Richard Conniff's Blog, page 84

Fashionable Slime

Sooner or later we all have to eat our words, and today it’s my slimy turn.  Here’s part of what I wrote about slime eels, also known as hagfish, in my 1996 book Spineless Wonders:  Strange Tales of the Invertebrate World:

Among other habits that have endeared them to seafarers, slime eels like to enter dead or dying bodies on the ocean bot­tom by way of mouth, gills, or anus, and gobble up everything except bones and skin, which remain intact. Fish immobilized in gill nets are particularly susceptible. In one study in the Gulf of Maine, slime eels gutted 3 percent to 5 percent of the catch. J. B. Heiser, a biologist at Cornell University’s Shoals Marine Laboratory in Maine, describes what’s left of the fish as “a bag of bones, literally . .. like it had been sucked dry by a high- powered vacuum cleaner.”

Slime eels are often still inside the fish when the bloated gill net spills its contents onto the fisherman’s deck, and Heiser, who has opened up several specimens, says the hags ensconced in their victim are typically well-fed and at ease, “smiling, slimy, usually snoring—gently.” In one case, the record, a single cod contained 123 slime eels, in a pink, wriggling mass.

It is a disheartening sight for fishermen, touching some source of horror beyond mere economic loss. One fisheries ex­pert has attributed this horror to the slime itself: “Being worth­less . . . the hag is an unmitigated nuisance, and a particularly loathsome one owing to its habit of pouring out slime from its mucous sacs in quantity out of all proportion to its small size. One hag, it is said, can easily fill a two-gallon bucket, nor do we think this any exaggeration.”

But, oh, how wrong, how terribly narrow-minded, of both me and my nameless expert, because hagfish slime is apparently destined to become the stuff of high fashion.  ScienceDaily reports:

Nylon, Kevlar and other synthetic fabrics: Step aside. If new scientific research pans out, people may be sporting shirts, blouses and other garments made from fibers modeled after those in the icky, super-strong slime from a creature called the hagfish. The study appears in ACS’ journal Biomacromolecules.

Lead author Atsuko Negishi, her supervisor Douglas S. Fudge and colleagues explain that petroleum is the raw material for making modern synthetics. Rising prices and the quest for more sustainable alternatives have led scientists to consider the possibilities of using protein-based raw materials, such as spider silk. Another candidate comes from the hagfish, an eel-like fish that produces a thick slime to protect itself against predators. A single Atlantic Hagfish can produce quarts of slime in seconds. It clogs the gills and may suffocate other fish. The slime consists of tens of thousands of remarkably strong threads, each 100 times thinner than a human hair. The scientists set out to investigate spinning spider-silk-like fibers from the proteins of these slime threads.

They developed a method for drawing hagfish slime thread proteins into fibers comparable to lab-made spider silk. It involved casting a thin self-supporting film of thread proteins on the surface of a salt solution, then grabbing it with forceps and lifting it upwards so it collapses into a single strand. The threads in hagfish slime, they indicate, might be models for synthetic fibers made from renewable, naturally occurring proteins.

The authors acknowledge funding from the Advanced Foods and Materials Network and the Ontario Ministry of Economic Development and Innovation.

It may all seem improbable, or we might at least wish that it were.  But the slime weel has had one previous moment in the fashion limelight:  In the 1980s, Wall Street types and others liked to sport wallets made from the slime eel’s curiously wrinkled skin.

SOURCE:  Atsuko Negishi, Clare L. Armstrong, Laurent Kreplak, Maikel C. Rheinstadter, Loong-Tak Lim, Todd E. Gillis, Douglas S. Fudge. The Production of Fibers and Films from Solubilized Hagfish Slime Thread Proteins. Biomacromolecules, 2012; 13 (11): 3475 DOI: 10.1021/bm3011837

Gonads Saved by Social Media? Oh, yeah.

Gotta like this report on the perils of the biologist’s life, and incidentally, how weird it must be to live in Maine.  It’s from a University of Maine graduate student named Skylar Bayer, who, God bless him, studies invertebrate fertilization and blogs at strictlyfishwrap:

This is my version of what happened Monday.

