Welcoming our avian tourists
There are always birding tourists on the Avalon in winter, but this year there have also been some bird tourists.
Every few years, redpolls arrive from the Arctic to bask in the warmth of a Newfoundland winter.
But the redpoll doesn’t come south for the weather. It comes for the food. In years when small seeds and grains are scarce up north, the redpolls hit the road.
They only travel as far south as they need to, and if food is plentiful in the Arctic, the tiny redpolls will stay put, despite the cold and the darkness of an Arctic winter.
Not many birds can pull off a stunt like that. Of about 75 bird species that occur in the high Arctic, only 12 are able to overwinter, and many of those don’t make a habit of it.
Five of those species are seabirds or gulls, and can only survive where there are polynyas — areas where warm upwellings prevent the sea from freezing. For the rest, all except the redpoll are large, heavily feathered birds such as the ptarmigan, the gyrfalcon and the snowy owl.
So, how does the redpoll do it? Shouldn’t such a tiny bird have to migrate to avoid the cold?
Well, their small size gives them one crucial advantage up north; they can shelter in the warmth and safety of lemming burrows, under the snow. Not only that, but they often take advantage of any seeds that have been stored in the burrows by the lemmings. When forced to feed on seeds above the snow, they can quickly fill a special storage pouch, located off their esophagus, and return to the warmth of the burrow to eat at leisure later.
The redpolls’ ability to better survive on smaller seeds than most finches is probably why they have been around Newfoundland this winter. In one of the poorest winters for finches of any kind since I have been birding, only the goldfinches and the redpolls have made much of an appearance this year.
Where are the purple finches, the pine siskins, the evening grosbeaks, the pine grosbeaks? It’s probably due to the lack of a good cone crop on the evergreens, but redpolls, surviving on weed seeds and small grains can do just fine. Alder cones are a real favourite and they can even eat grass seed.
The accompanying photo shows a mass of redpolls feasting on the niger bag in my front yard. I count 17 birds in the photo, but many more were fighting for a spot. Unfortunately, the photo is from 2008 when we had a huge redpoll invasion.
This year it has been a comparative dribble, with people reporting singles or doubles, rather than the usual flocks of birds. Maybe things are only medium bad up north.
If the common redpoll is surprising for its ability to survive in the Arctic, what are we to make of the other, rarer redpoll species? The hoary redpoll thinks that most of the Arctic is too far south for its taste, and will only breed on northern Baffin Island and points north! Tundra is its thing, so its classification as a “passerine” or perching bird is more of a formality for a bird that sees more of the ground than it does the trees.
Whenever we get the treat of redpolls in winter, the hard-core birders start looking for the rare hoary redpoll. There is nothing whorish about a hoary redpoll. They get their name from an overall paler, slightly greyer appearance than the common redpoll. The bill is slightly shorter than the common and the red crown (“poll”) patch is smaller, but the key diagnostic thing you have to see is the unstreaked white rump.
It seems there is something sexy about these diagnostic features on rare birds. Recently, Bruce Mactavish enthused about the creamy, white thighs, diagnostic of the rare grey heron. This week it is the absolute necessity of viewing the lovely pale rump of the hoary redpoll. Unlike a whorish redpoll, the hoary redpoll keeps its rump modestly hidden most of the time.
This was apparent to Bruce, John Wells and me in March when we tried to identify a hoary redpoll on the Cape Race Road. I took 50 photographs and ended up with only two of the 50 that showed part of the white rump, when the bird finally faced away from us with wings slightly parted. There are many birders in St. John’s who have never had the pleasure of even seeing that much of a hoary redpoll.
By next week, the redpolls will be leaving us. Stay tuned for spring.