The arrival of two Komodo dragons at the Reptile House at 2 a.m. on August 14, 1963 was the culmination of several years of negotiations with the Surabaya Zoo in Indonesia. Carefully protected, these monitor lizards could only be obtained with the permission of the Indonesian government, which rarely issued such permits. The two were advertised to be a male and female pair; and since it required a surgical procedure in those days to verify the sex, the Zoo went by the accompanying records. However, there was no observed breeding and no offspring. It wasn't until many years later, when the Zoo's Center for Reproduction of Endangered Species developed a hormone analysis technique to determine sex in lizards, that the dragons were discovered to both be females—much to the staff's annoyance. A male was then added to the collection in 1976 to remedy the breeding situation.