Cookies help us run our site more efficiently.

By clicking “Accept”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. View our Privacy Policy for more information or to customize your cookie preferences.

Pregnancy Is a War; Birth Is a Cease-Fire

News Feed
Friday, October 14, 2022

Evolutionarily speaking, every human is a bit of a preemie. The nine months most babies spend in the womb are enough for them to be born with open eyes, functional ears, and a few useful reflexes—but not the ability to stand, sprint, climb, or grasp onto their parents’ limbs. Compared with other primates, our offspring are wobbly and inept; they’d probably get their butts kicked by infant lemurs, gorillas, and even tiny tarsiers, which all come out more fully formed. Think of it this way: Researchers have estimated that, for a newborn human to be birthed with a brain as well developed as that of a newborn chimp, they would have to gestate for at least an extra seven months—at which point they might run 27 inches from head to toe, and weigh a good 17 or 18 pounds, more than the heftiest bowling ball on the rack.

The technical jargon that scientists use for underdone newborns like ours is altricial, though when experts are on the phone with journalists, they’re sometimes more apt to toss around words like useless or pathetic. “It’s almost embarrassing how helpless we are, when we compare ourselves to the wild world,” says Jared Stabach, a research ecologist at the Smithsonian. “It makes me wonder how we got to 7 to 8 billion people on this planet.”

Among animals, humans aren’t alone in emerging in such a state. Most songbirds are altricial, hatching in large clutches of chicks that come out pink, naked, blind, and struggling to keep warm, making them super dependent on their parents; much of the same is true for bears such as pandas, which deliver young that are just one-900th of the mother’s size and can’t pee without outside help. The pressures wild animals face—intense predation, food scarcity, environmental stress—can sometimes push certain species to emerge from eggs or wombs earlier. But experts don’t fully understand the reason people are born so vulnerable. One hypothesis, called the “obstetric dilemma,” holds that human hips, which shrank and slimmed as our species evolved to walk upright, are now too narrow to accommodate baby heads of any larger size. Another posits that birth is the termination of an unsustainable lease: Human parents may evict their fetal tenant around nine months to unburden themselves of its thirst for nutrients, or perhaps the baby gladly vacates the premises, having hit the point of diminishing returns.

[Read: Do you even lift, embryo?]

However you look at it, pregnancy is marked by intergenerational strife, if not an all-out war between an offspring and its parent. Birth, then, in addition to welcoming new life, can bring about an end to the harshest hostilities—and its timing partly reflects the terms of a tightly negotiated truce.

That idea might be tough to square with the common conception of pregnancy as “this joyous, wonderful, great time, with the fetus and the mom working toward the same shared interest,” Jessica Ayers, an evolutionary social psychologist at Boise State University, told me. The goals of child and parent, however, don’t always align, even when one is growing inside the other. Fetuses may maximize their chances of surviving after birth by extracting as many resources from their parent as they can. Their tool for mooching is the placenta—technically, the very first organ that any human produces, Ayers said—which allows a fetus to access its mother’s blood vessels and siphon out nutrients. The human placenta actually entrenches itself so aggressively into the uterine wall that it sometimes leads to severe hemorrhaging at birth, Ayers told me, when the tissue starts to rip away.

For the mother to prioritize her own well-being—and her chances of bearing more offspring—her body must hoard at least a few nutrients for herself. “So there’s a conflict over allocation,” says Ava Mainieri, an evolutionary biologist who studied maternal-fetal conflict at Harvard. The fetus repeatedly attempts to remodel its parent’s interior—her circulation, her blood sugar, even her immune system—in an effort to drain a few more drops of the reserves that she is vying to save.

Human mothers, then, may have forged a delicate détente with their offspring by delivering them in a feeble, naked, clingy state. But that’s not the only resolution that can be reached.

Plenty of other creatures give birth even sooner, yielding offspring in a more altricial state. Marsupials, in particular, take this strategy “to the extreme,” David Haig, an evolutionary biologist at Harvard, told me. A red kangaroo, for instance, will gestate her fetus for just four or five weeks before plopping a pink, hairless, jelly-bean-size joey into her pouch, where it will remain for another eight or so months. When little roos are born, their legs “aren’t even properly developed,” Haig said. Roughly 100,000 times smaller than their mother, the joeys are basically a mouth with giant forepaws, built to crawl into the pouch, grab onto teats, and suckle—and do little else. “The rest of the body catches up later,” Haig said.

Lactation is a massive chore for moms, often requiring many more calories than even gestation does—and some animals are born so underdeveloped that they have to nurse for an exhaustingly long time. But an early birth can still quell some of the roughest aspects of the maternal-fetal tussle. Offspring “have less negotiation power once they’re born,” Amy Boddy, a biologist and evolutionary theorist at UC Santa Barbara, told me. A pregnant animal can only do so much to keep a fetus from stealing nutrients from within; a new mother, meanwhile, can choose to pause feeding or coddling its newborn at any time. Chicks, pups, and infants may beg, cry, or whine to extort food from their parents—but these efforts aren’t as direct as what occurs in utero. “The solution to being completely manipulated by the baby is, kind of, to give birth,” said Boddy, who has two children of her own. (In that way, birds have a good gig: They package all the nutrients that their developing offspring need into an egg, then shuttle out the whole shebang … though this does mean that certain species, such as the kiwi, must first haul around eggs that can take up 20 percent of the space in their body.)

Yet other animals have struck an armistice with compromises of a different kind. Their offspring are precocial, born so well formed that they’re able to leapfrog nearly all the feeble travails of infancy. That self-sufficiency comes in handy for creatures that can’t afford to dote on their infants for long, or that are constantly on the move, like antelope, cattle, and horses. But it exacts a parental tax: The babies of precocial species tend to gestate longer—vacuuming up more of their parent’s internal stores—and emerge much larger. “I think of it as front-loading the investment, versus delaying it,” Boddy told me.

