Thursday, March 29, 2012

Soiled Trousers

Pants have received its first layer of white and green bird crap, the smell of uric acid emanates from my hands; field work has officially begun. Attendance of birds in the wooden artificial burrow boxes strategically placed around the island is on the rise. Yesterday while enduring steady rain and blistering 30 knot winds, we discovered five new Cassin’s Auklets incubating freshly laid eggs during a scheduled burrow check. Taxonomically Cassin’s Auklets are in the Alcid family, closely related to puffins, murres, murrelets, and guillemots; and unlike other groups diving birds, use their wings to essentially fly through the water reaching incredible depths  (200+ feet) in pursuit of pelagic invertebrates and fish. 

Cassin’s Auklets are among the first seabirds to breed on the Farallones, with the male and female sharing the duty of incubating an egg and rearing a chick. Arriving under the protection of darkness, each parent will return to its burrow most nights to relieve the other from the nest; with a bill load of seafood during the rearing period once the chick has hatched.  Their unique calls can be heard in the late hours of night, so it’s been fun to see them up close and in hand (aside from the scatted carcasses we’ve been finding, bits and pieces from Peregrine and Burrowing Owl kills). 

Common Murres have also been loafing in vast numbers along the jagged hilltops that dominate the landscape, reclaiming their small patch of turf and strengthening pair bounds in preparation for their breeding season.  A few days ago we began resighting banded murres in a colony on the northeast side of the island from a blind atop a cliff facing Shubrick Point, using steady binoculars and a good deal of patience. Looking down from the blind, the stark contrasting plumage of the murres forms a fluid like motion of black and white, enough to induce motion sickness for those with weak stomachs. I occasionally had to look away for several minutes to let my mind manage the optical abuse.
The highlight of the day, more so than measuring the Cassin’s, was a spelunking expedition led by Pete (the PRBO biologist) and accompanied by Cat and Jonathan from the USFWS, Ilana with PRBO, and myself into Rabbit Cave, a deep crevice in Lighthouse Hill. A certain narrow passage into the main chamber required crawly through mud on hand and knees… and it was awesome. We visited a site where the embalmed remains of an Aleut woman were discovered many decades back. She was removed by a team of geologists I believe, rumor has it her ghost now roams about the island (no sightings as of yet).  Pete also pointed out some old graffiti that read “Stewart 1906” on a wall in the terminal chamber.  Supposedly the endemic Farallon cricket can also be spotted in Rabbit Cave ‘although we found little evidence of it’ (which is a mild reference to “The Life Aquatic” if you caught that). 

In other news fog has returned to the Central Coast, at least for the next day or so. A new system should bring us more rain with a high probability of strong northwesterly winds in the coming week.  Surf’s up.

Friday, March 23, 2012

Wind Blown and Marooned Once Again

Greetings from the islands of Farallon. I’m currently sitting at a desk in the PRBO (Point Reyes Bird Observatory) house on Southeast Farallon Island. The window behind the computer screen in front of me provides a view of Little Lighthouse Hill and Maintop Peak on West End. The weathered granite rocks, draped in the lush green leaves and small yellow flowers of a plant in the sunflower family called Farallon Weed, are littered with the contrasting bright white dots of Western Gulls evenly dispersed throughout the landscape. The males are establishing nest boundaries, and are beginning to battle over land rights. Common Murres in the tens of thousands, dressed in black and white tuxedos, huddle together in dense aggregations along the upper slopes of Maintop and the surrounding peaks. Occasionally a Peregrine Falcon swoops down from one of these high perches to investigate a Pigeon Guillemot drifting at sea; a sea which is currently plagued with sharp windblown white caps, tipping a plume of spray over an eight foot swell rolling in from the northwest. 

