Do Dogs Get Jealous?
Inspiration struck psychologist Christine Harris when she was visiting her parents and their three border collie puppies. “I was petting two of them, and the third would take his head and push the others away,” she says. At the time, Harris was studying sexual and romantic jealousy in humans, which led her to wonder: do dogs show jealousy?
So, Harris and undergraduate Caroline Provoust decided to look into the question. They visited the homes of 36 dogs and videotaped them in three scenarios. (This procedure was adapted from a study of jealousy in 6-month-old infants.) In one scenario, dogs watched as their beloved human lathered affection upon a toy dog that barked and wagged its tail. Owners were asked to pet and coo at the toy as if it were real. In another scenario, the owner directed the same affection toward a jack-o-lantern pail (like the ones you fill with candy on Halloween). In the third scenario, the owner read from a musical pop-up book. “We weren’t sure what we were getting into,” says Harris. “We didn’t know if they would believe the interactions, or if they would they go ballistic.” Since there was a chance the study would rile up the dogs, they recruited small dogs whose owners reported they were rarely aggressive.
It turns out that dogs showed the most jealous behavior toward their toy dog rival. The study, published Wednesday in PLOS ONE, found that 78 percent of the canine participants nudged or pushed their owner’s arm away from the toy dog. Only 42 percent behaved this way when the owner was interacting with the jack-o-lantern. Additionally, 30 percent of dogs tried to walk between and separate the toy dog and owner. A quarter of dogs even showed aggressive behavior, lunging or snapping at the toy dog. In contrast, dogs were unfazed by their owner reading a book. During that scenario, “dogs just strolled off,” says Harris. “They were much more active and seemed more distressed when their owner was paying attention to the stuffed dog.”
Jealousy is often presumed to be a uniquely human emotion because it involves a sophisticated web of beliefs. The classic example of jealousy toward a significant other’s attractive new friend actually requires a lot of thought: You have to consider your relationship and your partner’s relationship with the new friend, and then assess what their friendship could mean for you. Dogs may be showing jealous behaviors in Harris and Provoust’s study, but are they really capable of all that analysis? “I don’t think dogs are necessarily doing that,” says Harris. In their paper, Harris and Provoust suggest that there could be a “primordial” version of jealousy that kicks in when you see a loved one giving attention to anything but you, leading you to take action by getting between your loved one and the possible usurper.
Though the majority of dogs showed some form of jealous behavior, not all did. In future studies, Harris hopes to find out what’s different about those dogs. It could be that those were the not-so-smart dogs who didn’t realize the fake dog was swooping in to steal their human’s attention. Or perhaps the dogs who didn’t react were actually the most clever, because they realized the fake dog wasn’t real competition. (The paper reports that 86 percent of the dogs sniffed the fake dog’s rear end during the study, which suggests that they suspected the stuffed dog was real.) Strength of the dog-owner bond could also be a factor; dogs who didn’t react may have just cared less about the interloper.
As much as we would love to know what dogs are thinking or feeling, this study can’t tell us that. From a scientific perspective, all we know is that they often engage in behaviors that we humans associate with jealousy. But, dog owners, if it makes you feel any better go ahead and believe this: Fido definitely loves you very, very much.
Watch Amazing Bird Artist David Allen Sibley Draw a Townsend’s Warbler
Famed illustrator, ornithologist, and author David Allen Sibley dropped by the BirdNote studio while in Seattle on a book tour. We talked to him about his art, the artistic process behind his best-selling The Sibley Guide to Birds, and how his appreciation of nature was cultivated as a child. He stayed a few extra minutes to sketch a bird for an appreciative BirdNote team. Thankfully, our cameras were rolling. David finds it easiest to sketch a bird he's seen recently. On this day, that fortunate bird was a Townsend's warbler spotted on a field trip David had taken that morning with the local Audubon chapter.
In preparation for his numerous publications, David has sketched literally thousands of birds. It was fascinating to watch as this bird gradually took shape, all from memory. We hope you enjoy this insight into his artistic process.
View the original video on YouTube. Here’s a transcript:
Drawing is a way—it’s a method of looking at birds, for me. And the sketching, it’s not so much the drawing that I produce but the process of getting there, the observation that is required. And that leads to all kinds of discoveries.
