If you have looked out your window today and seen a bird that you don't see often there is probably a reason, they are just passing through. A report from Portland points out that the  Songbird season has arrived in Maine. While some stay for breeding season, many are here for only a few weeks - ultimately headed for Canada's boreal (BOR-ee-ul) forest, the largest intact forest on Earth.

Comments from Dr. Jeff Wells, senior scientist, Boreal Songbird Initiative.

"From their beautiful songs to their stunning colors, birds are putting on their best displays this time of year. It’s the spring migration season, and more than half the birds you see at backyard feeders and soaring across the sky right now are headed north to Canada’s boreal forest. It's the largest intact forest on Earth. Literally, billions of birds migrate through the U-S. Dr. Jeff Wells with the Boreal Songbird Initiative says most of the flying is done at night, so people don't realize how massive it is. About three billion of North America’s land birds and 26 million waterfowl, including the Barrow's goldeneye, breed in the boreal forest. Dr. Wells says many of the birds are at risk as the forest faces new threats – and some species have already seen significant declines.  The birds also face challenges as they make their way north. For instance, the white lights on tall buildings and towers that are meant to warn pilots can actually attract and confuse songbirds, leading to collisions with the structure. Track your favorite birds' migration journey on the Boreal Songbird Initiative website: 'borealbirds-dot-org.'