What can you do to bring some of the Smithsonian’s 137 million objects to life? Put them in 3-D!

This is a full-time job for two of the Smithsonian’s very own “laser cowboys,” Vince Rossi and Adam Metallo, who work in the Smithsonian’s 3D Digitization Program Office. They work hard to document, in very high three-dimensional detail, many of the institution’s many priceless and important collections so that the objects are available for research, education and general interest.

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Rope, golf balls, sweat pants, bottles and aluminum cans are a few of the discarded items biologist Matt Klope says he has found inside the stomachs of the dead whales he has helped necropsy over the years in and around Puget Sound, Washington. A necropsy is a common procedure done to determine an animal’s cause of death and take blood, skin, blubber and organ samples.

Laid out on the floor of the Marine Mammal Collection building at the Garber Facility in Suitland, Md., the recently acquired skeleton of a gray whale is a much welcome addition. The large skull at left is from a fin whale stranded at Cape Hatteras. Standing from left are Maya Yamato, Museum Specialist John Ososky, Charlie Potter and Marine Mammal Curator James Meade. (Photo by Don Hurlbert)

“They all have plastic in their stomachs, every one of them,” Klope says of California gray whales in particular. “Gray whales are bottom feeders. They don’t feed in the mid-water column but take bites out of the ocean floor and then filter it. So anything that’s on the floor they eat, and that includes a lot of plastic.”

Despite this, gray whales have made a remarkable comeback in California, says Klope, a member of the Central Puget Sound Marine Mammal Stranding Network. “They were endangered years ago but today gray whales are plentiful. They are everywhere up and down the West Coast. We get many reports of dead ones.” So Klope was shocked, he says, when he learned the Smithsonian’s National Museum of Natural History in Washington, D.C., did not have a California gray whale skeleton in its research collection.

A team of volunteers prepares to salvage the skeleton of a gray whale on Whidbey Island in April 2012. (Photo by M.J. Adams)

“One of our goals for many, many years has been to acquire the complete skeleton of a California gray whale,” says Charles Potter, Collection Manager of the Natural History’s Marine Mammal collection. “The problem has always been, of course, getting a massive whale shipped here from the West Coast either unprepared, which would mean we’d have to freeze it, or as a clean skeleton.”

Klope, who is also manager of the Bird Strike Prevention Program for aircraft at the Whidbey Island Naval Air Station, has been shipping bird specimens to Carla Dove in the Natural History Museum’s Ornithology Department for many years. He was sensitive to the museum’s need for research specimens, no matter how large they may be. “I’ll take care of it,” he told Potter.

Volunteers make the first cut through the blubber of the whale. (Photo by M.J. Adams)

So when a 38-foot long 30-ton gray whale was spotted floating near Camano Island State Park, in Puget Sound, in April 2012, Klope and what he calls his “army of volunteers” were ready. First he arranged to have the whale towed ashore at Whidbey Island Naval Air Station. He also alerted Potter who flew out with Smithsonian Buck Post-Doctoral Fellow Maya Yamato to help dissect the whale and salvage its bones.

“It was a young adult male about 7 to 8 years old and 38 feet long,” Potter recalls. “We spent the better part of a week working up this whale and collecting its skeleton with an amazing group of volunteers from the Puget Sound Marine Mammal Stranding Network. We got a huge response from local volunteers. Every bit of that whale was taken off the beach by hand.”

Charlie Potter, left, and Matt Klope examine the spinal column of a gray whale during the salvaging of its skeleton on Whidbey Island, Wash. (Photo by M.J. Adams)

Next the bones were lashed to plastic pallets and placed into open-top plastic drums then submerged back into the ocean at the Naval Air Station for a number of months. This allowed fish, crabs and other sea creatures to feast on the excess bits of meat and connective tissue still attached to the bones.

Later the bones were recovered, dried, and barnacles removed by hand.  Next, members of the Fleet Logistics Center Puget Sound Naval Air Station Whidbey Island volunteered on weekends to carefully wrap each bone in shipping paper and secure them in wooden shipping crates.

Volunteers clean barnacles from the gray whale’s bones after the bones had been submerged in the ocean for a number of months. (Photo by M.J. Adams)

Finally, Klope arranged for the free transport of the bones aboard a C-130 on a Military Training Logistics Flight from Whidbey Island to Andrews Air Force Base in Md., were staff from the Museum Support Center were able to pick them up and drive them to their new home in a museum collections building in Suitland, Md.

“I think Charley was a little afraid the bones were still going to be a little smelly and oozing when they got to him,” Klope says. “But they would never accept anything like that aboard a military flight, so the bones were well cleaned and shelf ready when he got them.”

What killed this particular gray whale is undetermined.

Examination of its skeleton back at the Smithsonian by Potter revealed the whale had a broken thoracic vertebra and two of its cervical vertebra were damaged. “It got a good whomp, probably from a ship strike or something,” Potter says. Bone tissue growth at the site of the breaks show the whale survived this injury however.

Charlie Potter and Maya Yamato examine a section of the gray whale’s spinal column at the Smithsonian’s marine mammal storage building in Suitland, Md. (Photo by John Barrat)

Klope believes the whale may have starved to death as it was thin. Its stomach contained shrimp and crab, sea grass and bark chips, bits of plastic, string, rope, fabric and other items.

“From the research side of things this is a really important acquisition and a major addition to our collection,” Potter says. “The Marine Mammal Stranding Network volunteers in Washington were amazing, as was the can-do attitude of the folks at the Naval Air Station. With their help we finally got this done after many years.”

In the meantime Klope is awaiting a call from his stranding network for sightings of other expired gray whales. His plans are to acquire a second skeleton for the Smithsonian. “What they’ve got is a young male,” he says. “They now need an adult female.” –by John Barrat

Miniature camels and horses, a rhinoceros and a giant bear-dog are among fossils unearthed in the recent excavations of the Panama Canal expansion project. These findings shed light on events millions of years ago that altered the Earth’s climate and dramatically changed the geographic distribution of plants and animals.

