Can birds read? While a new study provides evidence of avian intelligence, no, our feathered friends aren’t literate (as far as we know).

Canadian researchers, working in France, have found that birds foraging on roads and highways vary the amount of time they take to leave the asphalt when they see a car approaching. And it appears to depend on the posted speed limit.

During Pierre Legagneux’s commute he noticed that birds let him drive closer if he was traveling on a slower road. Using a modern, hi-tech tool—a stopwatch—the scientist monitored the birds’ “flight initiation distances” (FIDs) from the safety of his speeding car.

“FID is basically the distance that the car is from the bird when the bird takes off,” explains Academy bird expert Jack Dumbacher. “When a car is moving slowly, the bird can wait until the car gets pretty close, but when the car is moving fast, it has to begin taking off when the car is still very far away—just to make sure that it can avoid being hit. He was able to measure this pretty easily on his commute by multiplying his speed by the time it took to reach the bird.”

Over a year’s time, Legagneaux measured the FIDs of 134 birds from 21 different species, including many crows (Corvus corone), sparrows (Passer domesticus), blackbirds (Turdus merula) and unidentified songbirds.

And what he found was astonishing! His actual speed had nothing to do with the FID. But the posted speed limit did. The birds’ FID was consistently farther away for faster roads. For roads with a 20 kilometers per hour posted sign, the birds’ FID was 10 meters; 90km/hour signs, 25 meters; and 110km/hour, 75 meters.

“The authors aren’t exactly sure how the birds know, but it appears to have more to do with the AREA than with the oncoming car,” Dumbacher says. “The birds are not assessing the speed of the car, but what speed they THINK the car OUGHT to be going in that area.  And thus, the best predictor in the models was the actual posted speed limit.

“The method is simple and elegant—and something that he was able to do while commuting and paying attention to traffic. (Apparently there aren’t laws against operating a stopwatch while driving in Europe.),” Dumbacher continues.  “All he had to do was jot down 1) his speed, 2) the speed limit, and 3) the time it took to reach the spot where the bird took off.  From his citations, it looks like something like this has been studied before, but this is a cool and interesting article—something that a high school student could do for her science fair project (if she were old enough to drive…).”

The research is published in Biology Letters.

Crow image: Mostly Dans/Flickr

Now this raven-sized early bird has had its brain examined. Amy Balanoff and her colleagues from the American Museum of Natural History recently took CT scans of more than two dozen specimens, including modern birds, Archaeopteryx, and closely related non-avian dinosaurs such as tyrannosaurs, to size up the different species’ brain power.

“Bird-brained” is actually a misnomer. (Crows demonstrate this again and again.) Modern birds are distinguished from reptiles by their brains, which are enlarged compared to body size. This “hyperinflation,” most obvious in the forebrain, is important for providing the superior vision and coordination required to fly.

By stitching together the CT scans, the scientists created 3D reconstructions of the skulls’ interiors. In addition to calculating the total volume of each digital brain cast, the research team also determined the size of each brain’s major anatomical regions, including the olfactory bulbs, cerebrum, optic lobes, cerebellum, and brain stem.

The researchers found that in terms of volumetric measurements, Archaeopteryx is not in a unique transitional position between non-avian dinosaurs and modern birds. Several other non-avian dinosaurs sampled, including bird-like oviraptorosaurs and troodontids, actually had larger brains relative to body size than Archaeopteryx.

“If Archaeopteryx had a flight-ready brain, which is almost certainly the case given its morphology, then so did at least some other non-avian dinosaurs,” Balanoff says.

“Archaeopteryx has always been set up as a uniquely transitional species between feathered dinosaurs and modern birds, a halfway point,” she says. “But by studying the cranial volume of closely related dinosaurs, we learned that Archaeopteryx might not have been so special.”

If not unique, where should we place Archaeopteryx in the tree of life? More research is needed. The current study is published this week in Nature.

Image: Amy Balanoff, American Museum of Natural History

Publishing online in Naturwissenschaften last week, Israeli researchers have discovered that these corvids are not only clever, they’re also crafty.

The scientists studied a pair of brown-necked ravens (Corvus ruficollis) and found that they were very good at stealing food from Egyptian vultures (Neophron percnopterus).