I know the shapes and the postures and the general color patterns. I know what I’m shooting for, based on all my own experience and my sketches. I use photographs as reference material to make sure I’m getting the details right. But I've found that what I’m sketching, what I’m drawing and then painting, the shapes and proportions and postures that I’m painting, they are never exactly what I see in a photograph. It’s always a merging of all kinds of different experiences that I had. But you won’t ever find that particular shape in a photograph because what I’m trying to paint is not one instant in time. It’s sort of the impression of many experiences.
So I spent years in the field, just traveling and birding and sketching. Just doing pencil sketches, getting to know the birds, learning the shapes and the postures and the general patterns. And then when I go into the studio to paint, I have my sketches. I gather together all the photographs I can find. I’ve already visited museums and looked at specimens and taken notes on those. So I have all that material and I’m working on paintings. But what I try to put into the painting is sort of a "summary" or a compilation, a synthesis of all of the things that I’ve seen, all the things that I’ve learned, and to show a generic … not generic... but a stereotypical bird of that species of that plumage.
Most people—I know it’s true for me—I enjoy looking at an artist’s sketches. If I’m at an art museum, the sketches that an artist does are often much more interesting than the finished painting. And I think part of that is that there’s so much left out of the sketch. It’s just an outline, a suggestion of what might be happening there. And we really have to interact with the sketch. We have to fill in a lot of the details in our mind, fill in the gaps and create a whole scene that, in our mind, fills in what the artist has started to suggest there.
And when I’m painting in the field guide, I’m trying to simplify as much as possible. So my paintings in the field guide, I’ve tried to just show the birds, the way they would look, at a distance, through binoculars, the broad outlines of patterns and colors, the shapes, but a sort of "generic" neutral posture for every species, neutral lighting, no background, no habitat. So there’s nothing there that suggests a particular experience that you’ve had. It’s just the bird and its distinguishing features. Sort of a "patternistic impression" of what that bird will look like.
You can look at the illustrations in the field guide and there’s a lot there, and a lot of details that aren’t there. A lot that you can fill in. A lot of blanks. You can superimpose your own experience onto it.
BirdNote thanks David for taking the time with us that day!
"David Allen Sibley Sketches a Townsend's Warbler" © BirdNote 2014
Video shot and edited by Adam Sedgley. Interview by Chris Peterson, recorded by John Kessler. Ambient audio edited by John Kessler.
These Flowers Have an Ingenious Pollination Mechanism
Flowers used to come with understood meanings. Marigolds were for the jealous and aggrieved; ambrosias a sign of love returned. Dumas fil’s heroine in Camille carried white camellias when in the mood for a tryst; red ones said, “not tonight, sweetheart.”
Un-plucked flowers, however, don’t leave their intentions up to human interpretation. They have evolved highly specific characteristics to ensure that whoever comes calling will help them bear fruit. A newly discovered pollination mechanism in the flowers of the South American Axinaea genus of shrubs, described in Current Biology, exemplifies this evolutionary ingenuity. These Andean blooms rely on birds to spread their pollen, and they have an elaborate floral architecture to make this happen.
Bird pollination is uncommon for plants of the Melastomataceae family to which Axinea belongs: Bees pollinate 98 percent of them. But ornithophily—as bird pollination is called—is known to occur in more than 500 genera of flowering plants. Many of them grow on mountainsides: Few bees buzz in high altitudes and windy conditions. Birds are more reliable when it rains, and they fly farther, potentially pollinating within a greater range. Research suggests that bird-pollinated plants in these regions are more successful.
But blossoms that are inviting to birds are harder to make than ones that attract bees. They have to offer more food energy (which usually means more nectar), taking more of a plant’s resources. They must be shaped to be reachable to a bird’s beak but protected against nectar poaching by other animals that will not help them breed. Bird-pollinated flowers are often bigger than bee-pollinated ones, with complex structures to heighten allure and easy (but not too easy) access: tubular blossoms if hummingbirds are likely to hover next to them or growing in clusters if frequented by perching birds. These traits have emerged independently in many plants. Botanists think most of these species adapted from first being bee-flowered to bird-flowered ones when the latter proved advantageous for their habitats.
