Wednesday, May 20, 2015

Now Eat Your Carrion

When the chick is young the parents pick up small pieces of food and feed them to the chick, but as it gets older, it picks up these regurgitated food items on its own. Chicks remain in the nest for two to three months and continue to depend on their parents for a period of time after fledging, until they learn how to find and compete for food on their own. By the time they are ready to fledge, at three to six months old, the chicks are nearly the same size as their parents and are fully feathered, but their coloration is different. - See more at: http://animals.sandiegozoo.org/animals/vulture#sthash.tegIA6vt.dpuf
"Now eat your carrion like a good little vulture chick!"
I recently had the opportunity to watch our black vulture parent introduce the chicks to solid food.  Initially chicks are fed by the parent regurgitating digested food into their open mouths.  As they get older, the parent picks up small pieces of food and feeds them to the chick, before it learns how to pick up these regurgitated food items on its own.

I opened the stall door where the 5 day old chicks and parents are living.  The adults are accustomed to my visits and ignored me, while the chicks made a soft hiss when they felt threatened.  This time there were several strips of meat on the floor.  While I got my camera out I watched one chick repeatedly pick up a piece, trying to throw its head back to get it into its mouth.  It quit in frustration just as I was ready to film it.

"Tried it, didn't like it."
I have read that vultures will occasionally glean ticks.  This parent was gleaning a lot more than ticks.  Each time I opened the door to the stall, the parent stepped back and then started picking at things in the dirt, sometimes dropping an object, other times making a movement to swallow it.  Once I could see it was a small bug or beetle.  As you will see in this video, the parent is walking around the stall, gleaning insects from the stall floor, carefully selecting what to eat and what to discard.

These chicks will remain in the nest for two to three months, continuing to depend on their parents for regurgitated food until they fledge.  Even after taking flights across the field, they will depend on parental feeding for a while although they are nearly the size of the parents. *

Eat what?
A vulture's diet is enough to gag a maggot, so how do they survive eating carrion rotting in the sun for several days?  They can tolerate large loads of bacteria growing on carrion due to their unique mix of Clostridia and Fusobacteria gut bacteria.  Also, their gastric juice is far more acid than most birds, a remarkable pH of 1 to 2.

Like mothers everywhere, the adult eventually ate the piece of carrion to clean the plate.
In some countries in Southeast Asia, vultures are dying in large numbers.  The cattle that are revered are also treated with drugs like diclofenac.  When they die natural deaths rather than being butchered by humans  they are eaten by vultures which frequently develop kidney failure from the drugs.

*Sandiegozoo.org
There is a good overview of black and turkey vultures at Trekohio.com.
When the chick is young the parents pick up small pieces of food and feed them to the chick, but as it gets older, it picks up these regurgitated food items on its own. Chicks remain in the nest for two to three months and continue to depend on their parents for a period of time after fledging, until they learn how to find and compete for food on their own. By the time they are ready to fledge, at three to six months old, the chicks are nearly the same size as their parents and are fully feathered, but their coloration is different. - See more at: http://animals.sandiegozoo.org/animals/vulture#sthash.tegIA6vt.dpuf

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