Juvenile dentition of Arretotherium merdionale, a hippo-like animal, from the Las Cascadas Formation, Panama Canal area. (Photo courtesy Florida Museum of Natural History)

On Friday, 26 Apr., scientists from the Smithsonian in Panama including Carlos Jaramillo, staff scientist and Bruce McFadden, visiting scientist and curator of vertebrate paleontology at the University of Florida, and officials from the Panama Canal Authority including Engineer Ilya Marotta, Vice President of Engineering and Administration of Programs, gathered to celebrate the major accomplishments of an initial 5-year partnership that resulted in:

• Ten new species described based on fossil finds
• More than 6,000 samples collected and georeferenced
• New estimates for the timing of the tectonic and volcanic events that contributed to the formation of the land-bridge
• 50 scientific publications
• An international symposium at the Annual Meeting of the Geological Society of America, 2012
• Presentations at many other international scientific meetings
• News reports in Panama and in major international media outlets
  

  University of Florida doctoral student Aldo Rincon holds the lower jaw of Aguascalietia panamaensis, a newly described species of ancient camel. The 20-million-year-old specimen was recovered from the Las Cascadas formation in Panama. (Photo by Jeff Gage, University of Florida)

“This is a win-win situation for both institutions and for the people of Panama,” said Elena Lombardo, from the Institute’s Office of External Affairs. “Just as the Panama Canal contributes to the world as a vital waterway for commerce, ongoing research in Panama contributes to the world’s understanding of geological history and the evolution of the plant and animal diversity in the American tropics.”

One of the most important results was the project’s contribution to training the next generation of scientists. The international division of the U.S. National Science Foundation granted an additional $4 million to researchers from the Smithsonian and the University of Florida to continue the project.

Following blasting to expand the Panama Canal, geologists and paleontologists organized by the Smithsonian Tropical Research Institute rush in to map, describe and recover any fossils they can find that might reveal more about the prehistoric ecology of Panama.

“These two projects, along with support from Panama’s national office of science and technology, SENACYT, have led to undergraduate and graduate-level training for students here and in the U.S.,” said Oris Sanjur, STRI’s Associate Director for Science Administration. “Panamanian doctoral student Catalina Pimiento organized the first paleobiology video telecourse for Panamanian students. The project also led to the first major in geology at the University of Panama, the first geology class at the Universidad Tecnológica de Panamá and major collaborations with the Universidad Nacional de Chiriquí, in western Panama.”

When the Panama Canal was built, enough rock was removed to bury Manhattan under 12 feet of rubble: 200 million cubic meters of earth. Now the slender waterway connecting the Pacific and the Caribbean is being widened to let through more and bigger ships, moving another 152 million cubic meters. This created the opportunity of a lifetime for geologists and paleontologists to understand Earth-changing events.

This fossil from a three-toed browsing horse, Anchitherium clarencei, found in the Panama Canal earthworks, is now in the collection of the University of Florida. (Photo courtesy Aldo Rincon)

More than 100 years ago, the scientific collaboration between Panama and the Smithsonian began when scientists conducted the Panama Biological Survey, basically an environmental impact statement for the construction of the Canal. From a storehouse full of fossil samples still to be processed and geological data to be analyzed, expect announcements of new findings about Panama’s unique geological and biological history for many years to come.

Covered in venomous spines the exotic and strikingly banded Indo-Pacific lionfish would be a painful mouthful to any creature that may try to catch and eat it. Brought into the United States by aquarium hobbyists untold years ago, scientists believe a few of these fish were discarded live into the Atlantic off southern Florida sometime around the late 1980s. Now this voracious species is found as far north as Virginia and south to Venezuela. They are spreading still.

At the Smithsonian’s Tropical Research Institute in Panama, Andrew Sellers is turning this invasion into opportunity by examining just what Atlantic parasites are adopting the lionfish as a host.

Andrew Sellers captures a large lionfish in Belize to take back to his laboratory for study.
(Photo by Edgardo Ochoa, dive officer at the Smithsonian Tropical Research Institute)

“Basically, I’m looking at how parasite abundance and diversity in the lionfish varies across latitudes,” Sellers explains.  “It has been suggested that invasive species don’t do as well in the tropics as they do in temperate areas, the theory being that stronger biotic interactions—competition for food, predators and parasitism—in the tropics may limit the success of an invasive species.

“As lionfish have spread so rapidly across such a broad lattudinal gradient, they make a very good model” says Sellers, who works in the Tropical Research Institute’s invasive species lab run by marine biologist Mark Torchin.

In addition to Panama, Sellers has traveled to Florida, Mexico and Belize catching lionfish and closely examining them to see what parasites are living on and inside their bodies. “For external parasites we’ve found—isopods and turbellaria, a flatworm that infects the gills. We have found that external parasites infecting the lionfish are more diverse at low latitudes,” he says.”

“Inside the fish we’ve found both trematodes [worms also known as flukes] and nematodes.”

Tropical Research Institute scientist Mark Torchin, left, and Andrew Sellers place a lionfish specimen in a special collecting bag which prevents the divers from being stung by the animals. This photo was taken in Belize.
(Photo by Edgardo Ochoa, Dive Officer at the Smithsonian Tropical Research Institute)

In his analysis Sellers examines and records the condition of each individual fish—size, weight, length—to see if the parasites are having any impact on their health.

“Overall, we are finding the abundance of parasites on the lionfish is pretty low, which is what we’d expect in an invasive species,” Sellers continues.

A lionfish in Bocas del Toro (Photo by Andrew Sellers)

Sellers also has begun looking into lionfish interactions with cleaner fish in the Caribbean. These small fish set up cleaning stations on brain coral heads where other fish—called client fish—congregate to have parasites removed from their bodies.

