A man had an argument with a friend about birds.  The result of the argument was one of the most famous books of all time.  What was the book?

The Origin of Species by Charles Darwin

Nope.

Was it published in the last 50 years?

Batman?

To kill a Mockingbird?

Was the argument about whether the bird was actually mocking him?

Was it published in the last 50 years?  The first publishing was not within the last 50 years.

Batman?  No.

To kill a Mockingbird?  No.

so you mean there have been reprints in the last 50 years? or it's been revised and republished?

Correct.

Hitchhiker's guide?

Oh no no, Lord of the Rings!

Neither, sorry.

so was it reprinted or was it republished in a different version (like the bible)?

Revised and republished.

Is it fiction or non-fiction?

Non-fiction.

is it scientifically related?

In part.

in the bookstore would it be in the science / reference section?

Reference, yes.

does it relate to religion?

Not really.

is it reprinted regularly?

Yes.

is it the Guinness Book of Records?

Yes, it is. +1 Bard.

Sir Hugh Beaver, managing director of Guiness, argued with a friend about which game bird flew the fastest.  He hired the McWhirters to research this, and ultimately, other facts which were compiled into the first Book of World Records.

You're on a roll.  Can you give us any more riddles not so doomy so we can get some points, too?

Wow... I had no idea that the records were started by the beer company... hang on, let me just grab a beer and think of a riddle for ya

Oh nice one Bard.