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A tail doused with floral, fruity cologne appears to be a strong move for male lemurs looking for love, according to new research.
Ring-tailed lemurs (Lemur catta), endangered primates native to Madagascar, engage in what scientists call “stink flirting” during breeding season. To get ready to impress the lady lemurs, males wipe smelly chemicals secreted from glands on their wrists all over their fluffy tails, they then waft their perfumed appendages in the direction of potential mates.
Now, researchers have used chemical analysis to identify a trio of chemicals present in those secretions that appear to pique females’ interest, reports Elizabeth Pennisi for Science.
Outside of the breeding season the male lemurs’ wrist secretions are bitter and leathery, mainly used to tell other males to back off. But when it’s time to mate those scents turn sweet and tropical. The researchers took great pains to collect enough of this breeding season cologne for chemical analysis, using tiny pipettes to gather the miniscule quantities of the liquid before it evaporated.
The analysis revealed three molecules that appeared to be involved in wooing females, the researchers report this week in the journal Current Biology. The smelly triumvirate is made up of the compounds dodecanal, 12-methyltridecanal and tetradecanal all part of a group of well known odorants called aldehydes. One of the aldehydes is known to be an insect sex pheromone and another smells sort of like a pear, according to Science.
Wherever the researchers sprayed the chemicals, females spent some extra time sniffing and even licking the perfumed object, but only during the breeding season and only when all three chemicals were present. The males’ production of this concoction was also tied to their testosterone levels, Touhara and his team note in a statement.
The female response to the spritzings of the chemical mixture suggests it may help males find a mate, according to the researchers, making the ingredients of the lemurs’ chemical cocktail candidates for the first ever pheromones discovered in a primate. But, they add, more evidence is needed before using the term "pheromone" officially.
“We don’t know what happens after the female is interested in this odor,” Kazushige Touhara, biochemist at University of Tokyo and the study’s lead author, tells Max Levy of Massive Science. “So we have to really show that this enhances mating to be able to say that this is definitely a pheromone.”
Broadly defined, pheromones are chemical compounds that transmit signals between individuals of the same species. But the definition has been hotly debated and deciding what is and is not a pheromone can be akin to “drawing a line in the sand,” Christine Drea, an environmental anthropologist at Duke University who was not involved in the study, tells Massive Science.
The clearest examples involve chemicals that prompt physiological changes or an obvious behavior across all members of a species.
Female silk moths, for example, secrete the molecule bombykol, which instantly beckons males as soon as they encounter it, reported Daisy Yuhas in Scientific American in 2014. Other pheromones are slower acting: the molecule alpha-farnesene in male mouse urine has been found to accelerate puberty in young female mice.
Despite droves of armpit sniffing experiments in search of isolating a human love potion, “there is no authentic pheromone that has been chemically identified,” Touhara tells Nicola Davis of the Guardian. But Touhara and his team had good reason to go looking for a potential primate pheromone in lemurs.
Lemurs branched away from humans and the great apes some 60 million years ago and have retained a well-developed sense of smell. They’ve got scent producing glands on their shoulders and genitals in addition to the ones on their wrists, and they deploy their arsenal of odors to start fights, jockey for position in the social hierarchy and, as this new research suggests, seduce mates. They even possess an active version of a scent discerning organ, called the Jacobson’s or vomeronasal organ, that is vestigial in humans and apes.
Massive Science asked Tristram Wyatt, a pheromone expert at the University of Oxford, whether this study’s findings might represent the first recorded primate pheromones. "These are really promising candidates," Wyatt says, "and we’ve not had those before, but what we don’t know at this stage, is that it actually affects anything to do with sex."
Touhara says the responses of female lemurs after smelling the male’s breeding musk are something his team intends to explore in future research. For his part, Touhara tells Massive Science that the lemur love potion smelled “pretty good, actually.”
When humans first arrived on the island of Madagascar around 1500 years ago, they encountered an array of remarkable species that have since gone extinct: gorilla-sized lemurs, giant tortoises, tiny hippos and a huge, long-necked, flightless bird that lumbered through Madagascar’s forests and laid the largest eggs of any known vertebrate, including dinosaurs.
The eggs of the Aepyornis, also known as the elephant bird, were a highly valuable food source for Madagascar’s human settlers. With a volume roughly equal to that of 150 chicken eggs, a single elephant bird egg could feed multiple families. Humans pillaged the elephant birds’ nests, which likely played a role in driving the animals towards extinction. Today, few of the bird’s gargantuan eggs survive; fewer than 40 are known to exist in public institutions. So staff at the Buffalo Museum of Science were nothing short of thrilled when they found an intact, foot-long elephant bird egg hiding in the museum’s vast collections.
