The Guardian Newspaper has a column: SEMANTIC ENIGMAS where theories on the origins or words/phrases are sought and then the correct theory is published or ratified. The following are theories on the origin of
"as sick as a parrot"?
1.TO AVOID United States quarantine and livestock importing restrictions, people smuggling parrots from South America into the US dope the birds on tequila as they near the Mexican border. Careful timing of the binge will ensure that the birds are sleeping it off through the border crossing The downside for the exotic loudmouths is coming to with a bad hangover. This queasiness manifests itself in the origin of the expression.
2.THE PHRASE originates from 1926 when the very low incidence of psittacosis became a pandemic of clinical importance, involving humans in 12 countries with more than 800 cases. The association of respiratory infections in man and contact with parrots was soon recognised.
3.IT IS A CORRUPTION of "sick as a pierrot" and refers to the typically pale/miserable face of the French pantomime character.
4. ANOTHER THEORY is that the Amazon parrot - a large green bird with yellow cheeks - was the most-sickly looking creature imaginable.
5. The simile refers the Monty Python "Norwegian Blue" sketch.
6. The phrase was originated by the dramatist Aphra Behn in her 1682 comedy, The False Count, in which the maid Jacinta says of her mistress Julia , "Lord, Madam, you are as melancholy as a sick Parrot." The simile is particularly apt as Julia is herself a bright and beautiful creature. The phrase is used to expresses a feeling of disappointment rather than one of nausea.
7.During a recent long trip to Indonesia, I found that by necessity I learnt the correct way of saying 'upset stomach' in the language of the country - 'Sakit Perut', pronounced: 'Sackit Paroot'.
8. In 1909, the Tottenham Hotspur team toured Uruguay and Paraguay. On the voyage to the UK they were gifted the ship's parrot by the captain of the vessel. The parrot lived happily at the club for 11 years until it keeled over and died in 1919 on the very day Spurs were relegated from Division 1 and Arsenal promoted in their place.
From these thories, The editor believed the last theory correct which would validate the prvious FT submission on this topic.
http://www.guardian.co.uk/notesandqueries/query/0,5753,-2035,00.html