Neighborhood Nature

Our Family's Nature Blog

A January Walk through Columbus Park January 17, 2010

As I monitored birds this morning in Columbus Park, I did an experiment. I took photos with my iPhone and uploaded them live to Facebook. It was kind of like a virtual nature walk!

Here the link to the public Facebook album with this morning’s photos:  A January Walk through Columbus Park.

Please let me know what you think!


First Hard Freeze for Our Jars of Water December 7, 2009

Filed under: Experiments,Fall,Geology,Puzzles and Mysteries,Seasons,Water,Winter — saltthesandbox @ 10:22 pm
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Back on November 29th we started an experiment on our front porch, with four plastic jars filled with water. At the start of the experiment, the jars looked like this:

Water jar experiment, Day 1, November 29, 2009

Here's what the experiment looked like five days ago, before the temperature hit the freezing mark.

Now, here’s what the experiment looked like on Friday, December 4th, after the air temperature went below freezing, hitting 24 degrees Fahrenheit overnight:

Water jar experiment after a hard freeze, December 4, 2009.

Here's what the water jars looked like after a hard freeze. Three of the five jars had frozen overnight: A, B, and D. Also, we had added a fifth jar: In Jar E, the water that had been BOILED first, then cooled, put in the jar, and sealed with a lid that had NO holes in it. (Thanks to J of Science Museum of Minnesota for suggesting this addition to the experiment.)

Three of the jars had frozen water in them, including the jar with SALTY water. No one predicted that! The two jars that did not freeze were both sealed tight — there were no holes in their lids.

Here’s a closer look at Jar A, which started out as cold, fresh tap water, and was covered by a plastic lid with holes drilled in it:

Jar A (fresh water, started cold, holes in top), Decmber 4, 2009, 24 degreees F

A closer look at Jar A shows intersecting sheets of ice, more densely frozen closer to the top of the jar.

Jar B showed a similar pattern, although the sheets of ice were more horizontal than vertical:

Jar B (fresh water, started warm, holes in top), Decmber 4, 2009, 24 degreees F

Jar B also had sheets of ice, more densely frozen towards the top of the jar -- but the ice sheets were more horizontal than vertical.

Jar D was most surprising. I was expecting the salty water wouldn’t freeze, but the top part of the jar was frozen fairly solid. However, the bottom of the jar was not frozen, but had a bunch of bubbles sticking to the side of the jar:

Jar D (SALTY water, started cold, holes in top), December 4, 2009, 24 degreees F

In Jar D, notice the clear division between frozen water above and unfrozen water below.

So, that leaves us with two mysteries to solve:

  • Why did most of the water in the salty jar freeze?
  • Why did the water in the sealed jars not freeze?

I have some ideas, but I won’t tell you about them yet. However, I will give you one hint about the second mystery. Here’s what the lower part of salty Jar D looked like on December 2, 2009 — three days after the experiment started, but before the temperature dropped below freezing:

Jar D (SALTY water, started cold, holes in top), December 2, 2009, 37 degrees F

Here's what Jar D looked like three days after I had mixed in several handfuls of sidewalk salt, but before the first hard freeze. How can this help us understand why the top of the jar froze, but the bottom did not?

Feel free to tell us your ideas in the comments section (below) or on Facebook.


Our First Ice of the Season! November 1, 2009

Filed under: Fall,Geology,Puzzles and Mysteries,Seasons,Water — saltthesandbox @ 2:01 pm
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According to the closest Oak Park weather station, the temperature hovered just above freezing early this morning. But skies were clear, so heat radiated from the upper layers of our backyard pools. By dawn we had our first backyard ice of the fall:

The first ice of the season formed as heat radiated from the upper layers of the water.

Ice formed as heat radiated from the surface layer of water.

If it had been cloudy, or if there had been a breeze to circulate the water in the pool, we wouldn’t have had ice. But with a clear sky and calm air, we got these fantastic ice patterns right outside our back door!

Why the triangles in the ice? I’m not sure, but that’s the pattern we got last year in similar situations. If you look at this blog post from last February, you’ll see another example of triangular-patterned ice. That post talks about “wrinkles” forming in the super thin ice — maybe triangles develop where three wrinkles intersect. Anyway, that’s a puzzle for me to work on over the next few months.