Wildebeest, one of the most precocial mammals known to scientists, must weather an eight- or nine-month pregnancy while migrating hundreds of miles across the savanna, often as they nurse an older calf—all before popping out a fresh kiddo that might weigh more than 40 pounds at birth, more than 15 percent of the mass of typical females. To carry such gargantuan offspring, an animal must be in tip-top shape—and constantly seek out resources to nourish her growing load. Still, the prenatal sacrifices really pay off: Just a few minutes after a wildebeest calf is born, even before the amniotic fluid on its flanks has dried, the animal is standing up and galloping around its parents; by the next day, it will be sprinting at almost full tilt, fast enough to keep up with the rest of the herd. It’s almost like giving birth to a “much more coordinated toddler” with the gams of a track-ready teen, says Anna Estes, a wildebeest expert at Carleton College,. All of that certainly behooves (sorry) the calves in question: “If they’re not moving, they’re dying,” Stabach, the Smithsonian ecologist, told me.

[Read: The great thing about mass wildebeest drownings]

Some superprecocial mammals have evolved ways to mitigate the toll of a heavy, extended pregnancy. The placentas of wildebeest and other hoofed creatures, Haig told me, aren’t as invasive as the ones that human fetuses produce—which makes birthing long-gestating, big-bodied calves less risky. When the little ones are delivered, “the placenta comes away very cleanly,” Haig said. Just as her newborn does, “the mother can also get up and walk off very quickly.”

That’s certainly not the tack that humans take. Our “childhood” tends to last for almost two decades in many parts of the world—far longer than the measly stretch a fetus spends camped out in the womb. Giving birth may offer a cessation of certain parent-offspring clashes. But the peacetime ends up being only temporary: When generations stay this tightly knit, more disputes are sure to follow.

Read the full story here.
Photos courtesy of

The Overlooked Danger That's Massacring Wildlife

A new book argues that there’s nothing worse for wild animals than cars.

The surface of the United States is crisscrossed by 4 million miles of public roads—more than that of any other nation in the world. Roads are an essential part of infrastructure; they allow people, goods, and services to flow quickly and efficiently from one corner of the country to another. Bud Moore, who began a long career with the U.S. Forest Service in 1934, and spent decades cutting roads into the American West, once believed that these incursions also benefited wildlife and wildlands. With better access, “elk could be cared for. Natural stream fisheries could be improved. Log jams could be moved … to create more room for fish to spawn.” Nature was messy, he reasoned; human beings could bring order to it.The environmental journalist Ben Goldfarb shows otherwise in his new book, Crossings: How Road Ecology Is Shaping the Future of Our Planet. Crushing turtles, severing ancient deer migration routes, isolating cougar populations—Goldfarb argues that “there may be nothing humans do that causes more misery to more wild animals than driving.” Even Moore realized this toward the end of his life, noting in his 1996 book that “none of us had the wisdom to foresee the consequences.”Crossings is a follow-up of sorts to Goldfarb’s award-winning first book, Eager. That book focused on the industrious beaver, a creature that fundamentally changes the world around it by constructing dams that can have the unintended but beneficial effect of preventing flash flooding and helping maintain groundwater levels. Goldfarb now turns his attention to another “infrastructure species”: humans.[Read: America is telling itself a lie about roadkill]Although scientists have been examining the negative impact of roads since at least the 1920s, only relatively recently, in the 1990s, was the subject given an English name: “road ecology.” Richard Forman, the Harvard ecologist who coined the phrase, defined it as “how life change[s] for plants and animals with a road and traffic nearby.” This is the concept that animates Crossings. Goldfarb expertly researches the history of American roads, shows how the freedom of movement they facilitate became part of the American identity, and outlines the negative and positive ways roads affect both wildlife and humans. Most important, the ideas in Crossings, which Goldfarb examined in a 2019 article for The Atlantic, explore how we can do less harm in the future by rethinking road construction and placement.The roadkill data that Goldfarb collates from scientific papers, citizen scientists, and state officials are alarming. He writes about roads in North America with nicknames such as “The Meatmaker” and “Slaughter Alley.” On one road by Lake Erie, cars killed almost 28,000 leopard frogs during a four-year period. On another in Manitoba, 10,000 red-sided garter snakes died in a season. Roads are usually built to maximize travel efficiency, and the faster cars can drive, the more destructive the result. Various species respond differently to the threat of an approaching antagonist. Some, such as porcupines and rattlesnakes, are confident in their defensive skills. Instead of scurrying from a road when a vehicle approaches, they stand their ground and brace for a siege. An F-150, however, is intimidated by neither quill nor venom, and its driver may not even notice the creature they obliterated.Other animals are hardwired to flee only when a predator is sufficiently close. Called a “flight distance,” this is an energy-saving tactic designed to counter a four-legged threat trotting up at five miles an hour or so, not an 18-wheeled one barreling forth at 70. As a result, deer and some birds don’t even try to escape until it’s too late. “Cars hijacked their victims’ own biology,” Goldfarb laments, “subverting evolutionary history and rendering it maladaptive.”Crossings explains that the ramifications of roads go far beyond skid marks and carcasses: Our roads are changing the molecular composition of wildlife. Cliff swallows nesting under highway bridges in Nebraska may be evolving shorter wings, which one researcher theorizes gives them more maneuverability to avoid vehicles; their less nimble long-winged relatives lie crumpled on the roadside. In areas with high traffic, some species won’t cross highways at all, resulting in genetic isolation. Researchers can look at the DNA of a black bear in Connecticut, or of an Amur tiger in Russia, and know which side of a major road it came from. This isolation can have catastrophic effects: Small wildlife populations are more prone to inbreeding, genetic abnormalities, and extinction. Roads have negative impacts on humans too, reducing walkability in our neighborhoods and increasing stress levels.Goldfarb writes early on that Crossings is “about how we escape” from this trap, a promise I clung to throughout the book like an overboard sailor might to a capsized ship. However, the hoped-for map turned out to be more like a trail of breadcrumbs. The author’s skill as a storyteller, the inspiring road ecologists he meets, and the flashes of successful mitigations could not mask the predominantly grim subject matter. Goldfarb guides the reader from “massive squishings” of frogs in Oregon to the “bloody carpet” of Tasmanian highways, and signs of optimism come only in fleeting spurts. The Netherlands, for instance, has built a wildlife crossing with a functioning wetland spanning a road, a railroad track, and a sports complex. In 2019, India completed the Kanha-Pench Corridor, which is a road mounted on stout pillars that allows elephants and tigers to continue roaming undisturbed underneath.[Read: A basic premise of animal conservation looks shakier than ever]Although drivers can and should take more responsibility for their actions, Goldfarb argues that the onus of wildlife safety should lie at the top—not on drivers like you and me, but on the institutions that cleared wildlands and laid the asphalt to begin with. “What could be more American than blaming deep-rooted problems on individual failings rather than corporate power structures?” he asks. “By all means, slow down at night, brake for snakes, and shepherd salamanders across the pavement. Yet making roads lie lighter on the land isn’t the job of individual drivers any more than swapping out light bulbs will solve climate change. Instead, it’s a public works project.”The key question Goldfarb seeks to answer in Crossings is not whether roads are inherently good or bad, but how we make them better. China’s ambitious Belt and Road Initiative will eventually link about 70 countries around the world with improved transportation infrastructure—which is an opportunity to build roads and rails that are less damaging to wildlife. Brazil, though not officially a member of the initiative, has received significant infrastructure investments from China. Its government is working with local nonprofits to install canopy bridges across highways in the Amazon to aid safe primate crossings. Elsewhere in that country, the road through Carlos Botelho State Park is closed to regular traffic at night, when most wildlife are active. The design of the road might also play a role in wildlife safety, as it’s filled with rises and turns that inherently encourage drivers to slow down and thus reduces the risk of collisions. Developers around the world should take note.In his highly influential 1949 book, A Sand County Almanac, the preeminent American conservationist Aldo Leopold introduced the concept of a land ethic. He believed that water, soil, plants, wild animals, and humans are all part of the same community—one that should be guided by mutual respect. “A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community,” Leopold wrote. Against this standard, Goldfarb notes, “roads are the wrongest things imaginable.” He extends Leopold’s idea to advocate for a “road ethic”: A road is good when it works with the land and its inhabitants rather than seeking to conquer them.For too long, road ecology has been the domain of academics. Researchers have counted the bodies of mammals, birds, reptiles, and amphibians lining our highways for a century; engineers have learned to design mitigations that continually lessen the carnage. But too many of the conversations around road ecology have been confined to the walls of conference rooms or the tight bindings of academic journals. Notably, Crossings is the second mainstream book in as many years to foist the discussion of road ecology on the wider public, after Darryl Jones’s A Clouded Leopard in the Middle of the Road. Beyond the staggering data and the constructive ideas, Crossings is an important book because it is timely: Road ecology is bleeding into the public consciousness at a moment when we can still act on its lessons.