Axinaea has evolved a unique anatomy to maximize pollen delivery by the birds that visit it, as Agnes Dellinger of the University of Vienna and her colleagues observed. Their cameras captured how some species of tanagers, ubiquitous local song birds, alight next to Axinaea blossoms and pick out and eat the large, brightly colored stamens encased by the flower’s rosy-hued petals.
It seems odd for a flower to offer up its reproductive organs for consumption. But Dellinger found that in the case of Axinaea plants, this was perfectly reasonable: The stamen of their flowers is hollow and filled with air as well as pollen. When a bird plucks one from the flower’s base, squeezing the stamen’s stem, it causes the air within to expel the pollen like a bellow, blowing powder onto the bird’s head before the stamen is gobbled up.
The stamens are high in sugar, the researchers found, explaining why tanagers relish them. Moreover, only birds could harvest them: Vibrations or small disturbances were not enough to dislodge a stamen and activate its bellow mechanism. That means fewer opportunities for insects to plunder all their stored energy without contributing to the reproductive cause.
One hundred and fifty million years of evolution have made flowering plants astonishingly adept at dressing up their blooms for greatest effect, whether through size, shape, or color. (Ornithophilic flowers, for example, are more likely to be red—birds see the color well, but bees can’t perceive it.) But few designs measure up to the Axinaea’s sophistication: No other plant is known to have a flower with a bellow structure quite like it, nor a stamen meant for eating. An old-fashioned romantic might consider presenting a sprig if he is trying to coyly convey a message about his cleverness, adaptability, and commitment to reproductive success.
How the World’s Largest Flying Dinosaur Avoided Crash Landing
In the dinosaur world, raptors have a reputation for being ferocious, fast, and having sharp claws to slash open their prey. A new fossil unearthed in China confirms that some raptors could not only rip your face off—they could also fly. The new species, called Changyuraptor yangi, is the largest known flying dinosaur. It was named for its hallmark feature: long feathers (chang yu), which grew on its tail and legs. Changyuraptors and other dinos from their family of raptors are often called “four-winged” dinosaurs because their long feathers make their legs look like a second pair of wings.
This is one of several recent discoveries that suggest flight did not originate with birds but with their dinosaur ancestors. Paleontologist Luis Chiappe has studied the origin of birds for more than two decades, but he was floored when he first saw the Changyuraptor fossil, the subject of a paper in today’s issue of Nature Communications. “It was stunning to see,” he said. “You have the quintessential feature of a bird—these long feathers that are remarkably similar to modern feathers—attached to the body of a fearsome dinosaur like a raptor—sharp teeth, sharp claws, and a long tail.”
The specimen Chiappe and colleagues studied was around 4 feet long, and they estimate it weighed around 9 pounds. As the largest flying dino, Changyuraptor had extra challenges in flight. Maintaining careful control during landings would have been especially important for survival, since large animals tend to fly faster, which creates the potential for dangerous crashes. Researchers’ analysis of the fossil found that its foot-long tail feathers were great for catching winds and helped direct its flight, especially during landings. “Just the same way you land in a plane, Changyuraptors needed to slow down and pitch their nose up,” said Chiappe. “Otherwise, they would crash.”
Part of the reason scientists were able to make such detailed observations of this fossil has to do with where it came from. This fossil was found in the Jehol Biota, an incredibly rich source of fossils in the Liaoning Province of northeast China. Hundreds of exceptionally well-preserved fossils have been found in this area, due in part to the conditions of its ancient environment. When Changyuraptor lived—120 million years ago, during the early Cretaceous period—the area was densely forested, with small lakes and streams and many active volcanoes. Volcanic ash buried animal corpses on land and in water; some were even buried in sudden, Pompeii-like eruptions. Lakes in the area had very little oxygen, which meant specimens were not scavenged by other animals, and were less prone to decomposition by bacteria. This preserved delicate soft tissues like feathers, skin, muscle, and guts.
Despite the exceptional preservation of this specimen, it wasn’t perfect; Chiappe said that in the fossil they studied, the Changyuraptor’s legs overlapped. Chiappe and his team believe these “hindwings” were useful in flight, but its not yet clear how useful.