“What I am looking at is whether potential native competitors to lionfish are receiving a benefit from these cleaner fish that lionfish are not, i.e. parasite removal,” Sellers explains. “In general introduced species are believed to harbor fewer parasites than natives, however these cleaners may be affecting this imbalance by removing parasites from the native but not the invader.”

Female lionfish reproduce by laying a buoyant egg mass that is fertilized by a male, Sellers explains. The egg mass is then carried off into the ocean currents—a very effective method of dispersal. By 2005 people began seeing lionfish in the Bahamas. “We started seeing them in Panama about 2008, 2009,” Sellers says. “Now divers can find them everywhere along the coast from 0 to 300 feet down.” Cold water intolerance has limited their spread north along the coast of the United States to just below New York.

“Basically it appears the Atlantic coast of Central and South America is a pretty good place for these fish,” Sellers says. “It appears they have plenty of food, no enemies and few parasites.” –John Barrat

Recent spectroscopic analysis of macaroni penguin (Eudyptes chrysolophus) crest feathers and king penguin (Aptenodytes patagonicus) neck feathers have shown they contain a yellow pigment that is chemically distinct from all other molecules known to give color to feathers. “Penguins use the yellow pigment to attract mates and we strongly suspect that the yellow molecule is synthesized internally,” explains Daniel Thomas, a fellow at the Smithsonian’s National Museum of Natural History, and lead author of the study recently published in Journal of the Royal Society Interface.

The vibrant yellow pigments found in the crest feathers of the macaroni penguin are chemically distinct from the five known classes of avian plumage pigments. This feather is in the collection of the Smithsonian’s National Museum of Natural History. (Photo by Daniel Thomas)

Using Raman spectroscopy Thomas and colleagues identified part of the molecular structure of this new pigment and hope to completely describe it in the near future. “At its very essence” explains Thomas, “Raman spectroscopy is a study of the way light and matter interact, and very specific interactions tell us about the chemistry of a sample.” The penguin pigment “is distinct from any of the five known classes of avian plumage pigmentation and represents a new sixth class of feather pigment,” Thomas says. “As far as we are aware, the molecule is unlike any of the yellow pigments found in a penguin’s diet.”

In birds, most yellow, red and orange plumage colors are easily linked to diet, Thomas explains. “Canaries are yellow because they eat seeds, fruits and insects that contain yellow carotenoid pigments. Canaries that eat a carotenoid-free diet have white feathers.”

Macaroni penguins, Hannah Point, Livingston Island, Antarctic Peninsula (Photo by Jerzy Strzelecki)

Parrots however are an exception. The red, orange and yellow pigments in the feathers of parrots, are synthesized internally and are not dependent on diet, Thomas says. Penguins can now be added to the list with parrots of birds that internally synthesize yellow feather pigments.

Although the yellow penguin pigment has only recently been discovered to have unique properties, it is by no means new, Thomas points out. “Very likely it has been made by penguins for more than 13 million years, and was possibly displayed by the extinct South American penguin Madrynornis mirandus”.

Co-authors of the paper “Vibrational spectroscopic analysis of unique yellow feather pigments in penguins,” with Thomas, include Helen James of the Smithsonian’s National Museum of Natural History, Odile Madden of the Smithsonian Museum Conservation Institute; Cushla McGoverin of Temple University; and Kevin McGraw of Arizona State University. –John Barrat

Click here for 14 Fun Facts about Penguins!

All bear species except for one live in either temperate or tropical woodlands. Only the polar bear is a stranger to the forest, living and foraging instead across vast expanses of barren polar ice. But don’t be deceived, its habitat is not thin and flat like a skating rink but a thick and complex mix of old multi-year ice, new seasonal ice and open water. Polar bears hunt seals in this environment and live and breed on top of their frozen habitat. Recently, warming temperatures have had an enormous impact on the domain of this remarkable mammal.

Here, bear expert Don Moore, associate director of Animal Care Sciences at the Smithsonian’s National Zoological Park, answers a few questions about polar bears, rising temperatures and the future for Smithsonianscience.org.

A polar bear on an ice floe in Wagner Bay, Canada (Photo by Ansgar Walk)

Q: How many polar bears are found in the wild today?

Moore: Polar scientists estimate there are 20,000 to 25,000 polar bears in the five polar bear countries—the United States/Alaska, Canada, Russia, Denmark/Greenland and Norway.

Q: How much ice does one polar bear require?

Moore: Polar bears range over hundreds and even thousands of miles. They come ashore only when their ice melts in summer, in the Western Hudson Bay for instance.

Q: Can you compare the amount of ice sheets in their ecosystem 10 years ago to now? 

Moore: Ten years ago the Arctic Ocean was land-fast with a lot of year-round ice. Recent summer ice losses have been enormous, and in 2012 summer ice losses in the Arctic were larger than the area of the United States. Since Arctic ice is the polar bear’s habitat, bear populations are declining as the ice declines.

Q: Has the polar bear population decreased significantly since you started to study them?

A polar bear on the Islands of Svalbard, the Netherlands. (Photo by Paul W.J. Groot)

Moore: More populations are declining now than before. For example, the Western Hudson Bay population in Churchill, Manitoba in Canada has declined by more than 20 percent in the last 30 years.

Q: When the polar bears’ habitat melts, how do they adapt? Do they use more land to migrate and hunt? What impact does that have on other land animals?

Moore: Polar bears whose habitat melts seasonally must move onto land. But it has been hundreds of thousands of years since polar bears evolved from brown bears. Polar bears are built for eating seals, and cannot live a healthy life for long periods of time eating rodents and plants that brown bears eat. Some have adapted by eating harbor seals or beluga whales, but this behavior will be short-term.

Q: How have changes in the polar bears’ habitat changed the way you conduct your research?