The Buffalo Museum of Science has been accruing its collection for well over a century and is currently in the process of updating its catalog, some of which still exists on cards and ledgers. While inputting catalog data into the museum’s computer system, Paige Langle, the collections manager of zoology, opened a cabinet that hadn’t been looked in for quite some time. Inside was an enormous, cream-colored egg. It measured 12 inches long, 28 inches in circumference and weighed more than three pounds. It was also labeled as a model.(The Buffalo Museum of Science, BSNS Q 257)
Langle, however, immediately suspected that the egg was “too realistic to be a model,” she tells Smithsonian.com. “I tried to shrug it off, but the more closely I looked at the surface of the eggshell and felt the weight of the egg, the more I kept thinking this has to be real.”
She was right. Searching deeper in the collections, she found a replica of the elephant bird egg that was obviously the model in question. Museum staff then looked through the institution’s archives and found records indicating that the museum had purchased a sub-fossilized elephant bird egg from a London purveyor of taxidermy specimens in 1939. They also found a letter written by a curator at the time, who listed various objects that he wanted to acquire for an exhibit on birds. One of those objects was a an elephant bird egg.
“From what we could tell, he mailed this list to all kinds of dealers all over the world, several of them in London,” says Kathryn Leacock, the museum’s director of collections. “A couple of them wrote back and said, ‘Oh no, you're not going to get one of those. They're kind of expensive.’ Fortunately he didn't let that deter him.”
Museum staff sent the specimen to SUNY Buffalo State to be radiographed and authenticated. Conservation experts there not only confirmed that the egg was real, but were also able to determine that it had been fertilized. They could make out the yolk sac and, Leacock says, “white fragments” that may point to the beginnings of a developing bird.
The 40 or so elephant bird eggs that are owned by public institutions exist in varying states of completeness. The National Geographic Society in Washington, D.C., has an intact sub-fossilized elephant bird egg, and inside is an embryonic skeleton. But other institutions “just have fragments of the shell,” Leacock says. (It is hard to know how many elephant bird eggs are held in private collections; David Attenborough has one, and in 2013, another sold for $100,000 at a Christie’s auction in London.)
Leacock hopes that the newfound specimen at the Buffalo Science Museum will prove valuable to experts who are interested in the elephant bird. There were several species of this massive creature. The largest towered 10 feet high and weighed around 1,000 pounds. These magnificent creatures died out relatively quickly once humans came to Madagascar; the last sighting of an Aepyornis was in the 17th century.The remains of Aepyornis maximus, a species of elephant bird that stood up to 10 feet tall. (Wikimedia commons)
It is not entirely clear why the birds went extinct, but anthropologist Kristina Guild Douglass said in an interview published on Yale’s website that “the answer is somewhere in the combination of climate change, changes in vegetation patterns, and human predation.”
“From my excavations,” she added, “human predation seems to be limited to egg-poaching.”
The elephant bird egg at the Buffalo Museum of Science has not been on display since the 1940s or 50s, Leacock says. The staff plans to feature the relic in an exhibition titled “Rethink Extinct,” which explores major episodes of extinction, from the age of the dinosaur to the present day.
“It's super, super cool to have this [egg] in Buffalo, and hope the community will be proud that we are one of a very, very few museums that have this as our cultural heritage,” Leacock says. “We're just very excited.”
For humans, disgust can be a powerful evolutionary force. In many ways, it works to keep us safe: Repulsion can cause us to discard damaged fruit (which might have worms in it), refuse to eat spoiled meat (which could hold tapeworm eggs) or avoid unwashed people (who could potentially carry lice). This reaction is so powerful that it can counteract logical reasoning—according to one study, people rejected fudge molded in the shape of dog poop, despite being completely aware that it was just fudge.
But the tendency to avoid gross and potentially harmful things may not be just limited to humans. At France’s Center for Functional and Evolutionary Ecology, a team of scientists has long been studying the evolution of social behavior in primates in a population of roughly 160 mandrills. This species of monkeys is known for its mutual grooming behavior, in which two monkeys will help clean each other's fur in a way that can reduce stress and help build social bonds.
