I asked Ralph Eldridge if he would share some of the migrating-songbird photos he has taken as a lighthouse keeper. He tends the Canadian lighthouse on tiny, treeless Machias Seal Island, which sits on the Atlantic Flyway migration route about 12 miles from the nearest points of land in Maine and Canada (Grand Manan Island). I was especially interested in a May 24, 2011, nighttime fallout of migrating birds at the lighthouse. Pamelia and I had seen a few shots Ralph took that night and were slack-jaw amazed by the sight of so many types of songbirds—especially the variety of warblers—together. The birds were exhausted and in desperate need of rest after flying for untold hours and miles on their journey from wintering grounds as far south as the Caribbean and South America.
Ralph sees an extraordinary mix of birds. Machias Seal Island and its surrounding waters are protected under Canadian law as a bird sanctuary. The island is not only a crucial migratory resting point, but also an important seabird nesting site. It is home to one of the southernmost colonies of Atlantic puffins. Songbirds drop onto the island day and night during migration season, Ralph says. "Some stay for a few hours while a few will hang around for several days," he notes on his web page. "Many of these birds congregate around the lighthouse and the lightkeeper's dwelling at night. During the night flights the house would fill with birds if the windows were left open."
Ralph agreed to write a few paragraphs about bird fallout based on his decades of watching it happen. Here's his description of fallout and what to do (or not do) if you ever encounter it:
"Fallout is a term for the frequent, sometimes spectacular grounding of migrant songbirds. These fallouts are sometimes confused with incidents involving birds being confused, lured and trapped by lights. However, they are distinctly different events.
"Perhaps a word of caution is appropriate to anyone fortunate enough to witness a big fallout, especially when birds have been flying over water. Regardless of appearances, the birds are utterly exhausted and everyone should resist the temptation to get close or otherwise disturb them. They desperately need to sleep, rest and feed, not waste energy avoiding people. That 'just one close-up' could well cost the bird its life.
Ralph continues: "With normal weather, millions of songbirds migrate through the night. They land early in the morning, rest and feed through the day and resume their travel the following night. While over land, the birds can disperse over a wide area and the daily 'fallout' goes mostly unobserved.
"Here's a link to an article about research into migrant use of coastal islands: http://umainetoday.umaine.edu/archives/spring-2011/songbird-superhighway/
"Birds get pushed close to their limits of exhaustion when they have to cross open water, so the birds tend to come down soon after making landfall. Adverse wind, fog, rain and cold further tax the birds' reserves and force them to land at the first opportunity.
"Also, the further along the route, the lower the birds' energy reserves. Our songbirds are little more than feathers and skeletons by the time they hit 45 degrees north latitude. They can't waste energy looking around for good habitat. It's more a matter of grabbing 40 winks and a quick mouthful anywhere they can, just to survive.
Ralph goes on: "An adverse weather system may completely stall the migration for days, so when the migration does resume there's a huge pulse of birds concentrated along the migration front. Any morning after a surge, big fallouts can be seen. It helps to have relatively open, barren habitat, like a treeless island or shoreline, to aid viewing.
"Now put all the adverse stuff together: migration stalled for days, an big open-water crossing, no favorable wind, precipitation and thick fog and poor visibility. The stage is set for a spectacular fallout.
"Taxed to their limits, many birds can barely reach the intended landfall. Many birds will not reach their landfall and are forced to alight anywhere that they can. Often that's into the water. Sometimes it's aboard a boat. And sometimes it's on an island along the route, like Machias Seal Island.
"The May 2011 fallout was just one event which I happened to post. Fallouts happen to lesser and greater extent every migration. Just like tornados or snow storms, they are somewhat predictable, but the size, intensity, timing, makeup and duration are subject to a host of variables.
"The May 2011 fallout was fairly typical. The weather was not stormy, but there was fog, drizzle and reduced visibility.
"I expect some birds every night during the migration, usually showing up around the lighthouse a few hours after dark through to the pre-dawn. In this case the adverse flight conditions, especially the low visibility, produced more than usual.
"Type and numbers in the 2011 fallout? No real idea. Certainly tens of thousands passing with lots dropping down, many milling about, lots trying to find a perch and some simply sitting on the ground and sleeping. This particular flight was well mixed, so there were dozens of species. Some flights are dominated by just a handful of species."
Many thanks, Ralph, for giving us a clearer picture of bird fallout and a glimpse of the remarkable species that visit the lighthouse on Machias Seal Island in the Gulf of Maine. For anyone who would like to see more of Ralph's stunning bird photos from the island, check out his web page at http://www.pbase.com/lightrae/image/135054460
—Craig Neff and Pamelia Markwood