If you happened to be hanging around the game pen up at Humboldt State University a couple autumns ago, you might have chanced upon a miserable huddle of characters puking their brains out like over-partied freshman. These guys were small and bright blue with pointy, soot-colored heads. And they'd just had some baaaad eggs.
The birds recovered soon enough. And, much to the delight of their tormenter, Pia Gabriel, the next time these Steller's jays came across eggs that looked like the ones that had made them sick, they avoided them. Later, Gabriel ventured into the redwood forest in Redwood National and State Parks with hundreds more of the yack-bombs -- small chicken eggs, painted to look like marbled murrelet eggs and injected with the emetic (makes ya puke) carbachol. After the first batch was set out and eaten -- cue the sad retching sounds -- predation on the second batch fell significantly. Gabriel's attempts to train Steller's jays to have a "conditioned taste aversion" to marbled murrelet eggs appeared to have worked.
And it's hard to trick a smart bird. Another HSU student, Sara Peterson, tried to scare the bejeezus out of snowy-plover-plundering ravens and crows out on Clam Beach by pretending to murder a raven (a stuffed roadkill) and then hanging it in effigy where plovers, in season, would be wont to nest. It didn't faze the predators, but Peterson plans to tweak some variables and try it again.
The egg trick looks promising. It's possible that a deployment of such eggs each spring just before marbled murrelet breeding season could improve the odds of survival for the tubby little bird that forages at sea, nests in the old-growth canopy, and is listed as threatened in California, Oregon and Washington.
Centuries of logging and other human activity have destroyed or altered much of the Pacific Northwest's murrelet nesting habitat, forcing the birds to crowd into smaller, fragmented forests. These forests -- with their town-abutting edges, their parks, their picnic tables and hiking trails -- attract creatures like Steller's jays, opportunistic omnivores who come for the heady mixture of foodstuffs. With everyone crowded in tighter, some Steller's jays have become major nest predators.
So scientists want to try to educate these smart birds. And, if recent discoveries in bird brain science are any indication, it's not that farfetched to expect the bad-egg-eating jays to not only remember the lesson, but to spread the word to their kids and to newcomer jays: "Dude, whoa, stay away from those dark-speckled turquoise eggs. Gack!"
Pre-dawn rain had misted everything -- rose bushes, fences, spider-webbed eaves, forget-me-nots blooming at the base of hedges. Clutching a giant plastic Coffeemate canister in one hand, Pia Gabriel walked quickly along Bayview Street, a narrow lane between houses at the top of the hillside neighborhood on the south flank of Humboldt State University. Just a few yards farther up the hill, the tall, dark redwoods of the Arcata Community Forest ruffled up their greenery and breathed.
Whee-hoo. Whee-hoo, Gabriel whistled, sounding as if she were calling a dog. Tall and slender, with her wavy brown hair swept into a loose bun, Gabriel wore a blue fleece jacket over jeans and T-shirt. She was in the forest this morning to check on the Steller's jay pairs she and other HSU researchers have been studying for years, and note who's here, who's doing what.
As she walked she shook the canister, and the peanuts inside it rattled like kibbles. Whee-hoo. "They know that that whistle means peanuts," she said, looking up and around, blue eyes scanning cloud-blotted sky and bright tree tips.
"Here, there's someone up in that tree," she said, aiming her binoculars at the bright blue Steller's jay looking down at her from a roof peak, the crest on its smudgy head cocked up. It flitted to the tip of a tall cedar in someone's yard, said shack shack.
"So this guy," said Gabriel -- the jay yelled again, shack shack shack -- "he's announcing that he owns this place. Could be a girl, too. This is the kind of call that both the girls and the guys do. He/she sits up there, calling, and that means "mine." She laughed. "Mine mine mine!"
Shack shack! said another jay, joining the first. This one's legs were muddy, a sign of nest-building. Possibly its mate, said Gabriel. Then he said Bleep-bleep! Bleep-bleep!
"Oh!" said Gabriel, excited. "That's the male call!" The male jay leaned over to the other jay and fed her an insect from his bill. "There," said Gabriel, laughing. "If you had any doubt whether they are a pair, now you know."
Gabriel grew up in Gruenwald, a small town near Munich in Germany, where she scrambled around the countryside with her parents and became entranced by birds and animals. She spent a year at Humboldt State University in 2001 as an exchange student in wildlife management, then returned in 2004 to work as a visiting scholar in wildlife management with Professor Jeff Black as part of her doctoral program in Germany. Black has been banding and following the campus-area Steller's jays since 1998.
