The number of young puffins has gradually increased. In 1981, four pairs nested beneath boulders at the edge of the island and the colony had increased to 37 pairs in 2001. The total population reached 188 pairs in 2019.
Between 1973 and 1986, 954 young puffins were transplanted from Great Island to Eastern Egg Rock and 914 of these successfully fledged. Transplanted puffins began returning to Eastern Egg Rock in June 1977. To lure them ashore and encourage the birds to explore their home, wooden puffin decoys were positioned atop large boulders.