That morning I drove up to Mount Desert Island to take care of a few things. The first item on my agenda was to have a meeting regarding my thesis progress. The second item was to recover scallop gonads that had been carefully collected and preserved by Andy Mays, a fisherman that I’ve been working with over the past year regarding my scallop reproduction work.

We agreed to meet at the Somesville One Stop, a gas station in Somesville, Maine. Andy had his kids that day, so he was running a pretty tight schedule. He saw a four-door blue Chevy with *official* University plates on it. The car was unlocked (only in Maine) and sans driver. He assumed it was my car and put the buckets of gonad sample jars in the back of the car.

Now, I was parked at the other end of the parking lot when I saw him drive across the street to where his next errand began. I walked over and he asked if I saw that he put the samples in the car. We both pointed to the spot where the blue car was parked and it was gone, as if in a movie or a sitcom, leaving us with the same “Holy-shit-did-that-just-happen” look on our face. You could still see its aura.

We both laughed nervously. I don’t think I could’ve even been angry because the situation was so ridiculous. All I could do was shrug my shoulders and all Andy could say was that his stuff always gets screwed up but always works out in the end. I went into the gas station and told the attendant what happened. She, too, had the same perplexed look on her face.

On my drive back I called my lab in an attempt to talk out and understand what the hell had just happened. I was in what I call ‘WTF-shock.’ My advisor had enough sense to tell me to call the Motor Pool at the University. I called them and then the CCAR program, the vice president of research and a few other graduate students up at Orono. My labmate up on the Orono campus went into the Motor Pool office asking around for me, too. It’s nice to know that in academia and science everyone completely appreciates the importance of your data and samples. It’s akin to the type of sympathy you’d receive if you’d lost a child or a pet.

Andy’s wife called me at work Tuesday afternoon. She informed me that she had told the police, posted on Facebook, informed the local radio stations and papers of the mixup so that hopefully all the media coverage would reveal what poor soul had my precious samples. Last night while at a conference in Portland I checked my Facebook page to find someone asking me if this was me. Ohmygod, I thought, I made it to Deep Sea News (at least my samples did, anyway).

This morning my friend up at Orono called me and asked if I’d read my e-mail yet. I said no, but I opened it up to find a message from the Motor Pool stating simply that my samples had been recovered by a teacher in the Education department. She had found out via a Facebook post and of course, my (scallop) gonads made it to the Bangor Daily News. And now, thanks to everyone involved, my ‘nads are making their way back to me!

 

Crab Heaven and Scientific Immortality

Tudge’s tiny crab

Here’s a nice piece about having a new species named in your honor, from ScienceDaily:

Areopaguristes tudgei. That’s the name of a new species of hermit crab recently discovered on the barrier reef off the coast of Belize by Christopher Tudge, a biology professor at American University in Washington, D.C.

Tudge has been interested in biology his whole life, from boyhood trips to the beach collecting crustaceans in his native Australia, to his undergraduate and PhD work in zoology and biology at the University of Queensland. He has collected specimens all over the world, from Australia to Europe to North and South America.

Until now, he has never had a species named after him. He only found out about his namesake after reading an article about it in the journal Zootaxa. Apparently, finding out after-the-fact is standard practice in the highly formalized ritual of naming a new species.

The two crustacean taxonomists and authors of the paper who named the new crab after Tudge, Rafael Lemaitre of the Department of Invertebrate Zoology at the Smithsonian Institution’s National Museum of Natural History and Darryl L. Felder of the University of Louisiana-Lafayette’s Department of Biology Laboratory for Crustacean Research, have known Tudge since he first came to Washington in 1995 as a postdoc research fellow at the Smithsonian.

Crustacean Elation

Lemaitre and Felder have been collecting specimens on the tiny Belizean island for decades and for more than 10 years, they had asked Tudge — who specializes in the structures of crustacean reproduction and how they relate to the creatures’ evolutionary history — to join them on one of their semiannual research outings. Finally, in February 2010, Tudge joined them on a tiny island covered with hundreds of species of their favorite fauna.

It was crab heaven for a cast of crustacean guys.

