A few years ago, scientists observed that some bottle-nosed dolphins held sponges in their beaks as they poked around the ocean floor, flushing out fish they promptly gobbled up—and that mothers taught this trick to their daughters. In a follow-up study published yesterday, the scientists shed some light on why dolphins go to all this trouble: They’re after fatty, energy-rich fish on the seafloor, and the sponges let them scare up a snack without scraping their beaks on sharp rocks or coral.
What’s the News: Parrots are even less bird-brained than previously thought, suggests a new study in the journal Biology Letters. In a series of tests, researchers have learned that some African grey parrots can use logical reasoning to uncover hidden food.
The 1970s: a time for Reggie Jackson, the first go-round of John Travolta, and adopting a chimpanzee to settle a scientific dispute.
The new film Project Nim by director James Marsh, the documentarian behind the acclaimed Man On Wire, debuted at the Sundance Film Festival in Utah this week. Marsh tells the tale of a chimp that was taken from its mother and raised in a human family just like a human baby; the experimenters were attempting to show that language is not unique to our species.
In Project Nim [Marsh] looks at a project dreamed up by Columbia University psychologist Herbert Terrace and carried out on Nim Chimpsky, a chimp named for famed linguist Noam Chomsky, who has argued language is uniquely human. Alternating between previously unpublished footage and interviews with participants in the experiment, the film shows how Nim initially connects with his family before his animal nature gradually takes over. [AFP]
Where a previous study had taught a chimp named Washoe symbols in American Sign Language, Terrace sought to go further with Nim. The chimp lived with the LaFarge family of New York, and for four years Terrace’s team tried to teach Nim to respond using a series of signs to make a sentence. (Nim’s Wikipedia article lists all the “phrases” he put together.)
Black kites are a raptor variety that lives on multiple continents, and like several other varieties of bird (including the crafty bowerbirds), they’re avid decorators. For whatever reason, these black kites are terribly fond of white plastic, and the birds use these bits of our refuse to decorate their nests. Scientists who studied these birds in Spain report in Science this week that there is a meaning—and a strict honesty—to the decoration scheme.
They found that, several weeks before females laid eggs, birds festooned their nests with pieces of white plastic. Fitter birds, in possession of the best territory, tended to use more plastic. Weaker birds, with less-desirable territory, used less. Elderly and very young birds used none. Territorial confrontations are common among kites, and proved closely linked to displays of plastic. Kites with much plastic in their nest were rarely challenged, while those with little were challenged daily, even hourly. [Wired]
With so much at stake, you might think these raptors have the ideal motivation to cheat—decorating more liberally than their status would allow, perhaps, as a “don’t mess with me” message to their rivals. But not so, Fabrizio Sergio and his team found. Kites tell the truth with their status symbols because it’s not worth the risk of being caught in a lie.
Do bees prefer certain colors or shapes in the flowers from which they forage? And can they learn on the fly to go to certain colors or shapes that prove to be more lucrative?
That was the question for the students of Blackawton Primary School in Devon, England. And by devising a clever experiment to find out, these kids became the youngest authors ever to have a study published in a journal of Britain’s Royal Society.
Their paper, based on fieldwork carried out in a local churchyard, describes how bumblebees can learn which flowers to forage from with more flexibility than anyone had thought. It’s the culmination of a project called ‘i, scientist’, designed to get students to actually carry out scientific researchthemselves. The kids received some support from Beau Lotto, a neuroscientist at UCL, and David Strudwick, Blackawton’s head teacher. But the work is all their own.
The class (including Lotto’s son, Misha) came up with their own questions, devised hypotheses, designed experiments, and analysed data. They wrote the paper themselves (except for the abstract), and they drew all the figures with colouring pencils.
Luis Populin never meant to study whether monkeys recognize themselves in the mirror. As DISCOVER blogger Carl Zimmer notes at the Loom, Populin’s team was working on a different project that required putting mirrors in monkey cages to stimulate their brains. Quite by accident, he noticed that monkeys with electrodes attached by the researchers spent an awful long time gawking at themselves in the mirrors.
