The average fall count is almost 800,000 birds, but in some years it approaches one million. More remarkable yet is that 70 percent of the migration, which includes over 75 species, occurs during a five week period (about October 7 to November 14). Double-crested Cormorant, Surf and Black Scoter, Red-throated Loon, and Northern Gannet, are the most abundant species, accounting for nearly 80% of the total flight.
Surprises come every year. The Sea Watch rarities list includes Atlantic Puffin, Long-billed Curlew, Wood Stork, Pacific Loon, California Gull, and Sandhill Crane. Pomarine Jaeger, Black-legged Kittiwake, Common Eider, King Eider and Razorbill are seen every year with a few exceptions.
Currently, we use the count data to assess changes in Atlantic Flyway water bird populations, and to understand how large-scale weather systems and ocean temperatures affect water bird migration.