However, the monkeys tended to avoid grooming certain monkeys at certain times, says Clémence Poirotte, a spatial ecology researcher there. Poirotte and her team suspected that the monkeys could be engaging in some kind of quarantine behavior. But they wanted to know: How did the mandrills know which of their peers were infected with parasites, so they could effectively avoid them?
In 2012, they decided to intensively monitor a group of 25 monkeys for 2.5 years to find out. The researchers documented how often each monkey was groomed by its peers in a month, documenting which ones would get shunned and which ones wouldn't. To see which monkeys were infected, they also collected fecal samples for all of the monkeys, which tend to be the main medium for transferring intestinal parasites like the protozoan Balantidium coli. Then they tracked which—if any—parasite infections appeared to correlate with less grooming time.
It turned out that getting infected with B. coli seemed to drive away other mandrills. "Parasitized individuals are less groomed by others," Poirotte concludes in a new study published in the journal Science Advances. Skin swabs found that the anal area of the infected mandrills was rich with potentially contagious B. coli. Not to get too disgusting, but healthy mandrills spend roughly 9 percent of their grooming time focusing on that specific area, according to the study, so grooming an infected monkey would put a mandrill at risk of getting infected itself.
So how did the monkeys know which individuals to avoid? They had developed a highly effective strategy: Smell their poop. Prior studies have found that mandrills have a powerful and sensitive sense of smell, which they use to detect chemical signals related to mating and social cues. And the new analysis of feces from infected mandrills found significant changes in the chemistry of the feces compared to healthy mandrill feces.
Mandrills didn’t seem to like poop with parasites: When researchers smeared two types of feces on sticks and presented them to the mandrills to inspect, they physically recoiled at infected ones, Poirotte says.Grooming is an important social behavior for most primates, including mandrills. However, it can potentially spread parasites. (Nory EL Ksabi / Science Advances)
It may not be pretty, but having an olfactory cue to avoid sick individuals is a crucial strategy for avoiding parasites, which comprise up to half of the world's estimated 7.7 million species. These freeloaders use other species for protection, food and transport, generally to the detriment of their hosts. However, parasites can't usually live solely off one host animal—because if that animal dies, they lose their main source of sustenance.
Instead, they try to spread their spawn to other members of their host species, often through mediums like feces and other bodily discharge. Animals that lead social lives, therefore, are most at risk. "Parasite transmission is one of the major costs linked to sociability," says Poirotte says. Parasites would have a much harder time spreading if every one of its hosts kept to themselves, but then those host animals would lose all the benefits of being in a herd or having social relationships.
Parasites have evolved a number of strategies to make this spread successful. Some are fairly straightforward; lice, for example, make their homes in human hair, and usually can only spread by crawling or falling into another person's hair with head-to-head contact. Others techniques are downright demonic: some parasites hijack the brains and nervous systems of animals to make Artemia shrimp get eaten by flamingos, crickets drown themselves, and cockroaches become the enslaved hosts for parasite eggs.
In response to these atrocities, host animals too have gotten creative with their survival strategies. Biologists have documented a long-running "evolutionary arms race" between the two, with hosts constantly developing new defenses against the parasites’ changing survival strategies. Hosts employ strategies from healing saliva (which animals can use to cover wounds and prevent parasites from colonizing) to tail-swatting instincts (which ward away bloodsucking insects) to immune system defenses (which can kill parasites more effectively).
Behaviors like social avoidance represent yet another kind of anti-parasite defense, part of what University of British Columbia psychologist Mark Schaller has dubbed the "behavioral immune system.
What does that entail, exactly? "It's a suite of psychological mechanisms designed to detect the presence of disease-causing parasites in our immediate environment, and to respond to those things in ways that help us to avoid contact with them," Schaller wrote in an article for Scientific American.
While not directly applicable to humans, Poirotte says that this study does throw into relief the great lengths that humans go to in order to stay far away from each other’s bodily waste. Pipes and waste treatment facilities are a kind of avoidance strategy to avoid any contact that could lead to potential sickness, she points out.
The study marks “a significant contribution to the field," says Martin Kavaliers, a behavioral neuroscientist at Canada's Western University. Kavaliers, who wasn’t involved in the study, adds that it’s one of just a few studies that have confirmed social avoidance behavior in animals. Some human studies have also found that the odor of a person injected with a bacteria-produced endotoxin is more repulsive to other people—perhaps representing a similar defense against getting too close to sick people.
Next, Poirotte plans to look more closely at why some of the mandrills appeared more adept at avoiding infected peers than others, and whether this helped them stay healthy. In the future, she also hopes to study gray mouse lemurs, a small primate species in Madagascar that appears to be succumbing to increasing parasitic infections as it loses its habitat to deforestation, to see whether the species is evolving any behaviors to compensate for this.
