In which San Francisco neighborhood can you find hundreds of visitors from Alaska, Hawaii, Chile and New Zealand during the month of August? If you answered the Farallon Islands, you've probably amongst the select few who have taken a boat trip to the Farallons during August to witness a seabird gathering with species that have traveled thousands of miles.
Birds are amazing long distance migrants – often traveling thousands of miles to their summering, wintering, nesting or feeding grounds. And seabirds are in a class of their own when it comes to migration and long distance flying. One amazing bird, a Manx Shearwater, is believed to have flown a total of 5 million (yes million) miles over its 50 year lifespan.
On my annual trip to the Farallon Islands in early August, we spotted 50 of one of these long distance migrants, the Sooty Shearwater. In the Atlantic Ocean, these birds can travel 9,000 miles between their breeding grounds in the Falkland Islands and their feeding grounds off the coast of Norway. The Sooty Shearwaters we were seeing left their nesting grounds in New Zealand in April or May (where they are commonly known as muttonbirds), traveled up the Asian side of the Pacific Ocean to sub-Artic waters, crossed over to Alaska, and were now traveling down the North American side of the Pacific on their way back to New Zealand.
This dark chocolate brown bird can dive up to 220 feet in search of fish and squid. They are declining in numbers, probably due to rising sea temperatures, and are considered near threatened. Shearwaters get their name from their flying behavior – they skim the surface of the ocean, often in large groups (collectively known an "improbability" of shearwaters).
The naming of groups of flying birds is fascinating. A flock of birds technically only refers to a grouping that includes unidentified species, or a mixture of species. Otherwise there are specific names for single species of flocks, some of which reveal attitudes towards certain species. An assemblage of crows, for examples, is referred to as a "murder of crows." Other names include an "unkindness of ravens," a "charm of finches," a "parliament of owls," a "convocation of eagles" and a "wreck of seabirds."
Getting back to Sooty Shearwaters, while the spend most of their lives on the open ocean, their nests are on land, at the end of 10 foot long burrows, dug by the parents. The parents share incubation of the single egg for up to 8 weeks, and then both feed the chick for another 14 weeks, before it heads out to the ocean.
Sooty Shearwaters were outnumbered on this trip by another other species of shearwater – the Pink Footed Shearwater, a dark brown bird with yes, pink feet. About 120 of these visitors from Chile were spotted on this trip to the Farallons. Just south of the Farallon Islands, we also encountered 16 Black Footed Albatrosses, visiting here from Hawaii.
We spotted one Northern Fulmer on this trip, an early arrival from its breeding grounds in Alaska. This gull like seabird often lives more than 50 years, and may not starting breeding until age 20. Northern Fulmer chicks have a unique defense mechanism – they can eject an evil smelling stomach oil six feet, which deters predators. Like many other seabirds, the Northern Fulmer is in a family of birds known as tubenoses, which evolved a pair of external nostrils on the top of the beak that gives the birds the ability to excrete salt, allowing the birds to drink seawater.
Not all the seabirds at the Islands were visitors. Four species of alcid, all of whom nest on the Farallon Islands, were present. The most welcome sight were 75 Cassin's Auklets, who are having a very successful breeding year this year with many pairs nesting twice this summer. This is a sharp contrast from 2005 and 2006, when not a single chick was born. Cassin's Auklets are very susceptible to climate variations, and when the ocean upwelling (which brings nutrients to the surface for wildlife) is disrupted, the birds stop having young.
One of the highlights of the trip was seeing 15 Tufted Puffins, with their unique and colorful bill, along with 10 of the closely related Rhinoceros Auklet. This nocturnal auklet, which may someday be renamed the Rhinoceros Puffin, gets its name from a horn like extension on its orange/brown bill. It's a great swimmer, but not such a great flyer, and builds its nest on land on an incline, to help it take off.
While they are entirely different species, Surf Scoters, a diving duck, always reminds me of Tufted Puffins. We spotted a Surf Scoter close to shore, one of the first of many on their way from Alaska to spend their winter in the San Francisco Bay Area.
Two species of phalarope were spotted during the trip. Phalaropes are among the few bird species where females are bigger and more colorful than males. Females also do the courting and find the nest site, but the male builds the nest, incubates the chicks, and nurtures the offspring, while the female may choose to mate with other males while the original mate raises their chicks.
Red Phalaropes spend 11 months of the year at sea, with one month on land in the northern Arctic. The Red Phalaropes we were seeing were on their way to the ocean just south of North America, while the Red-Necked Phalaropes were heading to more tropical oceans off the coast of Peru. One of the main stopping points in California for phalaropes is Mono Lake, where thousands will stop to get food during their 6,000 mile migration. Phalaropes have an interesting feeding strategy – they swim around in small circles, which stirs up plankton for them to eat.
Not all the wildlife highlights were birds. We were fortunate enough to spot four Blue Whales, four Humpback Whales and three Killer Whales. While Blue Whales and Humpback Whales are relatively common around the Farallon Islands in the summer, Killer Whales are not often spotted.
Trips to the Farallon Islands are available on virtually every weekend, run by the Oceanic Society.
All pictures were taken by David Assmann, Deputy Director of the San Francisco Department of the Environment. Do not reproduce pictures without permission.