Arriving at the largest island of the Farallones isn't easy. The surrounding waters are too rough for a dock to be built, so visitors and scientists are transferred to a smaller zodiac, which is hooked into a large crane. The crane lifts the boat out of the surf and onto land.

Biologist Russell Bradley navigates the transfer from air t... Moreo water.

Getting onto the Southeast Farallon Island has never been easy. In this 1939 photo, passengers are transferred to the island in a sling attached to a pulley system. Credit: San Francisco History Center, San Francisco Public Library

For the Coast Guard members and their families, who lived on the island in the 1940's and 50's, this was they only way to receive food and supplies from the mainland. Credit: San Francisco History Center, San Francisco Public LibraryLess

In this video, biologist Russell Bradley talks about those ubiquitous Western Gulls and the Farallones' importance as an avian breeding mecca.Less

The large paved area is rainwater collector, originally built to service the fog horn. In 1880, the Lighthouse Board approved a steam-fired fog signal to help ships stay clear of the rocky islands. The water helped cool the coal-powered boilers. The Farallones were the site of many shipwrecks. Credit: San Francisco History Center, San Francisco Pu... Moreblic LibraryLess

This is one of two houses built in the 1870's to for the lighthouse keepers and their families. They lived on the Southeast Farallon island year round, tending to the light.

One of the houses in 1954. You can see the water collector on the left. Credit: San Francisco History Center, San Francisco Public Library

Some of th... Moree Farallones' inhabitants in 1940. In 1942, with both Navy and Coast Guard personnel stationed on the island, 78 people lived there. Credit: San Francisco History Center, San Francisco Public Library

Today the houses are home to the PRBO Conservation Science staff when they live and work on the islands. For the past 40 years, they've had researchers on the island 365 days a year.Less

The lighthouse on the Southeast Farallon Island was built in 1853 on the highest point of island - 348 feet above sea level. Credit: San Francisco History Center, San Francisco Public Library

All the supplies to build the lighthouse had to be laboriously carried up the zig-zag path, including the lighthouse lens, which reportedly arriv... Moreed in 73 crates. The Frensel lens was ordered from France and its curved prismatic glass was the most advanced technology at the time. Credit: San Francisco History Center, San Francisco Public Library

The lighthouse was automated in 1969 and its Frensel lens was removed. Today it's on display at the Treasure Island Museum.Less

In this video, Biologist Russell Bradley describes one of the historical buildings on the island, which belonged to the Pacific Egg Company.Less

In this video, Biologist Russell Bradley shows us Common Murres, the most abundant species on the island during bird breeding season.Less

A PRBO Conservation Science intern checks out a Cassin's Auklet chick. This chick is fully feathered and ready to fledge. During the day, you won't see any Cassin's Auklets out and about on the island. They're nocturnal during the nesting season in order avoid predators like Western Gulls.

These strange boxes are actually man-made Cas... Moresin's Auklet dens. The birds nest normally nest in underground burrows, but in order to study the chicks as they mature, PRBO Conservation Science has built these structures. The wooden roofs come off so the scientists can take a look inside.

These small, black seabirds live on krill and dive underwater to catch it. In 2005 and 2006, they suffered a complete breeding failure on the Farallon Islands. Biologists at PRBO Conservation Science believe that ocean conditions weren't right for krill, meaning these birds didn't have enough food to raise chicks successfully. Credit: angrysunbird.Less

The sights and sounds of sea lions lounging on the Farallones.Less