March 25th – American Tree Sparrows…..On The Move?

Another beautiful early morning….but cold, much colder than yesterday starting out (-12). I parked at the entrance to the park and walked up to the banding lab just to enjoy it all. Adding to the enjoyment was a Sandhill Crane – I heard its raucous cronk from across the river. I never saw it but I imagine it (or maybe they) was feeding around the margins of the large ephemeral pond on the far riverflats, water left over from the recent flooding. Unlike the days before the snow storm, there wasn’t much visible migration. On nice days a search of the skies at almost any time would turn up a bird, usually birds, on the move – geese, swans, ducks, grackles, blackbirds, robins. Today there was very little of this. I think migrants are hunkered down, investigating their habitat at the time to find and take advantage of the best feeding spots, and waiting….waiting for that turn in the weather that will spur them on their journeys.

In this regard, I’ve been wondering about American Tree Sparrows. These hardy little birds, that breed along the edge of the tundra in northern Canada, spend the Winter in southern Canada – for them, our winters are like Florida. Through banding, we have found that they are philopatric; i.e., they return to the same place year after year. In the late Fall I look forward to retrapping birds that we banded the winter before or winters before – like the return of old friends or the prodigal son. Although we’ve been catching Tree Sparrows every time we’ve been out this Winter, we’ve been catching a lot of them in the past week. And almost all of them are carrying sizeable amounts of fat – the fuel of migration. Today we caught 30! Eleven of them were ‘new’ birds looking for a band and the other 19 were birds we’d banded before – some from December and January and some from yesterday or the day before. These birds, I think, are on the move – the fat loads indicate they have the energy capacity. They’re just waiting for the weather to warm up and the northerly winds to turn around. When this happens, it will be interesting to see what numbers we catch.

On the whole, we encountered 33 different species in the course of the morning. There was another Common Redpoll around (or maybe it was the same one as yesterday; I couldn’t get a good look at it). I was quite surprised to pull one out of the nets yesterday although I guess I shouldn’t have been given Maggie’s comments on yesterday’s blog: she’s getting 50+ at her feeder in Fonthill (as well as crossbills – maybe she could send a few of them our way……)

Turkey Vultures continue to filter through – we saw at least 8. It’s kind of interesting that when the Grimsby Hawk Watch folks report large numbers of raptors we tend to see more variety and bigger numbers here (although not nearly in the numbers they get). And when their numbers are down, so are ours. For the past couple of days they’ve been getting mostly Turkey Vultures….just like us. I always wonder how vultures deal with cold snaps like the present one given their bald heads. A hat works for me but what do they do?

Banded 18:
2 Mourning Doves
1 Black-capped Chickadee
11 American Tree Sparrows
1 Song Sparrow
1 Dark-eyed Junco
1 House Finch
1 American Goldfinch

Retrapped 34:
2 Black-capped Chickadees
3 White-breasted Nuthatches
2 Northern Cardinals
19 American Tree Sparrows
5 Song Sparrows
2 Dark-eyed Juncos
1 American Goldfinch

ET’s: 33 spp.


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