A Rare Advantage
Here’s one for the “small is good” category. We usually think species that exist only in small numbers are in danger of going extinct. But apparently, sometimes being rare may hold the ticket to a species’ survival.
When most people think of rare species, they think of ones endangered as a result of habitat loss, hunting, poaching, climate change, or other environmental disturbances. But some species have always been rare – occurring in small densities within their range – throughout their evolutionary history.
In a perspective paper published in the journal Ecology Letters, a team of researchers from the University of California, Davis suggests that for many species, such as a Tritonia nudibranch – a small member of the mollusk family that’s spotted in the Red Sea only once every few years – rarity is not a guarantee of impending extinction. Instead, the traits that enable some species to be what they term “chronically rare” could very well be an advantage during crises.
The researchers explored factors that make a species likely to thrive, even if its population is small.
Rare species, they found, can persist if fertilization occurs inside or close to an adult, which exponentially increases the chances of the gametes of both sexes actually getting to unite to form a zygote, and of that new life being protected. This might seem obvious, but many species, including sea urchins and abalone, use “broadcast fertilization,” where they simply release their gametes into the water and hope for the best.
It also helps if the species is highly mobile, or has help from pollinators or other animal intermediaries that deliver their egg cells and sperm over long distances. It doesn’t hurt if they can also signal and/or attract a mate over a long distance. And if two sexes are combined in a single individual, as is the case with many snails, worms, and some sea stars, all the better!
“During great extinction events, almost every species will suffer,” says Geerat Vermeij, a professor with the UC Davis Department of Earth and Planetary Sciences, who co-authored the paper. “The one that can withstand being rare and survive will have a real advantage during extinction events and crises.”
Knowing which traits enable species to be rare could help conservation managers better manage both rare and common species, and better design sanctuaries and preserves on land and at sea. “By learning how a species can be rare, we can also learn how to protect species that cannot be rare,” Vermeij says.
But, the paper notes, relatively little is known about rare species. They are notoriously difficult to sample since they are, by definition, uncommon. The researchers bluntly state that there is “virtually no reliable data to support our predictions” and calls for more research support on this topic.
The tiny country of Palau has taken an outsized stance on the environment. Over the past several years, the Pacific island nation has enacted legislation protecting hundreds of marine species, spoken boldly on the need for climate action, and established one of the world’s largest marine sanctuaries. Now Palau wants visitors to take a stand for the planet as well.
The Guardian reports that all tourists entering Palau are now required to sign an eco-pledge stamped into their passports. The pledge is addressed specifically to the children of Palau, who also helped craft it, and reads in full: “Children of Palau, I take this pledge, as your guest, to preserve and protect your beautiful and unique island home. I vow to tread lightly, act kindly, and explore mindfully. I shall not take what is not given. I shall not harm what does not harm me. The only footprints I shall leave are those that will wash away.”
The pledge represents the first time a country has changed its immigration laws in the name of environmental protection. Visitors will also receive a list of illegal activities upon entering the country, including the collection of marine life souvenirs, feeding marine life, touching coral, or littering.
President Tommy Remengesau hopes the pledge will help visitors understand the fragility of the environment, and that it will have a ripple effect beyond Palau. “While Palau may be a small-island nation, we are a large ocean-state and conservation is at the heart of our culture,” he said in a statement. “We rely on our environment to survive and if our beautiful country is lost to environmental degradation, we will be the last generation to enjoy both its beauty and life-sustaining biodiversity.”
In a desperate attempt to buy more time for the last few individuals of a dying species, a team of marine mammal scientists and conservationists set out to capture the world’s remaining vaquitas from Mexico’s Sea of Cortez last October. The idea was to hold these tiny porpoises in a temporary sanctuary where they could breed in safety.
Vaquitas have been disappearing at an alarming rate due to drowning in illegal fishing nets in the Gulf of California. There are fewer than 30 individuals remaining of this species, which is endemic to a mere 30-mile radius of the Gulf of California in Mexico. The goal of the joint US-Mexico rescue team, Vaquita CPR, was to bring the vaquitas into temporary human care until all gillnets for shrimp and finfish were banned and removed from their habitat.
Sadly, the rescue mission didn’t go well.
