Sunday, April 14, 2013

Hypotheses

Today we biked to a little natural area by the Winooski River, and then let the Little Lady run about to see what she could discover. This is my favorite part, when we let the scientific discoveries come naturally! We wound up discovering many things we couldn't explain right away, so we had to use our powers of observation to form and test hypotheses. For the record, the way the Little Lady defined a hypothesis is an "educated guess", so that means it is based on the information we found, rather than just an off-the-cuff guess.

The first thing we found was some beaver damage on a tree. We made the educated guess that it was beaver damage since we were next to a river and we happen to know beavers live nearby. The beaver hadn't felled the tree, but just nibbled on it. The beaver might have done this to get a snack. They only eat the layer of a tree just beneath the bark (the cambium), not the main wood. Another reason for gnawing this tree might have been to file their teeth. Beavers teeth never stop growing, like our fingernails, but they don't have nail clippers!

Other animals create similar damage. This picture is actually porcupine damage.
(I didn't have my camera today, so I'm using this picture I took earlier.)


We also found some fire damage. The Little Lady was concerned about our hypotheses for this, because "hypotheses must be testable." She's right of course, but we discussed how you can test a hypothesis through research, rather than experimentation. One way to do this would be to ask the people who manage the natural area. However, while we were there we used our powers of observation to see if we could make our hypothesis stronger, or disprove particular ideas. For example: since we didn't find a lightning strike, we don't think it was naturally caused. It might have been a controlled burn by people who are experts in that field.

The biggest part of the adventure was spent studying water current in the river. It was a completely self-designed experiment by the Little Lady herself. She threw a stick and a hollow reed into the river to try to see if the hollow one would get waterlogged and sink faster. They were swept downstream too quickly to tell that time, but then something else happened. She threw a tiny piece of reed very close to the bank, and it started moving backward! Lucky we had a friend with us today who is an experienced canoe paddler. He told us about how directly downstream from a point where something, like a rock or log, juts into the river, the steam will create an eddy behind the point. In an eddy the water moves upstream because of the faster water moving in the main stream channel. This difference in current means that sometimes at the edge of an eddy you can see tiny whirlpools.

Image borrowed from the New York State Department of Environmental Conservation website

We saw waterfowl in the river; a pair of Canada geese and two pairs of black ducks. We also heard birds. The Little Lady identified the crow call. I tried to point out the red-winged blackbird call, but there was also a black-and-white warbler calling, and she kept thinking I was referring to their squeeky-wheel sounding call. We also heard a mourning dove. I'll have to come up with a better system for incorporating bird calls into my lessons now that I'm getting better at them (I've been practicing!)

The best part of today, for me, is that I had no plan for this outing, I was just thinking a quick bike ride to the end of the road and back. You really never know what you're going to find to learn from when you walk out your front door! That's the amazing part about working with kids in nature: you can quite literally never run out of new things to learn about. Who knows what the next post will explore!

1 comment:

  1. I wish I could have been there! What a lovely adventure! Thanks for taking my Little Lady along with you. :D

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