“So you can take 40 steps off the island and you’re on the edge of the reef, and then the back part of the reef is what they call the lagoon,” Tudge recalled. “You slowly walk out into ever-increasing depths of water and it’s a mixture of sand and sea grass and bits of coral, and then there’s some channels. There’s lots of different habitats there. Some islands are covered by mangroves. So we would visit all the different habitats that were there.”

“We would collect on the reef crest, go and turn over coral boulders on the reef flat, snorkel over the sea grass beds. We pumped sand and mud to get things out of the ground. We walked into the mangroves and collected crustaceans from under the mangrove roots. We even snorkeled in the channels in the mangrove islands.”

But discovering the new species was much less involved: Tudge turned over a coral boulder in an intertidal area, saw 50 or so tiny crabs scrambling around, and stuck a dozen or so specimens in a bottle before going on with his work. Only later in the lab, under the microscope, was it determined that this isolated little group of hermit crabs might be unique.

As the journal authors write: “Given this cryptic habitat and the relatively minute size of the specimens (shield length range = 1.0-3.0 mm), it is not surprising that these populations have gone unnoticed during extensive sampling programs that have previously taken place along the Barrier Reef of Belize.”

Getting the Word

Tudge found out only recently found out that Areopaguristes tudgei — a tiny hermit crab differentiated from others in its genus by such characteristics as the hairs growing on some of its appendages — was joining the list of about 3 million known species. Lemaitre emailed him a PDF of the finished article. A note said only, “Here’s a new species. What do you think?” The note had a smiley emoticon.

That’s the way it works, said Tudge’s colleague American University’s College of Arts and Sciences, biology professor Daniel Fong. There’s no warning; one day you just find out. Fong has also had species named after him, and he has discovered new ones as well.

“You go through several emotions when a species has been named after you,” Fong said. “It is truly an honor, in the most formal sense of the term, that your colleagues have thought of naming a species after you. It is a very special type of recognition of your contribution to your research field by your colleagues.”

Amid their exhaustive taxonomic description, complete with drawings and photographs of Areopaguristes tudgei, the journal article authors explain why they chose its name: “This species is named after our colleague Christopher C. Tudge (American University) who first noticed and collected populations of this diminutive hermit crab living under large dead coral boulders during joint field work in Carrie Bow Cay. The name also acknowledges his unique contributions to knowledge of the reproductive biology of hermit crabs.”

The Medical Martyrs

As an afterthought, when I was writing The Species Seekers, I included a listing of people who had died in the quest to discover new species.  The Wall of the Dead: A Memorial to Fallen Naturalists turned out to be one of the most popular features of the book.  It’s also part of a current exhibition at The British Natural History Museum’s annex in Tring, and it’s a constant object of reader interest at this blog.  Since I posted it here early in 2011, more than 28,000 people have visited (and considerably added to) The Wall of the Dead.

Now I’m working on a new book, The Great Deliverance, about the fight to understand and treat epidemic disease.   This topic may seem like a reach for many readers who know me mainly as a writer on natural history.  But understanding disease has always been a matter of understanding that our own bodies are part of the natural world, and the natural world is part of our bodies.  We are a habitat,  though often against our will.

Many doctors, nurses, and researchers have given their lives to identifying and defeating the pathogens that have routinely killed us.  So I am now beginning to put together a new list, under the title The Medical Martyrs.  As with The Wall of the Dead, I invite readers to send me names of their colleagues, friends, loved ones, and heroes who died while working to stop epidemic disease.  I’ve drafted a few examples to get things started.  Here’s the format:

Last name, first name (year of birth-death), brief description of specialty and also of the occasion and cause of death, as well as the age at death.  Please include links to articles, obituaries, web sites, or other useful biographical material.   I’ll get your suggestions up onto the list at frequent intervals.

And here are a few examples of medical heroes who gave their lives in the quest to control epidemic disease:

Jesse Lazear

Lazear, Jesse W. (1866-1900), a Johns Hopkins Hospital physician, joined the U.S. Army and served with Walter Reed on the commission to investigate yellow fever in Cuba.  He confirmed the theory that mosquitoes transmit the disease.  But without telling his colleagues he experimented on himself with infected mosquitoes, and died of the disease, age 34.