Moore: The Arctic is a forbidding place, and very dangerous to travel in during the 6 months of darkness when winter sets in. Most of my biologist friends take helicopters from land bases to the ice offshore where polar bears live in spring and fall. These times of year can be very stormy, and as the ice has melted it has gotten farther away from shore. Biologists take huge risks flying hundreds of miles by helicopter to the nearest ice. Many researchers have cancelled research trips in recent years so they don’t endanger their study teams.

Q: For most of us, the problems of the polar bear are remote and far away. How do our actions impact these animals hundreds of miles away?

Moore: To help slow climate change we need to change our behavior and put less carbon into the atmosphere. Carbon comes from factories, cars, and other polluting, man-made objects on the planet. If we reduce, recycle and reuse we can reduce the amount of gas going into the atmosphere. Every single person can make a difference and help conserve the planet’s resources.

–Emily Grebenstein

Marmosets on track for obesity appeared to be more efficient in their feeding behavior. “Although all animals consumed the same amount of liquid, the ones taking in more on each lick were the ones that later became obese,” said Corinna Ross, lead author of one of two new research articles published in the journal Obesity.

This early life obesity also resulted in metabolic damage such as insulin resistance and poor blood sugar control, a companion study, lead by Michael Power of the Smithsonian Conservation Biology Institute, showed.

An obese marmoset. (Photos taken at the Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, by Lester Rosebrock)

“For marmosets that are getting fat at a fairly early age, their pancreases basically have to work extra hard putting out higher levels of insulin to achieve normal levels of stability in glucose in the blood,” Power explains.“By the time they are one year old they are showing great signs of insulin resistance.”

The studies were conducted at the Southwest National Primate Research Center in San Antonio.

In previous research, Power and Suzette Tardif, associate professor of cellular and structural biology in the School of Medicine, found that obesity patterns begin just 30 days after birth in the marmosets. A 30-day-old marmoset infant is the equivalent of a 5- to 8-month-old human infant. At 6 months of age, a marmoset is as old as a juvenile child before puberty. At a year old, the small non-human primate is the equivalent in age of a human adolescent.

Animals that eventually became obese, Power says, as infants appeared to be slightly more developmentally advanced. “They have several developmental behaviors that seem to occur at a slightly earlier age: they seem to be a little more independent, they are trying to get solid food on their own and they are off [not being held by] a father, brother or sister [normal among marmoset infants] earlier. They basically seem to be going through each stage of life three, four, five days earlier than the infants that end up being a normal size.”

A lean marmoset.

Marmosets have significantly less body fat than humans, but in the marmoset it takes considerably less fat to generate metabolic dysfunction.  Animals that are going to be normal weight gain lean mass, such as muscle, at a faster rate than they gain body fat. “That’s true for human children, as well,” Tardif says. But marmosets that became obese gained both fat mass and lean mass faster than their normal-weight counterparts. This meant that the obese animals’ percentage of body fat grew during infancy and adolescence.

Being obese requires a lot more work for the pancreas, which has to produce a lot more insulin to maintain homeostasis, Power explains. “To a certain extent any mammal that lives long enough will become diabetic, because eventually their pancreas is going to give out.  Marmosets usually become diabetic at 11, 12, 13 years of age. Obese marmosets, we predict, will become diabetic at five, six or seven years of age, because their pancreases must work extra hard, continually running at a high rate. It becomes old earlier relative to the rest of the body.”

Obesity is a condition that is never seen among wild marmosets, Power says. “Even in the best season with plenty of food there is too much activity going on,” for wild animals to get obese.

And rising obesity is a strange thing happening in our captive colonies, Power continues. “In the 1990s we started a colony that eventually became the one we are studying now, and we had nothing but lean animals then. And they were on the same diets as they are today. Now it’s almost like a ceiling has been removed. Now we’re seeing fat animals where before it was very rare to see a fat animal. Now it’s becoming more common. Obesity is creeping in and it is not very clear where this change has come from.”

Overall, “the marmoset serves as a good model for looking at what happens in human beings,” Power says. “It’s a little surprising however, as to how rapidly obesity is occurring and how significant those changes were.”

Africa isn’t the kind of place you might expect to find penguins. But one species lives along Africa’s southern coast today, and newly found fossils confirm that as many as four penguin species coexisted on the continent in the past. Exactly why African penguin diversity plummeted to the one species that lives there today is still a mystery, but changing sea levels may be to blame, the researchers say.

Only one penguin species lives in Africa today — the endangered black-footed penguin, or Spheniscus demersus. But newly found fossils confirm that as many as four penguin species coexisted on the continent in the past. (Harvey Barrison photo)

The fossil findings, described in a recent issue of the Zoological Journal of the Linnean Society, represent the oldest evidence of these iconic tuxedo-clad seabirds in Africa, predating previously described fossils by 5 to 7 million years.

Co-authors Daniel Thomas of the Smithsonian’s National Museum of Natural History and Dan Ksepka of the National Evolutionary Synthesis Center happened upon the 10-12 million year old specimens in late 2010, while sifting through rock and sediment excavated from an industrial steel plant near Cape Town, South Africa.

Jumbled together with shark teeth and other fossils were 17 bone fragments that the researchers recognized as pieces of backbones, breastbones, wings and legs from several extinct species of penguins.

Based on their bones, these species spanned nearly the full size spectrum for penguins living today, ranging from a runty pint-sized penguin that stood just about a foot tall (0.3 m), to a towering species closer to three feet (0.9 m).

Only one penguin species lives in Africa today—the black-footed penguin, or Spheniscus demersus, also known as the jackass penguin for its loud donkey-like braying call. Exactly when penguin diversity in Africa started to plummet, and why, is still unclear.

Only one penguin species lives in Africa today — the endangered black-footed penguin. (Photos by Daniel Thomas)

Gaps in the fossil record make it difficult to determine whether the extinctions were sudden or gradual. “[Because we have fossils from only two time periods,] it’s like seeing two frames of a movie,” said co-author Daniel Ksepka. “We have a frame at five million years ago, and a frame at 10-12 million years ago, but there’s missing footage in between.”