For her doctoral thesis, Gabriel wanted to find out if Steller's jays have individual personalities -- in research-speak, a suite of traits they exhibit consistently, called "behavioral syndrome." She measured how far an individual would go for food, whether it would try a new kind of food, and how soon it would return to a feeder/trap after having been trapped in it. Using a fake raven, she also observed which jays mobbed it (ganging up on it and squawking) and which didn't.
"What I found was, individuals who traveled farther, who took greater risks at a trap, they also were more willing to mob a potential nest predator and more willing to explore a novel food source," Gabriel said. "Then there were ones who hardly traveled, who were very shy of a novel feeding opportunity and who were very unwilling to enter a trap. And I found individuals along this whole continuum."
Most intriguingly, she found that neither shyness nor boldness was the key to overall reproductive success. What matters more, for Steller's jays, is that they choose a mate with a personality similar to their own. That is, a pair of shy, retiring Steller's jays and a pair of bold, adventuring jays will both have more success in fledging chicks than a mismatched-personalities pair of jays -- with successful fledging, in this study, meaning that a pair raised at least one fledgling in a season.
After HSU wildlife professor Rick Golightly caught Steller's jays on camera attacking and burgling a marbled murrelet nest, in 2008, the bad-egg project was born, paid for through a fund created to compensate for a 1998 oil spill off the San Mateo coast.
Gabriel's thesis work on personalities proved useful for the egg experiment. Birds eggs are not the usual eats for Steller's jays. Rather, an egg is something a jay stumbles upon while foraging for something else, like insects -- say, along a high, mossy limb where a murrelet likes to nest. The jays likely to discover an egg in this manner are the risk-taking, new-food trying, far-ranging ones. And that means the deployment of puke-inducing fake eggs selectively targets only the culprits; the stay-at-home, non-egg-eating jays won't be affected.
But will the puking jays pass their uncomfortable lesson on to others?
Earlier this month, wildlife scientist John Marzluff re-captured Elvis. Fooled him with a net gun hidden in a trash bag, staked out with a plate of french toast and bacon near the entrance to the North Cascades Institute, an environmental learning center in Washington's Skagit Valley. But that was after Marzluff had spent nearly two hours the day before trying to lure the fat, bacon-loving raven into his car.
"I sat in my car covered with blankets so he wouldn't see me, with my window down and with food next to me -- a bag of bread and stuff," said Marzluff, who's a professor at the University of Washington in Seattle, by phone a few days after he and Elvis tangoed. "I could hear him outside clicking his bill, and then he jumped on the car so hard I could feel it shake."
Like Steller's jays, ravens are corvids -- a bird family that also includes crows and magpies. They're smart, and this one needed to be taught a lesson. Elvis has been a backpack-raiding, breakfast-snatching, sandwich-nabbing, chips-gobbling pest. And he's not normally afraid to enter cars, which he's done often, pulling things out from under the seats.
"Elvis has been getting into a lot of trouble," Marzluff said.
Marzluff last caught Elvis five years ago, and for a few years after that harmless but unpleasant experience Elvis restrained himself from going after people food.
Marzluff hopes this second round of aversive conditioning -- getting trapped -- will once again imprint on Elvis that french toast and bacon are not for him.
The trouble with birds like Elvis is, they're too smart for their own good. That's also the nice thing about them. Their intelligence can be manipulated for their good, if need be -- such as changing their behavior with aversion treatments.
"It's a way for us to keep the birds out of harm's way [from angry people] and keep them performing their natural function in the ecosystem -- eating dead animals, dispersing pine seeds," Marzluff said.
Marzluff has co-authored several books about crows and ravens. Gifts of the Crow, with writer and illustrator Tony Angell, came out in hardcover this month. Like people, he writes in that book, crows live long lives, have "flexible and complex social lifestyles," and have large brains relative to their body size.
The most exciting stuff Marzluff's been doing in his lab lately is conducting brain scans on crows. First, he shows a bird images of a "caring" face or "threatening" face -- each associated with a good event or bad event previously experienced by the bird. Then, with the bird still awake, he connects its brain to the PET scan device which tracks how the crow's brain has processed the image.
"What we have shown them is the person who captured them initially," Marzluff said. "And then we have shown them the person who fed and took care of them."
(To keep things consistent, and simpler, for such studies, the people in Marluff's lab wear a mask of the face of one specific person when they capture crows and ravens. They wear the mask of another person's face when they feed and care for them.)
Marzluff's team then compares what happens in the crow's brain when it sees the caring face versus the threatening face. "We've found that they perceive the face very intently," he said. "And they use a lot of the place in the fore brain -- the visual cortex -- to analyze the sight. That means, in both cases, they're thinking a lot about it."
When a crow sees the caring face, there's also a lot of activity in the striatum -- the middle part of the brain, which in the human brain is where we form associations with things such as rewards. "So in the bird we think the activity signals that the bird has formed an association between food and the caring face."