Matthew Lukwiya

Lukwiya, Matthew (1957-2000), medical director of a hospital in Gulu, Uganda, during an Ebola outbreak.  He was awakened when none of the other staff would touch a patient who had fallen out of bed, coughing blood.  Lukwiya put on most of his protective gear, but not a face shield to protect his eyes, and lifted the patient back into bed.  He contracted Ebola himself and died soon after, age 43.  At the funeral of a colleague in the same outbreak, he had declared, “It is our vocation to save life. It involves risk, but when we serve with love, that is when the risk does not matter so much. When we believe our mission is to save lives, we have got to do our work.”

 

Janet Parker

Parker, Janet (1938-1978), a medical photographer at the University of Birmingham Medical School, contracted the world’s last case of smallpox and died, age 40, when improper procedures caused the release of a smallpox strain being used for research one floor below her darkroom.

The Natural History of a Wood Picture Frame

When you see an old picture frame with worm holes, you’re looking at one of the many places where art meets natural history.  Here’s the story from ScienceDaily:

Down the “worm” hole of a picture frame

By examining art printed from woodblocks spanning five centuries, Blair Hedges, a professor of biology at Penn State University, has identified the species responsible for making the ever-present wormholes in European printed art since the Renaissance. The hole-makers, two species of wood-boring beetles, are widely distributed today, but the “wormhole record,” as Hedges calls it, reveals a different pattern in the past, where the two species met along a zone across central Europe like a battle line of two armies.

The research, which is the first of its kind to use printed art as a “trace fossil” to precisely date species and to identify their locations, will be published in the journal Biology Letters on Nov. 21.

Hedges explained that most printed “wormholes” were formed in the carved woodblocks by adult insects and not by the worm-like larvae. After landing on a piece of dry wood, beetles lay their eggs in cracks and crevices. The larvae then spend three to four years burrowing inside the wood, nourishing themselves on the wood’s cellulose and growing until they enter the cocoon-like pupal stage when they transform into adults. The adult beetles then burrow straight up toward the surface of the wood, exiting to find a mate and to begin the life cycle anew. “The so-called ‘wormholes’ found in wood — including furniture, rafters, oak floors, and woodblocks that were used to print art in books — are not made by worms as the word suggests; rather, most are ‘exit holes’ made by those newly transformed adult beetles boring up to the surface and flying away,” Hedges said.

When these wormholes were present in an artist’s woodblock, they resulted in empty circles within the inked prints made from the woodblock. “These tiny errors or interruptions in the print serve as ‘trace fossils,’” Hedges said. “They aren’t the animals themselves but they are evidence of the animal’s existence. They show that beetles invaded a particular piece of wood, even if that wood no longer exists.” Hedges added that studying the prints, rather than the much rarer woodblocks themselves, provides better and more accurate information. A piece of wood can acquire new wormholes throughout the years, and it is difficult to know whether a particular hole was made 10 years ago or many centuries ago. Even a museum specimen that has been protected in recent years could have wormholes from beetles that landed on it just a few years prior to its arrival in the museum.

“By studying printed wormholes, we are seeing only the wormholes that were made at a specific moment in history,” Hedges said. “Because most prints, including those in books, have publication dates, we know that the wormholes in question were made very close to that date, or at least between that printing and the first printing. It’s an almost perfect biological timestamp. And in most cases, we also know where the book was printed. For example, if printed wormholes appear on a print made in Bamberg, Germany in 1462, then we know that the beetles that made the wormholes in the corresponding woodblock must have lived in or around that place at that time. So wormholes can tell us when and where a species existed with fairly good accuracy, more than 500 years ago, and that is amazing.”

Hedges measured the size of more than 3,000 printed wormholes in works of art and books spanning five centuries, from 1462 to 1899. He found that prints from northern Europe — including England, the Netherlands, Germany, and Sweden — had holes that were small and round, averaging 1.43 mm in width. However, woodcuts from southern Europe — including Spain, Portugal, most of France, and Italy — had larger holes averaging 2.30 mm in width, as well as some unique tracks, including long holes.

