 percent since 1970. “Due to their long generation time and the current greater speed of global warming,” the International Union for Conservation of Nature reports, “it seems unlikely that polar bear will be able to adapt to the current warming trend in the Arctic. If climatic trends continue polar bears may become extirpated from most of their range within 100 years.”

Brown or grizzly bears have meanwhile begun to move north as the climate warms, and they occasionally interbreed with polar bears, producing hybrids known as “pizzlies.” Thus the polar bear’s extraordinary adaptations to life on top of the world may unravel even faster than they first evolved.

 

Cormorants Like Fish Ladders, Too.

Clever cormorant says, “Howdy” to alewife.

 

A few weeks ago I wrote about the new fish ladder bringing alewives back to Rogers Lake in Old Lyme.  These devices are built mainly to help fish recover old breeding grounds blocked off long ago by dams.  But the alewives aren’t the only ones to benefit.  In its weekly report on fish-counter results at fish ladders around the state, the Connecticut DEEP recently included this photograph from the fishway at Bunnell Pond in Bridgeport.  Something about the shadow-puppetry character of the photo makes it especially creepy.  Another photo showed an otter doing the same sort of thing.

U.S. Postal Service Sends Baby Birds To Woodchipper

Surviving nestlings in an incubator (Photo: Paul Chinn, The Chronicle)

The U.S. Post Office, known for being clueless in almost all regards, has now out-done itself, feeding nestling black-crowned night herons into a wood chipper in the middle of Oakland, California.

Here’s the report from SFGate:

Oakland has come to love the squawking black-crowned night herons that have taken up residence downtown. City work crews leave them alone, and residents say they adore the colony’s rain-forest-like cacophony – a bit of nature amid the hardscrabble urban landscape.

But the shorebirds aren’t so cute to the . Officials at the downtown post office ordered nearby trees trimmed Saturday because nesting birds were defecating on the mail trucks.

The result, witnesses said, was a feathery massacre

that ended with nests – and baby birds – fed through a wood chipper …

Read the full story here.

How To Put Really Legal Seafood On The Dinner Table

Here’s a dismaying statistic to swallow: When you buy fish from the supermarket, it almost always comes from an industrial seafood company, and the typical distance from landing dock to point of sale is an astonishing 5,476 miles. That’s farther than a road trip from Fairbanks, Alaska, to Key West, Fla.

It’s worse than that, really: According to a recent study in the journal Marine Policy, 91 percent of seafood purchased in the United States is imported, and up to a third of that is a product of “illegal, unreported, and unregulated” fishing—also known as IUU, or pirate fishing. Still worse, the leading suppliers of the imports at your supermarket seafood-display counter—that glistening salmon, those tuna steaks—are China and Thailand, both notorious strongholds of illegal fishing.

What’s the average American, who consumes 15 pounds of seafood a year, supposed to do? The Seafood Watch Pocket Guides from the Monterey Bay Aquarium are a good place to start, and you can find the one for your region here. But when the pocket guide says king crab is a good choice, it can’t tell you whether the crab in your supermarket was illegally harvested in Russia, as often happens.

A better alternative, according to an upcoming study in the journal Fisheries Research, is to buy from a community supported fishery, or CSF. That’s the seafood counterpart to community supported agriculture, or CSA. In both cases, the idea is for consumers to support local producers and ensure a steady supply of sustainable food by paying in advance for shares of what nearby farms or fisheries can harvest. It generally means picking up a regular order of a pound or two of seafood at regular intervals from a nearby distribution point.

Colby College conservation biologist Loren McClenachan says she and her co-authors first became interested in CSFs when they realized that, while many people pay attention to the “food miles” it takes to get a meal from farm to dinner plate, they seldom apply the same thinking to seafood. So McClenachan and her team set out to see how well  the CSF idea is working at 15 CSFs in New England, California, British Columbia, and North Carolina are doing. These CSFs serve anywhere from 100 to 1,000 customers, with a typical annual share of about 48 pounds of seafood.

