Tree sparrows' rebound is early Christmas present

It was something of a banner year for “my” portion of the annual Lisle-Arboretum Christmas Bird Count. In a good count year, we get a little more than 40 species. This year we had 50.

It was a bit of a surprise as the foggy weather meant that we wouldn’t be able to see birds at a distance. Forget observing any of the Bald Eagles patrolling the Des Plaines River Valley. It just wasn’t going to be possible to see that far.

Foggy conditions greeted the dozens of birders who participated in a day-long bird count on December 15.

TWiB has been tracking the American Tree Sparrow population every Christmas for the past few years. There’s mostly been a decline since 2013, which has been cause for some concern. Back then, we’d get 800 tree sparrows across the count. Some years lately it dipped below 200. As I wrote last year:

These are northern breeders, from around the Arctic Ocean and Hudson Bay, that travel south to our area each year. There’d been chatter that the decline was due to a couple reasons: perhaps the winters weren’t cold enough any more to send the little birds farther south. Or perhaps we’d done such a good job clearing brush from forest preserves that the sparrows no longer had their preferred habitat.

American Tree Sparrows “breed near the northern treeline, where straggling thickets of alder, willow, birch, and spruce give way to open tundra,” according to All About Birds.

I thought it might be a fairly decent year for the songsters (I’d been seeing them consistently all fall), and that turned out to be the case. Unofficially, tree sparrow numbers were back above average. My own little sliver of the count had 95 individuals.

Then there was the eternal question about open water. Would the quarry ponds be frozen or not? Because of an earlier cold snap, they were indeed frozen, with a slick of water on top due to temperatures around 40. We got decent numbers of Mallards and one small flock of Gadwall, though.

The highlight for the day (for me) took place just about an hour after dawn. One of our party espied a bird perched about a quarter-mile away in a poplar. We quickly waved it off as a Blue Jay and kept walking. A few minutes later, we took another look. “Wait a minute, is that a…shrike?” someone said. And yes indeed it was, the first I recall encountering on this parcel.

This reminds of the truism that it’s always good to study the common birds. You never know what you’re going to get.

The Christmas Bird Count concludes with a Countdown Dinner. In recent years, that’s taken place at Imperial Oak Brewing in Brookfield.

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Appreciating the Moa

Last week I was leafing through The Birds of Eastern North America Known to Occur East of the Nineteenth Meridian, something of an early field guide with simple black-and-white portraits and species accounts. There’s a set of introductory pages providing general background on birds and ornithology. On one page, there are multiple species standing beside a human, I imagine to give some sense of scale.

I had to do a double-take, though, when I saw the skeleton of the now-extinct Moa, a bird that inhabited New Zealand until about 600 years ago. I know birds descend from dinosaurs, but this one really looks like a dinosaur. Something like the brontosaurus.¹

About the only thing I know about the Moa is that it was flightless. Then I read the little blurb with the image, and it wasn’t just flightless, it was wingless. If you look at the image, you can see there’s no sign of appendages.

Source: The Birds of Eastern North America Known to Occur East of the Nineteenth Meridian by Charles Cory, 1899, printed by the Field Columbian Museum.

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Merry Christmas!

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1. I don’t know much about dinosaurs these days. Is there still a “brontosaurus” or is it called something else?