A Great Start to Fall Migration!
September 18, 2018
As the last of the seabird chicks fledge, and the summer breeding season winds down, our focus shifts to monitoring the great annual migration, keeping track of the variety and abundance of birds which find their way to our island during their journey south. Point Blue Conservation Science is now into the third week of its 51st fall season of monitoring bird migration on Southeast Farallon Island. This year our crew includes biologist Jim Tietz, returning intern Kurt Ongman, who decided he wasn’t satisfied with just one fall, Amanda Spears, a lingering seabird intern who also happens to be very good at baking and finding rare birds, and new arrivals Sarah Hecocks and me, John Garrett. During the last 50+ years, the Farallones have gained a reputation as a place where regular western migrants may stop for a period of rest and refueling, but also a unique outpost where keen observers may encounter lost or rare birds (vagrants). So far, the 2018 migration has gotten off to an excellent start.
A trickle of migrants, including a Tennessee Warbler, greeted us as we stepped off the boat on August 18. Within a week, the trickle swelled, and each morning the lighthouse had a smattering of Townsend’s, Hermit and Black-throated Gray Warblers, Blue-gray Gnatcatchers, and other species of regular migrants.
In addition, several vagrants spiced things up, such as a fly-by Buff-breasted Sandpiper, a Caspian Tern (very rare on the island, especially in fall), a Scripps’s Murrelet, a Lark Bunting, two Virginia’s Warblers, two Northern Waterthrushes, three Canada Warblers, and singles of Blackburnian and Chestnut-sided Warblers. Several Short-eared Owls, too regular on the island to be considered ‘vagrants,’ quite literally stirred things up by sending the already noisy hordes of Western Gulls into a shrieking frenzied aerial maelstrom every time one wandered around the island. A Wood Duck photographed flying through the fog was only the third record for the island. Although it happens with regularity, just about any songbird that lands on the island overwhelms the brain and the soul – the thought of a Pacific Wren crossing the 25+ miles to get here certainly does.
Several days of strong northwest wind–better for encouraging birds to depart than arrive–allowed us to recuperate before the next wave of migrants. The light winds and high overcast on September 3 yielded some pleasant surprises, including a Red-eyed Vireo (a much rarer bird than it used to be in California) and our first Bobolink and Magnolia Warbler. September 4 was yet more fruitful, with another Scripps’s Murrelet and a Green-tailed Towhee arriving. It was already an excellent early September.
But September 5 was the day to remember. The first bird I saw in the morning was a Connecticut Warbler that briefly landed on the kitchen windowsill while I was washing dishes. When we ran outside for better looks, I heard a Mourning Warbler chipping in the PRBO tree. We eventually relocated the Connecticut in the Coast Guard tree (one of two Monterey cypresses on the island), where it shamelessly strutted all day. Throughout the day, western migrants and eastern vagrants continued arriving. By the end of the day, we had tallied 15 species of warblers alone, including an Ovenbird, four Tennessee Warblers, a male American Redstart, and a Blackpoll Warbler. Everyone was very busy, mistnetting and banding birds, racing around the island, while also struggling to do the normal daily chores (like eating). Later that day, while monitoring for sharks from the lighthouse, I noticed that the project scope was caked in salt spray and cobwebs. After wiping it off, I tested how much brighter it was by training the scope on Saddle Rock, where the brick-red feet of a young Red-footed Booby really popped…Wait. Red-footed Booby! I radioed down to the house, and the crew enjoyed watching as this rare bird took off and circled the island. It continued circling the island until sunset, often mixing with flocks of Brown Pelicans and coming quite close to the lighthouse. This represents only the third record of a Red-footed Booby for the island, and the first since 1975. On Southeast Farallon Island, the bizarre is often reality; even after decades of monitoring, unusual events are still almost regular.