Florida has become a zoo. A literal zoo.

A veiled chameleon in a patch of trees near a canal east of Fort Myers. | Benji Jones These monkeys, reptiles, and birds don’t belong in Florida. Should we kick them out? FORT LAUDERDALE, Florida — I was told the monkeys would be here, although nothing about this spot seemed particularly suitable for wildlife. On a stifling morning in late July, I stood in a large parking lot near Fort Lauderdale-Hollywood International Airport, about 40 miles north of Miami. Cars drove in and out. Planes passed low overhead. It reeked of gasoline.The only visible natural habitat was a sliver of forest, just a few hundred feet wide, wedged between the paved lot, a field of oil tanks, and a highway. I couldn’t find monkeys in the lot, so I tried my luck in the forest. It turned out to be more of a swamp. With each step, thick mud crept past my ankles, making it difficult to move. A thorny underbrush etched puffy red lines into my bare legs.Half an hour in, when I was about to turn back in pursuit of air conditioning and a fresh pair of socks, I heard a rustling overhead. I froze in place and looked up. There, through the branches, I saw the unmistakable face of a monkey. Benji Jones A vervet monkey spotted in a small swamp near Fort Lauderdale-Hollywood International Airport. To see exotic animals in Florida, one could visit Disney’s Animal Kingdom, Busch Gardens, or Zoo Miami. Or they could just step outside. The Sunshine State is utterly brimming with nonnative species. More than 500 of them have been reported here, which is more than in any other state, and many of them are considered “invasive,” meaning they harm humans or ecosystems. For most of their evolutionary history, these species have never set foot in Florida — they’ve never been near a Publix, or Magic Kingdom, for that matter. In the last few decades, Florida has become an unmanaged zoo, an uncontrolled experiment. And each year, the decision of what to do with it gets harder. Benji Jones The monkeys I spotted were vervets, a species native to Africa. That afternoon, I followed a troop from the swamp back to the parking lot, where they lounged in the shade under a parking shuttle and fed on peanuts that someone had put out. One of the monkeys was carrying an infant. A different population of monkeys — a group of rhesus macaques, a species native to Asia — lives in a state park north of Orlando. Some of those are infected with a form of herpes that can be deadly to humans. While monkeys are still somewhat rare in this part of the world, there’s another group of nonnative animals that’s absolutely everywhere: the reptiles. The iguanas and pythons, geckos and basilisks, anoles and agamas. In South Florida, the ground literally moves with green and brown lizards. The trees do, too; some of them are home to color-changing chameleons native to Africa and the Middle East.These creatures are unwelcome — and in some cases, despised. Exotic species are blamed for harming local ecosystems and damaging human property, so the state is trying to get rid of them. It’s gone as far as turning eradication into a sport. Florida’s Fish and Wildlife Commission (FWC), the state wildlife agency, sponsors “rodeos,” events where people compete to kill as many of a certain invasive species as possible. At times, Florida’s battle against exotic species turns violent. Videos online show people hunting lizards, frogs, and other species with blowguns, air rifles, and slingshots, all in the name of saving the environment. For the most part, these efforts aren’t working. And it’s not clear what could. By transforming the natural environment, and covering it with buildings, lights, and lawns, we’ve created the perfect place for many of these exotic species to breed and thrive. Meanwhile, nonnative animals continue to leak into the environment from Florida’s gargantuan pet industry. Eradication has become a game of whack-a-lizard. That leaves Florida in a tough position: Killing sprees are often futile and even cruel, and yet the state can’t simply let all introduced species run rampant. Florida is a zoo. Are its keepers up for the job?This question brought me to Florida during a heat wave in July, where I went on a safari, of sorts — an invasive species safari. My aim was to travel around the state in search of nonnative animals and in the process, answer another, more basic question: Why are there so many exotic creatures in Florida to begin with?A major advantage of this kind of safari is that you don’t have to travel far to find wildlife. One afternoon, I was walking around a gated community in a suburb of Miami. I passed a man unloading groceries from his trunk and another resident walking his dog. Nothing stood out, except for the giant reptile lying in a pile of lawn waste. It was an Argentine black and white tegu, a species native to South America that can grow nearly 5 feet long. Benji Jones An Argentine black and white tegu, a large lizard native to South America. Like most of Florida’s nonnative reptiles and amphibians, tegus were brought to the state by the local pet trade. The industry here — made up of pet breeders and sellers — is among the largest in the country, and this is especially true for reptiles, as journalist Bryan Christy writes in his 2008 book The Lizard King. Florida is a place where you can drive into the country and stumble upon snake farms off of dirt roads. Benji Jones Steven Tillis, a snake breeder and academic researcher in Florida, holding a blood python that he bred. Many scientists blame the pet trade for releasing exotic animals into Florida. Sometimes those introductions are an accident: Hurricanes and other storms can destroy reptile breeding facilities, allowing the animals to escape. In other instances, the problem is more like carelessness. In South Florida, for example, tegus, among the most popular reptile pets in the US, escaped from a breeding facility “where they were kept negligently in open cages,” Frank Mazzotti, a professor of ecology at the University of Florida, wrote in the book Exotic Amphibians and Reptiles of the United States.Sometimes, however, nonnative species are just deliberately put into the environment. In South Florida, there’s such a thing as “chameleon ranches’’ — outdoor spots where people raise chameleons to sell. As opposed to breeding these animals indoors, which can be challenging and expensive, people will place them in trees outside, where the animals will reproduce on their own. Outside, chameleons