The original colony of African penguins on the island was completely exterminated by 1800. But since 1983 a new colony has been established there, and the modern island is again an important breeding area for the species. The colony grew to a size of ~16,000 individuals in 2004, before starting to decline in size again. , this decline has been continuous (to a colony size of ~3,000 individuals). Such a decline has been found at almost all other African penguin colonies. Its causes are still largely unclear and likely to vary between colonies, but at Robben Island are probably related to a diminishing of the food supply (sardines and anchovies) through competition by fisheries. Easy to see in their natural habitat, the penguins have been a popular tourist attraction.