The pair of ravens had their eyes on a high quality food source, large ostrich eggs.  Female ostriches lay their eggs in a communal nest—resulting in large concentrations of as many as 40 eggs. The dominant female and breeding male can only incubate 12-14 of these and discard the rest, creating a circle of unwanted eggs around the nest.

The ravens are after the discarded eggs, but the eggshells are so thick, they are inaccessible to these birds. According to a previous study by two of the same authors, the intelligent ravens are known to recognize their limitations.

That’s where the vultures come in. The vultures are smart birds, too, and like the ravens, are known to use tools. (In the avian world, scientists have found that tool-use equals bigger brains.) The vultures have found a way into ostrich eggs—rounded stones. They use the stones to crack the eggs and their sharp beaks do the rest.

So the ravens wait patiently, hiding from the vulture until the work has been done opening the egg and revealing its contents. At that moment, the ravens, working cooperatively, begin to harass the vulture until it flies away, leaving behind the delicious, accessible egg.

The vulture is not as bright as the ravens—and doesn’t learn from its mistakes. The ravens have targeted the same vultures more than once, with the same results.

The researchers seem to applaud the ravens’ kleptoparasitism. From the study:

It appears that the intellectual flexibility and response to ever-changing conditions has allowed this highly intelligent family to persist in extreme conditions—from the freezing tundra to the hot deserts…

Most apparent in the ravens is their innovative thinking and ability to predict the actions of the potential host or prey.

That’s Andrew Revkin, in his Dot Earth blog in the New York Times, writing about avian keratin disorder—a disorder of unknown origin affecting bird species in the Pacific Northwest and Alaska at ten times the usual rate over the past decade.

USGS biologists published two papers (they can be found here and here) last week about this disorder that causes beak deformities across almost 30 different species of birds. Stunning news! The studies and Revkin’s comparison really got our attention.

We asked our own bird expert, Dr. Jack Dumbacher (Curator and Department Chair of Ornithology and Mammalogy), about this epizootic (an epidemic among wildlife).

There are a couple dozen species that appear to be affected, but the two most impacted appear to be Black-capped Chickadee (Poecile atricapillus), and Northwestern Crow (Corvus caurinus). Other corvids (jays, ravens, etc.) also appear to be more affected.  Although there were some reports in the early 1990s, the number of affected birds appears to have peaked in the 2000-2001 season, and again in the 2006-2007 season.  It seems to be more prevalent in adults, suggesting that it is an acquired condition.  It appears to most profoundly affect the keratin layers of the bill, causing the bill to overgrow and often cross, but it can also affect other keratinized layers of skin, legs, feet, and claws.

The deformed beaks hinder the birds’ ability to eat, clean themselves, and care for their young.

Jack expressed surprise about the findings:

I had known of strange growths caused by knemidocoptes mites, and these can sometimes cause bills to overgrow, scales to enlarge or slough off, and other deformities.  I’ve even seen these in the field (in South African Cape Robins).  But this was specifically examined, and these birds appear not to have knemidocoptes mites.  I’d certainly not heard of this in multiple species in one place.

Some diseases—like avian pox or the disease caused by West Nile Virus—have affected multiple species, and have had significant impacts across bird species. In parrots, a circovirus causes a disease called Psittacine beak and feather disease, and can sometimes cause overgrown beaks and crossed beaks.

The cause remains unknown, and it may prove challenging to discover.  Many factors require consideration, including environmental contamination, bacterial, fungal, or parasitic infections, and dietary deficiencies.

Jack provided some insight and hope for response from the community.

It is hard to say.  The authors looked at the most likely causes—knemidocoptes mites, malnutrition, liver malfunction, other diseases, and nothing came up positive.  It is possible that this is caused by a new disease agent that is not yet known.  For example, when frogs first began declining, it was hard to pin down the cause, but now we have some evidence that a fungal pathogen—Chytrid fungus—may be part of the cause. There may be an unknown pathogen causing these deformities in birds.

One hopes that now that these excellent papers have been published, we will all keep an eye out for such issues.  The USGS has requested information on this phenomenon, and they have set up a website that discusses it and allows you to report an incidence.

Scientists and bird watchers alike can help researchers learn more. Jack, who has done virus research in avian populations around the world, hopes to lend a hand (and needle) to the project, too. Stay tuned.