According to Official Guinness Records,
The largest collection of stamps featuring birds belongs to Daniel Monteiro (India) and consists of 4,911 stamps from 263 countries, as of 24 December 2011, in Brahmavar, Karnataka State, India.
Daniel Monteiro started collecting stamps at the age of 11 in 1973. He specialises in water birds.
For a complete list of 2011 records, please visit 2011 Guinness Records in India.