Humans probably aren’t to blame, the researchers say, because by the time early modern humans arrived in South Africa, all but one of the continent’s penguins had already died out.

A more likely possibility is that rising and falling sea levels did them in by wiping out safe nesting sites.

Although penguins spend most of their lives swimming in the ocean, they rely on offshore islands near the coast to build their nests and raise their young. Land surface reconstructions suggest that five million years ago — when at least four penguin species still called Africa home — sea level on the South African coast was as much as 90 meters higher than it is today, swamping low-lying areas and turning the region into a network of islands. More islands meant more beaches where penguins could breed while staying safe from mainland predators.

But sea levels in the region are lower today. Once-isolated islands have been reconnected to the continent by newly exposed land bridges, which may have wiped out beach nesting sites and provided access to predators.

Although humans didn’t do previous penguins in Africa in, we’ll play a key role in shaping the fate of the one species that remains, the researchers add.

Numbers of black-footed penguins have declined by 80% in the last 50 years, and in 2010 the species was classified as endangered. The drop is largely due to oil spills and overfishing of sardines and anchovies — the black-footed penguin’s favorite food.

“There’s only one species left today, and it’s up to us to keep it safe,” Thomas said.–Source: National Evolutionary Synthesis Center/ Robin Ann Smith

Among vertebrates few animals rival poison dart frogs for their vibrant electric blue, yellow, red and orange skin colors. Some experts have long believed these pigments serve as a visual warning for hungry birds, snakes and other animals to steer clear from the frog’s deadly skin toxins. Now, new research by Paul Weldon, a chemical ecologist at the Smithsonian Conservation Biology Institute, has thrown this long-standing assumption into doubt. In a recent study Weldon and his colleagues have discovered a number of poisonous alkaloids (naturally occurring chemical compounds) on the skin of dendrobatid (poison dart) frogs that are better suited for defense against ants and other biting forest arthropods, than vertebrates.

Paul Weldon

Here Weldon answers a few questions about the study, recently published in the journal Naturwissenschaften, for Smithsonianscience.org.

Q. How many alkaloids do poison dart frogs have on their skin and how many have you tested?

Weldon: Some 500 alkaloids representing 20 different structural classes of chemicals have been identified on the skin of these frogs. We’ve tested 20 and in the process stumbled on some so potent to ants, that, in my view, it is clear they are designed to defend against arthropods, not vertebrates.

Think about it, frogs probably encounter a couple of vertebrates every few days but they come into contact with ants and millipedes and many other potentially offending arthropods all the time. What we’ve shown in this paper is that the consumers these frogs typically encounter are stopped quite effectively by a few of these alkaloids.

Q. Certainly others have studied these compounds before you?

Weldon: Yes. Few vertebrates have been studied as intensely as the dendrobatid frogs for their chemical defenses. Yet no one, and I mean literally no one, has focused on arthropods as the offenders of these frogs. People have entered into the study with the foregone conclusion that their alkaloid toxins work against vertebrates.

Blue Poison Dart Frog, Dendrobates azureus. (Photo by Jessie Cohen)

It turns out that some of these compounds clearly seem customized to go through the cuticle (thick waxy coating) of an ant, which in and of itself is a task, and to target the neurochemistry of the ant once inside. An ant is covered with wax, the cuticle is really a chitin, a polymeric sugar, a polysaccharide that it has all over it, a waxy covering that prevents the loss of water. So any compound that goes through the cuticle has to go through a layer of wax and then has to go through a layer of polymeric sugar. There aren’t too many compounds with properties that allow them to penetrate those two kinds of layers.

Q. Do the frogs create the toxic alkaloids found on their skin?

Weldon: No, the frogs ingest ants, millipedes, mites and other leaf-litter arthropods that have these compounds naturally occurring in their skin. These smaller creatures biosynthesize the toxic compounds from things they eat on the forest floor, such as decaying plant material. The frogs eat them and the compounds are then transferred into the frog’s skin glands where they are stored and secreted.

Head view of a red imported fire ant, Solenopsis invicta, showing its cuticle or waxy coating . Source AntWeb.org

Frog skin chemistry ultimately reflects to one degree or another, what particular prey they have taken. You can find geographic variation in the skin chemicals of these frogs based upon what the available arthropods are in the different locales. Poison dart frogs raised in captivity and fed upon fruit flies don’t have skin chemicals that protect them.

Q. How do the toxins get from the frogs’ stomachs to their skin?

Weldon: We know very little about how these frogs transfer alkaloids from their food to their skin glands. It probably goes through the intestinal lining or it might have something to do with bile acids facilitating the transport of the compounds into the body—but that is pure speculation. Apparently they can get a lifetime supply of skin compounds from just one afternoon’s feeding of ants.

Q: Where do you get these compounds for your experiments?

The Ecuadorian poison dart frog, Epipedobates anthonyi

Weldon: From the National Institutes of Health. Years ago NIH scientist John Daly traveled to the tropics and isolated these compounds from the skin of dendrobatid frogs. While we know what the compounds are, we need more accurate information on their abundances and concentrations on the frogs’ skin.

We tested the ambulatory responses of individual fire ants after contact with a very small amount of the dried residue of these alkaloids. Thirteen compounds had contact toxicities, seven had none. We tested the compounds in a very fine-tuned way by serially diluting the solutions and showing that some of them work in very, very vanishingly small concentrations. The dilutions of some of the compounds went down amazingly low, representing a huge amount of work. This paper was about six years in the making.

Q. Seven of the compounds had no toxicity?

Weldon: That is correct. To call all of these compounds ‘toxins’ is misleading. Nontoxic skin compounds may have other uses such as making the frogs taste bad or they may be antibiotic in their mode of action. They also could just be something the ants ingested and that appears on their skin.

