I think it is only two.
There are only two Liver Birds in existence. Both birds are fastened securely to the top of the Liver Building, Pier Head, Liverpool, with thick cables so that they could never escape. If they did manage to escape, Liverpool (or so the fable goes) would cease to exist.
In Liverpool, apparently!:-) Years ago (in the 70's, I think?) there was an extremely popular TV series entitled 'The Liver Birds' ... a sit-com about the trials and tribulations in life of two 'Liver Birds). I'm not aware, however, that this term is in common usage (as in Scousers from Liverpool, Brummies from Birmingham, etc) There is a building in the centre of Liverpool in England with statues of Liver birds on top.
The Liver Birds
There are four clock faces on the Royal Liver Building in Liverpool, one on each side of the tower. The clock faces are one of the defining features of the building and are a prominent landmark in the city.
Liverpool mascot is called liver bird
The duration of The Liver Birds is 1800.0 seconds.
The Liver Building.
The Liver Birds was created on 1969-04-14.
The Liver Birds ended on 1978-12-29.
The logo of Liverpool football club is the liver bird.
The "Liver Bird" is often used as the logo for Liverpool. It has represented the city since medieval times and takes the form of a cormorant-like bird with a frond in it's beak. The most prominent example of the Liver Bird is on top of the Royal Liver Building. Liverpool Football Club is also represented by the Liver Bird and the Club now hold the copyright to the symbol.
The Liver Birds - 1969 is rated/received certificates of: Australia:PG