The parrot with no feet

A guy is not getting along with his wife.  He thinks maybe he'd like to have a pet and goes to a pet shop. After looking around he spots a parrot sitting on a little perch. It doesn't have any feet or legs.
The guy says out loud, "Geez, I wonder what happened to this parrot."
"I was born this way," says the parrot. "I'm a defective parrot."
"Ha, ha," the guy laughs. "It sounded like this parrot actually understood what I said and answered me."
"I understood every word," says the parrot. "I am a highly intelligent, thoroughly educated bird. "
"Yeah?" the guy asks. "Then answer this: how do you hang onto your perch without any feet?"
"Well," the parrot says, "this is a little embarrassing, but since you asked I'll tell you. I wrap my little parrot penis around this wooden bar, kind of like a little hook. You can't see it because of my feathers."
"Wow," says the guy, "you really can understand and answer, can't you?"
"Of course. I speak both Spanish and English. I can converse with reasonable competence on almost any subject: politics, religion, sports, physics, philosophy ... and I am especially good at ornithology. You ought to buy me. I am a great companion."
The guy looks at the price tag. "$200!" he says. "I can't afford that."
"ssst," the parrot hisses, motioning the guy over with one wing. "Nobody wants me cause I don't have any feet. You can get me for $20 -- just make an offer."
Guy offers $20 and walks out with the parrot. Weeks go by. The parrot is sensational. He's funny, he's interesting, he's a great pal, he understands everything, sympathizes, gives good advice. Guy is delighted.
One day guy comes home from work and the parrot says, "pssst," and motions him over with one wing. Guy goes up close to the cage.
"I don't know if I should tell you this or not," says the parrot, "but it's about your wife and the mailman..."
"What?" says the guy. "What?"
"Well," the parrot says, "when the mailman came to the door today your wife greeted him in a sheer nightgown and kissed him on the mouth."
"What happened then?" asks the guy.
"Then the mailman came into the house and lifted up the nightgown and began petting her all over," reports the parrot.
"Oh No!" the guy says, "Then what?"
"Then he lifted up the nightgown, got down on his knees and began to lick her body, starting with her breasts and slowly going down and down ..."
The parrot pauses for a long time.
"Then what....what happened Next...WHAT HAPPENED?" says the frantic guy.
"I don't know," says the Parrot, "I fell off my perch."

how can the parrot fall off from his perch?