In April 2011, I once again arrived on the Farallon National Wildlife Refuge to start another season of seabird research working with PRBO Conservation Science. In my seventh and perhaps last season, I decided to start a photo a day challenge for myself. The challenge is to share a new and interesting photo for each day I am on the island this year.
The little blue foot there is the foot of a mostly feathered Cassin's Auklet chick and it's about to get some jewelry. Once the chicks are nearly fully grown, they get an individually numbered leg band. This band will last their entire lifetime and it allows us to track this individual across years. If it returns to breed as an adult, the band number tells us how old the bird is. These known-age birds are especially valuable since they allow us to answer questions about how survival and reproduction change with age and how many young and old birds there are in the current population.