The researchers published their findings this week in PLoS One, in which they write:
We hypothesize that the head implant, a most salient mark, prompted the monkeys to overcome gaze aversion inhibition or lack of interest in order to look and examine themselves in front of the mirror. The results of this study demonstrate that rhesus monkeys do recognize themselves in the mirror and, therefore, have some form of self-awareness.
For a video of a monkey checking itself out in the mirror, as well as much more detail about the study, its implications, and other primatologists’ doubts about it, check out Zimmer’s post.
In New Caledonia, an island off the eastern coast of Australia, a crow is hunting for beetle grubs. The larvae are hidden within a decaying tree trunk, which might seem like an impregnable fortress. But the New Caledonian crow is smarter than the average bird. It uses a stick to probe the tunnels where the grubs are sheltered. The grubs bite at intruders with powerful jaws but here, that defensive reflex seals their fate; when they latch onto the stick, the crow pulls them out.
This technique is not easy. Birds need a lot of practice to pull it off and even veterans can spend a lot of time fishing out a single grub. The insects are fat, juicy and nutritious but do they really warrant the energy spent on extracting them? The answer is a resounding yes.
Check out the rest of this post, including video of the crows at work, at Not Exactly Rocket Science. (The video above, of the birds making hooks, is from a different study a few years ago.)
And for plenty more about bird geniuses, be sure to read the DISCOVER feature “Who You Callin’ Bird Brain?” It includes more avian smarts, such as hiding food underground and going back later to move it, just in case other birds were watching the first time and thought about stealing a meal.
Right from its entrance, Disneyland is designed to cast an illusion upon its visitors. The first area – Main Street – seems to stretch for miles towards the towering castle in the distance. All of this relies on visual trickery. The castle’s upper bricks and the upper levels of Main Street’s buildings are much smaller than their ground-level counterparts, making everything seem taller. The buildings are also angled towards the castle, which makes Main Street seem longer, building the anticipation of guests.
These techniques are examples of forced perspective, a trick of the eye that makes objects seem bigger or smaller, further or closer than they actually are. These illusions were used by classical architects to make their buildings seem grander, by filmmakers to make humans look like hobbits, and by photographers to create amusing shots. But humans aren’t the only animals to use forced perspective. In the forests of Australia, the male great bowerbird uses the same illusions to woo his mate.
Stop patting yourself on the back. You’re not so special. Orangutans, a new study suggests, also use complex gestures or pantomimes to communicate.
Looking through twenty years worth of orangutan observations, researchers believe they have found 18 examples of pantomimes. The study, which appeared today in Biology Letters, supports the claim that we’re not unique when it comes to abstract communication and lends credence to other observations of great ape gesturing, according to lead researcher Anne Russon.
[Orangutans and chimpanzees were already known] to throw an object when angry, for example. But that is a far cry from displaying actions that are intentionally symbolic and referential–the behaviour known as pantomiming. “Pantomime is considered uniquely human,” says Anne Russon from York University in Toronto, Canada. “It is based on imitation, recreating behaviours you have seen somewhere else, which can be considered complex and beyond the grasp of most non-human species.” [New Scientist]
Of the eighteen observed orangutan pantomimes, four took place between orangutans and 14 between a human and an orangutan. If you ever find yourself in the Indonesian jungles, here are some examples of messages that you might expect:
Hounds, pointers, and other dogs bred for their excellent abilities to pick up a scent tend to have longer snouts—but it’s not just that a bigger nose is a better one. Researchers have found that human domestication of dogs has shifted the structure and alignment of some dogs’ brains. And in those varieties with shorter snouts—which humans bred for other reasons, like appearance—the olfactory brain region rotated to a different part of their skull, leaving scientists to question whether we’ve crossed up their smelling abilities (and perhaps more).
Since the first wolf was domesticated an estimated 12,000 years ago, “selective breeding has produced a lot of [anatomical] variation, but probably the most dramatic is in terms of skull shape,” said study co-author Michael Valenzuela [National Geographic].
For this study, which appears in the open-access journal PLoS One, Valenzuela and colleagues examined the brains of 11 dog breeds and found great variation in the size and shape of their skulls. The breeds with shorter snouts had brains that rotated forward by as much as 15 degrees over the generations, the scientists say. That means that the olfactory lobe, as well as other parts of these dogs‘ brains, has shifted position and shape because humans guided their evolution through domestication.