This is a rare glimpse into the beginning stages of flight evolution, showing that even fairly sizeable dinosaurs could fly. “In the context of a dinosaur, this is a small guy, but in the context of a flier, it’s quite sizeable,” said Chiappe. “I’m sure we’ll find even bigger animals in the future.”
Rosie O’Donnell, New Co-Host of The View, Killed an Endangered Hammerhead Shark
After controversial anti-vaccine activist Jenny McCarthy was let go from The View, the producers were presumably looking for someone with less of a history of being on the wrong side of public policy. In Rosie O’Donnell, they made an awful choice. O’Donnell killed an endangered hammerhead shark for fun, bragged about the experience, and insulted conservationists who were upset at her actions.
O’Donnell has been a frequent customer of “Mark the Shark,” an infamous shark hunter—that is, one of the few charter boat operators in Florida who doesn’t practice catch and release when fishing for sharks. He claims to have personally killed more than 100,000 sharks. Mark the Shark’s website, which features a photo gallery of scantily clad women lying on top of dead fish, includes warnings like “photos on this site may not be suitable for children, the faint-hearted, or PETA members,” and “We DON’T fly release flags, but we DO hang fish upside down.” I met him once, and the picture you’ve probably formed in your head from reading the description above is pretty accurate.
On one trip, O’Donnell and her family caught and killed a great hammerhead shark and then posed for a picture next to their “trophy.”
Though many species of sharks are in trouble, hammerheads are in particularly bad shape. It is illegal for fisherman to kill great and scalloped hammerheads in Florida state waters, though that wasn’t the case at the time O’Donnell caught this shark. Both species were already considered Endangered by the IUCN Red List, and both had suffered severe and well-publicized population declines due to overfishing. The Florida ban went into effect shortly after O’Donnell’s trip. Scalloped hammerheads sharks recently became the first species of shark ever listed on the U.S. Endangered Species Act.
When this story broke in January of 2012, I joined many in the marine science and conservation Twitter community in criticizing O’Donnell and asking for an apology and a promise never to kill an endangered animal for fun again. She mocked our concerns, insulted us, and refused to apologize. She made nonsensical claims such as “chill, my family fishes,” and “it wasn’t endangered 11 days ago.” As I explained to her at the time, I am not opposed to recreational fishing; I’m opposed to killing endangered species for fun.
Hamsters Don't Eat Burritos. They Eat Each Other.
A few months ago, a video made the rounds featuring a tiny hamster eating a tiny burrito. If you haven’t seen it yet, then behold the pinnacle of human-hamster achievement:
I’ll admit, this is probably the cutest thing to happen to us since baby sloths, surprised red pandas, or goats on sheet metal. Those little hands, that scrunched-up little face—I mean, these are the reasons hamsters are such wildly popular pets.
But anyone who actually had hamsters growing up, as I did, knows what should really be on that tiny poker chip plate—and that’s another hamster.
In the case of this video, we’re looking at the species Mesocricetus auratus, more commonly called a golden hamster or a Syrian hamster. Walk into any pet shop in America and you’ll find these fluffy little rodents. This is more than a little ironic since the International Union for Conservation of Nature lists them as “vulnerable” in their native habitat along the Turkey-Syria border. That’s one step above “endangered,” FYI.
It’s also strange that Syrian hamsters should be popular, considering they’re ferociously territorial. If you’re going to keep two or more adults in the same tank, they require lots of personal space. The animals have scent glands on their flanks, which they use to mark territory, so it’s also recommended that you provide separate food, water, and bedding sources. Fail to give them enough space or resources, and they’ll eat each other for fun.
I’ve seen it.
I thought I’d provided Frank and Shirley with a hamster Taj Mahal. They had tubes leading to running wheels and skylights and loop-de-loops. Fresh water and all the seeds they could eat. All the same, one day I came home from elementary school to find Shirley huddled up in a corner. What was left of Frank—a wad of wet fur, a few toothpick-like bones—lay among the wood chips.
For her Ph.D. work on Syrian hamsters, neurobiologist Annaliese Beery wanted to study seasonality and reproduction, which necessitated breeding hundreds and hundreds of them. “I certainly never set out to study hamster cannibalism,” she told me, “but when you breed a lot of hamsters, that’s definitely something you observe.”
