Pharyngula::Clever birds

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Thursday, December 09, 2004

Clever birds

PZ Myers • 18 Comments

Photographs of representatives of the crow-like Corvidae (ravens, crows, rooks, jackdaws, magpies, and jays) family of passerine birds. There are approximately 120 species of corvids, dispersed all over the world except in the polar regions. (A) Raven. [Photograph by N. Emery] (B) New Caledonian crow. [Photograph by A. Weir and A. Kacelnik] (C) Clark's nutcracker. [Photograph by R. Balda] (D) Jackdaw. [Photograph by A. von Bayern] (E) Western scrub jay. [Photograph by S. de Kort] (F) Rook. [Photograph by A. Seed]

Remember that clever, tool-using crow? There is a new review in Science that explores the world of bird brains in a little more detail. I learned that the brain/body ratio of the crow is approximately the same as that of a chimpanzee, and that in particular, the crow has a disproportionately large nidopallium and mesopallium, which are the regions that correspond roughly to our primate prefrontal cortex.

Graph displaying how the relative size of the apical part of the hyperpallium, densocellular part of the hyperpallium, mesopallium, and nidopallium are relatively larger in passerines and particularly in the corvids (Eurasian jay and carrion crow) than in quail, partridge, and pheasant.

The article has a list of avian accomplishments of genius.

New Caledonian crows build hook tools in the wild to fish insects out of holes.
Crows cut Pandanus leaves to make barbed probes that they use to snag insects in leaf litter.
Clark's nutcrackers cache 30,000 seeds in various spots over a wide area, and can remember where they are six months later.
Scrub jays cache food with discrimination, distinguishing between perishable and non-perishable food and consuming them in an appropriate order.
Corvids observe other birds caching food, and can retrace their way to caches for pilfering days later.
To prevent pilfering, corvids hide food behind barriers, only cache when unobserved, lead potential pilferers away, and even make false caches containing stones.
When confronted with meat suspended from a string attached to a perch, ravens can solve the problem on the first trial: they pull the string up with their beak, step on it to hold it in place, pull up another stretch, etc., until the meat can be reached.

I guess I won't be using "birdbrain" as an insult anymore.

Emery NJ, Clayton NS (2004) The Mentality of Crows: Convergent Evolution of Intelligence in Corvids and Apes. Science 306(5703):1903-1907.

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Comments:

#10603: John Wilkins — 12/09 at 10:15 PM
But you can still crow over your own accomplishments...

Anything on parrots? In particular the African Grey?

John S. Wilkins : evolvethought.blogspot.com

#10606: PZ Myers — 12/09 at 10:21 PM
Next to nothing; there's a brief mention that the only competitors with corvids in the avian brain size race are the parrots.

In some ways, the article is rather frustrating. It mentions that there are interesting differences in cortical organization between birds and apes (nucleated vs lamellar), but it gives no details. There are some articles I'm going to have to track down.

PZ Myers
Division of Science and Math
University of Minnesota, Morris

#10611: John Wilkins — 12/09 at 10:45 PM
I would like to see you report on the results of that search, if you would be so kind. I think Corvids and Psittaciformes are equally interesting, but I put my money on the latter; they are typically social birds, and I think sociality is the cause of intelligence.

#10618: coturnix — 12/09 at 11:29 PM
Bernd Heinrich's "Mind of a Raven" is an interesting account of his work on ravens (including the "meat on the string" experiment described above). Niki Clayton has published a few good reviews of her (and others') work on various jays and nutcrackers - she also gives a helluva talk if you are looking for seminar speakers...

#10620: — 12/09 at 11:34 PM
Ravens at least also have a well developed sense of play. Outside Flagstaff, Arizona, on one of the myriad forest service roads surrounding the San Francisco Peaks, I once saw a Raven do the damnedest thing. It was one of those high country high wind days. The low clouds were being whipped into froth by a northeast gale, but as I do every day, I was out walking my dog. The trees in the area were all second growth Ponderosa Pine about 40 years old and 60 to 80 feet tall with the occasional big snag emerging from the canopy. Next to the road on top of one such snag was a Raven, horizontal into the wind. As I watched, he(?) dropped down into the protected canyon of the road and flew upwind for perhaps 50 to 70 meters. At that point he popped up above the trees and into the 40 mph + gale. In spite of flapping hard into the wind he was moving backwards in relation to the ground, and as he neared the old snag, would look between his dangling legs and try to land on his perch WHILE MOVING BACKWARDS! He accomplished this three times. There was no survival value to this activity. It was for the simple sensation of doing it. I smile every time I think about it.

#10623: — 12/09 at 11:46 PM
Some Corvids are every bit as social as Psittaciformes John. Ravens take years to mature and spend the first 3 or 4 years of their lives in juvenile "gangs" before paring off for life as adults. Very complex behaviors are apparent in both stages. That said, I'm not voting against the larger parrot species, just giving them a little competition.