We arrived at the East Landing on SEFI on March 17th, after a three hour crossing from below the main span of the Golden Gate Bridge, on a twenty something foot long retired lobster boat named Sari Ann.  Thus far the weather has been warm (warm being a relative term) with dense high stratus clouds. Today is the first completely clear day, although the temperatures are down due to the strong northwesterly blowing. My first few days have been everything I’ve come to expect from a remote field camp and its crew of volunteers; common living spaces, water rationing, the stress of cooking for large groups of fussy eaters, the awkwardness of meeting new people, and the excitement of experiencing something new.  Along with a few unexpected luxuries, such as a warm shower, reliable phone and internet, and a bed to sleep in. 

 Still early for breeding seabirds, however we have discovered an Ashy Storm Petrel in the walls of the carpentry shop (Carp Shop), and a Cassin’s Auklet with an egg in one of the artificial burrows; so most of the days have consisted of shorebird counts, Burrowing Owl roost checks, song bird sighting, and Elephant Seal re-sighting. There are a few terraces on SEFI where Elephant Seals hull out and pup. This time of year the bulls have finished their breeding, with a few still lounging around in the sun; the females have already weaned their pups and are back out at sea foraging in the depths beyond. Most hanging around are the weaned pups (termed weaners), adult females (termed cows), and immatures which haul out this time of year to molt. We go around and note the position and number of colored tags on their hind flippers; pink being from this site, with varies colors from San Miguel, Ano Nuevo, and other islands and beaches along the California Coast.

I’m hoping the weather stays clear tonight, with the new moon and lack of clouds overhead, there could potentially be good conditions for stargazing atop Lighthouse Hill. It’s been clear enough to see all the way to Bodega Head (40+ miles away) with amazing views of the Golden Gate and the city. I’m sure the clear conditions won’t last, so I should go out and enjoy them.

First I must check on the chicken enchiladas in the oven, people are beginning to linger in the kitchen. 

Photos: PRBO House with West End in the background from midway up Lighthouse Hill. East Landing. Bull Northern Elephant Seal with female in foreground. Venus above Jupiter setting over West End from atop Lighthouse Hill, white streaks are Western Gulls illuminated by the SEFI light. 

Wednesday, March 14, 2012

The Farallon Islands

In an effort to educate you the reader and myself on the subject, I’ve written a brief history of the Farallon Islands; a place that will become my new temporary residence for the next four months.

The name, age, origin, and current location of the Farallon Islands derive from an ancient and now extinct tectonic plate. One hundred million years ago, shortly following the evolution of flowering plants and prior to the extinction of the dinosaurs, the Farallon Plate underwent a subduction event.  Through a process not entirely understood, this plate slid in an easterly direction beneath the massive North American Plate, upwelling super heating minerals which then cooled and solidified into a batholith of granite; a massive string of formations that have since eroded into the Sierra Nevada Range. Around 20 million years ago, after a prolonged period of subduction, the Farallon Plate split along the convergent boundary of the North American Plate, forming the Juan de Fuca Plate to the north (which is still subducting and fueling volcanism below Washington State) and what was then the Cocos Plate to the south. This split also initiated the northern movement of the Pacific Plate along the North American Plate, a right lateral strike-slip boundary referred to as the San Andreas Fault, providing current day residents of central and southern California with frequent and often dramatic earthquakes. Fast forward another 10 million years, still well before the emergence of our genus Homo, some granitic material of the southern Sierra Nevada began to drift in a northerly direction, carried by the movement of the Pacific Plate along the San Andreas Fault. This northerly movement continued for a final 10 million years bringing us to the present, where spires of 100 million year old granite rock, the Farallon Islands, now rise from the depths of the Pacific 28 miles offshore of San Francisco; continuing on a slow migration north at a rate on average of 35 centimeters annually.