are easier to raise. They’re also easier to lose. (Chameleons are famously good at hiding.)One night after dark, I drove to a rural neighborhood in southwest Florida with a pair of reptile researchers who had agreed to help me find chameleons. We parked by a canal on a quiet road with a few small homes. The waterway was lined with untidy clusters of palm trees and bushes, and it was there that we searched for these long-tongued lizards. Chameleon ranches tend to be unmarked and somewhat secretive. Putting nonnative animals outdoors is illegal and pet chameleons are pricey; ranchers don’t want people just taking them for free. Fortunately, we had a strong lead. One of the researchers had found sightings of chameleons here on iNaturalist, an app where nature enthusiasts record animal observations. It wasn’t clear that this was an active ranch, but we were certain there were chameleons to find. Of all of the stops on my safari, chameleon ranches, I was told, would be the most dangerous. Although our proximity to the canal meant we were likely on county property, people are “very protective” of their chameleon spots, Natalie Claunch, a reptile researcher at the University of Florida, told me before my trip. (She was not one of the two researchers with me that night.) I was advised to wear a reflective vest, which might make me appear more official.Adding to this risk: You have to search for chameleons at night. Although these animals expertly blend into leaves during the day, chameleon skin appears pale under the harsh beam of a flashlight, making them much easier to spot. Benji Jones A Cuban tree frog perches on a palm tree branch. They’re native to Cuba and a handful of other Caribbean islands. We almost immediately found something exotic — not a chameleon, but a Cuban tree frog, which was perched on a palm tree branch near the canal. Cute, with big eyes and toes, it’s one of the most abundant nonnative species in Florida, with a croak that sounds like a squeaky shoe. We shined our flashlights on the underside of leaves and on the tips of tall grasses. I walked through more spiderwebs than I could count. A screech owl flew by. Benji Jones An eastern screech owl. Not long into our search, I turned over a dead palm tree leaf that was still attached to the tree. There, tucked inside, was a veiled chameleon. Roughly a foot long, with a fin-like protrusion atop its head, the lizard was shaded in muted greens, yellows, and oranges. The colors grew brighter as we drew closer. The chameleon’s eyes — which famously can move independently from each other — were striped like a circus tent. I could easily see why someone might want one of these as a pet. They’re stunning, timid creatures. Benji Jones A large veiled chameleon found clinging to the underside of a dead palm frond. Benji Jones A young veiled chameleon. The pet trade introduces exotic animals to Florida, but it’s the climate that has allowed them to proliferate. Release an iguana in New York City and it won’t make it through the winter; it’s too cold. Let one go here, in tropical Florida, and it might start a family. All it takes for animals to get a foothold is an introduction or two.Not only pet breeders but also pet owners have helped stock the state with exotics. Pet stores have been known to sell animals to people who don’t have the knowledge or equipment to care for them. Green iguanas can grow over 5 feet long. Burmese pythons can reach more than 15 feet, and they feed on mice, rats, and rabbits. Once these pets become too difficult to care for, people might release them into the environment.The state’s peculiar culture likely also plays a role. There’s a sense in Florida that you can do whatever you want and not be bothered, said Adam Rosenblatt, a biologist at the University of North Florida. “There’s an attraction of people who want to live a lifestyle that maybe wouldn’t be acceptable everywhere else,” he said. “Maybe that lifestyle involves having lots of large snakes in your house.” Two other researchers told me that the idea of “Florida man” is real, referring to people in the state with behaviors or attitudes that are odd and perhaps irrational and may include things like throwing an alligator through a Wendy’s drive-through window or getting arrested with a monkey attached to their chest. Yet it’s hard to say whether this oddball culture fuels the spread of nonnative species. Exotic animals have taken other routes into Florida, as well. Those monkeys in Fort Lauderdale, for example, descended from a group of primates that escaped from a zoo and research facility many decades ago. Cuban tree frogs, meanwhile, likely arrived as stowaways in shipping crates. But no matter their path here, several hundred exotic species now live in Florida. Should the state kick them out? Nonnative species have caused an immense amount of destruction worldwide. Some of the most visible ecological damage is in Australia, where they are the primary cause of extinction. Australia’s invasive feral cats alone are largely responsible for the extinction of more than 20 mammals, including the desert rat-kangaroo and a species of bandicoot. Exotic animals can also harm economies, whether they are invasive mussels that clog pipes in the Great Lakes or insects that damage crops globally. Between 1960 and 2020, invasive species cost the US about $1.2 trillion in losses, damages, and management, according to a study published last year. Fire ants, “killer” bees, and a species of mosquito that spreads yellow fever, dengue fever, and chikungunya were among the most costly, the study found. Worldwide, the economic cost of invasive species has at least quadrupled every decade since 1970, according to a new report by the United Nations. Benji Jones Bartoszek holds Luther, a male Burmese python that he tracks and uses as a sentinel to find other pythons. Some of Florida’s exotic animals are undoubtedly destructive, too. Although they appear angelic, gliding through the ocean with delicate, fan-like fins, nonnative lionfish, for example, threaten coral reefs by preying on native species. The state is also home to as many as 17 nonnative mosquitoes. Some of them spread nasty diseases like dengue fever, including the costly one above.Then there are the Burmese pythons. First introduced from Asia by the pet trade in the 1900s, these snakes are now widespread in South Florida, where they are known to grow extremely large. In July, a man caught a record 19-foot Burmese python that weighed 125 pounds