A Fuzzy Infiltrator – Improving Penguin Studies

America has a seemingly undying love of penguins, and for understandable reasons. Their babies are awkwardly waddling adorable fluffballs; their adults are graceful swimmers of freezing seas; their cartoons are endearingly spunky. Zoos and aquariums across the country offer penguin experiences, letting fans get up close and personal with the waterfowl. As penguin habitats become increasingly threatened by global climate change, these warm and fuzzy feelings help encourage conservation efforts and build support for scientists who study the animals.

Yet for wild penguins, a human encounter is often a source of discomfort rather than delight. The presence of people increases stress in penguins, raising their heart rates and changing hormone levels in ways that can harm reproduction. This puts conservation scientists in a bind: they need to work closely with penguins to obtain good data, but their very presence can harm the birds they want to study. Yvon Le Maho, a French Antarctic scientist, recently published a study in Nature Methods that offers a clever workaround for this conundrum: remote-controlled penguins.

Courtesy of Popular Science

Le Maho and his colleagues reasoned that penguins would be far less stressed by an intruder if it looked more like one of their own kind. To this end, the scientists designed a remote-controlled car topped by a stuffed animal version of a penguin chick. Getting the rover right was a matter of trial and error; the researchers tried five different versions of their device, including a fiberglass version that seemed to disturb the birds even more than undisguised humans did.

Once the team developed a suitable penguin “spy,” they compared the responses of penguins to approaches by humans and the car. By measuring penguin heart rates and observing their behavior, Le Maho and collaborators determined that the birds were four times less stressed when the car made its way into their territory. The disguised rover could join an emperor penguin creche, a tightly packed circle of penguin chicks, without arousing suspicion. Adult emperor penguins even began to sing at the contraption, leading Le Maho to comment, “they were very disappointed when there was no answer. Next time we will have a rover playing songs.”

Although the fuzzy little car seems frivolous, its built-in radio-frequency identification (RFID) reader allows it to identify tagged penguins without disturbing them, which is very important for studying the community structure and distribution of the birds. Similar devices could be designed to zip past other wary wild species; the scientists note that their penguin car also went unmolested by elephant seals, which in their words “generally react strongly when humans approach their tails.” If researchers add cameras and microphones, the car might someday get a bird’s-eye view of penguin life. Of course, in the case of these flightless waterfowl, that perspective will be stuck to the ground.

From the Vaults: A Wooly Issue – Deextinction of Mammoths

Editor’s note: Thanks to you, the readership of Sword of Science has significantly increased from my first posts nearly a year ago. I recently started volunteering at the Cincinnati Museum Center, and in honor of their emblematic Ice Age Trail, I’m reposting one of my earliest pieces, about efforts to bring back extinct species such as the woolly mammoth.

A little less than a week ago, a team of Russian scientists announced a startling find in the frozen wastes of Siberia: the complete carcass of a woolly mammoth, a relic from the most recent ice age over 10,000 years old. Although mammoths have been unearthed from the permafrost before, they are rarely recovered in such pristine condition, and never have they been found with liquid blood. Of course, there are only two words that come to mind when the blood of extinct species is mentioned: “Jurassic Park.”  The central conceit of Michael Crichton’s novel is that dinosaur DNA from blood trapped in amber-preserved mosquitoes is used to resurrect the Mesozoic beasts, with dire consequences.

While it’s unlikely that a herd of woolly mammoths will go rampaging through an ice age theme park anytime soon, it is becoming increasingly feasible that the genetic resources necessary to clone a mammoth will be developed. Blood itself is actually a rather poor medium from which to extract ancient DNA: red blood cells, or erythrocytes, do not contain any genetic information, and white blood cells, or leukocytes, are fairly fragile. In the words of Stephen Schuster, the biologist behind the sequencing of the mammoth genome, the genetic material in the mammoth blood is probably “as shattered as if you took a mirror and threw it on the floor.” Research is already in progress to clone a mammoth from bone marrow cells, which are more resilient and have better-preserved DNA.

A frozen baby mammoth, courtesy of National Geographic

Considerable amounts of effort are being invested in this project, but why (or is it even) a worthwhile investment? The “wow” factor of bringing back an extinct species is certainly a large part of the rationale. The sense of reaching back into the past, of letting people see something that hasn’t been seen for millenia, excites the imagination and draws attention to science in general. Conservation biology has a similar concept in the “flagship species,” a charismatic large animal that serves as a focus for  the ecological concerns of the general public. The plight of the manatee, for example, draws in attention and funding for the preservation of the Florida Everglades. Bringing back a mammoth would encourage a new generation of young scientists to explore the fields of molecular biology and paleontology. This kind of project may also put a more favorable public light on genetic technology, which has recently received a lot of negative attention due to the fight over GMO labeling and a recent Supreme Court case involving the agribusiness giant Monsanto.

Some scientists, like Jose Folch, see a bioethical imperative for work on de-extinction. Folch, whose team successfully cloned the extinct Pyrenean ibex (albeit one with a lifespan of seven minutes), believes that his work may serve as a basis “for future cloning-based conservation.” There is a sort of inherent justice in the thought that species wiped out by direct human impacts, like the passenger pigeon and the Steller’s sea cow, might one day be restored by direct human effort. However, there are many steps remaining between cloning an individual and reestablishing a population of an extinct species. Clones are genetically identical, and therefore rather vulnerable to disease or ecological stresses. Evolution and migration have shaped ecosystems in the absence of extinct species, even over the short timespans some have been extinct, and it is likely that not all species would fit comfortably back into their niches. A less obvious danger is the thought that with this sort of technology, the importance of traditional conservation is somehow reduced. Why bother with protecting existing species if we can call them back at will? Yet as scientists have continually learned, all species are connected; the loss of one obvious organism could have unforeseen effects on countless others, and it’s best to conserve as many as possible while we try to understand the web of life.