For those in the hamster biz, it’s accepted that more than 75 percent of Syrian hamster dams (mommies) will cannibalize part of their litter within the first day of birth. Beery’s own research suggests this estimate is probably on the low side.
In fact, in an experiment that had her up at all hours of the night checking for births, Beery found that 100 percent of her dams ate between 2 and 11 pups. (A second experiment showed a cannibalization rate of 74 percent, though Beery says they only checked the litters in the morning, which means they likely missed middle-of-the-night cannibalization in the other 26 percent.)
Why Syrian dams should be so om-nom-nommy toward their offspring isn’t completely understood. But Beery says that we have numerous “just-so stories” that make sense.
For instance, we know dams eat their young when resources are scarce. But the dams in Beery’s study had plenty of food—so they commit infanticide during both feast and famine. Her research also showed that mothers cannibalized female pups more often then males and in numbers great enough to significantly alter the sex ratio.
Beery says you can read hamster cannibalism two ways. “You could either see it as the cannibalism benefits the ones left behind because they get more milk and they grow bigger, or you could see it as the mom has eaten the smaller pups and left the bigger pups behind,” she said. “And I don’t think we can distinguish between those interpretations.”
Still, there are plenty of other species that manage boom and bust cycles without resorting to cannibalism. And isn’t it sort of wasteful for the mother’s body to build and deliver all those babies only to eat them hours after birth?
“It turns out that from an energy perspective, at least for rodents, it’s lactation, not gestation, that’s really the hard part metabolically,” says Beery. In other words, it’s a lot easier to make babies than is to nurse them.
Unfortunately for the hamsters, the carnage extends beyond birth. Syrian hamsters are solitary in the wild. When they’re not in heat, females are extremely aggressive. And because estrous occurs about one out of every four days, that means enterprising males run the risk of disembowelment about 25 percent of the time. (Remember those scent glands? A male hamster’s ability to detect estrous may save his life.)
Despite all of this, Beery says Syrian hamsters make excellent pets. They’re a lot more docile than Siberians hamsters, another pet store favorite, and they’re very friendly if handled regularly. “I just wouldn’t breed them,” says Beery. (It’s pretty easy to determine a Syrian hamster’s sex before you buy it. Their testes are what Beery called “really obvious.”)
While I’m all for letting nature take its course, I didn’t expect the next viral hamster video, below, to include wanton acts of cannibalism. The video series is actually a clever piece of content marketing by Denizen, a creative agency in Los Angeles, and the second episode premiered this week. This time, the hamster (named Bogart) attends a birthday party for a hedgehog.
Oh yeah, and that “tiny hamster eating a tiny pizza” that surfaced just days after the burrito video? That hamster is an imposter. “It’s not canon,” wrote Denizen co-founder Joel Jensen in an email. Neither is the video of tiny hamsters eating tiny tacos or tiny hamsters eating tiny Caprese salads.
“We’ll take it as imitation being a form of flattery,” said Jensen, “but hopefully people can distinguish the real thing from them.”
Hey, I guess this means I’ll need to write about hedgehog cannibalism—because they do it, too.
Common Pesticide Is Linked to Declining Bird Populations
Some bird species in the Netherlands have been disappearing at an alarming rate, while others have been doing quite well. Scientists have been examining factors that may explain why bird populations thrive or wither. Human impacts such as habitat destruction, introduced species, and pollution are known to harm birds. Now there’s new evidence that the pesticides we use could be a major cause of bird declines.
Ecologists at Radboud University and the Sovon Centre for Field Ornithology in the Netherlands analyzed population data for 15 bird species as well as their government’s measurements of imidacloprid, a widely used insecticide, in surface water. Imidacloprid is an insect neurotoxin in the neonictinoid family widely used to kill insects on farms and in gardens, and recent research has linked it to disappearing bee populations. The analysis published today in Nature found that areas with high concentrations of imidacloprid had fewer birds.
The ecologists aren’t certain exactly what causes the bird decline. While imidacloprid is lethal to insects, it’s toxic to birds only in large doses, so it’s more likely any effects on bird declines are indirect. The researchers’ leading theory is that because the pesticide kills off insects, it disrupts the food chain.