There’s no natural water where kids can go and play, except after big storms and snow melts, and they set things up so even that’s supposed to drain away. There are no streams, no lakes closer than Columbus Park — just some human-made garden ponds in fenced off yards. And the Park District swimming pool. And the drainage ditches along the highway, which have cattails and Red-winged Blackbirds and mosquitos, but those are also fenced off too. But there’s no stream or pond or swamp where I can let the boys wade free, throwing rocks, racing sticks, collecting frogs and eels.There’s no place like I had growing up.So, we import our water through pipes, then fill containers in our back yard. There’s a plastic swimming pool where our pet turtles swim in summer; another half sand, half water, with a pump to make a stream; a pool with buggy water from the golf course pond behind Grandma’s condo; a black container for panning gold; and a pool that’s just for playing.

Every fall I promise to drain the pools and store them, but it never happens. Then I wake up on a winter morning and find this


Two More Signs of Spring at Columbus Park March 16, 2009

Filed under: Fish,People,Spring,Water — saltthesandbox @ 3:06 pm
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A Mourning Cloak Butterfly, out of hibernation and trying to warm up:

Apparently dark plastic in the sun was as warm as it got!

Apparently a dark plastic trash bin in the sun was the warmest thing around.

A fisherman on the bank of Columbus Park lagoon:

The fisherman I talked with said he hadn't caught anything yet, but that was OK -- he was "just playin'."

The fisherman I talked with said he hadn't caught anything yet, but that was OK -- he was "just playin'."


The Cold Is Back — But So Are the Robins March 11, 2009

Filed under: Animals,Birds,Seasons,Spring,Water,Winter — saltthesandbox @ 1:23 pm
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It was 19 degrees Fahrenheit and windy on this morning’s walk through Columbus Park. Despite the wind chill, I enjoyed both the patterns in the ice and the scores of Robins feeding on the golf course.

The most interesting ice formed at the edges of golf course puddles:

The surface water froze as the water below slowly soaked into the soil.

The surface water froze as the water below slowly soaked into the soil.

I saw at least 80 Robins, almost three times what we saw on Sunday.


Eight American Robins in the foreground, with white Gulls and a black Crow on the golf course behind them.

Most Robins fed on the golf course, on the east sides of wooded areas. There the early morning sun warmed them while trees sheltered them from cold west winds.

Tuesday’s warm front brought the Robins to the Park and filled the puddles. As usual, a cold front followed — its bitter winds froze the puddles and the soil. If the Robins can’t find worms, they’ll probably switch to fruit, their winter food. That’s why we put out raisins for our backyard Robins.

To read about other birds we’ve been seeing in the Park, go to this page.

To read about whether Robins are a reliable sign of spring, go to this page.


Nature Note added at 6:15 p.m. the same day: Late this afternoon I watched as our backyard Robin pulled a huge nightcrawler from the soil below the thistle feeders. It was so big he had trouble eating it. I guess I won’t have to worry about that Robin, despite the freezing temperatures.

Nature Note added at 6:50 a.m. the next day: It was 16 degrees this morning. When I saw a Robin in a tree near our yard, I did worry. So I put out more raisins.

Nature Note added on March 28 (more than 2 weeks later): This past week there have been even more Robins in the neighborhood. On Friday, March 27, I found at least 200 Robins in Columbus Park, mostly on the golf course. On Tuesday, March 25, I counted 136 Robins on a 2.5 mile walk through south Oak Park.


Refilling Ancient Lake Chicago March 10, 2009

Filed under: Animals,Birds,Geology,Seasons,Spring,Water — saltthesandbox @ 6:48 am
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Our neighborhood was once the bottom of a lake. That lake shrunk in size to become Lake Michigan, but ten thousand years ago the larger version covered most of Chicago and Oak Park. That prehistoric lake is known as “Lake Chicago.”

When rains are long and hard, the ghost of Lake Chicago tries to make a comeback. Storm sewers usually rescue residential areas from its return. But, after three and a half inches of rain over the past weekend, Lake Chicago has returned to Columbus Park:

Canada Geese swim across the flooded fields in the southeast corner of Columbus Park.