There are so many compounds on the skin of these frogs that I think one must actually enter into the study of them expecting beforehand that different organisms will be affected by different compounds. And we’ve just shown from our very brief survey of 20 compounds that a few act very well as anti-arthropod toxins.

Q. One might assume that your interest in these compounds is in developing some type of insecticide?

Weldon: When you say insecticides that implies potential industrial use, it implies technology transfer, and it implies maybe even patents. I don’t get involved in any of that. I’ve been very fortunate because people, who I’ve identified as collaborators at the U.S. Department of Agriculture, support my work. But it’s not with the standard expectation that this discovery will ultimately end up in a patentable product. I particularly argue against that. I can’t do work with any animal extracts if that is the understanding.

The limosa harlequin frog (Atelopus limosus), an endangered species native to Panama, now has a new lease on life. The Panama Amphibian Rescue and Conservation Project is successfully breeding the chevron-patterned form of the species in captivity for the first time. The rescue project is raising nine healthy frogs from one mating pair and hundreds of tadpoles from another pair.

“These frogs represent the last hope for their species,” said Brian Gratwicke, international coordinator for the project and a research biologist at the Smithsonian Conservation Biology Institute, one of six project partners. “This new generation is hugely inspiring to us as we work to conserve and care for this species and others.”

A limosa harlequin frog (Atelopus limosus) on a U.S. quarter. (Photo by Brian Gratwicke)

Nearly one-third of the world’s amphibian species are at risk of extinction. The rescue project aims to save priority species of frogs in Panama, one of the world’s last strongholds for amphibian biodiversity. While the global amphibian crisis is the result of habitat loss, climate change and pollution, a fungal disease, chytridiomycosis, is likely responsible for as many as 94 of 120 frog species disappearing since 1980.

Between its facilities at the Smithsonian Tropical Research Institute in Gamboa, Panama, and the El Valle Amphibian Conservation Center in El Valle, Panama, the rescue project currently cares for 55 adult limosa harlequin frogs of the chevron-patterned form and 10 of the plain-color form. The project has had limited success breeding the plain-color form of this species, and has successfully bred other challenging endangered species, including crowned treefrogs (Anotheca spinosa), horned marsupial frogs (Gastrotheca cornuta) and toad mountain harlequin frogs (A. certus).

Each species requires its own unique husbandry to thrive and breed. The project’s animal care team and scientists learn husbandry techniques as they work with a limited number of individuals. Jorge Guerrel, conservation biologist at the Smithsonian Tropical Research Institute, arranged rocks in the breeding tank to create the submerged caves that appear to be the preferred egg-deposition sites for limosa harlequin frogs. Like other Atelopus species, tadpoles require highly oxygenated, gently flowing water between 22 and 24 degrees Celsius. The tadpoles’ natural food is algal film growing on submerged rocks, which Guerrel and his colleagues re-created by painting petri dishes with a solution of powdered spirulina algae, then allowing it to dry.

The mission of the Panama Amphibian Rescue and Conservation Project is to rescue amphibian species that are in extreme danger of extinction throughout Panama. The project’s efforts and expertise are focused on establishing assurance colonies and developing methodologies to reduce the impact of the amphibian chytrid fungus so that one day captive amphibians may be reintroduced to the wild. Current project partners include Cheyenne Mountain Zoo, Houston Zoo, Smithsonian’s National Zoological Park, Smithsonian Tropical Research Institute and Zoo New England.

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Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute

According to legend St. Patrick (circa 387–460 or 492 AD) banished all snakes from Ireland, chasing them into the sea after they attacked him during a 40-day fast atop a hill.

Today we suspect that snakes never lived in Ireland, likely because Ireland is an island surrounded by a frigid ocean inhospitable to these creatures. Still, banishing or removing snakes from any environment is a bad idea, says James Murphy, curator in the Reptile House at the Smithsonian’s National Zoo. His office is surrounded by a wide variety of different snake species.

Emerald tree boa at the National Zoo (Photo by Jessie Cohen)

Being carnivorous, some snakes keep down populations of certain animals such as rodents so they are beneficial to farmers, Murphy says. In addition, rodents can carry diseases to which humans can be susceptible. Snakes also are eaten by other animals, providing food. Snake venom has been shown to have medicinal qualities that have helped in the development of certain medicines. Snakes are an integral part of many ecosystems and, “from a personal perspective, they are just plain fascinating,” Murphy says. “The more I learn about them the more interesting they become. They always surprise me.”

As far as attacking St. Patrick, “snakes basically survive by avoiding conflict, not attacking. Many of them are secretive and generally not aggressive toward humans,” Murphy explains. “I’ve collected snakes literally throughout the world all my life and the only snake that I can say was actually aggressive toward me was a nonvenomous black snake when I was in high school,” the 73-year old herpetologist says. “A male was courting a female and he probably just wanted me away from there.”

Sinaloan milk snake is native to Sonora, Sinaloa and into southwestern Chihuahua, Mexico

Snakes are representatives of earth’s incredible diversity and important pieces of its ecological puzzle, Murphy continues. “People are afraid of snakes because they are so much different than we are. They don’t have limbs, they don’t have eyelids, they aren’t very tall, they don’t scream from pain, and they don’t have the kinds of human characteristics comforting to us.  Anything that is so unusual, humans are just unsettled by as opposed to cute, fuzzy mammals like giant pandas or great apes.”

The abnormal fear of snakes is called ophiophobia, after Ophion, the great serpent of the waters in Greek mythology, who mated with Eurynome, the goddess of all things. Eurynome took on the appearance of a bird, laid a giant egg, and Ophion coiled around and incubated the egg until it hatched, producing all living creatures.

“Those of us who work with snakes are bewildered by the widespread fear and loathing directed toward them by humans,” Murphy says.

A newly born tentacled snake at the National Zoo. Tentacled snakes are aquatic and live in South East Asia.