in South Florida. Big snakes have big appetites, which does not bode well for Florida’s native species. Sharp declines in the sightings of raccoons, opossums, bobcats, and other common mammals have coincided with the spread of Burmese pythons, one 2012 study found. Another study, published a few years later, found that these snakes are driving down the population of native marsh rabbits in Everglades National Park. That could have negative knock-on effects across the broader ecosystem, as predators like panthers depend on smaller mammals for food. Burmese pythons are “public enemy number one,” said Ian Bartoszek, a wildlife biologist at the Conservancy of Southwest Florida who has been tracking and removing pythons for more than a decade. “Do not underestimate the Burmese python.” Bartoszek and other researchers are confident that “Burms,” as locals call them, are harming Florida’s native ecosystem. Yet for many of Florida’s other nonnative species, the story is far more complicated. Benji Jones The skeleton of a 14-foot female Burmese python. In a vacant lot by a canal in Cape Coral, a city on Florida’s west coast, Ali Mulla held an antenna in front of his body. He was tracking one of Florida’s largest lizards.A graduate researcher at the University of South Florida, Mulla is studying a species native to Africa called the Nile monitor lizard, which arrived decades ago by way of the pet trade. It’s a semiaquatic reptile, with a long, forked tongue, that can reach more than 6 feet from head to tail. Ali Mulla listens to a receiver connected to an antenna in search of a Nile monitor lizard. Like many of Florida’s nonnative reptiles, Nile monitor lizards don’t have a great reputation. Some news reports say these animals are aggressive and terrorize families. Tabloids have suggested they’re capable of eating children. FWC, meanwhile, says they pose a “very high” risk to native wildlife, such as by outcompeting or consuming local species. The state also claims that monitor lizards damage human infrastructure like sidewalks and seawalls by digging burrows and that they pose a risk to human safety. Mulla, a former assistant biologist at FWC, is testing some of these assumptions and trying to answer other basic questions, such as where they live. To observe their behavior, he’s had radio-tracking devices implanted in some of the animals in Cape Coral. Those devices send signals to a receiver that’s attached to the antenna. I joined Mulla on a muggy afternoon during his field season to locate a couple of these lizards. The idea is that as he gets closer to the transmitter — closer to the lizard — the receiver produces louder and louder beeps. These animals aren’t just lumbering down city streets; they’re skittish and highly elusive, often hiding underground and underwater. The receiver would be beeping loudly and there’d be nothing but fallen branches and some green iguanas in front of us.Later that afternoon, the receiver indicated that we were on top of a monitor. I crept toward the edge of the canal, trying to avoid breaking sticks beneath my feet, and there on the bank, I finally saw one: a small monitor, just over 2 feet long, with striking yellow and black scales. Then, with a splash, it was gone. Courtesy of Ali Mulla A small Nile monitor lizard spotted by a canal in Cape Coral. Courtesy of Ali Mulla Although they’re called “monsters” and “beasts” and compared to Godzilla, Nile monitors are not aggressive toward humans and are very timid, Mulla said. Meanwhile, there’s “no evidence to suggest that Nile monitors cause population-scale impacts on native species,” he said. Data indicating that they outcompete native fauna and damage infrastructure by burrowing is similarly absent from the scientific literature, he said. (Mulla noted that a lack of evidence is not proof that these animals don’t harm the environment.) Arguing that nonnative lizards are bad because they dig burrows can also harm the reputation of native animals, Mulla added. Native species, such as gopher tortoises, an imperiled species, dig burrows, too, he said. In fact, monitors often occupy burrows dug by other animals, though they’ll sometimes widen them.In a statement to Vox, FWC said it “uses the best available science to determine which nonnative species could present a high risk to human health and safety, the economy, and/or the environment.” The agency declined to comment on the lack of scientific evidence linking Nile monitors, green iguanas, and cane toads to environmental harm. In reality, the ecological impact of Nile monitor lizards is unclear. The same is true for several other nonnative species in Florida, such as green iguanas and cane toads. Blamed for harming native fauna, these animals have similarly bad, or worse, reputations — and they are often treated accordingly. “People love sharing stories with me about the disgusting things they do [to cane toads],” said Melinda Schuman, a biologist who studies cane toads at the Conservancy of Southwest Florida. She was reluctant to share examples with me, due to their gruesome nature, but said they include shooting the animals with BB guns and whacking them with shovels and golf clubs. (FWC encourages people to kill nonnative species humanely.) Benji Jones A baseball-size cane toad in the grass by a well-lit parking lot in Naples. Native to Central and South America, cane toads do have some frightening features. They’re poisonous; when threatened, milky white toxins ooze from glands on their heads. That can be a problem for dogs. When curious pets bite or lick these amphibians they can get sick and, on rare occasions, die. But again, it’s not clear how these toads are impacting Florida’s local fauna, Schuman said. Wild animals in the state may know to avoid cane toads because they’ve evolved with another native toad that also produces toxins (albeit in smaller quantities). And while cane toads will eat pretty much everything, including mice and small birds, they seem to mostly consume invertebrates, she said. In a new study led by Schuman, researchers examined the stomach contents of cane toads found in two golf course communities in Naples. The most common invertebrates they consumed, she found, were urban pests, including insects like weevils, which feed on turf grass. (This makes a lot of sense, as cane toads were originally brought to Florida to control agricultural pests, Schuman said.) Benji Jones Biologist Melinda Schuman looks through vials containing insects and other animals found inside the stomachs of cane toads in Naples. Benji Jones A vial containing a weevil, a common pest. Ultimately, cane toads, iguanas, and many other nonnative species in Florida seem to be more of a nuisance to humans than a real blight on the environment. People understandably don’t want their pets to get sick. They don’t want iguanas gorging on plants in their gardens. (Residents also complain that the loud croaks of cane toads and Cuban tree frogs can make it hard to sleep.)