Sunday, March 17, 2013

Asphalt clams

Visit any parking lot around the Puget Sound when the moon and the sun aline just right and you may get to see this.

Fragments of tiny clam the size of a quarter along with and barnacle pieces

 The is an enormous  number of piles of broken shell shards. They look just like sunflower seed husks littering the parking lots, sidewalks near the waters edge.  Then the thought emerges where are all these little things coming from? and why are they there? 

When the low tide coincides with daylight during good weather, the local crows rush in for a rare delicacy.  The true definition of a delicacy, requires a huge amount of energy to grasp that tine morsel of goodness. The hard earned  elusive prize that may be more of a status symbol then an end to a dietary need.  

So it plagues me how does a crow go about extracting this prize?
I know how he physically does it.
I just can not fathom why. 

First these little treasures have to be found. 

Not all of the crows know how to do this. Younger crows learn from their elders.  Feeding baby crows this way would be very labor intensive but there are only a couple hours until the tide returns. 

Seeing an adult crow share with another adult crow is moving.

Transported to  suitable location.

Position for the best aero dynamic characteristics , calculate angle of impact and began your approach.

Lifted to a given height above a hard surface that is the balance point between the expended energy to do it while  maximizing the amount of damage our nemesis gravity could inflict upon the clam upon impact.


Repeat as nessesary

 It is hard work and there are many who don't want to expend the energy but want the reward.  Remind you of anyone in your flock?

Finding refuge to relish your hard won reward is to often short lived

Again in their world as well as ours, if anything is worth having is worth working for. Or stealing.

Once the shell of the hapless clam is shattered the crow uses it's body as a lever and tears off tinniest of morsels.

Down the hatch.

I can't imagine the crow is doing this to appease a refined taste. The tidbit just goes straight down. I have always wondered how much or if crows could taste their food.   I have eaten clams. I am not a fan but I cannot imagine expending that much energy for the reward to gain equation.  

This technique the crow are using is not just limited to clams.

Discarded peach pits and sometimes items that are not edible get the same treatment.  The crows here are not all that different then any other crow. This behavior is common to their who family around the world.  

Crows are not alone with this skill. Heavy bombers have found their own delicacies.

Here is a local gull with a Moon Snail. Moon Snails prey on other mollusks in the Puget Sound and are hated by many humans but loved by the gulls.  They can reach the size of a baseball or larger so most of the time they are too heavy for a crow to lift to a sufficient height to damage the shell.

So the next time the tide is low and the and he weather permits see if you can find a show.  There is always squabbling and jockeying and stealing.  I don't think they do it for the food. I thing they do it because they can, it is difficult and expends way more energy then returned.  They do it to show the other crows that they are accomplished, skilled and a survivors.  

Not to mention show offs.

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