Wednesday, May 18, 2011

Vulture Eggs

Black Vulture
I took several friends out to the barn to see the barn swallow nests and found a surprise.  As we walked toward the back, something large and black flew out of a side wall and landed on a wooden fence rail.  It took us several seconds to register as we didn't expect to see a black vulture in a barn.

A black vulture finding prey in a barn is unlikely in a species that hunts mainly by sight.  We opened the door carefully and there on the thick straw on the floor lay two large eggs.  We took several pictures and left it alone.  The next day we confirmed that she was back on the nest.

Click to Enlarge
In a recent blog we discussed the differences between turkey vultures and black vultures.  As they hunt by sight instead of smell like turkey vultures, they generally avoid heavily wooded areas.  We occasionally see black vultures soaring but they are much less common that turkey vultures in the valley.

Black Vultures, Coragyps atratus, usually lay 1-3 eggs in cracks and caves along cliffs or in a stump or dense vegetation.  There is no nest built, and the parents take turns incubating the eggs over 37-48 days.   Once the eggs hatch, the young are fed by the parent's regurgitation.  You would think this would encourage them to leave early but they don't take off for around 80 days.

Vulture Society
Unlike turkey vultures, the black's chicks are yellow-tan, with feathers extending over their head.  They will eventually lose the head feathers, going bald like some humans.  This helps keep their head clean when they immerse themselves in their food (no further comment required).

Vultures defense against intruders is to vomit on them "with power and speed."  Having retired from gastroenterology several years ago, I do not intend to intrude on them up close and personal.  However we will cautiously take pictures at intervals.

1 comment:

  1. To all naturalist and their neighbors:
    You do not have to personally like the Kipfers to help them raise vultures! Simply collect all available road-kill, age it for 7 to 10 days (partial sun), in a shallow pan - then drop it off on their front porch at your convenience. log your volunteer hours under "sanitation and benevolence". Buck