“Bird populations in farmland areas may have having trouble finding food, so they may leave those areas,” said Ruud Foppen, one of the paper’s authors. Populations may be less likely to survive without a reliable food source; nine of the 15 species studied ate insects exclusively, including barn swallows and willow warblers. “[Birds] need to have a lot of insect prey for their young,” said Foppen, which could lead to a cascading effect. “It affects food; then by food, their reproduction rate; then by their reproduction rate, the population trends.”
In light of research linking the insecticide to bee population decline, the European Commission has placed restrictions on the use of imidacloprid until at least 2015. “Let’s use this time to figure out what’s going on," says Hans de Kroon, another co-author. "Something must be done," he says. De Kroon acknowledges that these restrictions may not be a long-term solution, since insecticides support our food supply. “We plea for a dialogue between everybody who is involved.”
Meanwhile, in the United States, the Environmental Protection Agency does not ban or restrict use of imidacloprid but is reviewing the risks of it and other neonictinoids.
The Strange, Sordid History of Dosing Animals With LSD
Human experiments on animals are more fraught than ever, but their long and sometimes sordid legacy is here to stay. That history is rarely stranger than the effort to give animals hallucinogenic drugs. Fish, monkeys, dolphins, and at least one unlucky elephant were dosed with LSD in the years after it was first synthesized in the 1938, and as the video above shows, the results varied wildly.
Solar Power Plants Are Literally Roasting Birds In-Flight
For proponents of renewable energy, it seems like every time a technology is primed to save the world, it gets dogged by some ironic bit of environmental unpleasantness. Wind turbines can be dangerous to birds and bats. Biofuels require so much land, fertilizer, and water that they may use more energy to produce than they provide. Hydropower dams screw up a whole lot of river habitat and stop fish from spawning.
The latest on this list of “dark green” technologies is thermal solar power, which is coming into vogue in the southern California desert. (Full disclosure: I work at an environmental organization that has opposed the locations chosen for some of those facilities.) A new study from the National Fish and Wildlife Forensics Laboratory obtained by KCET gives some depressing and gruesome details of bird deaths occurring at industrial solar facilities.
U.S. Fish and Wildlife employees and energy company staff found 233 birds of 71 different species at three California solar facilities—Ivanpah, Genesis, and Desert Sunlight—during random surveys over two years. That’s not a huge number of birds (though the limited scope of the collections means it’s just a fraction of the actual deaths), but what’s shocking is the way some of these birds are dying: They are literally being burned alive, in midair.
Each of these facilities employs a different strategy for deriving energy from the sun. Ivanpah is a “solar power tower” plant, which scatters thousands of mirrors over an area larger than Central Park and aims them all at a single, water-filled tower. The reflected, concentrated heat reaches 800 degrees Fahrenheit, boiling the water in the tower and generating electricity. Genesis employs a trough system, generating steam by reflecting sunlight from parabolic mirrors onto water-filled tubes. Desert Sunlight is a photovoltaic system, converting sunlight directly into energy using an array of 8.8 million solar modules spread over 6 square miles.
Industrial-scale facilities like these are exactly the kind of places that can help wean this country off fossil fuels. Once they’re at full capacity, these solar plants together will generate about the same amount of power as a small coal-fired plant, but with none of the nasty emissions. They’re located on public lands, paying rent to the federal government and providing jobs in areas with few other well-paying opportunities.
Yet despite its blazing unwelcomeness, the California desert is anything but empty. The desert is home to thousands of species of plants and animals. Many of them are rare or endangered, including the desert tortoise and the desert bighorn sheep, or are found nowhere else. Perhaps surprisingly, it’s also a major route for migratory birds working their way north. Indeed, more species have been found on the Salton Sea—a stinking oasis in the middle of the desert—than at any other single spot in California. According to the U.S. Fish and Wildlife report, all these birds now have solar mega-traps in their path.
Researchers found that the bright lights created by the facilities—brighter even than surrounding daylight—attracted insects. At Ivanpah, researchers found “hundreds upon hundreds” of dead butterflies, including already-stressed monarchs, some with singed wings. Birds came to feed on the insects, and bigger birds came to feed on the insect-eaters. When birds flew into the hottest areas, observers saw them emit streams of smoke from their feathers. On-the-ground staff found birds with their flight feathers burned away, some still alive but unable to fly. During their visit to Ivanpah, the report states, USFWS staff saw birds burn in midair “every two minutes.”
