"Two Irishmen are standing on" joke

Two Irishmen are standing on the top of a cliff, looking out over a huge
drop to the rocks below.
One turns to the other and says, "OK, Paddy, a pact is a pact. We're
going to do it, right?"
Paddy says, "If you tink we should, Murphy, I'm with you all the way. As
you say, a pact is a pact, but you go first."
Murphy thinks about this for a moment, then says, "But you'll be right
behind me, yes?"
"Oh, yes, Murphy. I'll do it, but I want to watch you first."
"OK then Paddy. I'm going. Goodbye!"
With that, Murphy takes a budgerigar out of his coat pocket, ties some
string around its legs, and straps it firmly onto his head. He steps
forward to the edge of the cliff, and throws himself off.
The budgie flaps its wings like mad, but to no avail. It can't hold the
weight of a thirteen stone Irishman in the air by itself. Murphy falls
splat, and breaks both legs on the rocks.
Paddy has seen all this, but thinks, "A pact is a pact. I have to do
it."
He takes a parrot out of his jacket pocket, straps it to his head,
salutes, and jumps off the cliff.
Now the parrot is bigger than the budgie, and Paddy is quite a bit
lighter than Murphy, so for a moment the parrot seems to be holding its
own against gravity. However gravity doesn't get tired, and gradually
Paddy starts to descend.
It seems he is going to make a graceful landing, when about halfway down,
he takes a gun out of his other pocket, and carefully points it at the
parrot on his head, and shoots it dead.
Of course he now falls splat, and breaks his legs too.
Lying there together, Murphy looks at Paddy and says, "I don't tink much
of dis budgie jumping, Paddy."
Paddy replies, "And Parrotshooting is not all it's cracked up to be
neither!"