Among other benefits, the typical CSF cuts the travel distance from fishing dock to point of sale—and thus the carbon footprint—from 5,476 miles down to just 40. That distance varied from zero, for pickups at the dock, to 194 miles, for a CSF serving the inland communities of Raleigh and Durham, N.C.

Apart from the carbon footprint issue, the researchers found that CSFs are more sustainable than supermarket seafood in five ways:

1. While industrial fisheries often discard their bycatch or sell it for bait, wasting millions of pounds of non-target species, CSFs bring the bycatch to market. In British Columbia, for instance, octopus can turn up in the prawn trap fishery and it usually ends up as bait. But octopus is a delicacy in many parts of the world, and when CSFs serve it up to customers, it means a 50 percent increase in price for fishermen.

2. The CSFs also create markets for species that are abundant but underutilized. For instance, lobster traps in New England now frequently catch Jonah crabs, which have become more common as sea urchin populations have declined. Jonah crabs are kin to Dungeness crabs, but there’s no real commercial market—except through CSFs.

3. CSFs also create local markets for foods that would otherwise be shipped abroad. For instance, California fishermen catch longspine and shortspine thornyheads to serve a strong demand from Asia. (Thornyheads are also sometimes called “idiot cod,” but let’s just think of them as rockfish.) By introducing these unfamiliar fish to local markets, CSFs avoid the energy costs of freezing food and transporting it overseas, “and because the fresh market commands a higher price, fewer individuals need to be caught to return the same profit,” says McClenachan.

4. Some CSFs provide incentives for fishermen to use gear with reduced environmental impact. For instance, fishermen supplying California CSFs use trawls with reduced roller weights to minimize damage to the sea floor, and they’ve also expanded use of hook-and-line fishing.

5. Many CSFs also provide member education about seafood issues, restoring a sense of connection between suppliers and consumers. Recipes for the week’s catch are also often part of the deal. At the Village Fishmonger CSF in New York City, recent offerings included recipes for sesame tuna, hake fish cakes with paprika lemon mayonnaise, and calamari al forna.

If this all sounds a little too good to be true, well, yes, in some ways it is. Since the CSF movement began in 2007 in Port Clyde, Maine, it has grown to a total of just 30 CSFs in all of North America. Living on the coast makes it more likely that there will be a CSF nearby (here’s where to find your nearest one). But it’s no guarantee. I live in sight of Long Island Sound, and I’d need to make a roughly 50-mile round trip to the nearest CSF pickup point, completely tanking the carbon footprint argument.

But McClenachan describes CSFs as a “back to the future” solution that’s attracting increasing interest. “It’s really consumer demand–driven, and as more people know it’s an option and are willing to buy into this, more of these will develop,” she says. Most times it takes a nonprofit or a university to organize a network of buyers and the fishermen willing to supply them. Local Catch, a coalition of fishermen, organizers, and consumers, can also help.

And for the rest of us stuck with our supermarket seafood? “We really want consumers to look for seafood labeled as sustainable, which for us means the Marine Stewardship Council logo,” says Roberta Elias, the World Wildlife Fund’s deputy director of marine and fisheries policy. Consumers should also consistently ask retailers where the fish they sell is caught and whether the retailer can document that it is legal. (Beware, for instance, that as much as 40 percent of tuna imported from Thailand is caught illegally or without proper documentation, as is 45 percent of the pollack and 70 percent of the salmon from China.)

Asking those questions, says Elias, “trains retailers that consumers really want the assurance that they are buying what they think they are buying, and that it’s a good, legal, sustainable product.” The guy behind the seafood counter won’t have the answers at first, Elias admits, so consumers also need to push for industry and government action to ensure that all seafood being sold is legal and traceable. Experts say the United States does a better job than most countries at managing its fisheries for sustainability. So when it all gets to be too much to think about, it’s a smart choice to just buy American.