If you find yourself the unintended host for a parasite in the near future, don’t lose hope. Fortunately, in mandrills as in humans, social avoidance generally doesn’t last forever. In the study, the researchers actually cured 16 monkeys of their parasitic infections with medication and found that they shortly started receiving much greater amounts of grooming again, says Poirotte.
The creeping, crawling, flying, growing, flowering life on this Earth is going extinct at least 1,000 times more rapidly than if humans were absent from the scene. Some call this the sixth mass extinction.
The causes of the crisis are many: climate change, ocean acidification (it has triggered extinction before), habitat loss, deforestation, invasive species and even odd fungal diseases. Many of these factors are intertwined and complicated. So with creatures both adorable and ancient on the brink of disappearing from the Earth, and with countless, even nameless, others already gone, it could seem like now is the time to start accepting the idea of mass extinction. Or feel depressed.
But some think we don’t have to accept this extinction. One of the main researchers on the Science study that quantified that death rate, mentioned above, is one such visionary (or Pollyanna, depending on your bias). Stuart Pimm, of Duke University, recently told Brad Plumer at Vox why he’s not despairing. Plumer writes:
By assembling data on exactly what species are endangered and where, he said, scientists can now do more than ever to help conservation groups fend off extinctions. One example: more detailed research on Brazil's rainforests can give people an idea of which tracts are actually most cost-effective to protect.
The full Q&A is worth reading, but here are some quotes from Pimm that point toward a way forward that might have a little less death:
- "We have really good maps now showing where a lot of species are, on land and in freshwater and the oceans. We can identify the key places that matter."
- "What my NGO, Saving Species, does is we take our data and identify exactly where we think the most important fragments are. And then we raise money from Brazilian conservation groups to buy up the land between the fragments and reforest it. So we reconnect it — stitching habitat fragments to form much bigger habitats."
- "Do we need more resources? Yes. Do we need to focus more on the places that matter? Yes. But it's not as if we're blundering around not knowing what to do. I think the conservation profession now is very sophisticated, very clever, and has a lot of different techniques. We just have to be smart; we have to focus our energies. We have to solve difficult problems."
It’s all about strategy, Pimm explains. Some conservation efforts might have their heart in the right place but their resources in the wrong place. "But those conservation efforts aren't always the places that are optimal. Some places are bad," he says. "We need to encourage people to protect the places that matter — using scientifically informed decisions."
Focusing on individual species, like the Endangered Species Act does, can be most useful when the organism in question is recognized as an icon whose threat comes from a disrupted ecosystem. Fix the habitat issues; help the "poster child" species. Pimm also emphasizes the use of smartphones to document biodiversity and the importance of local conservation actions.
Of course, slowing climate change would also make a big difference. Pimm closes the interview with:
We're also still struggling with the overarching political question of what sort of planet we're going to hand to our children and grandchildren. That's a difficult one — it's obvious on global warming, but it's broader than that. I think this is a global debate about how we shape our global future — whether we want to have a planet that will continue to get hotter and hotter and hotter, whether we're going to use resources on land and oceans unsustainably, whether we're going to allow this wave of extinction to deplete the diversity of life on earth. That's a global issue, and I do worry about how poorly we are grasping this.
It sounds like something out of a crime show: police pouring through data from surveillance cameras, using facial recognition software to nab the perp. But now, researchers have adapted this software for use in the forests of Madagascar, identifying and tracking the whereabouts of endangered lemurs.
As the BBC reports, the software, known as LemurFaceID, allows scientists to more effectively track and protect the primates. The software can distinguish individual lemurs from digital photographs with greater than 97-percent accuracy. Researchers hope the tool will improve conservation of the species while providing a more humane, noninvasive way to identify individual lemurs. The team recently published their work in the journal BioMed Central Zoology.
To track lemurs, scientists traditionally trapped and tagged individual animals. They cataloged their physical characteristics—body size, markings, notable scars or injuries. But tracking these lemurs as their appearance changes over time is both time consuming and challenging, hampering long-term studies.
“[We] weren’t particularly satisfied with the common approaches used in lemur research,” Rachel Jacobs, a co-author on the paper, tells the BBC. “[S]o we aimed to do something different with red-bellied lemurs, and we sought the expertise of our computer science collaborators.”