Today, says Murphy, modern humans, like St. Patrick, seem to be driving many animal species, including snakes, not into the sea but to extinction. A recent study published in January in the journal Elsevier predicts that nearly one in five reptilian species are threatened with extinction due in part to human-induced habitat loss and animal harvesting. Extinction risks for certain snakes species may be underestimated due to lack of information on their numbers.

“As herpetologists my colleagues and I are very concerned about the loss of snake diversity,” Murphy says. “What we are watching today is basically an extinction event that includes many snakes, as well as a number of other reptiles and amphibians. An unprecedented number of animals are disappearing from the planet.”

Small migratory male birds that winter in a stressful environment age faster than those that winter in a high-quality habitat, according to research stemming from a collaborative National Science Foundation grant between the University of Maine and Smithsonian Conservation Biology Institute.

A male American redstart (Photo by Dan Pancamo)

The team of biologists, led by former postdoctoral researcher Frederic Angelier working under the direction of UMaine Professor of Biological Sciences Rebecca Holberton, focused on telomeres — the long, repetitive noncoding sequences of DNA at the end of chromosomes that protect chromosomes from degradation and play a role in the aging process.

The researchers found that telomeres of male American redstarts (Setophaga ruticilla) that winter in the arid Jamaican scrub habitat shortened significantly faster than telomeres of male American redstarts that winter in a lush Jamaican black mangrove forest.

The findings suggest birds’ nonbreeding environment impacts the rate of telomere shortening and has important indirect effects on migratory bird population, the team says.

Male American redstart

The researchers also found males with shorter telomeres are less likely to return to the nonbreeding territory the ensuing year than those with longer telomeres, confirming previous studies that telomere length is related to survival in vertebrates.

American redstarts generally arrive in the Font Hill Nature Preserve in Jamaica in mid-September, where they remain until spring migration in April or May.

The NSF project is part of a long-term collaboration between Holberton and Peter Marra, a research scientist at the Smithsonian’s Migratory Bird Center. Holberton is a migratory bird expert who researches how external and internal factors affect avian survival. The Smithsonian Migratory Bird Center is dedicated to fostering greater understanding, appreciation, and protection of the grand phenomenon of bird migration.

Angelier is now a researcher at Centre d’Etudes Biologiques de Chizé in France. Angelier, Holberton and Marra were joined in the NSF research by Carol Vleck, an associate professor in the Department of Ecology, Evolution, and Organismal Biology at Iowa State University.

The team’s findings were published in the Jan. 31, 2013 edition of Functional Ecology.–Source: University of Maine

He’s a classic symbol of pride and independence: a majestic white-tail buck standing tall against a backdrop of deep forest. The image is a familiar sight on everything from pick-up truck decals to throw blankets.

These days, in Virginia at least, a more accurate depiction would show an antlered buck snacking at someone’s backyard bird feeder or crossing the paved driveway of a suburban development. Forget the deep forest, “today the highest densities of deer in the state of Virginia are in suburbia,” says William McShea, ecologist and research scientist at the Smithsonian’s Conservation Biology Institute in Front Royal, Va.

White-tailed deer. (Photo by Forest Wander)

McShea is co-author of a recent study in the Wildlife Society Bulletin examining the forces at work behind parcelization—dividing up large farms and woods into small, individually owned parcels—and how it might be responsible for the dramatic rise in white-tailed deer (Odocoileus virginianus) populations in Virginia.

“For some reason deer densities shoot up in areas where large properties have been divided up into small pieces,” McShea says. “We don’t know exactly why this occurs, but we have two ideas.”

“One is that hunters are not allowed to move across a parcelized landscape to get to where the deer are. When you have a big piece of property you can pretty much chase those deer down or go to where the deer are known to hide,” McShea explains. “But when you get into these 2- to 5-acre parcels, you stop at the edge of your property or your friend’s property, and the deer just keep going onto the next parcel and the parcel after that and you can’t get access to them.”

White-tailed deer. (Photo by Forest Wander)

The second “is that when a property is divided into smaller units there is a much higher probability that there is an owner nearby who does not hunt their deer or allow deer to be hunted on their property. Deer have the capacity to figure out where they are not being shot at, and that is where they go.”

At any rate, “individual parcels and subdivisions with ownership restrictions preventing deer harvest effectively create deer refuges,” McShea says. Wildlife managers seeking to control deer populations in suburban areas should focus on gaining hunter access to smaller parcels, particularly parcels less than 19 acres.

The increase in deer is not related to more suburban yards with new plantings of domestic shrubs and cover for deer to eat, McShea explains. “We found a lot of places where somebody had bought a big piece of property, divided it up into little parts—some of it was being built upon but most was not—and the deer density would just go crazy in there. So it isn’t the presence of houses but the land being divided-up that caused deer density to rise,” McShea says.

You do reach a critical point in development when you get down to parcels below 2 acres—1 acre to quarter-acre lots with houses—when the deer densities start to drop again, McShea says. “It becomes a matter where there are a lot of houses, the road density gets too high and the actual human footprint becomes too high.”

White-tailed deer. (Smithsonian Wild photo)

For their study McShea and his co-authors picked 11 study blocks in Frederick County and two in Rappahannock County, Virginia. Each block was roughly 13.4 miles square and had representative levels of forest cover, housing density, and road density for their counties. Maps were used to determine land use throughout each study block and landowners were identified through tax map records. Owners were then surveyed either in person, by phone or mail. Surveys included questions such as: Is hunting allowed on your property and, if so how many deer were harvested last year?

A second aspect of the study involved nighttime spotlighting and counting of deer to get a good estimate of the deer numbers in specific areas of each study block.

One reason for concern about exploding deer populations, McShea says, is the relatively recent presence of chronic wasting disease in Virginia. This fatal disease in adult deer is characterized by chronic weight loss and is passed on when deer come into direct contact with one another or in contact with the saliva of an infected animal. The disease thrives in areas with high deer densities and, because of it, Virginia wildlife managers are encouraging landowners to harvest more deer.