“The species that made the wormholes were identified by a process of elimination. For example, the size of the beetle closely matches the size of the hole made, and most species have preferences for the wood they eat. This left two species as the probable hole-makers,” Hedges said. “The northern European wormholes most likely were made by the Common Furniture Beetle, Anobium punctatum. The wormholes in southern Europe most likely were made by the Mediterranean Furniture Beetle, Oligomerus ptilinoides.” Hedges added that, by comparing the diameters of the wormholes found in art from many different regions of Europe, he was able to determine that the Common Furniture Beetle lived only in a geographic area extending northward from northern France, Switzerland, and Austria, while the Mediterranean Furniture Beetle lived only south of that dividing line. “This is surprising because it means that the two species’ ranges were in close contact but, oddly, did not overlap along a precise dividing line,” Hedges said. “However, today and for the past 100 years, because travel, shipping, and furniture transport tends to spread insects around, we find both species all over northern and southern Europe and elsewhere in the world.” Hedges suspects that the contact zone of the two species across Europe may have been maintained for centuries because of competition for the same food source. All of those details of the species’ distribution, including the contact zone, were previously unknown.

Hedges said that this method can be used to study different beetle species in other regions, such as eastern Europe, the Americas, and Asia, and the method even could be used to study earlier time periods. He also predicts that old DNA from the beetles might be recoverable from original woodblocks preserved in museums. “Woodblocks that have been long-preserved in museums have been protected from any recent beetle activity,” Hedges explained. “So one exciting possibility would be to examine those woodblocks for traces of DNA from the beetles that made the wormholes, adding a genetic dimension. This research could be done without damaging the rare woodblocks and it would help to confirm identities of the species and their relationships.”

Hedges added that his new method has relevance not just to biology, but also to art history. “There are some situations in which a book or print’s origin is unknown because a printing location was never added to the text,” Hedges said. “Now that we know that different species of beetles existed in different locations in Europe, art historians can determine whether a book was from northern or southern Europe simply by measuring the wormholes.”

Share this story on Facebook, Twitter, and Google:

Like Studying Stars that Have Blinked Out

On average, it takes 21 years from the time a new species is collected before scientists get around to describing it.  That delay can make a life-or-death difference in the middle of an extinction crisis.  Here’s a report from Carrie Arnold at Science Magazine:

High in the Himalayas in 2008, a tiny flash of yellow caught Paul Egan’s eye. The poppy intrigued the doctoral student in botany at Trinity College Dublin, as he was alreadyattempting to study the ecology of several species of Himalayan poppy. Egan extensively documented the bright yellow blooms that he found, tentatively concluding that this flower was a new species. However, he eventually figured out that other scientists had collected samples of the same flower starting in the 1960s but didn’t realize it was new. The samples sat on shelves for nearly 50 years, until Egan finally published the first formal description of Meconopsis autumnalis and the closely related M. manasluensis last year in the journal Phytotaxa.

Such a delay is not unusual, a study published today in Current Biology finds. On average, more than 2 decades pass between the first collection of samples of a new species and the publication of the species’ description in scientific literature. With species falling into extinction at record rates, many already-collected organisms may die out before they ever make it into scientific literature, researchers say.

Read more here.

Or take a look at the report from ScienceDaily:

Many of the world’s most unfamiliar species are just sitting around on museum shelves collecting dust. That’s according to a report in the November 20th issue of the Cell Press journal Current Biology showing that it takes more than 20 years on average before a species, newly collected, will be described.

It’s a measure the researchers refer to as the species’ “shelf life,” and that long shelf life means that any conservation attempts for unknown, threatened species could come much too late. The problem, the researchers say, is due to a lack of experts and of the funding and resources needed to do the job.

“Species new to science are almost never recognized as such in the field,” says Benoît Fontaine of Muséum National d’Histoire Naturelle in Paris. “Our study explains why it often happens that we describe species which were collected alive decades ago and which can be extinct now — just as astronomers study the light of stars which do not exist anymore.”

Part of the problem is that many species are rare and may be represented in collections by a single specimen. Taxonomists will usually wait until more specimens of any new species are available before they will describe it. In that sense, increased effort to seek out new species and specimens in the field would help to move things along in the world’s museums and herbaria, the researchers say.

