Gannets are fish-eating seabirds that make their nests in the rocky cliffs of coastal areas. In 2003, a colony of gannets began inhabiting the Noup Cliffs region of Scotland. Since 2003, the gannet population there has been rapidly increasing. The graph shows the number of gannets in the Noup Cliffs region since 2003. Which factor would most likely limit the Noup Cliff’s gannet population size?