Relative abundance of four species of fish returned to Forster’s tern (Sterna forsteri) colonies.

Forster’s tern breeding colonies were sampled in south San Francisco Bay, California during 2005–2015. Temporal trends for four main prey species of Forster’s terns are color-coded by colony. Silversides (Menidia audens and Atherinops affis) increased in relative abundance over time, whereas longjaw mudsucker (Gillichthys mirabilis) and three-spined stickleback (Gasterosteus aculeatus) decreased over time. Trends of staghorn sculpin (Leptocottus armatus) relative abundance varied among colonies. Not every location had a breeding colony of Forster’s terns each year.