The rescuers had never captured live vaquitas before, and no one knew how the animals would cope with the stress. The first individual they captured in October, a six-month-old female, had to be released within a few hours because she began showing signs of stress in the holding facility. The team modified its floating pen and tried again in December. This time they captured a mature female, who, the team reports, “showed some positive signs of acclimating to her new environment.” But then, her condition, too, started deteriorating. The team released her but she circled right back to them seeking, the team believes, emergency care, and died shortly thereafter.
Devastated that they had brought this critically endangered species even closer to extinction, the team halted its capture operations indefinitely.
For now, the project is focused on counting the remaining animals by using underwater listening devices and taking photographs of their dorsal fins, each of which carries unique scars and markings, The Washington Post reports. The Mexican government might give each one identified a name, officials said, in hopes that personalizing the cetaceans – known as “pandas of the sea” for the black rings around their eyes – might galvanize public attention.
Has your teen been acting up? It could be something in the air. A new study shows that higher levels of air pollution mess with developing brains and result in increased teenage delinquency.
The impact of air pollution on the respiratory and cardiovascular health of the young and old alike is well known. But in recent years, more and more research has begun linking air pollution to human brain function.
Now new research by the University of Southern California suggests that microscopic pollution particles, called PM 2.5, in ambient air can creep into developing brains, cause inflammation, and may damage brain pathways responsible for emotion and decision-making.
PM 2.5 is particularly harmful to developing brains because it can damage brain structure and neural networks and, as our study suggests, influence adolescent behaviors,” says Diana Younan, a preventive medicine research associate at USC’s Keck School of Medicine and lead author of the study that was published in the Journal of Abnormal Psychology.
It is possible that growing up in places with unhealthy levels of small particles outdoors may have negative behavioral outcomes similar to exposure to lead, Younan says, noting how previous studies have shown that early exposure to lead (in air or in soil) disrupts brain development and increases aggressive behavior and juvenile delinquency.
The study followed 682 children in the Greater Los Angeles area for 9 years, starting when they were 9 years old. The researchers used air quality monitors to measure the ambient PM 2.5 levels outside each child’s home. Meanwhile parents completed a child-behavior checklist every few years and noted if their child had engaged in rule-breaking behaviors such as lying and cheating, truancy, stealing, vandalism, arson, or substance abuse.
About 75 percent of the research participants breathed ambient air pollution that exceeded the federal recommended maximums of 12 micrograms per cubic meter. Some areas had nearly double the recommended limits of these particles. Unsurprisingly, these areas comprised poorer, less ideal neighborhoods, including housing developments near freeways with limited green space or foliage.
The researchers found that bad behaviors associated with increased outdoor air pollution levels were magnified when children did not have good relationships with their parents, lived with depressed mothers, or grew up in homes with higher levels of parental stress.
“Both lead and PM 2.5 are environmental factors that we can clean up through a concerted intervention effort and policy change,” Younan says. Not an easy task in this fraught political climate. And sadly, even if accomplished, neither would help establish the “healthy family dynamics” that Younan recommends.
The northern stretches of the Great Barrier Reef offer refuge to a thriving population of endangered green sea turtles. This colony – which, with 200,000 sea turtles, is among the largest in the world – faces a new, unusual challenge: It is not producing any males.
According to a recent study published in Current Biology, more than 99 percent of all turtles born on beaches along the northern stretches of the reef since the late 1990s have been female. The culprit behind this imbalance? Rising temperatures associated with global warming. As scientists have long known, sea turtle gender is influenced by temperature – cooler temperatures favor male turtles, whereas warmer weather produces more females.
The researchers compared female-to-male turtle ratios in two distinct Great Barrier Reef populations: one in the southern reaches of the reef where temperatures are lower, the second in the north where temperatures have consistently exceeded the so-called “pivotal” temperature that favors production of female green sea turtles, 85 degrees Fahrenheit.
Their findings were dramatic. Within the southern population, roughly two-thirds of the turtles were female. (This is a typical sex ratio for the species.) Within the northern population, however, 86 percent of adult turtles were female. And among turtles between the ages of four and twenty-three, practically all turtles were female.
“Virtually no male turtles are now being produced from these nesting beaches,” the scientists wrote of the northern population.
The findings could have far-reaching implications. Green sea turtles are far from the only animal with temperature-dependent gender determination. Many reptile species could be similarly impacted as their “pivotal” temperatures are more frequently exceeded as the climate warms. Many of these same species are also endangered, including six of the seven sea turtle species that live in US waters.