When the crow sees the dangerous face, the amygdala is activated -- which in the human brain is where we process emotions and is associated with learned fears (and pleasures).
So they're having thoughtful and emotional reactions. It's an important discovery, but not entirely unexpected. Researchers comparing bird brains to mammal brains over the past decade have discovered that bird brains, though they look different, are architecturally and functionally similar to human brains.
If you slice into a mammal brain and look at it with the naked eye, you see a core of gray matter, which is the nerve cells. Then there's a layer of white matter -- axons, the cables linking nerve cells to each other. And then you see the cortex -- the thin and highly layered, folded rind where higher level functions are thought only to occur.
If you cut into a bird brain, it just looks like the gray matter of the mammal brain. Smooth, simple.
The assumption scientists have long made is that as the mammal brain evolved it added the new, sophisticated layers onto that core -- the so-called "reptile brain" -- giving us consciousness, adaptive learning abilities and other higher functions. The bird brain, meanwhile, remained primitive, they assumed.
"That whole idea is really just not fundamentally correct," said Marzluff's colleague David Perkel, in the University of Washington's departments of biology and otolaryngology. "That core is deeply involved in cognitive function ... and is intimately connected to the outer layer."
Ever-more-sophisticated techniques for examining the bird brain on the cellular level have revealed a much finer and more complex structure than assumed.
"This is still a little bit controversial, but one idea is that fundamentally the rind in mammals has a counterpart in birds that, though it doesn't look the same, it has the same types of neurons, the same types of building blocks," Perkel said. "The architecture is pretty much the same."
Furthermore, Perkel has discovered that birds learn their songs from other birds, just like humans learn to speak from other humans. And this vocal learning occurs along similar neural pathways in both human and bird.
"Birds individually learn vocal patterns, usually from their fathers," Perkel said. "They first listen to sounds. Then they go through a babbling phase. And then they go through a long stage of practice where they're trial-and-error learning to make sounds like their father's song. After weeks and months of practice, they achieve that."
And then their father's song becomes crystallized -- it doesn't change.
"Other primates don't do this," Perkel said. "Very few mammals do -- there's some evidence for whales and dolphins, and some suggestions about bats."
He learned this by experimenting in the lab with zebra finches -- a ubiquitous pet-shop bird that breeds year-round. Raise a baby human in isolation, and you'd get nonsense sounds. Raise a baby bird in isolation -- same story.
Sure, a naturalist can walk through the woods and pick out the songs of different bird species, which seems to indicate that bird language is innate. And it partly is, said Perkel. But even an amateur birder notices that, from region to region, bird calls in the same species slightly vary -- in other words, birds have dialects.
This passing of the song from father to chick, bird to bird, is called cultural transmission. A few birds -- mockingbirds, corvids, starlings, parrots and such -- can keep learning new stuff, adding to their repertoire.
Perkel's primary interest is the brain, and how a songbird's brain might be used as a model for understanding human vocal learning -- which could lead to development of speech therapies, for instance. But bird researchers like Marzluff find his work just that much more compelling evidence for seeking humane ways to manage "problem" birds like crows and ravens and Steller's jays.
One early morning at Elk Prairie Campground in Redwood National and State Parks, as sunshine flooded the openings between the tall trees, it was hard to tell who was busier -- the birds or the people.
Wrens and chickadees and kinglets chitter-squeaked in the understory of the towering redwoods, a hermit thrush trilled repeatedly and a lone raven with a ragged tail wafted low overhead trailed by a yackety mob of angry Steller's jays. Mothers towed sleepy-eyed children to the campground bathrooms then walked slowly back, talking quietly. Couples rose from their tents to make coffee and sip it, eyes closed, in the sunshine, while others noisily spread breakfast out on picnic tables. Before long campers were taking turns scrubbing their dishes at the water spigot, inadvertently leaving soggy crumbs behind for the birds. Soon they would be packing their cars and driving away, leaving behind food scraps and wrappers and other delectables for foragers to eat.
Will Goldenberg and Katlin Overeem, meanwhile, were setting up some bird traps in an empty campsite. One was a "bow net" trap -- a concealed, coiled net that could be snapped quickly over its victim with the tug of a string; Goldenberg placed a plate of fake pancakes and eggs inside it. This was the latest, and most complicated, trap Goldenberg had used out here, and the jays weren't familiar with it yet so it might work.
Goldenberg and Overeem, master's degree students in wildlife biology at Humboldt State University, are both studying Steller's jays. Overeem has been conducting paternity tests on the Steller's jays who live around campus in Arcata -- to find out if the mate-for-life corvids cheat (some do, which might disappoint romantics). She often helps Goldenberg, her boyfriend, with his field work (and both of them have helped Gabriel band and monitor her birds).
