Zoo Joke: Who's There?

A bird keeper arrive at work on morning and notices some leaky pipes in the Bird House.  He puts in a call to a local plumber, then begins his daily routine deep with the Bird House.

About an hour later, the plumber arrives.  He walks up to the service door of the Bird House and gives a quick knock.  The keeper, way back in the building surrounded by noisy birds, doesn't here it.  A great horned owl in an exhibit right by the door, however, does.

"Who?" calls the owl in response to the knock.

"It's the plumber," calls the man outside, thinking that the voice from within is a human.

"Who?" the owl calls again.

"I said, 'it's the plumber'" the plumber repeats, a little louder this time.  After a moment of silence, he knocks again.  "Hello?"

"Who?" the owl hoots once more.

"I said, 'IT'S... THE... PLUMBER!", yells the plumber, really beginning to loose his patience.

"Who?" the owl says.

"IT... IS... THE... &#&*$(#@( PLUMBER!!!" screams the frustrated plumber.  He's so angry that his heart gives out and he drops down, dead on the spot.

Shortly later, the bird keeper comes to the door, wondering whatever happened to that plumber he'd called. As soon as he opens the door, however, he finds a dead man's body sprawled outside.

"What on earth!" he exclaims, bending down to check the man's breathing.  "What happened?  Who is this?"

"It's the plumber," the owl replies with a shrug.