That being said, it’s not yet clear how many male turtles are required to sustain a population. “A few males can go a long way in a sea turtle population,” Michael Jensen, study co-author and researcher with the US National Oceanic and Atmospheric Administration, told News Deeply. “What we need to know is how far you can push the female bias before it becomes a problem.”
The researchers plan to expand their study to other green sea turtle populations in the Pacific Ocean. And then, armed with additional information, conservationists might turn to solutions, such as shading nesting beaches to keep them cool during egg incubation.
Animal suffering in the name of human entertainment is nothing new. The modern circus dates back to eighteenth-century England, and the first wild animal circus acts emerged in both America and Europe in the early nineteenth. The animals rights movement, too, dates back centuries, and for years activists have been fighting the use of animals in roving shows, pointing to the cruel training, horrendous living conditions, and grueling travel circus animals are forced to endure. In recent years, their cause has been picking up steam.
A decade ago, just a handful of countries had banned the use of wild animals in circuses. Today, more than 40 countries have passed some sort of legislation against the use of wild animals for entertainment, including roughly three-fourths of the European Union. And a smattering of nations have outright banned use of any performing animals, wild or domestic, in these shows. In places where national bans don’t exist, municipalities have jumped in to fill the gaps: In the US, for example, more than 80 cities and towns have passed full or partial bans on animals in circuses. There’s still much progress to be made, but it seems more than plausible that animal-focused entertainment could soon become a thing of the past.
As is the case with many environmental issues, Costa Rica leads the pack when it comes to animal rights. The Central American nation banned circuses with animal acts back in 2002. In 2005, Costa Rica also took a stand on cetacean rights, making it illegal to touch, feed, catch, or kill marine mammals, or to keep marine mammals captive.
There is no federal ban on animal performances in the US. But over the past several years, dozens of cities across nearly 30 states across have enacted various circus-related animal bans. In many ways, California has led the way. In 2014, both Los Angeles and Oakland banned the use of bullhooks – a painful tool used to train elephants – in circus performances, effectively preventing elephant performances in the cities. In 2015, San Francisco took things further, banning all performances of wild and exotic animals for public entertainment, including in circuses or on movie and TV sets. And in 2017, Los Angeles became the largest US city to ban wild animal performances for human entertainment.
In 2009, Bolivia became the first country to ban any and all use of animals – wild and domestic – in circuses, enacting a law that states that the use of animals for public entertainment “constitutes an act of cruelty.” It also includes a ban on marine mammal performances. Several other South American countries have enacted nationwide bans on wild animals in circuses, including Colombia, Ecuador, Paraguay, and Peru.
Italy has one of the biggest circus industries in the world, with an estimated 100 circuses and 2,000 circus animals. In November 2017, the parliament voted to ban all animals in circuses and other travelling shows. The Italian ban comes as part of a wave of animal entertainment bans sweeping Europe in recent months: In January, Ireland, Scotland, Latvia, and Romania all banned the use of wild animals in circuses, and Wales and England are currently considering bans; they would be joining more than a dozen European countries with bans on wild animal performances.
In 2017, India became one of the only nations in Asia to pass a ban on all wild animals in circuses. The county previously banned the use of bears, apes, lions, tigers, and leopards, and had cancelled registration for several individual circuses following animal cruelty findings. The 2017 decision extends to all wild animals and all circuses. Since 2013, it has also been illegal to keep dolphins in captivity for public entertainment purposes in India. Elsewhere in Asia, Singapore has banned the use of wild animals in circuses since 2002, and Iran effectively enacted a ban in 2016 when it announced it would no longer issues permits for wild animals in circuses.
It’s a well-documented fact that air pollution is bad for our health. Every year, millions of premature deaths are linked to the toxic air we breathe. An estimated one in six people die from the combined impact of air, water, and soil pollution. But can polluted air literally knock us down in our tracks? According to new research, it just might.
A study published in Earth and Planetary Science Letters found that acid rain from the burning of coal may have contributed to a deadly 2009 landslide in southwestern China. The landslide, which killed 74 people, had no clear trigger, such as an earthquake or heavy rains. The researchers, geoscientists Ming Zhang and Mauri McSaveney, believe that sulfur dioxide and nitrogen dioxide released from coal combustion and then converted to sulfuric and nitric acid in rainwater changed the chemical composition of rock at the site of the landslide. The result, they propose, was a less stable rock formation.
