Saturday, September 5, 2009

Fall Bird Migration Season

Migration season can be a great time to go birdwatching, as birds often flock together to make the trip, increasing the concentration of birds in an area and thereby making it easier to spot something - sometimes a great many somethings. Fall migration is often taken at a more leisurely pace than spring migration, when birds are anxious to reach their breeding habitat and stake out territory, so you're less likely to have them all blow through over a short period. Shorebirds, hawks and warblers are some categories of migrating birds to watch for, though I'm sorry to say that for many shorebirds their migration season started weeks ago and they are long gone.

I'm a great fan of shorebird-watching, myself. The ones we see around here, like the greater and lesser yellowlegs, are relatively large (though many shorebirds are small) and tend to stay in one spot for a while, grazing for food on mudflats or in very shallow water. Warblers, being insect-eaters, tend to dart constantly from one branch or tree to another. Many of them are lovely little birds and a treat to see, but one tends to get a stiff neck from looking up and trying to track birds as they fly overhead.

On the other hand, as my resident bird expert notes, finding shorebirds is more hit-and-miss, in part because of changing water levels year to year that turn an area that is a nice hospitable mudflat one year into a swimmable pond another year. The warblers tend to return more predictably to the same wooded areas.

Duck migration occurs somewhat later in the fall (waterfowl-hunting season in Minnesota starts October 1, not coincidentally). Ducks are a great place to start birdwatching, as again they are large enough to spot fairly easily and although they can certainly be spooked into flight (or into diving), at least they don't flit!

Radar reports provide good insight into bird migration patterns. Yes, radar can actually pick up the air disturbances caused by groups of birds and show areas of greater activity. A Minnesota blogger who regularly posts the latest bird/radar reports is Roger at Minnesota Birdnerd, who I had the chance to meet on the recent Birders Who Blog, Tweet and Chirp outing. The radar map he's got on his latest blog post (which I've borrowed here) shows concentrated activity along the North Shore, the upper St. Croix, and the La Crosse area. He predicts the potential for good birdwatching this weekend, with pleasant weather and light winds (no roaring winds out of the north to drive the birds onward).

We haven't made our weekend plans yet. Maybe we'll wander over to Lake Byllesby, where we've sometimes had very good luck seeing shorebirds and pelicans (and one notable osprey). Maybe we'll just head out and see where our instincts take us. It's fall migration time for birdwatchers, not just for birds.

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