In the Crossfire – Pacific Fishers and the War on Drugs

America’s “War on Drugs” has claimed many casualties, but one group impacted by drug policy has no history of use, sale, or possession; it even lacks the opposable thumbs needed to roll a joint. The Pacific fisher (Martes pennanti), a rare relative of otters and minks native to the West Coast, is in danger of extinction due to chemical use at illegal marijuana cultivation sites in the Sierra National Forest, one of its crucial habitats.

The Pacific fisher, courtesy of Sierra Forest Legacy.

The use of marijuana for medicinal purposes is legal in the state of California, but the drug is still considered a Schedule I substance under U.S. law, and federal agents continue to destroy hundreds of thousands of plants in the region every year. These raids have pushed some growers to establish grow sites on isolated portions of public lands such as forests and parks, which are more difficult to patrol. Operating outside any regulatory framework, these grows pose a number of environmental hazards, including watershed pollution, habitat destruction, and wildfire risk.

According to Craig Thompson of the U.S. Department of Agriculture Forest Service, a previously unrecognized problem is the unregulated use of rodenticides, or rat poisons, to prevent damage to marijuana plants. These poisons can impact a wide range of nontarget species, including the Pacific fisher. Thompson and his colleagues tracked fishers using radio collars over a five-year period, monitoring their home ranges and performing autopsies on any that died during the study. Of the 46 deceased animals analyzed, 39 (85%) tested positive for a rodenticide. When the home ranges of these fishers were examined, the scientists found that they contained significantly more illegal marijuana grow sites than the ranges of fishers that tested negative for the poisons. As the animals rarely entered into legitimate agricultural lands or human-inhabited areas, the team hypothesized that the grow sites were the sources of the rodenticides.

Although only one fisher died directly due to rodenticide poisoning, lower doses of these compounds still have dangerous effects. Sluggish reflexes, reduced rates of healing, and even brain damage can all result from exposure to rodenticides, rendering the fisher more vulnerable to starvation and infection. As Thompson explained, “By increasing the number of animals that die from supposedly natural causes, these pesticides may be tipping the balance of recovery for fishers.” The species is currently a candidate for protection under the Endangered Species Act, and its estimated U.S. population as of 2012 (roughly 4,600) is far under its historical numbers.

Regulating the environmental effects of marijuana production is impossible when production itself is outlawed. By providing a proper legal framework for marijuana growers, officials can create a more sustainable and environmentally friendly market, benefiting humans and fishers alike.

A Woolly Issue – Deextinction of Mammoths

A little less than a week ago, a team of Russian scientists announced a startling find in the frozen wastes of Siberia: the complete carcass of a woolly mammoth, a relic from the most recent ice age over 10,000 years old. Although mammoths have been unearthed from the permafrost before, they are rarely recovered in such pristine condition, and never have they been found with liquid blood. Of course, there are only two words that come to mind when the blood of extinct species is mentioned: “Jurassic Park.”  The central conceit of Michael Crichton’s novel is that dinosaur DNA from blood trapped in amber-preserved mosquitoes is used to resurrect the Mesozoic beasts, with dire consequences.

While it’s unlikely that a herd of woolly mammoths will go rampaging through an ice age theme park anytime soon, it is becoming increasingly feasible that the genetic resources necessary to clone a mammoth will be developed. Blood itself is actually a rather poor medium from which to extract ancient DNA: red blood cells, or erythrocytes, do not contain any genetic information, and white blood cells, or leukocytes, are fairly fragile. In the words of Stephen Schuster, the biologist behind the sequencing of the mammoth genome, the genetic material in the mammoth blood is probably “as shattered as if you took a mirror and threw it on the floor.” Research is already in progress to clone a mammoth from bone marrow cells, which are more resilient and have better-preserved DNA.

A frozen baby mammoth, courtesy of National Geographic

Considerable amounts of effort are being invested in this project, but why (or is it even) a worthwhile investment? The “wow” factor of bringing back an extinct species is certainly a large part of the rationale. The sense of reaching back into the past, of letting people see something that hasn’t been seen for millenia, excites the imagination and draws attention to science in general. Conservation biology has a similar concept in the “flagship species,” a charismatic large animal that serves as a focus for  the ecological concerns of the general public. The plight of the manatee, for example, draws in attention and funding for the preservation of the Florida Everglades. Bringing back a mammoth would encourage a new generation of young scientists to explore the fields of molecular biology and paleontology. This kind of project may also put a more favorable public light on genetic technology, which has recently received a lot of negative attention due to the fight over GMO labeling and a recent Supreme Court case involving the agribusiness giant Monsanto.

Some scientists, like Jose Folch, see a bioethical imperative for work on de-extinction. Folch, whose team successfully cloned the extinct Pyrenean ibex (albeit one with a lifespan of seven minutes), believes that his work may serve as a basis “for future cloning-based conservation.” There is a sort of inherent justice in the thought that species wiped out by direct human impacts, like the passenger pigeon and the Steller’s sea cow, might one day be restored by direct human effort. However, there are many steps remaining between cloning an individual and reestablishing a population of an extinct species. Clones are genetically identical, and therefore rather vulnerable to disease or ecological stresses. Evolution and migration have shaped ecosystems in the absence of extinct species, even over the short timespans some have been extinct, and it is likely that not all species would fit comfortably back into their niches. A less obvious danger is the thought that with this sort of technology, the importance of traditional conservation is somehow reduced. Why bother with protecting existing species if we can call them back at will? Yet as scientists have continually learned, all species are connected; the loss of one obvious organism could have unforeseen effects on countless others, and it’s best to conserve as many as possible while we try to understand the web of life.