“When the idea came to us, we surprised ourselves,” Zhang told Science.
To test their hypothesis in the lab, the researchers submerged a sample of shale from the landslide site in an acid bath. The acidic liquid dissolved the calcite in the sample. Calcite helps cement the rock together. Once dissolved, it left behind a weakened, more slippery rock.
Another impact of the acid rain is that it may be fertilizing microorganisms living in the shale. The researchers believe the rain provides these organisms with oxygen and nutrients needed to thrive, and in turn, the microorganisms feed more quickly on the organic material in the rock, destabilizing it. “It’s an interesting and plausible hypothesis,” said Richard April, a geochemist at Colgate University in New York, who was not involved in the study. He noted, however, that acidic water had rained down on mountains for thousands of years, so it’s unclear exactly how much acid rain linked to recent air pollution would accelerate the weathering of these slopes.
Zhang plans to continue testing the hypothesis using evidence from different parts of the world in an effort to determine whether bad pollution may indeed be contributing to deadly landslides everywhere from China to the United States.
There are few landscapes in the United States that evoke the raw, primal power of nature as strongly as the canyon country of the Colorado Plateau. Here, amid a 130,000-square-mile swath of the Southwestern US, jaw-dropping cliffs and narrow slot canyons plunge hundreds of feet into layers of undulating sandstone.
Within this otherworldly region are some of North America’s most important pre-European archaeological sites, including cliff dwellings; granaries; and ceremonial pits called kivas, tucked under soaring rock alcoves.
On December 28, 2016, after a long collaborative process between the federal government and the Hopi, Navajo, Zuni, Uintah and Ouray, and Ute Mountain Ute tribes, President Obama signed an order establishing the 1.35-million-acre Bears Ears National Monument, protecting these stunning lands.
But last December, in keeping with his obsession to undo the work of his predecessor, President Trump signed an executive order that downsized Bears Ears National Monument by 85 percent, and nearby Grand Staircase-Escalante National Monument, established by Bill Clinton in 1996, by 46 percent.
Condemnation from environmental groups was swift. “This strikes at a core American value – our commitment to set aside special places that preserve our heritage, enrich our lives, and honor the people who forged our history,” said Rhea Suh, NRDC president, in a statement. “It’s an affront to the tribes who forged an historic proposal to co-manage these sacred areas … And this is just the beginning of the Trump administration’s assault on our national monuments.”
“Navajo people have advocated for protection of the Bears Ears for decades, and continue to use and value the land for their livelihoods and cultural practices,” said Navajo Council delegate Davis Filfred. “This monument represents part of our history and our future.”
Many see the president’s actions as a concession to extractive industries looking to exploit coal and uranium deposits that are scattered across the region. However, the rugged, arid terrain has thwarted many a past mining venture. Others say that the decision undermines tribal self-determination, and fear that it paves the way for further downsizing, or outright elimination, of other monuments.
One rumored to be in the president’s sights is Nevada’s Gold Butte National Monument, also designated in the last days of the Obama Administration. It is the site where scofflaw rancher Cliven Bundy illegally grazed cattle for years.
Immediately following the Trump Administration announcement, various tribes and environmental groups announced five separate lawsuits. The plaintiffs are arguing that while the Antiquities Act allows a president to designate national park and monuments, it does not have a protocol for the abolishment of one.
President Emmanuel Macron isn’t taking President Donald Trump’s climate denialism lightly. In December, in a tongue-in-cheek dig at Trump’s “Make America Great Again” campaign slogan, the French president offered 18 climate scientists – 13 of them from the US – grants to move to France and conduct research to “make our planet great again.” The grants follow a promise by Macron to make France a “second homeland” for US climate researchers during the Trump presidency.
Nearly 2,000 researchers applied for grants through the program, the vast majority from the United States. France will launch another round of awards next year, and in total, expects to fund 50 research projects with $70 million. Awardees will pursue three- to five-year-long climate research projects, a timeline that roughly matches the remainder of Trump’s term in office.
“If we want to prepare for the changes of tomorrow, we need science,” Macron said at an event to unveil the first batch of winners.
