RICHARD O'Grady, the director of Glasgow Zoo, has died of a brain aneurism after collapsing at work.

The 54-year-old had been complaining of a pain in his ear shortly before his collapse on Wednesday evening and was unconscious before the ambulance arrived.

The father-of-two was taken to Monklands District General Hospital, Airdrie, but died at about 7am yesterday without regaining consciousness.

Mr O'Grady had fallen in love with the struggling zoo since he became director almost 30 years ago. In recent years, he had even taken to living in a cabin on site.

William Smith, chairman of the Glasgow Zoological Society, was a close friend of Mr O'Grady.

He said staff at the zoo were ''shattered'' by the news and paid tribute to the man he described as ''optimistic where lesser people would have given up''.

''Richard was Glasgow Zoo,'' he said. ''He had a passion and enthusiasm that led him to work extraordinary hours to keep the zoo going. One minute he would be handling a difficult problem concerning the zoo's running, the next he would be on the phone to a little girl from Partick explaining to her how her tortoise would sleep over the winter.

''That was the type of man he was. He loved his work. It is a sad sad day for everyone here because he was much loved.''

Mr O'Grady, a divorcee, was a graduate of Dundee University and joined the zoo in 1972.

The Cambridge-born animal lover had worked to realise his dream of an education-based zoo, rather than just animals in cages. He had previously worked at Culzean Castle, where he had been instrumental in setting up Robert Adam Home Farm - Scotland's first educational country park.

Mr Smith said: ''Richard was an ideas man. He was always on the go and coming up with new ways to either help children understand more about wildlife or promote the zoo to enable us to get more funding.

''He lived for the zoo and it is difficult to think of the place without him.''