Farallon Islands

Bill Load of Fish by Michael Johns

This animation represents the total number of prey delivered by common murre parents to awaiting chicks during a 14-hour diet watch. Each red dot depicts a single breeding site in one of our followed study plots on Southeast Farallon Island. Circles appear when a fish is delivered, and intensify in color as more fish are brought in throughout the day. Common murres deliver a single item after each foraging trip, the size and species of which are identified by Point Blue field scientists as birds fly into their respective sites. On this particular day in 2016, foraging parents were bringing in predominately anchovy, followed by juvenile rockfish and a mix of less common items such as squid, smelt, flatfish, and juvenile salmon.

Seabird Sizes by Michael Johns

This figure depicts the relative sizes of seabirds that breed on the Farallon Islands. Larger circles mean more massive birds, smaller circles less massive. Species in the order Pelecaniformes, colored in shades of blue, are among the largest birds that breed on the island. The Ashy Storm-petrel in yellow, although a part of the order Procellariiformes which includes some of the largest seabirds like albatrosses, is small enough to fit inside the palm of your hand. The diverse order Charadriiformes in shades of red includes all of the gulls and auks, the latter of which contains all of the wing-propelled pursuit divers like puffins, murres, guillemots, and auklets. Mass information was gathered from the Sibley guide to birds. This plot was made almost entirely in R, with a few minor tweaks made in Photoshop. A full size image can be downloaded HERE.

Make It An Animation by Michael Johns


Sometimes, an animated figure tells the story better than a static one. We have been tracking the non-breeding movement patterns of Cassin’s auklets from Southeast Farallon Island since 2015, in an effort to understand the environmental drivers of their winter dispersal. Part of the work I’m doing for my PhD is linking the movements of auklets to remotely sensed conditions relevant to their foraging ecology, in the case of this animation chlorophyll-a concentration (left) and sea surface temperature (right) from November 2017 through January 2018. Chlorophyll, the photosynthetically active molecule that gives plants, algae, and certain types of bacteria their green pigment, is used as a measure of the concentration of phytoplankton. Krill, which comprises much of the Cassin's auklet diet, graze on phytoplankton, so it’s reasonable to assume productive areas with high concentrations of chlorophyll-a likely contain greater densities of krill than areas of low chlorophyll-a. Similarly, lower sea surface temperatures are generally associated with nutrient rich cold water from depth, which help spark blooms of phytoplankton. One hypothesis, visualized with this animation, is that Cassin’s auklets are searching for colder regions of higher productivity during the winter months. The next step is to test this hypothesis with a series of competing models, to see which best explains the patterns observed in the data.

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. 

Rabbit Cave by Michael Johns

We monitor the breeding population of Rhinoceros auklets on the Farallones by checking artificial wooden nest boxes distributed across the island. These boxes are visited on a regular basis to note which ones contain an active breeding pair, whether those pairs are successful at hatching an egg, and ultimately how many pairs end up fledging a chick; giving us an estimate of the annual breeding success for this species. In addition to the nest boxes, we also monitor breeding activity in Rabbit Cave, a large vestige of the islands geologic past that acts as a kind of massive burrow for Rhinoceros auklets. The entrance to Rabbit Cave starts out as a narrow crawl space that opens up into a cavernous amphitheatre at the back. 

Landscape of a Year by Michael Johns

Animals tend to be fairly predictable in their reproductive timing and migration patterns. The figure above depicts a series of density curves, with peaks and troughs corresponding to the average timing of key biological events for a select number of marine species that are monitored on or from Southeast Farallon Island.

Pinnipeds, a taxonomic group that includes seals and sea lions, are found hauled out on the island year round, with peak pupping events occurring in the summer. Northern fur seals, which have made an astounding recovery on the Farallones following the days of the Russian Fur Trade, remain at sea for several months of the year and are only seen in force from summer to late fall. Whales are also visible from the island year round. Gray whale numbers peak in January as they migrate south to their breeding grounds off Baja California Mexico, and again in March during a northward migration back to their feeding grounds in Alaska. Humpback and blue whales are most abundant in the productive summer months, where they are seen gorging themselves on krill and schooling fish. For seabirds, breeding occurs only in the summer months, with the exception of the ashy storm-petrel which extends chick rearing well into October. Three distinct peaks represent the timing of egg laying, hatching, and chick fledging. 