“We tend to blur the lines between what’s a human inconvenience versus what’s an ecological problem,” Mulla said.That doesn’t mean that the desire to rid Florida of nonnative animals is never justified. But we should be clear when we’re getting rid of them for humans’ sake — for our convenience or our economies. Hunting down nonnative species is not always some selfless act to protect the environment.Florida, like any spot on Earth, will never return to some historic version of itself. Over hundreds of years, humans have irreversibly transformed the environment. We’ve razed natural habitats and created new ones. It’s no surprise that in this new ecosystem, there are new species; we’ve literally created novel ecological niches for them to occupy. But the question still stands: What do we do with all of them?One idea is to simply embrace nonnative species. From a somewhat fringe perspective, nonnative species actually increase the state’s biodiversity, a common measure of ecological health. As far as scientists know, exotics have yet to drive any native species extinct; they only increase the total number of species in Florida ecosystems, according to Ty Park, the owner of Iguanaland, a reptile zoo and breeding facility near Sarasota. “The world has changed,” Park said. “We have to live with that.” Benji Jones Park poses next to his pet rhinoceros iguana, Donkey Kong, which he keeps at Iguanaland. There’s also little evidence that eliminating invasive species once they’re established in Florida can even work, according to Sean Doody, an invasive species expert and reptile researcher at the University of South Florida. “Eradicating or stopping the spread of tegus, iguanas, brown anoles, Cuban tree frogs, and Burmese pythons into suitable habitats with appropriate climates and resources is like trying to stop a hurricane,” Doody wrote in a recent book review. “It cannot be done.”Consider Florida’s python hunting challenge. During the highly publicized competition, snake hunters compete to kill as many pythons as possible for a grand prize of $10,000. These sorts of competitions remove only “modest numbers” of Burmese pythons, and “will not result in a measurable reduction in numbers,” Doody wrote in his review. “What it will do is (falsely) convince the public that it is helping to save the native mammals in those parks.”There is a flip side. Even if nonnative animals are not driving local wildlife extinct, they’re obviously altering ecosystems that are already under siege. Burmese pythons are apex predators, and they need to eat. Native toads can mistake cane toads for mates, potentially screwing with their chance at reproduction. And in many cases, exotic species are competing with local ones for food and other resources. Why not err on the side of caution and get rid of as many of them as possible? Benji Jones Four different nonnative lizards. Top left: Peter’s rock agama. Top right: Brown basilisk. Bottom left: Brown anole. Bottom right: Night anole. Perhaps the best approach lies somewhere in the middle. Florida should measure the impacts of nonnative species and go from there. That sounds basic, but that’s not how management works today in Florida, Doody said; the science to support whether something is truly harmful is lacking. (Mazzotti, the University of Florida ecologist, makes the point that when a new invasive species is discovered, it pays to act quickly, even without sufficient evidence of harm, so the animal doesn’t have time to spread beyond control.)Bartoszek’s work is a good example of where eradication efforts might pay off. Instead of killing every python he encounters, his team tracks male snakes and uses them as sentinels. The males lead them to females that are much larger. Over the last decade, his team has removed more than 31,000 pounds of snakes. The pet trade bears responsibility, too, as it remains a fuel for the spread of nonnative species. Reptile breeders I spoke to acknowledged that the industry has played a role in introductions, but they say it’s more careful now. There’s a way to do it right, such as breeding smaller reptiles that owners are less likely to release and in colors that make them an easy target for predators, should they ever get out. (FWC has also banned the breeding and possession of a number of nonnative species including tegus and green iguanas.) What we shouldn’t do is rally the public against nonnative animals like iguanas and tegus simply because we don’t like them. This is at best unhelpful and at worst cruel. Sure, it’s easy to demonize animals we find icky and blame them for destroying the environment. But in reality, it’s us; it’s humans who have been wreaking ecological havoc, allowing these species to thrive in the first place. Animus toward nonnative species is often little more than a distraction from our own behavior. The truth is these animals are here because of humans — because we altered the environment in such a way that allows them to thrive. “They seem to want to live where we live,” Schuman said of cane toads. “We provide everything they need to be comfortable. We bring bugs for them to eat. We turn on sprinklers at night. We’ve made it a utopia.”On my four-day safari, in which I ultimately spotted more than 20 species, I also learned that it’s possible to admire and respect nonnative species, while, at the same time, acknowledging that they can be harmful. I visited a small park in Miami on my last day in Florida, where I’d heard there were exotic parrots. I saw the birds flying overhead before I even exited my rental car. These weren’t just any parrots but blue and gold macaws — majestic creatures, measuring 3 feet from head to tail, with colors so brilliant they looked artificial. Benji Jones A pair of blue and gold macaws. Benji Jones I didn’t have to travel to the jungles of Central or South America, their native range, to see them; I just had to drive 15 minutes from my hotel. They squawked and preened each other and fought over water. These animals are not from here, but this is their home.