Aside from its unique geologic origins, the Farallones reside in a biologically significant location. The islands are situated just six miles east of the continental slope; a distinct bathymetrical feature where the relatively shallow 500 foot continental shelf drops dramatically and abruptly into the 6,000 plus foot abyssal plain. As you can watch in a glass of fine silt, particles denser than water eventually settle on the bottom, including biologically important nutrients such as phosphates and nitrates in the ocean which settle on the seafloor. The California coast is renowned for its strong northwesterly winds that occur predominately in the months of spring; winds that drive a phenomenon along the continental slope known as upwelling. Upwelling essentially is a horizontal bottom up current that drawls deep nutrient rich water up to the photic zone near the surface, in reach of tiny single celled algae and other phytoplankton which use these nutrients to drive photosynthesis. Phytoplankton are the basis of the marine food web (aside from deep dwelling extremophiles which rely on chemosynthesis of methane gas expelled from ocean vents), and just like gazelles grazing on the grasslands of Africa, small zooplankton (copepods, larval stages of vertebrates and invertebrates, and jellies to name a few) graze on phytoplankton as they comb through sunlit surface waters of the temperate oceans.  Thus the close proximity of the Farallones to the productive phytoplankton enriched currents welling up from the continental slope, provide an important habitat for open ocean travelers like seabirds to rest, feed, and rear their young.

The transfer of energy from phytoplankton, through the food chain to the larger prey items of seabirds such as schooling fish and squid, takes time. Given that the biologically important nutrients previously mentioned typically don’t become available until the spring winds kick in; productivity around the Farallones doesn’t occur in full force until summer. Seabirds seem well aware of this reality, and coupled with the generally mild summer weather of coastal California, May through August is a great time on the Farallones to find a mate, build a nest, and lay an egg. Twelve species of seabirds, as far as I know, find the Farallon Islands to be a nice place to rear a chick (or several chicks); Western Gulls, Common Murres, Pigeon Guillemots, Tufted Puffins, Rhinoceros Auklets, Cassin’s Auklets, Ashy Storm Petrels, Wilson’s Storm Petrels ?, Pelagic Cormorants, Brandt’s Cormorants, and Double-crested Cormorants. Some species are more coastal than others, however the Storm Petrels in particular likely spent and extended period of time (years possibly) well offshore without ever touching their webbed feet on solid ground. The islands are also an important stopover for migrating shorebirds and passerines, and a haul out and breeding site for Northern Fur Seals, Northern Elephant Seals, Steller Sea Lions, California Sea Lions, and Harbor Seals; as well as a destination for the infamous white shark for reasons I just listed.

Although well known by the wildlife for millions of years, the Farallon Islands were only occasionally visible to native North American peoples. Cloaked in fog and mystery they remained untouched up until the 16th century, when they were eventually ‘discovered’ by Sir Francis Drake in 1579 (then just Francis Drake as he was knighted in 1581), during his second circumnavigation of the globe. It didn’t take long for Europeans and the subsequent rebels of the infant American colonies to realize the potential for economic exploitation of the islands natural resources.  Russians established a sealing station on Southeast Farallon Island in 1812, harvesting 1,200 to 1,500 fur seals annually for 30 years, until the operation was eventually abandoned due to a declining yield and pressure from the Americans who eventually conquered the land of California from the Spanish in 1846. California became a state of the union in 1850, with the Farallon Islands included within the city boundaries of San Francisco. Although the seal populations were virtually exterminated, many nesting seabirds persisted; in particular the Common Murre, which proved to be of important economic value to the booming population of the egg-deprived citizens of San Fran following the gold rush. Apparently there was a shortage of chickens in those days, with the Common Murre and its single rich-orange yolk filled egg supplying the demand for omelets, cakes, and overall protein.

The extensive egg harvesting and general occupation of the Farallones by a select group of San Franciscan’s had a massively negative impact on the islands nesting seabird populations. Along with the current modern impacts of overfishing, global fluctuations in climate, and increased ocean temperatures, seabird populations not just on the Farallones but worldwide are experiencing the strain of human influences on the environment. It is for these and other factors that in 1968, Point Reyes Bird Observatory (PRBO) biologists first began monitoring the recovery and in some cases seasonal decline of the 12 species of nesting seabirds on the Farallones. This ultimately brings us to the immediate present, where in a few days, I along with a few other PRBO volunteers will carry on the traditions and legacy of this unique history of the Farallon Islands…and likely cake our fowl weather gear with many depositional layers of bird droppings.

More to come on the research ahead, I’ll wait until I experience the island for myself before I write any further.