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

Just like humans, some birds have better luck than others. From city life to dance moves to penises, the natural endowments of birds vary in so many ways! Several recent science publications demonstrate diversity in the bird world, so we thought we’d provide a sampling for you…

A study last week in the Proceedings of the Royal Society B determines that city birds keep much longer hours than their forest-dwelling brethren. Researchers studied European blackbirds (Turdus merula) in different environments in Germany and discovered that the artificial lights and noises of the city mean the blackbirds start their activities earlier in the day and keep on going later in the evening.

In fact, studies in the lab revealed that the city birds’ biological clocks were sped up compared to the forest birds’. And the authors are convinced that birds aren’t the only animals affected by city life. From the abstract:

Urban environments can significantly modify biologically important rhythms in wild organisms.

City dwellers, take note!

Australia’s superb lyrebird males possess some of the most brilliant plumage in the avian world, and researchers have now determined that the feathered creature is also a brilliant song-and-dance bird. Scientists found that the birds have a distinct dance for each of four distinct songs. Wired posted a short video of a male lyrebird strutting its stuff that you have to hear and see to believe!

This mating ritual demonstrates that “the coordination of independently produced repertoires of acoustic and movement signals is not a uniquely human trait,” according to a recent publication in Current Biology.

Maybe the male lyrebirds song-and-dance routine makes up for the fact that these males have no penises. 97% of birds simply lack the organ, using an opening called the cloaca instead. Originally, all birds had penises, but along the evolutionary path, most birds lost them. There are theories for why the organ was no longer needed (lighter for flight, more female control over mates), but the reason is still not known.

However, a new study, also in Current Biology, uncovers the mechanism behind the loss. Researchers compared embryos of the well-endowed Pekin duck (it has a corkscrew penis that can grow the entire length of its body) to those of the cloaca-ed rooster and found that both embryos begin to form penises, but around day eight or nine, the roosters’ stop growing. The scientists determined that one gene, Bmp4, caused the rooster embryo’s penis to stop growing.

Carl Zimmer, writing in the New York Times, explains why this research not only paints a bigger picture of bird evolution, but also illustrates how understanding these genetic mechanisms can help humans, too.

Superb lyrebird image: Melburnian/Wikipedia