Goldenberg's research into jay habits, partly funded by the park service, could have distinct practical applications. By strapping radiotransmitter backpacks onto Steller's jays, he's been able to gather basic ecological data -- how big their home range is, whether they're territorial, where they sleep, if they're even the same birds from year to year. It's basic information that remarkably had never been gathered locally on these ubiquitous birds, and serves as a baseline for other researchers. Gabriel has already used his home range data to decide how many fake eggs to bring into the forest and how far apart to space them.
Goldenberg's chief goal was to find out whether urban (campground) jays' habits and population densities are different from jays who spend their time deeper in the park, away from people.
"In Redwood National Park, we fear Steller's jays are gaining more sustenance by scavenging for human food, and maybe we're bolstering their population," Goldenberg said.
The radiotransmitters have revealed that the same jays live in the same territories year after year. And something else rather surprising: The campground jays have the same size home ranges as the non-campground jays. Goldenberg had expected the campground jays to have smaller home ranges because they don't need to look far for food. But they are different in another way: Their home ranges overlap more with their neighbors', by as much as 75 percent compared to the about 10-percent overlap of non-campground birds' home ranges.
"There's so much food, and so many birds coming in for the food, that the birds can't maintain their territory," Goldenberg said. "The only space that campground birds call their own is where they sleep and where they nest."
The big question is, is that increased Steller's jay density impacting the marbled murrelet? "We don't know," Goldenberg said. Maybe it makes the jays fat and happy, and less likely to explore for other food and stumble upon a murrelet nest. Or, maybe it makes them robust and able to forage farther afield, increasing their chances of egg discovery. It's a question for future study, he said.
With their trap baited, Goldenberg and Overeem walked through the campground, saying "Good Morning" to the campers.
"Did you have any jays coming in and robbing your campsite?" Goldenberg asked a group of guys strolling by.
"Yeah, been a few," one of them said, smiling. "Pretty awesome."
("Well, sort of," Overeem muttered quietly, laughing.)
They passed a campsite whose occupant had scattered her possessions across the picnic table as she repacked her car. A jay landed in the midst of it and began snooping around. Quick as a jay herself, the woman grabbed a rock and flung it at the bird, scaring it off.
"That's the first rock throwing I've seen," Goldenberg said. "I have seen shoe throwing."
Back at the campsite with the traps, Goldenberg took out an MP3 player and hit a button to play a female jay's call, a sort of buzzing sound. He also "pished" -- pshh pshh pshh. Then he played this campground's male Steller's jay call -- an unusual dialect that includes bill-clicking, never recorded elsewhere.
Jays started coming in and, eventually, one fell for the bow net trap. For its trouble, it got a swift health check-up and new orange leg band to replace a faded one.
There is no question that Steller's jays, like their big brothers the ravens and crows, are smart -- and smart in individual ways. Gabriel has observed some smaller jays, who can't shove one peanut down their throat before grabbing another, do a thing she calls "doublenutting." They grab one peanut in their bill, turn it sideways, and then grab another peanut and cross it over the first peanut so the indented middles lock together. Once, after Gabriel scattered peanuts over her computer keyboard and opened her office window, an observing Steller's jay hopped in and casually retrieved them. One day Goldenberg watched a jay wait by one of his traps until a chipmunk ran in, grabbed the peanut and squeezed back out between the bars of the closed trap. Then he watched the bird follow the chipmunk to see where it cached the nut, wait for the chipmunk to leave, and steal the nut.
But are they smart enough to do what Gabriel and others are hoping they can do? Teach others to not touch the marbled murrelet eggs?
Marzluff, in "Gifts of the Crow," talks about how his students took to walking around campus in the same caveman mask that they'd worn when they captured crows for their studies. More than three years after the captures had occurred, most of the crows on campus who encountered the masked student scolded him.
"He was hounded the entire time he wore the mask," writes Marzluff. "Even birds of other species ... scolded him." The scoldings increased in intensity each year after that -- and many of these angry birds had never been captured, nor seen another bird captured, by that particular "face." They were learning to fear it by watching other birds' actions -- a cognitively complex process called social learning. And that's how smart creatures, including humans, create traditions -- or culture -- writes Marzluff.
Gabriel and Golightly, in a report to the park service late last year, suggested that placing a few fake, treated eggs in the park would be a cost-effective, quick way to condition resident Steller's jays to not eat murrelet eggs. The park service is considering it. Researchers don't know for certain that the jays would teach their young, nor whether they would need to repeat the egg deployment to condition new jays migrating in.
But it's possible that the Steller's jays in Redwood National Park could start their own new tradition -- staying away from those dark-speckled turquoise eggs.
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