Saturday, January 22, 2011

Following the Frazil

Never seems to fail. Every time I babysit my grandkids I catch a cold. So I didn't feel up to much strenuous activity today, despite that radiant blue sky and lots of nice fresh snow. But I had to get out, at least for a little bit, and a drive up to the Hudson Ice Meadows north of Warrensburg seemed a good destination. The river runs swift and swirly up there, frothing and tumbling over rocks, kicking up tiny droplets of water that freeze in the frigid air (which was well below zero last night). These frozen droplets -- called "frazil" ice -- collect in slushy masses that eventually pile up and dam the flow of the river, which then rises and deposits this ice in massive heaps along the banks. I was hoping I might see one of these pile-ups happen today while I stood on the bridge at The Glen. Well, I didn't witness anything quite that dramatic, but I did see lots of frazil flowing under the bridge.

Here's the view upstream from the bridge:


And the view downstream:



I then followed the ice downstream by taking the road that runs along the east bank. By the time I could next get a clear view of the river, the whole expanse was covered from shore to shore. As the winter wears on, this ice will continue to mount up, reaching heights of ten feet or more. Such a massive build-up creates a distinctive grassland habitat called an "ice meadow," where only plants that have evolved to tolerate these harsh conditions can thrive.



On my way home I stopped off in South Glens Falls to see what the Hudson looked like along the Betar Byway. As this photo shows, the quiet bays were frozen over, but the river still ran open out in the middle. To my amazement, I watched a pair of cormorants fly along low over the water (too quickly to be included in this photo).



I had hoped to spy a Bald Eagle fishing here, but I doubt any eagle will venture into this area while these thousands of crows are roosting in the trees. What a racket they were making! A real "caCAWphony!"


Crows are just such amazing birds! It's quite an experience to see thousands of them assemble from all directions for their nightly roosts, a phenomenon that happens only in late fall and winter. I once saw a huge river of crows, thousands and thousands, flowing across the sky from horizon to horizon, all heading toward the same spot. How on earth do they send out the word about where to gather? It's a mystery. While trying to find the answer, I found a wonderful web site about crows by Cornell ornithologist Kevin McGowan. You can check it out by clicking here.

5 comments:

Ellen Rathbone said...

Welcome, but I'm sorry to hear you are under the weather. Nice photos of the river!

Louise said...

Hope that you feel better soon. I agree that crows are fascinating creatures. When I was working, south of Rochester, many times in the morning I'd see them spreading out from their roosting place somewhere nearer the city for a day's scavenging. There was an article in the Democrat and Chronicle newspaper a few days ago about the fact that they are roosting near one of the churches, and causing a huge mess.

June said...

Imagine the tiny bits of frazil coagulating bit by bit until it blocks a whole river. There is a myriad of symbolism there.

I love crows. So smart, so social, so funny.

catharus said...

Yes, the posted stories I've read recently about frazil ice make it all the more fascinating. And yes, Corvids are amazing birds! Two easy, fun, books to read that take you on a path of discovery are Bernd Heinrich's "Ravens in Winter" and "Mind of a Raven". If you're fascinated by crows, I think you'll like these; I recommend the former first.

Woodswalker said...

Hello Ellen, Louise, June and catharus: Thanks for stopping by to leave your always welcome comments. And thanks, catharus, for the book suggestions. I have read both of them and marveled at all the amazing behaviors of corvids.