Friday, December 10, 2010

The Australasian Gang That’s Taking Over the World

Blue jay

Ravens, crows, jays, magpies, jackdaws, rooks, nutcrackers, treepies, and choughs.  What a rowdy gang.  Their ancestors came from Australasian roots and have taken over the world except for the polar ice caps and the tip of South America.  No polar explorers these.

European Magpie

Known as the Corvid family, they are now considered to be intellectually on a par with some of the great apes.  It gives new meaning to the phrase “bird brains”.

American crow

Collectively, the family makes up more than half of all bird species.  They can range in color from black or dark blue, black-and-white pied, or purplish-blue iridescent, although in the tropics they have bright colors.  In size they range from the Dwarf Jay (1.4 oz. and 8.5 inches) to the Common Raven (3 lbs, 26 inches).

Rufous Treepie

Corvids tend to be monogamous, sometimes mating for life.  Mate selection is complex and involves playing social games and aerobatic feats.  Mates build nests together, and have even been known to console one another, especially after the male has been involved in some kind of male dominance event.  Young corvids usually remain in the nest for up to ten weeks, depending on the species.  Both parents provide for them.  These kids participate in elaborate social games, akin to “follow the leader” and “king of the mountain”.

European Magpie


These raucous and, frankly, rude birds are very aggressive.  Don’t go near their nests unless you want trouble, and a lot of it.  I live with dozens of ravens and Western scrub jays, and I’m here to tell you they are not shy.  And thick as thieves they are.  I’ve watched them start trouble just as a distraction so their cohorts can steal something – food, eggs, or very young nestlings.  Yes, they will eat invertebrates, nestlings, small mammals, and carrion.  Since they don’t have the beaks necessary to open flesh, they can only dine on carrion whose flesh is exposed, such as road kill.  But they will eat people food, too.

Western scrub jay

I once had an outlaw band of jays living in the trees over my rental house in a canyon.  I never threw any foodstuffs away, I just put them outside and they were consumed immediately.  Once, in my own kind of peculiar experiment, I put out some coffee grounds.  They ate them.  In my current home, I’ve found the ravens like tortillas – preferably whole.  They’ll grab one and fly around in circles squawking loudly, bragging about the swag they’ve scored.  I once saw a red-tailed hawk flying by with a small rodent in its beak.  Following close behind, and sweet-talking it profusely, was a pair of ravens.  How sweet of them to offer assistance!

Clark's Nutcracker

The funniest experience I had with ravens was in our last house on a hill in a canyon.  There was an abandoned mine in which neighbors told us was a nesting pair of golden eagles.  The eagles remained unseen until one day, when I was baking in the kitchen I heard the ravens making an incredible racket.  Alarmed, I swung open the kitchen door to the patio, and there about ten yards away from me was an eagle, standing on the ground on one foot, with wings spread (the wingspan was huge!), holding a raven in one of his talons.  Two other ravens were screaming at him and attacking him.  When the door flew open, they all stopped and looked at me.  In this incredible, one-in-a-lifetime moment, I blurted out, “What’s up, guys?”  At this fine example of human imbecility they took off, the caught raven dropped.  I was too squeamish and chicken to go and look at at to see if it was okay, so I rousted my husband and made him go look.  Not a creature in sight.

Raven scavaging on a dead shark.

Crows and ravens can be taught how to talk, and there is an instance of a crow being able to count to five.  My raven buds make a loud clucking sound that I love.  When I’m outside I will imitate it, and they will come close and stare at this stupid human who can’t cluck correctly.  But they play the game.  I tire of it before they do.

Rook

In brain-to-body weight Corvid brains are among the largest in birds, and have similar ratios to the great apes and cetaceans, and almost as high as humans.  Part of their intelligence scientists attribute to their long childhood and nurturing care by their whole community, not just parents.  When test results of the ability to seek food were compared with those of dogs and cats, the corvids fared better than the mammals.  Although new ways and new types of tests to measure their intelligence are being conducted constantly, the preliminary results for corvids reveal high cognitive ability.  They can even recognize faces.




There are documented cases (see video above) of crows placing nuts on a street and waiting for them to be run over by vehicles to crack them open.  They are capable of watching where other birds hide food, then stealing it later.  They can remember where they have stashed food up to nine months later.  But most of all, it is their ability to use tools, once thought only the domain of humans and apes, that is remarkable.



These hooligans and bullies have successfully survived the spread of humankind and have even thrived because of it.  (In my case they get tortillas and other goodies.)  It’s nice to know that some species can survive us.  Perhaps in time their intelligence will surpass ours, as we kill each other off, and then the earth will truly be for the birds.

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Images courtesy of Wikipedia
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2 comments:

  1. I believe that like Morse Code, a language based upon 2 things, the dot and the dash and the spaces in between, we'll find one day that the language of corvids is based upon not just their caws and cackles, but in the pattern and rhythms of their clucking.

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  2. I'd never considered relating their clucks to Morse Code, but what an intriguing idea! I believe you are right - a simple but expressive language.

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