Since 2000, the majority of the Humboldt penguin chicks that hatched during each of the reproductive seasons on beaches S4 and S5 within Punta San Juan, have been individually identified and marked with semi-permanent wing bands or webtags. Thanks to the long term presence on-site of Punta San Juan Program personnel, marked individuals re-sighted at the colony have been recorded from year 2000 to present day. However, the proportion of chicks returning to their natal colony has not been quantified. The objective of my thesis is to determine the proportion of Humboldt penguins (Spheniscus humboldti) that return as adults and / or as actively breeding adults to the natal colony S4 /S5 in Punta San Juan, Ica, Peru. Furthermore, I am interested to understand how various factors may influence these returns. To achieve this, the proportion of re-sighted individuals was estimated from the number of individuals that have been marked as chicks on the study beach and which have been re-sighted as adults and/or reproductive adults in their native colony from year 2001 until year 2015. I also used different statistical measures (Pearson correlation test, Spearman correlation and logistic regression to explore how the weight when fledging the nest, age of the first re-sight, age of the first reproductive return and success of the first reproduction may influence future returns to the colony.