Awardee Camille Parmesan of the University of Texas-Austin told the Associated Press that it was “such a psychological boost, to have that kind of support, to have the head of state saying I value what you do.” Parmesan will pursue research in the French Pyrenees regarding the impact of climate change on plants and animals.
This isn’t the first time France has taken a strong stance on climate while simultaneously calling out US backpedaling on climate policy. This summer, following President Trump’s announcement that he would withdraw the US from the Paris climate accord, France reacted by announcing that the country would become climate neutral by 2050.
It may take more than 50 research projects to truly make our planet great again, but France’s push to bolster climate science seems like a good place to start.
As far as predictions go, expect the worst. That’s the verdict from two top US climate scientists who set out to determine which climate models are most accurate in terms of predicting how much our world will warm by the end of the century.
Raw climate modeling results for a business-as-usual scenario – which assumes we will continue to spew greenhouse gases at our current rate – indicate that we can expect global temperatures to increase anywhere between 3.2 to 5.9 degrees Celsius over preindustrial levels by 2100. That’s a pretty wide range. Patrick Brown and Ken Caldeira of the Carnegie Institution of Science undertook a study to find out whether the upper or lower end of this range is more likely to prove accurate and concluded that the upper range is the “most likely.”
Their finding, which was published in Nature in December, suggests that most of the models used by the Intergovernmental Panel on Climate Change may be underestimating future warming.
“There are dozens of prominent global climate models and they all project different amounts of global warming for a given change in greenhouse gas concentrations, primarily because there is not a consensus on how to best model some key aspects of the climate system,” Brown explains.
The researchers focused on comparing model projections of the spatial and seasonal patterns of how energy flows from Earth to space. Their strategy relied on the theory that the models that are going to be the most skillful in their projections of future warming should also be the most skillful in other contexts, such as simulating the recent past. And they found that these models tend to project greater-than-average warming in the future.
“It makes sense that the models that do the best job at simulating today’s observations might be the models with the most reliable predictions,” Caldeira says. “Our study indicates that if emissions follow a commonly used business-as-usual scenario, there is a 93 percent chance that global warming will exceed 4 degrees Celsius by the end of this century. Previous studies had put this likelihood at 62 percent.” Yikes!
Camera traps have been a boon for conservation. Thanks to the automated devices – which take a flash photo when motion detectors are triggered – scientists, conservationists, and nature lovers the world over have glimpsed the private lives of animals, uncovered previously unknown behaviors, and even discovered new species. But the ways in which camera traps might be affecting wild species are not as well understood. These devices are considered less invasive than other field observation techniques, but a recent study suggests that female jaguars in particular are becoming camera-shy, calling into question just how unobtrusive the technology really is.
The research, published last month in the journal Mammalian Biology, raises the concern that female jaguars may learn to avoid camera traps. Female jaguars are typically snapped less frequently than males during surveys, mostly because they move around less, and don’t traverse such vast territories. However, during a 54-month study in Brazil’s Atlantic Forest, 83 percent of all camera trap photos taken of female jaguars were taken during the first year of the study. After the first year of the study – which was conducted over five sample periods between 2005 and 2013 – it was nearly a male-only show. According to study author Ana Carolina Srbek-Araujo, this suggests that the females may have been deliberately avoiding the traps. Males also showed similar behavior, but to a much lesser extent, she adds.
Past studies have demonstrated that animals both see and hear camera traps. Individuals of some species seem to move towards cameras after detecting them. Others – including coyotes, snow leopards, and tigers – are known to steer clear of camera traps once they’ve triggered them. Whether or not jaguars in Brazil’s Atlantic Forest are exhibiting similar behavior remains unclear, but according to Srbek-Araujo, preliminary data suggests they may be.
“We are dealing with predators that have a much sharper perception of the environment than we can grasp,” Srbek-Araujo says.
Camera avoidance could lead to “a bias in determining both population size and sex ratios in jaguars,” Srbek-Araujo writes in the report. And if, as the study warns, jaguar cubs learn to copy their mothers, “it will result in a large underestimation of reproduction and incorrect estimates of populations dynamics.” Previous jaguar population studies also may well need to be revaluated to account for this human-induced behavioral trait. “Here and elsewhere, evidence suggests that we must recognize that camera traps can be an intrusive sampling method for some species,” the study concludes.
Camera traps may be offering up new insights into the animal kingdom, but they are raising more questions in their wake, questions that may not be resolved by the snap of a shutter.
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