If that wasn’t bad enough, birds are dying in a completely different—but equally ugly—manner at other facilities. Researchers found an unusually high number of water birds dead at the Desert Sunlight facility. These birds, including grebes, herons, ducks, and even pelicans, died not from the heat but from blunt force trauma. The cause was clear, as stated in the report: “A desert environment punctuated by a large expanse of reflective, blue panels may be reminiscent of a large body of water.” These birds—tired from flying over the hot desert—home in on what looks like a calm lake but instead crash into hard panels. They either die instantly or, as researchers found, lie helpless for land-based predators. Grebes need to take flight from water, so being marooned on land makes them sitting ducks for predators, should they survive the impact of landing on the panels or desert floor.
The report’s authors offered some possible improvements, including adding striping to panels and spacing them farther apart to make them look less like lakes and turning off the solar towers during peak migration. But they don’t seem to put much faith in these fixes. Wildlife groups are challenging the environmental reviews of these projects, armed with new information about the impacts to birds, but have yet to achieve significant changes. With several more solar plants under construction, it seems that these facilities will keep their place alongside wind farms, buildings, outdoor housecats, habitat loss, and good old fashioned climate change as deadly human-caused obstacles in the path of a successful bird migration.
Put some seed in your feeders, would you? These guys need a break.
The World’s Largest Flying Bird
If we had lived 3 million years ago, our holiday beach visits would not have been so pleasant. North American ocean fronts were home to Pelagornis sandersi, the largest known marine bird. It had a wingspan of up to 24 feet. For comparison, imagine the length of four humans head-to-toe, or the height of a two-story building. If its size isn’t terrifying enough, the bird also had pseudoteeth—all the better to impale its prey with.
The first P. sandersi fossil was found in 1983, when crews in South Carolina began construction to expand the Charleston International Airport. Charleston Museum volunteer James Malcom and museum curator Albert Sander removed a stone block containing the fossil and brought it to the museum for further inspection. (The sandersi in the species name is a homage to Sanders.) Nearly 30 years later, paleontologist Daniel Ksepka rediscovered it when he was invited to study the Charleston Museum’s fossils. “I was pretty confident it was a new species right away,” says Ksepka. “The size jumps out at you. I found a single wing bone longer than my arm, so I thought, this must be important.” Ksepka’s results are published today in the Proceedings of the National Academy of Sciences.
The newly described monster bird is part of a family of giant seabirds called Pelagornithids, named for teeth found on the edges of their bills. Unlike human teeth, which have roots and are covered with enamel, pelagornithids’ teeth were made of bone and were likely covered with beak tissue. Scientists believe these birds’ beaks resembled those of modern birds, only with bony, saw-like edges. “They were very sharp, but not made for slicing,” Ksepka says. “They could use them to catch fish or squids near the surface and impale them.”
The pelagornithid family was known for its ubiquity; species within the family have been discovered on every continent. According to Ksepka, it’s fairly rare for bird families to inhabit so many different climates. “Not that many birds make it to Antarctica,” he says.
Based on the structure of its bones, scientists are fairly certain that P. sandersi did fly. This raises one big mystery: How did something so large stay in the air? Bigger animals require more power to keep their bodies in flight. “It’s a scaling problem,” says Ksepka: Theoretically, extremely large birds cannot fly, because the amount of power they need to fly surpasses the power of their muscles. Some researchers calculate that this upper limit is around 17 feet, so by these estimates, a flying Pelagornis sandersi should be impossible. However, these calculations are based on the energy required for birds to stay in flight by flapping their wings; in new calculations, Ksepka proposes that large flying birds could have used other strategies. “They could harvest energy from the environment, like taking advantage of wind gusts,” he says. Like modern-day albatrosses, Pelagornis sandersi could have used their long wings to catch ocean winds and glide across the sky, rather than powering their flight with energy-intensive flapping.
This study is a first glimpse at an amazing ancient animal, but much is still unknown about how Pelagornis sandersi flew and hunted. “I’m looking forward to finding out how they launched and landed, and how maneuverable they were,” says Ksepka. Next time you’re at the beach, be thankful you have to shoo away only seagulls from your picnic snacks.