Whilst at the zoo decided to stop and have lunch at the cafe near the tortoise enclosure. When I walked by on way to cafe they were lodged right up to the concrete barrier fencing in such an awkward spot to photograph. A short time later there was a lot of noise coming from their enclosure and this is what I found. Just a couple of notes in regard to these giant tortoises: Sexual maturity is determined by size rather than by age; they usually begin to reproduce when they reach approximately half their full-grown size, which is usually around 25 years of age. Typically, the females lay between 4-14 eggs. Usually less than half of the eggs are fertile. Incubation is temperature dependant - in warm temperatures eggs hatch in about 110 days whereas in cool temperatures eggs take 250 days to hatch. The Aldabra tortoise is one of the longest-lived animals on earth, surpassing 100 years of age. However exact figures are not known as the tortoises studied have outlived the scientists studying them and proper records have not been maintained.