To develop the software, Jacobs, a biological anthropologist from George Washington University, turned Anil Jain, a biometrics expert and distinguished professor at Michigan State University.
Jain and his students in the computer science department created a dataset comprising 462 images of 80 red-bellied lemurs primarily taken in Ranomafana National Park in Madagascar. The researchers also included an additional 190 images of other lemur species to help expand the software’s capacity. To identify an individual, LemurFaceID first identifies its eyes and then analyzes the characteristics of each surrounding pixel in the image.
“Like humans, lemurs have unique facial characteristics that can be recognized by this system,” Jain tells MSU Today.
The new software will give lemur researchers and conservationists a new tool for tracking lemurs over time. Long-term data provides researchers with crucial metrics to measure population growth and decline, like the rates of infant and juvenile mortality.
The software could also aid in the fight against illegal captures of the big-eyed primates. With only a clear digital image, locals and tourists can report sightings to law enforcement and researchers to quickly identify captive lemurs.
The researchers believe LemurFaceID could be adapted to protect other mammals with variable facial and skin patterns as well. Jain tells MSU Today that he believes the software could work for bears, red pandas, raccoons and sloths.
Facial recognition tools are used in criminal investigations and when you tag your friends in photos on Facebook, but now, its usage is getting a little fishy—literally. A fish farm company hopes to use face identification technology in high-tech salmon farms to check the animals for a parasite called sea lice and other health problems.
The Norwegian fish-farming firm Cermaq Group AS is planning on implementing the facial recognition software as part of a high-tech fish farming suite they are calling iFarm, reports Agnieszka de Sousa at Bloomberg Businessweek. The tech, which should be ready for commercial use in five to six years, is likely going to be in high demand.
Currently, most fish farms assess the health of their salmon as a group, not individually. If a few fish are found to have a disease or parasite, the whole farm is treated. But the iFarm system aims to assess each individual fish, allowing fish growers to determine how fast each fish grows and check for the presence of disease or parasites.
To do this, the system will use a machine called the BioSort vision recognition system. De Sousa at Bloomberg reports that the system relies on the biology of the fish. In an iFarm, about 200,000 salmon would live in 525-foot circular net. About every four days, salmon need to come to the surface to take a gulp of air to regulate their swim bladder. When they do, a pyramid shaped device guides them into the camera that recognizes their face based on the pattern of dots on their snout and gills and also scans their entire body. If the fish shows signs of a problem, it is then guided into a holding pen for individual treatment.
The iFarm tool is especially helpful in dealing with sea lice, a parasite which has become huge problem in the salmon industry, infecting fish farms in Norway, the U.S., Canada, Chile and Scotland. The lice, which are a type of crustacean, cost the salmon farming industry $1 billion per year.
Farmers are trying all sorts of techniques to rid their fish of the lice, including dousing them with pesticides, breeding genetically resistant fish and even using lice-zapping lasers, reports Patrick Whittle at The Independent. Others are experimenting with raising certain fish species that will slurp the lice off salmon. Some are using a technique that raises the temperature of the water briefly to cause the lice to detach. But the iFarm system would allow farmers to be more targeted in their approach.
“We know that sea lice are very unevenly distributed amongst the fish, and this system enables us to avoid mass lice treatments,” Cermaq Norway Managing Director Knut Ellekjær tells Nicki Holmyard at Seafood Source. “Similarly, we can sort salmon on the basis of weight and remove only those fish ready for harvest, without stressing the others.”
It’s estimated that the system could cut fish mortality from sea lice by 50 to 75 percent. Even when lice don’t kill the fish, the salmon are still rendered unsellable because of the lesions and sores the lice cause.
“Only the fish that actually need it will be sorted out for treatment, which means typically 5 to 20 percent,” Geir Stang Hauge, CEO of BioSort, the tech company collaborating with Cermaq tells De Sousa. “This avoids stressful treatment for all the healthy fish.”
It’s hoped that such a system would help bring down the price of farmed salmon, which has become more expensive as the lice spreads.
Salmon aren’t the only species getting special treatment using facial recognition. The agribusiness giant Cargill announced earlier this year that it is investing in the Irish software company Cainthus. Using image monitoring, Cainthus software is able to track individual dairy cows and monitor their food and water intake as well as their behavior patterns to determine any signs of disease or illness.
Facial recognition is also being used in animal conservation. Last year, researchers at Michigan State University created a system that could recognize the faces of individual lemurs. It’s hoped that, with some refinements, such systems could help count, track and even keep tabs on the health of endangered species in the wild.