#10640: Stephen Brophy — 12/10 at 04:06 AM
Impressive, but they've a long way to go to match Google's Pigeons (CF: http://www.google.com/technology/pigeonrank.html)

#10648: — 12/10 at 06:30 AM
I'm not sure caching is such a good measure of intelligence. Chickadees are cute but dumb, and they cache somewhere around 5000 seeds each winter. They have something like a 95% recovery rate, and they also will retrieve perishable food before seeds. A specialized hippocampus does not a genius make.

Rrawr!

#10653: — 12/10 at 08:34 AM
Without anything to add on the intelligence question, I'll just offer my vote for ravens as generally really cool birds. For whatever its worth, I think it is telling that they are the objects of reverence in North American indigenous mythology where they are regarded as clever tricksters. Something about that is really appealing.

In particular I think ravens have some of the coolest vocalizations. If I believed in reincarnation and had the choice, I think I wouldn't mind coming back to life as a raven.

#10660: Chris Clarke — 12/10 at 09:53 AM

I’m not sure caching is such a good measure of intelligence. Chickadees are cute but dumb, and they cache somewhere around 5000 seeds each winter. They have something like a 95% recovery rate, and they also will retrieve perishable food before seeds. A specialized hippocampus does not a genius make.

Fair enough point.

Interesting note about Clark's nutcrackers' caching technique: one study I recall citelessly showed that the birds' memory of cache locations relied at least to some extent on landmarks. If a bird cached a seed a meter from a big rock, and then the researchers moved the rock half a meter, the bird's search location would be half a meter from the cache.

Clark'ses are formidable opponents as camp robbers. They're not as ballsy and confrontational as crows or blue jays, but they are persistent and cunning. I just really like them for some reason.

"I do not think we should antagonize the religious when it is not warranted, though I think we should be willing to do so whenever it is.”
-- Glen Davidson

#10669: — 12/10 at 10:13 AM
CC, all birds (afaik) that need very specific spatial memory rely on similar landmark usage. Check out the work of Sue Healy on how hummingbirds find flowers for a good example.

Rrawr!

#10705: — 12/10 at 02:05 PM
CC and Gwangi...In my own observations Hummingbirds will go to the exact spot in three dimensional space where a feeder "flower" WAS the first couple visits after the feeder has been moved...even if only a foot. They hover at the spot for a second or two before adjusting to the new location. Not much room in that little skull for brains, but they do well.

#10708: — 12/10 at 02:06 PM
See? God did create them!

#10714: mattH — 12/10 at 02:37 PM
Ravens also hold a big place in Irish-Celtic mythology, often being the physical manifestation of The Morrigan, the Celtic Goddess of War.

#10719: — 12/10 at 03:14 PM
Ravens are also considered by Mongols to be one of the several animals possessing a soul.

On a practical note, Ravens and crows have long been considered (no stats) to be capable of distinguishing between a garden tool and a weapon. While living on a remote (!) ranch in Nevada, the Ravens would bug out as soon as they saw a rifle or shotgun, but if I was hunting Chukar, they would feel safe and come close to examine me and, incidentally, caw a warning to their feathered bretheren.

What is that rattling sort of call they make when resting?

MattH: I envy your knowledge of things Gaelic. Does "mor" mean death in Gaelic as in the other Indo-European languages? Would the name "Morrigan" have to do with a goddess of battle death? Am I reaching too far for a connection? Still, it would make sense as the Raven is usually the first scavenger to arrive at the scene of carnage.

#10904: Wesley R. Elsberry — 12/12 at 08:26 PM
Diane and I have been told several times that it really helps to be at least a bit smarter than the critter that you are trying to train. We're not talking about the corvids or parrots in our case, just good old raptors, not usually considered up there for smarts in the bird world. And yet there have been times when we've come up on the short end of the stick. In our circumstances, it has meant that the birds in question have figured out how to get away from us before we were finished convincing them that staying with us had its benefits. One bird, a female Harris's hawk we called Minerva, watched our food preparation techniques. We had a refrigerator next to a slick countertop. Minerva would get on the countertop, grap the fridge door handle, and try to pull. The slick counter was the only thing preventing her from getting into our cache.

#10907: — 12/12 at 08:43 PM
"living on a remote (!) ranch in Nevada"

Richard, My dad live north of Winnemucca. I am pretty sure that remote is redundant in the context of Nevada ranches !!

Trivia: Treasure Valley Community College in Ontario,OR uses the Chukar as their mascot.

#10951: — 12/13 at 11:17 AM
DD: Re: Remote—agreed. Chukar have to be one of the most successful artificially added wild species in the world. They don't compete with anything indiginous, they're very successful and they make for darned good eating. They also force those who would hunt them to stay in good shape—not being called "heart attack birds" for nothing.

One can be sure that the college is glad of the word Chukar instead of Red Legged Mongolian Partridge

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Thursday, December 09, 2004

Clever birds

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