"The Duck" joke

A duck walks into a pub and orders a pint of lager and a ham sandwich. The landlord looks at him and says, "But you're a duck"
"I see you're eyes are working" replies the duck.
"And you talk!" exclaims the landlord.
"I see you're ears are working" says the duck, "now can I have my beer and my sandwich please?"
"Certainly," says the landlord, " sorry about that, it's just we don't get many talking ducks in this pub. What are you doing round this way?"
"I'm working on the building site across the road" explains the duck. So the duck drinks his beer, eats his sandwich and leaves. This continues for about 2 weeks. Then one day the circus comes to town.
The ring leader of the circus comes into the pub and the landlord says to him; "You're with the circus aren't you? I know this duck that would be just brilliant in your circus, he talks, drinks beer and everything!"
"Sounds marvellous" says the ringleader, "get him to give me a call."
So the next day, the duck comes into the pub. The landlord says, "Hey Mr Duck. I reckon I can line you up with a top job. Paying really good money!"
"Yeah?" says the duck, "Sounds great, where is it?"
"At the circus" says the landlord.

"The circus?" the duck enquires.
"That's right" replies the landlord.

"The circus? That place with the big tent? With all the animals? With the big canvas roof with the hole in the middle
"That's right!" says the landlord.
The duck looks confused. "What the fuck do they want with a plasterer?"