“His age is estimated because he was “fully mature” when brought to Saint Helena in 1882. “Fully mature” means at least 50 years old, giving him a hatching date no later than 1832.[8] A photograph featuring Jonathan originally thought to date from 1902 actually dates from 1886,[2] showing Jonathan four years after his arrival on Saint Helena. Measurements taken from the photograph show that he was fully mature in 1886.[citation needed]”