We Need to Talk About Roadkill

As perilous as it is for you to ride in a vehicle, cars may be even more treacherous for wild animals on the road. “It has never been more dangerous to set paw, hoof, or scaly belly on the highway,” writes science journalist Ben Goldfarb in his new book, Crossings: How Road Ecology Is Shaping the […]

As perilous as it is for you to ride in a vehicle, cars may be even more treacherous for wild animals on the road. “It has never been more dangerous to set paw, hoof, or scaly belly on the highway,” writes science journalist Ben Goldfarb in his new book, Crossings: How Road Ecology Is Shaping the Future of Our Planet. The book is teeming with horrifying statistics: More birds die every week on US roads than were killed by the Deepwater Horizon oil spill; each year, frogs are squished by the millions; in New York alone, a deer collision occurs every eight minutes. And, it’s getting worse—as many as 12 percent of land-dwelling mammals end up dying on the road, four times what it was 50 years ago.“Name your environmental ill—dams, poaching, megafires—and consider that roads kill more creatures with less fanfare than any of them.”Yet, as an environmental concern, America’s roadkill problem has largely been kicked to the, well, curb. “Name your environmental ill—dams, poaching, megafires—and consider that roads kill more creatures with less fanfare than any of them,” Goldfarb writes. In part, he says, that’s because of roads’ ubiquity, or more specifically, their normal-ness. “Their impacts have gone understated both by journalists and, until relatively recently, by conservation groups,” he tells me.And while human car deaths in the US number around 40,000 every year, we put up with that risk in exchange for fast, convenient travel—that is, freedom. America’s animals are afforded no such luxury. “Even as roads encourage human mobility, they do the precise opposite for wild animals,” Goldfarb says. “They curtail animal migration and mobility and movements.” That tension is what Crossings is about, he says. The book also sheds light on possible solutions. Wildlife crossings like overpasses and underpasses have been shown to dramatically cut down on animal collisions. Take one example from Wyoming: In the early 2000s, officials installed a series of underpasses in Nugget Canyon, near the Utah border. “Roadkill plunged, from almost ten victims monthly to fewer than two,” Goldfarb writes. Road ecologists estimated that the underpasses prevented 95 wildlife-vehicle crashes per year. This wasn’t just good for animals. In economic terms, that was a savings of at least $627,000 in human pockets, in avoided hospital visits and car repairs. “Crossings weren’t lavish expenditures; they were downright thrifty,” he writes.They’re also extremely popular. In today’s polarized world, Goldfarb tells me, “it’s so difficult to get anybody to agree on anything, especially when it comes to environmental issues and conservation interventions.” Wildlife crossings are an exception; by some estimates, more than 80 percent of residents in western states such as Colorado, New Mexico, and Nevada favor the installations. Crossings, out this week, is Goldfarb’s second book, after Eager: The Surprising, Secret Life of Beavers and Why They Matter (a book, I argued last year, that was in part responsible for the rodents’ long overdue rebrand as environmental heroes). In a way, the two books are odd cousins. As Goldfarb and I discussed last week, both beavers and humans are builders, with one critical difference: “Beavers build in ways that are beneficial to all other life on Earth,” he tells me, “whereas our construction tends to be really detrimental to all other life on Earth.” While that may sound bleak, Crossings is at times surprisingly funny. When we spoke, I asked Goldfarb about his love for long road trips and finding moments of joy in reporting about roadkill. You can read an edited and condensed version of our conversation below:Why roads? Of all the environmental ills to focus on, why this one?Roads are largely underappreciated as an environmental impact. Think about how much has been written about climate change, for example, and obviously, rightfully so. But when you think about the forces that are destroying biodiversity right now, roads are—their impacts are enormous. And because they’re such ubiquitous parts of our daily lives, they’re kind of invisible to us. There are so many [conservation] groups focused on climate change and poaching and deforestation, and roads touch all of those other environmental impacts. As I say in the book, they’re the routes—r-o-u-t-e-s—of all evil; they facilitate all of those other ecologically devastating activities.Roadkill, you write, is a very visible environmental problem. As a kid, for instance, I remember seeing in my neighborhood a dead cat that had been just squished by a car, eyes bulging out. That image has stuck with me my entire life. Do you think that’s helped make this a bipartisan environmental issue? That unlike, say, climate change, people see it in their own daily lives?In a lot of respects, roadkill is the way in which we interact with nature. If I had to guess, I would say that more Americans have seen a road-killed opossum than an alive one. As that cat was for you, it is viscerally shocking and upsetting when we see it. I’d like to imagine that most people fundamentally care about wildlife, not just for conservation reasons, but because we are fundamentally compassionate toward animals at our core. Even if that fades as we age, I think it’s still within us. Nobody wants to see an animal dead by the road. So yes, I think that the visibility of the problem induces us to care about it.“If I had to guess, I would say that more Americans have seen a road-killed opossum than an alive one.”In the epilogue, you discuss the “Anthropause”—the mass quieting of the world as a result of pandemic lockdowns. How did Covid, if at all, shape your view of roads?It was kind of an inadvertent experiment: What would happen if we abruptly shut off traffic? And the animal response was amazing. Roadkill rates declined dramatically. Covid revealed how severe roadkill was by abruptly turning it off. Suddenly, when millions of animal lives are being saved by us not driving, you start to think, Wait a second, why are millions of animals dying in the first place? One point that you touch on a few times is the idea of humans, Homo sapiens, being defined by infrastructure. Like, we are a species that builds stuff—Just like beavers.Yes, exactly—like beavers! And while our roads do have negative consequences, like fracturing landscapes, they also can be a source of food for other animals, as you write, like vultures. It made me wonder, philosophically, are roads “nature”?That’s something eco-philosophers have debated in many different forums for decades. I think that what we do is fundamentally unnatural, in so many ways. And obviously, yes, we are an animal like any other. But we’re also unlike any other in the scale and scope of our construction.For those species that benefit from roads, like scavenging birds, vultures, and golden eagles, for example, the road is still potentially an ecological trap for them. It lures them in with the promise of carrion, and then it kills them with cars. The road is a habitat in its own right. But it’s also fundamentally and profoundly dangerous.So much of your book is about roadkill—deer, toads, butterflies, anteaters, the list goes on—yet, it strikes a tone of levity. In writing it, how did you find humor in all of that death?I think it was something that I was very conscious of on the page. This is going to be, like, the most pretentious, stereotypical, white guy thing but, for much of my adult life, my favorite novelist was David Foster Wallace—I know, embarrassing. I’ve got Infinite Jest on permanent display in my house. It’s such a cliche. But I was actually thinking about him a lot with this book because one thing he does well is write about really dark themes—mental illness and addiction and suicide—using really light, funny prose. And I was thinking the same thing: How do I guide the reader through a dark thematic book that she might not otherwise be able to stomach? I felt like the answer was to try to keep it light and funny on the level of the sentence.I came away from Crossings with a feeling of optimism. Maybe, as we’ve become more aware of our own destruction, we’re able to do something about it. Did you intend for that feeling—for that sense of agency?It’s difficult because there are no perfect solutions, right? It’s easy to say, for example, “We need to improve mass transit.” And, certainly, that’s the case. We need to get people out of cars. But I live in rural Colorado, and it’s pretty hard to imagine the public transportation infrastructure that would get people out of their cars here.Wildlife crossings are another kind of imperfect solution. They’re very helpful in that they tackle certain problems—they reduce roadkill and they allow animal migrations to continue on either side of the highway. But they don’t address road noise or tire particulates or road salt being indiscriminately applied and changing the chemistry of [the environment].There are all these different solutions out there. And they all address small pieces of the problem. But there is no single solution. So it’s interesting that you ultimately felt that the book was optimistic because that’s not always how I feel.Throughout the book, you seem to grapple with your own use of roads. You write, for instance, that you enjoy long road trips. But as you said, roads may be “the routes of all evil.” Did this conflict shape the book?That conflict profoundly shaped the book. One of the things that I was very conscious of was not being ‘holier than thou’ and lecturing my readers, because I drive a lot. I don’t have a daily commute, but I use my car several times a week to access these natural places that I love. I am part of the problem. Just a couple of nights ago, I hit an owl driving back from a hiking trip and felt, of course, miserable about it. I am complicit.“If I wrote a book that just hectored people about their driving habits, I’d be unlikely to change their minds.”I think about road ecology in kind of the same terms as climate change. For a long time, I think the environmental movement was very focused on changing people’s individual behavior, the ultimate symbol of that being, If we all just change our light bulbs, we’re going to solve climate change. And, of course, that wasn’t effective, right? Both because individual behavior isn’t really the scale at which you need to tackle the problem, and also because, when you just nag people about their light bulbs you can turn [the people] off. I think road ecology is similar. If I wrote a book that just hectored people about their driving habits, I’d be unlikely to change their minds.I truly believe that getting individual Americans to stop driving isn’t particularly realistic. What we really need is systemic change, whether that’s better mass transit or more wildlife crossings. We need to solve this problem at an infrastructure level, rather than at the individual behavior level.

