This year will go down in history. Well, all years go down in history, but specifically regarding North American birds, this year is unusual.
We've been seeing a lot of songbirds from the far north this year. Northern finches are notorious for having fluid winter distributions, going to where the food is available. They can be present in our part of the country one year and then not show up again for another 10 years. This winter, a broad diversity of finches moved south out of the north country into the Midwest. And it happened continent-wide, not just in one region. The fall of 2012 and 2013 had pine siskins moving south to yards in California to New Jersey. This is a rare event. What is going on?
Northern finches move south when food up north is low or absent. Finches can handle the cold, but can't keep the furnace going without fuel, and their fuel is seeds, commonly from spruce, pines and conifers, even birch and alders. Each of the winter finch species has a different bill shape adapted for harvesting one or a few seeds; food specialization is key to winter finches. So why do food sources have booms and busts? It's too complex to say for sure, but the main culprit is weather. This past year there were weather anomalies throughout the North - in particular, it was dry. The result is low seed production among many tree species across a wide region. This means many finches had to head south - way south.
The big story this year is pine siskin irruption. They are being seen at everybody's feeders. And they are being seen as far south as the Rio Grande in south Texas. When pine siskins head south, they absolutely love backyard feeders and particularly thistle (Nyjer) seed. And then there are the redpolls, close relatives of the siskins. There are two species - the common redpoll and the hoary redpoll, and both have been seen often in the Hamilton County area.
Another rare far-north bird wintering in our area is the crossbill. I'm getting lots of reports of red and white-winged crossbills this winter. They are the specialists of the bird world. Their thick and powerful bills with long tips cross each other so they can retrieve seeds from pine cones. They use this unique bill to get in between the scales of the cones, grab the base of the seed, and then twist it out. Can you believe there are even "right-billed" and "left-billed" crossbills? It's true and it allows two crossbills to position themselves on opposite sides of the some one simultaneously, one working it from the left and the other from the right. Nature thinks of everything. Two species of grosbeaks are also on the move this winter: the evening grosbeak and the pine grosbeak. They are showing up in many of our parks. Ironically, the one bird that did not come out this winter is the one that comes south the most often - the snowy owl. Unique among the northern birds, the snowy owl has the most and most often the most cyclic winter irruptions southward into the U.S. from the Arctic. They just didn't show up this winter. But then they rely on rodents which were plentiful in the Arctic regions this year, as opposed tot he finches which rely on the seeds. And have you noticed the hawks this winter. Especially the huge red-tailed hawks. Most, for reasons nobody seems to know, did not migrate south this fall. They stuck around all winter. Telephone and high line poles in the Midwest were covered with perching hawks this winter. I think about every 20th electric pole along Beach Street between Webster City and Bell's Mill had a red-tail hawk perched atop it.
And did I mention sharp-shinned hawks? No, I don't think I did. Everyone who has a bird feeder has had a sharp-shinned hawk show up at their feeder to grab one of their songbirds and fly off with it. Many a bird at our local feeder has ended up being the meal-of-the-day for a sharpie.
I hope you are seeing winter finches in your yard or local birding spot this year. Enjoy the irruption because it does not occur every year. It may be another 10 or 12 years before they show again.
The good news is I've already had a few folks call me to report seeing robins in their yards.
And now have a good weekend.