Canada Geese swim across the flooded ball fields in the southeast corner of Columbus Park. The white flecks in the background are hundreds of gulls on the partially flooded golf course.

The gulls congregated on the soggy golf course. Photo by Ethan Gyllenhaal.

Hundreds of gulls fed and loafed on the soggy golf course. Photo by Ethan Gyllenhaal.

Jens Jensen knew about the prehistoric lake when he planned Columbus Park a century ago. He incorporated ancient beach ridges into his design. I don’t know if he planned the flooded ghost of Lake Chicago — if so we birders appreciate his efforts.

Visiting the flooded Park as the storm subsided, the boys and I checked every gull and goose. We hoped to find rare visitors who nest much further north. In previous years we’ve seen a Snow Goose, three Ross’s Geese, and two Greater White-fronted Geese in the Park. This time we only found a Cackling Goose, a much smaller relative of the abundant Canada Geese. About dozen gulls visit the Park on most late winter days, with larger pink-legged Herring Gulls out numbering the yellow-legged Ring-billed Gulls. The floods brought hundreds more Ring-bills to the Park, but so far no rarer gulls, like Glaucous, Great-black Backed, or Thayer’s. (We’ve never seen those in the Park, but we can always hope.)

On Tuesday, another warm front brought south winds and heavy rains to our neighborhood, so the fields should stay flooded for a few more days. We’ll return to Columbus Park to see what migrant birds rode the winds to our neighborhood. To read about what we find, you can check our eBird lists for Columbus Park.


Wading Pools in Winter and a New Theory of Dinosaur Extinction February 25, 2009

With today’s temperature in the 50s, I urged Aaron and his friend Matt to explore the backyard instead of the icy expanses of Club Penguin. Eventually they agreed, leaving penguins but not ice behind.

Within minutes they called me to the backyard to record a “discovery” they made. I took some photos and wrote a story to go along with them. (The story was inspired by dinosaur books for kids, which I’ve been reading in preparation for a writing project.)

This only happened because we leave out plastic pools filled with water all winter long. That’s one way we make our neighborhood a better place for outdoor play, a place with No Child Left Inside.


Aaron and Matt found a dinosaur disaster in our backyard! An imaginary world of dinosaurs and ice was being destroyed.

What had done this terrible thing to Ethan’s old collection of giant plastic dinosaurs? (Ethan is Aaron’s older brother — he’s loved dinosaurs since he was a little kid.)

Can you help us solve this mystery?

Can you help us solve this mystery?

Matt carefully studied the ice layers searching for clues:

The ice, unfortuantely, held no useful clues to the origin of the disaster.

The ice, unfortunately, held no useful clues to the origin of this disaster.

The team decided to excavate in search of answers. After much digging and clearing of ice, Matt reached into the water with his bare hands. He pulled out a giant rock!

Aaron pulled out a large rock, the cause of the disaster.

Matt pulled out a giant rock, the cause of the disaster.

It was obvious that a flying rock had shattered this icy world. But where did the rock come from? From outer space? From a volcano? Gradually, the true cause of this disaster became apparent, as the rock struck once again:

The evidence was clear -- there were multiple impacts...

The rock struck again -- how did that happen?

There were multiple impacts, in multiple places.

The rock then smashed into another pool.

Aaron and Matt imagined the rock had come from space — that was their Theory of Dinosaur Extinction. Should I believe them?

Do you have a better theory? Who will Ethan agree with?


Thanks to Aaron, who let me tell the story my way, instead of the way it really happened.

With my kids, throwing rocks and smashing ice happen so predictably that they seem almost instinctive. The boys adding characters and plot to the adventure also seemed quite natural. I’ll let evolutionary psychologists explain how these behaviors contributed to our ancestors’ survival on the plains of Africa.

Here’s something that occurred to me — by destroying the ice, the boys found out about the physics of ice, water, and flying rocks. They also learned biology — the smell of dead leaves festering on the bottom of the pools. Smashing things may be the starting point for certain kinds of science, although building things and understanding wholes no doubt have different roots.

And the gender thing: Parents of boys may see more of this than parents of girls, and grown-up boys may better appreciate these images. But if Aaron and Matt’s friend Hannah had been here, she would have been in the thick of it. That’s one reason she’s their friend, and I’m glad they’ve made room for her.