The study of seasonal life-history patterns is called phenology, and it can tell us a lot about the stability of a system. As I mentioned, animals tend to be fairly predictable in their phenology. Individuals cue in on environment and biological signals, so shifts in the timing of reproduction or migration can indicate changes in environmental condition, food availability, or the health of a population. For species found on the Farallones, the major cause for concern in the face of a warming ocean is the availability of key prey items, namely krill, which sustain the rich biodiversity in this region. A mismatch between the timing of krill and the timing of reproduction for seabirds can lead to major declines in breeding success, and subsequent declines in population numbers. 

Data courtesy of a partnership between Point Blue Conservation Science and the USFWS. The plot was created in R with the ggplot2 and ggridges packages. 

Sei Whales Off The Farallones by Michael Johns

In addition to daily opportunistic sightings, we conduct standard 1-hour whale watches from atop Lighthouse Hill to document the timing and abundance of Cetaceans around the Farallon Islands. These data are useful in particular for showing where whales are in relation to shipping lanes leading into San Francisco Bay, to better inform mitigation measures aimed at reducing the number of ship strikes.

On one particular whale watch, during an exceptionally calm day, I came across a feeding flock of 6 black-footed albatross and several dozen pink-footed shearwaters. I considered the possibility that this flock was associated with killer whales, since albatross have been known to scavenge on orca kills, and killer whales had been reported in recent days just south of us in Monterey Bay. Sure enough, after watching for a few minutes a tall black dorsal fin came into view, followed by two smaller fins. A pod of transient killer whales that were feeding on some unknown pinniped at the surface. After radioing the sighting to the rest of the crew, everyone made it up to the lighthouse for a look before they eventually departed to the west. 

After the killer whales had left we decided to keep looking around for other sightings. Within minutes a blue whale surfaced right next to the East Landing mooring ball, in water probably half as deep as the length of the animal itself. As if that wasn't good enough, someone pointed out a small pod of whales swimming toward the island. They were all dark baleen whales with a visible blow, six of them traveling in tight formation towards an islet we call Sugar Loaf. Initially, I assumed perhaps it was a group of minke whales, clumping together in response to a pod of their natural predators nearby. The shape of their rostrums, size, behavior, and blow were all wrong though, and as they got closer we couldn't see an signs of white patches indicative of minkes on their pec fins. They were too small to be fin or blue whales, too big to be minkes, and definitely not a toothed whale. The only other obvious possibility for this part of the world is the sei whale, a species of rorqual found in temperate waters worldwide, but generally seen much further offshore and rarely sighted off California. 

To put this sighting into context, only 17 sei whales have ever been seen on the Farallones since 1987, and generally the sightings consisted of a solitary individual. Not only did this group contain a Farallon record breaking 6 animals, but they swam close enough to the island for us to get excellent looks for a prolonged period of time, and even photos of the event (of which my favorite is of a western gull pondering whether it can eat one of the whales). Truly a rare and amazing sight. 

Photos taken through Point Blue Conservation Science | USFWS

Relative Size by Michael Johns

Probably the most important question in the conservation work that we do, and the most popular question people have about the Farallones, is the population size of the various seabird species on the island. The answer, such as roughly 250,000 murres, 20,000 auklets, and 500 puffins, may not be fully appreciated when taken at face value. The figure above is an attempt to put these numbers into context by representing each population as a collection of boxes, where the area of each box is scaled in proportion to the other boxes. With this visualization, you can see just how abundant Common Murres are in relation to Pigeon Guillemots or Tufted Puffins. With continued monitoring and management, hopefully all of these boxes will continue to grow in size.

Data courtesy of a partnership between Point Blue Conservation Science and the USFWS. The plot is called a "Treemap", created in R with the ggplot2 and treemapify packages. 

Cassin's Known-age by Michael Johns

One of the more exciting projects we conduct on the Farallones is the Cassin's auklet known-age study, which was first initiated in 1983. The birds are known-age because they are banded as checks, and once those chicks recruit into an unoccupied nest box we can gather valuable information on mate selection and retention, changes in breeding performance with experience and age, and signals of individual quality; all of which help managers better understand how individual contributions lead to population level changes. The work involves checking the contents of over 400 nest boxes distributed across the island, and taking various measurements of adult birds like bill depth, wing chord, and weight, which are used to determine body condition and sex. 