Costa Rica Wildlife: The Ant Acacia’s Other Animal Interactions

The ant acacia is a small, thorny tree found in different parts of Costa Rica. It is famous, not for its impressive thorns or its ability to thrive in harsh environmental conditions, but because of its relationship with different species of ants. As we’ve covered before, each ant acacia tree in Costa Rica provides food […]The post Costa Rica Wildlife: The Ant Acacia’s Other Animal Interactions appeared first on The Tico Times | Costa Rica News | Travel | Real Estate.

The ant acacia is a small, thorny tree found in different parts of Costa Rica. It is famous, not for its impressive thorns or its ability to thrive in harsh environmental conditions, but because of its relationship with different species of ants.As we’ve covered before, each ant acacia tree in Costa Rica provides food and housing for one of four species of ants which pay for their room and board by aggressively defending the tree from predators and competitors. It’s a fascinating relationship that an ecologist could dedicate years to studying the intricacies of the interaction. As it turns out, there are even more wildlife interactions layered upon the ant acacia’s ecological dance with the acacia ants. Let’s take a look at a few.Ant Acacia + Even More AntsPicture a group project from your schooldays. There are a few people dedicated to working together so that the project comes to a successful conclusion, but then there’s always a few others who attempt to ride the coattails of the group and reap the same reward without actually contributing anything. This is the role of the parasitic acacia ants.While the hardworking mutualistic ants are earning their keep by defending the acacia tree, the parasitic ants take advantage of the tree’s hospitality without actually defending it. I suppose there are hangers-on in every society.Ant Acacia + BirdsWhile it’s smart for many species, Homo spaniens included, to try to avoid interacting with ant acacia trees, some species of birds seek them out. They see a thorny tree covered in stinging ants and think “That’s a great place to raise a family.” It may seem counterintuitive, but ant acacias can be an ideal place to build a nest. A few species of birds, like the rufous-naped wren and streak-backed oriole, often build their nests atop these well-fortified trees. The garrison of ants and the large, stabby thorns provide excellent protection from predators that would like nothing more than a bird egg snack.These birds start their nest construction by quickly placing their dry nesting material atop the tree. The ants do what they do and begin investigating/attacking the nest material. As this process continues, the repeated ant attacks result in a nest that’s covered in the ants’ own chemical smell. Due to this, the attacks eventually cease, and the birds are free to raise their young with the constant protection of a spikey tree and a mess of stinging ants.Ant Acacia + Veggie SpiderI only recently found out about this interaction, and it blew my mind. As many nature-lovers know, spiders are carnivorous. Many species eat insects, some eat fish and other aquatic organisms, and there are huge spiders that can eat creatures that most folks would consider way too large for a spider to eat. Well, within the tens of thousands of species of arachnids, there’s at least one vegetarian. The ant acacia jumping spider.While these spiders were described in the late 1800’s, their diet was only discovered in the last few years. Two separate groups of researchers stumbled upon this fascinating information at approximately the same time. The vast majority of this spider’s diet consists of the Beltian bodies that the ant acacia produces to feed the acacia ants. The spider spends its days avoiding the aggressive ants and chowing down on their specialized supper.The ant acacia tree and the acacia ants alone are a captivating example of different species interacting while fighting to survive. The addition of these extra layers of species interactions points to the interconnectedness of all of the organisms in the natural environment. Who knew what seemed to be a tree with some ants on it would turn out to be so complex and interesting?About the AuthorVincent Losasso, founder of Guanacaste Wildlife Monitoring, is a biologist who works with camera traps throughout Costa Rica. Learn more about his projects on facebook or instagram. You can also email him at: vincent@guanacastewildlifemonitoring.comThe post Costa Rica Wildlife: The Ant Acacia’s Other Animal Interactions appeared first on The Tico Times | Costa Rica News | Travel | Real Estate.

Suggested Viewing

Join us to forge
a sustainable future

Our team is always growing.
Become a partner, volunteer, sponsor, or intern today.
Let us know how you would like to get involved!


sign up for our mailing list to stay informed on the latest films and environmental headlines.

Subscribers receive a free day pass for streaming Cinema Verde.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.