Birds and Coconuts

Soldier: 'Who goes there?'
King Arthur: 'It is I, Arthur, son of Uther Pendragon, from the castle of Camelot. King of the Britons, defeater of the Saxons, Sovereign of all England!'
Soldier: 'Pull the other one!'
King Arthur: 'I am, and this is my trusty servant Patsy. We have ridden the length and breadth of the land in search of knights who will join me in my court at Camelot. I must speak with your lord and master.'
Soldier: 'What? Ridden on a horse?'
King Arthur: 'Yes!'
Soldier: 'You're using coconuts!'
King Arthur: 'What?'
Soldier: 'You've got two empty halves of coconut and you're bangin' 'em together.'
King Arthur: 'So? We have ridden since the snows of winter covered this land, through the kingdom of Mercia, through...'
Soldier: 'Where'd you get the coconuts?'
King Arthur: 'We found them.'
Soldier: 'Found them? In Mercia? The coconut's tropical!'
King Arthur: 'What do you mean?'
Soldier: 'Well, this is a temperate zone.'
King Arthur: 'The swallow may fly south with the sun or the house martin or the plover may seek warmer climes in winter, yet these are not strangers to our land?'
Soldier: 'Are you suggesting coconuts migrate?'
King Arthur: 'Not at all. They could be carried.'
Soldier: 'What? A swallow carrying a coconut?'
King Arthur: 'It could grip it by the husk!'
Soldier: 'It's not a question of where he grips it! It's a simple question of weight ratios! A five ounce bird could not carry a one pound coconut.'
King Arthur: 'Well, it doesn't matter. Will you go and tell your master that Arthur from the Court of Camelot is here?'
Soldier: 'Listen. In order to maintain air-speed velocity, a swallow needs to beat its wings forty-three times every second, right?'
King Arthur: 'Please!'
Soldier: 'Am I right?'
King Arthur: 'I'm not interested!'
Second Soldier: 'It could be carried by an African swallow.'
King Arthur: 'Will you ask your master if he wants to join my court at Camelot?'
Soldier: 'Oh yeah, an African swallow, maybe, but not a European swallow. That's my point.'
Second Soldier: 'But then the African swallow's not migratory...'