Fontaine and his colleagues calculated shelf life based on a random sample of 600 species described in the year 2007. The data show that those species had a shelf life of 20.7 years on average, with a median of 12 years. Shelf life did vary according to biological, social, and geopolitical biases, they report. In fact, amateurs as a group describe new species more rapidly today than professionals do.

The findings come as yet another reminder of how much there still is to do when it comes to understanding and protecting the diversity of species on Earth.

“Our knowledge of biodiversity is still very scarce,” Fontaine says. “Describing new species is — or should be — part of the everyday work of taxonomists, and we need to hurry; new species are disappearing faster than we can describe them.”

Benoît Fontaine, Adrien Perrard, Philippe Bouchet. 21 years of shelf life between discovery and description of new species. Current Biology, 2012; 22 (22): R943 DOI: 10.1016/j.cub.2012.10.029

The Species Sideshow

Coconut octopus (Amphioctopus marginatus, described in 1964 by Taki), from the western Pacific. The common name is said to come from its habit of using coconut shell halves as hiding places.

Choose one: A riddle wrapped up in an enigma. Or: A hairy frog fish (Antennarius striatus, described in 1794 by British Museum naturalist George Shaw) from Indonesia (Photo: Gary Peart)

The Mathematics of Being Down a Blind Allee

African wild dogs in Botswana, photographed by Chris Johns for our 1999 National Geographic cover story

One of my failings as a writer is an almost total lack of formal science education.  Another is that anything mathematical gives me the willies.  So I was not previously aware of the Allee Threshold, the point at which a small population starts to decline more quickly than might have been expected, nor had I heard of Allee Effects.  And I should probably steer clear of a paper about the mathematics of Allee Effects.

But this paper has to do with one of favorite animals, the highly threatened African wild dog (Lycaon pictus).  I wrote about them in National Geographic in 1999, and again in my 2009 book Swimming With Piranhas at Feeding Time.  Last I heard, the wild dog population has actually increased over the past decade, because of intensive conservation efforts and the discovery of new populations.  So with that caveat, here’s the press release from ScienceDaily:

Disease, destruction of habitats, pollution, chemical and pesticide use, increased UV-B radiation, and even the presence of new species are some of the causes for disappearing species. “Allee effect,” the phenomenon by which a population’s growth declines at low densities, is another key reason for perishing populations, and is an overriding feature of a paper published last month in the SIAM Journal on Applied Mathematics.

Authors Avner Friedman and Abdul-Aziz Yakubu use mathematical modeling to analyze the impact of disease, animal migrations and Allee effects in maintaining biodiversity. Some Allee effect causes in smaller and less dense populations are challenges faced in finding mating partners, genetic inbreeding, and cooperative behaviors such as group feeding and defense. The Allee threshold in such a population is the population below which it is likely to go extinct, and above which persistence is possible. Declining populations that are known to exhibit Allee effects currently include the African wild dog and the Florida panther.

Author Abdul-Aziz Yakubu explains how disease can alter the behavior of populations that exhibit Allee effects. In infectious disease studies, the reproduction number or Ro is defined as the expected number of secondary infections arising from an initial infected individual during the latter’s infectious period. For regular populations, the disease disappears in the population if (and only if) the Ro is less than 1. “In the present paper, we deal with a population whose survival is precarious even when Ro is less than 1,” says Yakubu. “That is, independent of Ro, if the population size decreases below a certain level (the Allee index), then the individuals die faster than they reproduce.”

A previous study by the authors showed that even a healthy stable population that is subject to Allee effects would succumb to a small number of infected individuals within a single location or “patch,” causing the entire population to become extinct, since small perturbations can reduce population size or density to a level below or close to the Allee threshold.

Transmission of infectious diseases through a population is affected by local population dynamics as well as migration. Thus, when trying to understand the resilience of the ecosystem, the global survival of the species needs to be taken into account, that is, how does movement of animals between different locations affect survival when a disease affects one or more locations? Various infectious disease outbreaks, such as the West Nile virus, Phocine and distemper viruses have been seen to spread rapidly due to migrations.

