Farallon Islands

Visualizing Long-term Data /  by Michael Johns

Point Blue Conservation Science has amassed an impressive long-term dataset on the breeding histories of known-age Cassin's auklets on Southeast Farallon Island. These data are visualized in the figure above. The dedication to maintaining and checking 400+ artificial nest boxes every 5-days for the past 34 years has allowed researchers to reveal some unique patterns in the life history of this small seabird. For example, Cassin's auklets are the only member of the taxonomic Alcid family to attempt two complete broods in a single breeding season, known as double brooding. In a recent study published in the journal Proceedings of the Royal Society B, my colleagues and I used these data to examine how double brooding impacts future reproductive potential and survival for birds that attempt such a behavior multiple times over the course of their lives. It turns out that so called "repeat double brooders" represent a subset of high quality individuals that can offset the short-term costs of increased reproductive effort, living well into old age and producing more offspring than birds that never double brood. Visit the publisher’s website by clicking HERE. 

Listers /  by Michael Johns

The Farallon Islands are uniquely situated for people interested in the hobby of finding and identifying birds, otherwise known as "birding". The cluster of jagged rocks are located just far enough offshore to provide a stable platform for spotting rare pelagic species like the Cook's petrel, and close enough to the mainland to catch vagrant song birds and other terrestrial species lost in the fog at sea. Over the course of 50 years of research out on the Farallones, some biologists and staff have been keeping a detailed list of all of the different bird species they've encountered while out on the island, a record known as "The Faralist". This figure is a graphical interpretation of that list, modified from R code for a similar graphic depicting the number of days spent on island by various people over the years. Collectively, a total of 429 different species have been seen from the Farallones; not bad for a small collection of guano-covered rocks with only 3 trees.

Download a high resolution file of this figure HERE.  

Final Chicks of the Season /  by Michael Johns

Ashy storm-petrels are endemic to the California Current System, which means their entire population occurs in the offshore waters of the California coast. Half of the world's estimated 10,000 individuals breed on Southeast Farallon Island, their chattery calls a regular sound after the sun goes down in the summer. They are amazing swallow-sized seabirds that spend much of their lives exposed to harsh winds and rough seas, thriving on small planktonic items they pluck from the productive surface waters of the Pacific. These enigmatic relatives of the albatrosses have a more prolonged occupation on the Farallones compared to the other breeding seabird species, extending chick provisioning efforts well into early October. They are generally the last chicks to hatch on the island, small grey puff balls that can be viewed on occasion in shallow crevices if you look hard enough.