We added a few resident as well as wintering birds in February that we had missed in January. At the end of the month the first of our spring migrants began to appear, with Tree Swallows, Turkey Vulture and Rufous Hummingbird all making an appearance. Barn Swallows were already seen in January, which was part of a wide spread presence of this species in western Washington this winter.
What was unusual about this was the quantity of the reports as we expect some winter appearance of Barn Swallows. After the last migrants leave in late October there may be no Barn Swallows seen until early January, then there will be random sightings until late February. Then another gap in reports occurs until the first spring migrants appear about April first.
This odd seasonal pattern has led some to theorize that the winter birds are not our local breeders trying to over winter, but rather birds from southern South America that have migrated north for the austral winter, then when it comes time to return south for nesting they mistakenly continue north and end up here, where they slowly succumb to the weather conditions. To the best of my knowledge this theory has not been confirmed by DNA research as of yet.
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