In this study, the authors extend their previous research by using a multi-patch model to analyze Allee effects within the context of migration between patches. “We investigate the combined effect of a fatal disease, Allee effect and migration on different groups of the same species,” Yakubu says. In their conclusions, the host population is seen to become extinct whenever the initial host population density on each patch is lower than the smallest Allee threshold. When the initial host population has a high Allee threshold, the population persists on each patch if the disease transmission rates are small and the growth rate is large. Even in the case of high Allee thresholds, the host population goes extinct if the disease transmission rate is high, and growth rate and disease threshold are small. The presence of a strong Allee effect adds the possibility of population extinction even as the disease disappears.

The research can be applied to various kinds of populations for conservation studies. “Our models and results are very general and may be applied to several declining populations,” says Yakubu. “For example, the African wild dog, an endangered species, is vulnerable to fatal diseases like rabies, distemper and anthrax. Our models can be used to investigate how the Allee threshold of one subpopulation of an African wild dog pack at a geographical location is influenced by the collective migrations of several wild dog populations from different packs with different Allee thresholds.”

The authors’ mathematical models and rigorous analysis can be extended with the help of field data. “Future work will need to get specific field data in order to refine the model and use it to design conservation strategies for preservation of these somewhat endangered and declining populations,”says Yakubu.

SOURCE:  Avner Friedman, Abdul-Aziz Yakubu. Host Demographic Allee Effect, Fatal Disease, and Migration: Persistence or Extinction. SIAM Journal on Applied Mathematics, 2012; 72 (5): 1644 DOI: 10.1137/120861382

Our Undiscovered Earth

Out of its depths

I’m still playing catch up in the aftermath of Hurricane Sandy (no damage but no power at home), and a reporting trip to the Centers for Disease Control and Prevention.  This item by Michael McCarthy in The Independent caught my eye, about finding a whale no one had ever seen before, and what that suggests about how much we still need to learn about life on Earth:

We all know the baleen whales, which have baleen plates, or giant filters in their mouths to trap plankton, because these 15 or so species include the world’s biggest animals, such as the blue whale and the humpback, and around British coasts, the minke whale. And we all know the toothed whales, because this group of 50-plus species includes all the dolphins and porpoises, and other very familiar creatures such as the sperm whale – Moby Dick in Melville’s epic – and the orca or killer whale, and the white whale, the beluga.

But the beaked whales are largely a mystery, to zoologists as well as to general wildlife enthusiasts. Cuvier’s beaked whale, Gervais’ beaked whale, Blainville’s beaked whale, Sowerby’s beaked whale – ever heard of any of them? Top of the class if you have. This group of about 20 species is undoubtedly the least-known of all marine mammals, and very likely the least known large mammals on earth, because they spend much of their time at tremendous depths in the ocean, feeding on squid, and are rarely encountered on the surface.

I have always been fascinated by them, so I was even more fascinated to learn that the rarest of them all has just been seen and described for the first time. This is the spade-toothed whale, Mesoplodon traversii, known for more than a century only from a partial jawbone found in New Zealand, and two subsequent skulls. But two years ago, a cow and a calf were stranded in New Zealand’s Bay of Plenty. They were originally identified as examples of Gray’s beaked whale; yet subsequent DNA analysis showed that mother and infant were indeed spade-toothed whales, the first complete specimens ever seen. (The finding is reported in the latest edition of the journal Current Biology.)

This is a discovery up there with the finding of the okapi in Central Africa in 1901, or with the discovery of the saola, or Vu Quang ox, in Vietnam in 1992. Those two large, hitherto unknown beasts came from the world’s deepest and most impenetrable jungles. But the deep ocean is infinitely larger than the rainforest, and even more impenetrable, who knows but there may still be great beasts left to discover?

Here’s to the spade-toothed whale. It is heartening to realise that even now, when much of the earth can be mapped on your mobile phone, some of the mystery still remains.

Looking at the American Landscape

Wisconsin road by Gregory Conniff

I am about to run away from Hurricane Sandy and not sure when I will be able to post next.  But I’d like to put in a plug for my brother Greg Conniff’s photography show at a gallery in Madison, Wisconsin.  His photographs are about the American landscape, and how we have altered it, and they are worth savoring.  The show runs until December 23.  He’ll also be posting daily on his Tumblr blog.