Teamwork: That’s what it takes to get lucky (if you’re a certain kind of firefly).
Suppose you’re a single male firefly, fluttering about on a muggy night. You flash your bioluminescent signal to try to catch a lady’s attention, but how is she going to pick out your blip from all the other points of light ablaze when various species of firefly zoom around? About 1 percent of firefly species have figured out how to beat the noise: They team up and flash their lights in an unmissable, synchronous signal. And in a study in this week’s Science, researchers unlocked the inner workings of this sexual back-and-forth.
Biologists had long known about the synchronous flashing, but had not tested the idea that each species has its own rhythm—its own signal to complete the optical call-and-response between male and female.
To do this, Andrew Moiseff of the University of Connecticut in Storrs and Jonathan Copeland at the State University of New York at Stony Brook turned to LEDs. They put female synchronous fireflies (Photinus carolinus) in a Petri dish surrounded by green LEDs, and flashed the lights in the same pattern used by male fireflies. The females responded with their signature pattern 82 per cent of the time – but only if the LEDs were synchronised. When the lights did not flash in unison, female response dropped to 10 per cent or less [New Scientist].
Apparently, in the animal kingdom, it’s better to be a girl. We have seen that women macaques are superior conversationalists. We learned that lady humpbacks enjoy long-lasting friendships. Now research published in Current Biology shows that baboon ladies with good friends around them may live longer.
At Botswana’s Moremi Game Reserve, Joan Silk of the University of California, Los Angeles and her team spied on 44 female chacma baboons over the course of six years. Among other things, Silk looked at which girls had the most visitors and how often the women picked junk out of each other’s hair. In other words, true friendship. She also tracked each baboon’s circle of friends, seeing how each lady’s top three buddies changed over time.
Silk saw a correlation between sociability and longevity. She divided the baboons into three groups, and found that the least friendly lived 7 to 18 years, while the friendliest group lived from 10 years on (they were still kicking when the study ended). They also found that those baboons who formed stable, enduring bonds were more likely to have long lives than those with flightier friendship habits.
Scientists have long thought humpbacks loners. New research shows this isn’t so: Researchers have observed some female whale form friendships that last for years. The behavior has only been observed in lady humpbacks of similar age, with the whales going their separate ways during the breeding season, but reuniting in the open ocean each summer. These bonds can be quite strong: the longest association endured for six years.
The study appears in the journal Behavioral Ecology and Sociobiology, and it also found that the whales with the longest-lasting associations gave birth to the most calves–another animal kingdom example that friendship is beneficial. The whales are probably improving their feeding efficiency, suggests lead author Christian Ramp.
“Staying together for a prolonged period of time requires a constant effort. That means that they feed together, but likely also rest together…. So an individual is adapting its behaviour to another one.” [BBC]
When it comes to the relationship between bees and African elephants, size does not matter. The massive pachyderms are terrified of bees, which can painfully sting elephants around their eyes and inside their trunks. Baby elephants are the most vulnerable to bee stings, as their skin isn’t thick enough to ward off the insects. And researchers have now found that the elephants have developed a special strategy to help them avoid these bees that scare the bejesus out of them.
When an elephant takes note of a swarm of bees, it emits a distinct rumbling call. This bee alarm, which the scientists termed a “bee rumble,” helps draw the herd’s attention to the bees and allows them to run off unharmed, the researchers write in the journal PloS ONE. What’s more, they respond to an audio recording of the bee rumble as if it were the real thing, giving farmers a tool they could potentially use to fend off unwanted elephants.
It’s not just that some birds can use tools, as primates can. Their smarts stretch even further: New research this week suggests that New Caledonian crows can solve a three-step problem, in which the three steps must be completed in succession to reach a tasty snack. Alex Taylor and colleagues document this discovery in the Proceedings of the Royal Society B.
Here’s the setup: There’s a short stick dangling from the bird’s perch on a string. That short stick isn’t long enough to grab the food that’s tucked inside a long and narrow box, but there’s a longer stick in a separate box. If the birds could figure out the first two steps—grabbing the short stick, and using it to get the longer stick—then voila, they could use the longer stick to reach the food.
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].