In addition to questions about deer harvest, the landowner survey also queried landowners about their knowledge of chronic wasting disease.

“Two or three years from now we can use our deer count estimates as a baseline to go back and learn if there are less deer in a region because the state is encouraging people to shoot more deer,” McShea says. “Or, if we may find that many people are pretty firm in their ideas of how many deer to harvest on their land, and that things are not going to change regardless.”–John Barrat

“Land parcelization and deer population densities in a rural county of Virginia,” Karen R. Lovely, William J. McShea, Nelson W. Lafon and David E. Carr; Wildlife Society Bulletin, Feb. 5, 2013.

Love is blind, and to illustrate this point Cupid is often shown wearing a blindfold. Two wings on Cupid’s back are meant to symbolize the flightiness of lovers and how easily affections can change. For some at the Smithsonian’s Conservation Biology Institute in Front Royal, Va., however, a pair of wings can indicate just the opposite: strong fidelity and loyalty to a mate.

Chris Crowe, keeper of the National Zoo’s 15 white-naped cranes, is well acquainted with the strong attachments these graceful Asian birds form with their mates. Couples are monogamous and stay together for life. Critically endangered in the wild, white-naped cranes typically live for 10 to 20 years in the wild and 40 to 50 years in captivity.

Keeper Chris Crowe with Walnut, a female white-naped crane. (Photos by Mehgan Murphy)

Their monogamy, Crowe explains, has nothing to do with romance and everything to do with parenthood. “Males and females take turns sitting on their eggs during the month-long incubation and they both cooperate in feeding, protecting and raising their chicks to independence at 8 months. Staying with a proven mate that you know can do a good parenting job enhances the probability of your raising chicks successfully over and over.” The National Zoo’s oldest pair of white-naped cranes has been together since 1998.

A white-naped crane couple with their chick at the Smithsonian Conservation Biology Institute.

During the breeding season a white-naped crane pair becomes fiercely territorial, not in fear of an interloper stealing their mate, but “because they must ensure there is enough food around for them and their chicks,” Crowe says. Chicks leave the nest 24 hours after hatching and then follow the adults around to find food. By protecting their turf they are defending the nearby supply of insects, crustaceans, reptiles, tubers, worms, seeds and small mammals the cranes find tasty.

Staying close

Each year wild white-naped crane couples migrate from their breeding grounds in China, Mongolia, and Russia to their wintering grounds in southeastern China, Japan, and the Korean Demilitarized Zone. It is a perilous journey of thousands of miles during which they must contend with habitat loss, human disturbance, illegal shooting and predators. Nonetheless, a pair is rarely out of sight from one another, and never out of earshot. When separated “they emit a very loud location call. Each partner recognizes its mate’s voice, even in a large flock,” Crowe explains.

At the Zoo, “for their quality of life and well being, we don’t separate a pair of white-naped cranes unless absolutely necessary,” Crowe explains. “If the male and female of a separated pair can still hear the other calling from another enclosure they will always want to get back together with that one and never re-pair with someone else.”

A white-naped crane chick in the hands of a keeper at the Smithsonian Conservation Biology Institute.

At the death of a mate, the surviving bird will “do a lot of location calls and looking around,” Crowe says. “Their appetite will suffer. It is not as obvious as it would be, say with a person where you can easily see their emotions, but the loss of a mate does seem to make these cranes kind of depressed and to exhibit abnormal behavior.”

Dancing, quick copulation and eggs

During breeding season a white-naped crane couple does a lot of dancing, jumping up and down, tossing objects together and building a nest. They also sing a unison call, Crowe explains, “where both the male and female are calling at the same time. The male raises and lowers his wings as he calls while the female points her head upward and calls twice for each call from the male.” Unison calls advertise a pair’s territory, “but it also seems to strengthen the bonds between a pair.”

Copulation “is pretty quick and is precipitated by more dancing that can go on for 5 to 10 minutes,” Crowe says. Then the female leans forward, raises her tail a bit, spreads her wings and the male flies up and lands on her back. She raises her tail and then their two cloacae [reproductive organs] meet. “All their reproductive organs are inside the cloacae, so basically there’s no phallus for the male,” Crowe says. “He just jumps up on top, leans down and their cloacae meet in what we call a ‘cloacal kiss.’  He jumps off and they dance a bit more. That’s it.”

An egg is usually laid a few days after copulation. They then copulate again for a second egg, which completes their normal annual clutch.

“When we pair these birds at an early age we do it based on their genetics, to help increase the genetic diversity of our flock,” Crowe explains.

Once they are paired the keepers also use artificial insemination to increase the flock’s genetic diversity, primarily by capturing the genes of birds that cannot breed naturally due to behavioral or physical problems, but also mating two birds that are paired with others.

Walnut

Interestingly, one female white-naped crane under Crowe’s care is paired with Crowe. “Walnut and I both arrived here in 2004,” he says. “She was hand-raised at another zoo and is socially bonded with people instead of cranes.”

Chris Crowe and Walnut

Walnut had never produced any chicks of her own by age 24 and arrived at the Zoo as the most genetically valuable white-naped crane in captivity. “Today, she directs all her breeding behavior towards me,” Crowe says, “dancing, jumping up and down, and soliciting me to mate with her. I bring her favored treats—mice, grapes, and mealworms—help her build a nest, dance with her—if I am sure nobody is watching—offer verbal praise, and spend time with her to maintain our pair bond. I am her primary keeper, taking care of her 5 out of 7 days a week.”

Normally, Zoo staff must catch and restrain the cranes to do artificial insemination, but over time Crowe has trained Walnut “to stand still and let me do it by myself and without restraining her. She is very aggressive towards everyone else, even the other keepers, but always very friendly with me.”

The Zoo has produced 5 female chicks from Walnut through artificial insemination. “Two of these chicks have gone on to breed naturally and produce chicks of their own, making Walnut and I grandparents,” Crowe says proudly. —John Barrat