Photo taken through Point Blue Conservation Science | USFWS

April Showers by Michael Johns

This spring has been dominated by unsettled weather. We've been receiving a steady stream of moisture from the south, with descent downpours occurring every week. The weather makes for some dramatic early morning scenes, and has also been keeping the yellow flowers of the Farallon weed around for a little bit longer. 

Photo: Point Blue Conservation Science and USFWS

50 Years of Bands by Michael Johns

It's been 50 years since scientists from Point Blue Conservation Science (then Point Reyes Birds Observatory) began a continuous monitoring effort on SE Farallon Island. Some of this work includes banding certain species of seabirds to learn more about their movement patterns, survival and mortality rates, population status, and individual breeding behavior and success; all important information guiding management decisions and tracking the potential effects of climate change. Point Blue has amassed an impressive sample of banded birds since work first started in 1967, totaling nearly 125,000 individuals as of 2016. The graphic below illustrates the total bands put out by year and cumulatively since 1967 for 8 target species. 

Navigating With The Sun by Michael Johns

One of the easiest ways to study basic life-history and behavior of seabirds is to outfit them with devices the passively record data for you. The tricky part is getting those devices back in order to download and analyze those data. So far this season, we have recovered 19 geolocator tags that were secured to the legs of Cassin's auklets breeding in artificial nest boxes last year. These tags are designed to be very small and light, and have zero affect on the breeding performance and survival of birds that carry them. Geolocators record ambient light levels experienced by the bird as it flies around it's environment. These light level recordings are later used to estimate roughly where the bird was twice a day throughout the deployment period, using the timing of sunrise and sunset (which varies depending on longitude) and the duration of day-length (which varies by latitude). The photo above shows a row of tags calibrating in the sun on SE Farallon Island. 

Noting The Weather by Michael Johns

For roughly 50 years now, researchers on the Farallones have recorded daily island weather observations that include the wind intensity and direction, air temperature, and sea conditions. And for roughly 50 years the instruments used to collect these data haven't changed much. This long time series of direct weather observations provides information on meteorological and oceanographic patterns that impact the productivity and success of species that breed on the island, from short-term phenomena such as El Nino, to long-term trends associated with climate change. Recently, strong gusts from the Northwest have been tipping the anemometer needle beyond the 30 knot mark, a good spring wind to drive the upwelling.

Watching The Sea by Michael Johns

Well, I'm back on the Farallones for another seabird season, and so begins another series of stories from the field. I've decided this year to briefly describe all of the different projects we do out here during the summer. From simple tasks such as taking the weather, to complex tasks like keeping track of 400+ Cassin's auklet nest boxes. To kick off this series, I choose one of my favorite morning rituals, "sea watch". Every morning, the designated sea watch person (Katie in the case of the photo above) sets up a 50x spotting scope on the front porch of the PRBO House where we live, orients it southwest over the marine terrace, and watches the sea for a standard 5-minute period. The idea is to count any pelagic species other than the ones that breed on the island that pass through the fixed field of view, to get a sense of long-term changes in the timing and abundance of seabirds that use the waters around the Farallones. 

Visualizing Effort on SEFI by Michael Johns

As the name would suggest, long-term datasets take a long time to develop. Not only does it take a continuous supply of resources to support the work, someone has to physically go out every year and collect the data. To visualize the time investment and sheer number of people required to collect 50 years of seabird and marine mammal data, I designed this circular bar plot, illustrating the extreme commitment by some and small contributions by many over the years. It depicts the total number of days spent on Southeast Farallon Island (SEFI) by current and former staff and interns of PRBO (now Point Blue Conservation Science). Each concentric circle radiating from the map of SEFI in the center represents an additional 500 days of service, with Pete Warzybok in the lead at over 2,000 days! To keep the plot from getting too cramped, I narrowed the number of names displayed to just partial or full PRBO associates with more than two months spent on island, so this plot excludes many more island residents affiliated with various agencies, contracts, and universities, as well as people with brief stints – sorry if that applies to you. The graphic was created entirely with the ggplot2 package in R, aside from the border and line below the title that were added later in Photoshop. A high resolution 16 x 20 .png file of the graphic can be downloaded here: DOWNLOAD FILE