Neighborhood Nature

Our Family's Nature Blog

Our Chicago Urban Christmas Bird Count Data 2009 December 20, 2009

The boys and I spent the entire day conducting our part of the Chicago Urban Christmas Bird Count. Nationally, Christmas counts are organized by the National Audubon Society. The Chicago Urban count circle is sponsored by Evanston North Shore Bird Club and Chicago Audubon Society, with Jeff Sanders as the compiler.

Our part of the count covers the following areas in Chicago and Oak Park: Birding on foot in Columbus Park, Douglas Park, and south Oak Park residential areas; feeder watching at our home on South Elmwood in Oak Park; and driving through industrial and residential areas in between these sites.

This year, birding from sunrise to sunset, we found a total of 26 species. The highlights of our day included:

  • Four species of hawks, including a MERLIN at Columbus Park (photo below), 2 AMERICAN KESTRELS, 2 COOPER’S HAWKS, and 2 RED-TAILED HAWKS.
  • A WINTER WREN beside the Columbus Park lagoon (where we saw this species often through the fall — photo below).
  • An AMERICAN PIPIT at Columbus Park, in the same field where we saw a Pipt on December 11 (photo below).
  • A SWAMP SPARROW at Columbus Park (photo of its rump, below), plus 20 AMERICAN TREE SPARROWS (15 at Douglas, 5 at Columbus).

We were also pleased that WHITE-BREASTED NUTHATCHES put in 2 appearances, since we’ve been seeing them much more frequently this year. We also were happy to see a BLUE JAY, because they were common this summer, then mostly disappeared within the last few weeks. We were disappointed that overall sparrow numbers were down at Douglas Park, where the golf-course sanctuary often holds 50 or 60 sparrows this late in the year. And we were very sad that we did NOT see the Great Horned Owl that had been roosting near Austin in late November and early December. (We still hope it returns in time to be registered as a count-week species!)

Here’s our entire list for today, with count numbers:

Canada Goose    280

Cooper’s Hawk     2

Red-tailed Hawk     2

American Kestrel     2

Merlin     1

Herring Gull     1

Ring-billed Gull     5

Rock Pigeon     115

Mourning Dove     45

Downy Woodpecker     4

Hairy Woodpecker     3

Blue Jay     1

American Crow     9

Black-capped Chickadee     9

White-breasted Nuthatch     2

Winter Wren     1

American Robin     55

European Starling    350

American Pipit     1

American Tree Sparrow    20

Swamp Sparrow     1

Dark-eyed Junco     25

Northern Cardinal     21

House Finch     14

American Goldfinch  30

House Sparrow     180

We also have two count-week species so far for our areas:

1 Red-bellied Woodpecker  (seen in Douglas Park 12/17/09)

2 African Collared-Dove and/or African X Eurasian Collared-Dove (seen in south Oak Park 12/18/09).  We are soliciting input on these photos, taken on Dec. 18th — what do you think they are?

Here are some of Aaron’s photos from today:

Merlin, Columbus Park, Chicago, Illinois, December 20, 2009.

The Merlin roosted in several trees around the lagoon, but it was tough to get a good photo because of the distance and overcast skies. Note the back color, streaking on the side of the breast, and minimal patterning on the head (all of which we could see much better through our binoculars). Photo by Aaron Gyllenhaal.

Merlin, Columbus Park, Chicago, Illinois, December 20, 2009.

This shot, from even further away, gives another view of the Merlin's head. Photo by Aaron Gyllenhaal.

Winter Wren, Columbus Park, Chicago, Illinois, December 20, 2009.

Although it was hard to get a clear shot at the Winter Wren, a few times it hopped into the open, possibly to get a better look at us! Photo by Aaron Gyllenhaal.

American Pipit, Columbus Park, Chicago, Illinois, December 20, 2009.

There was a large, if late, migration of American Pipits to inland parts of Chicago earlier in December. We were happy that one stuck around Columbus Park for the Christmas Count! Photo by Aaron Gyllenhaal.

American Pipit, Columbus Park, Chicago, Illinois, December 20, 2009.

Here's a front-on view of the American Pipit. It was hanging out at the north end of the large ball field that fills the southeast corner of Columbus Park, sometimes visiting a seepage area that has some unfrozen water. Photo by Aaron Gyllenhaal.

Swamp Sparrow, Columbus Park, Chicago, Illinois, December 20, 2009.

Although we got good binocular views of the Swamp Sparrow's gray-patterned head, Aaron only got photos of its butt! Photo by Aaron Gyllenhaal.

We’ll post links to Ethan’s photos once he gets them online.

 

No Owl Today, Just Fast-Frozen Owl Pellets December 16, 2009

Filed under: Animals,Birds,Seasons,Winter — saltthesandbox @ 7:12 pm
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The neighborhood crows and I were both disappointed that we didn’t find the Great Horned Owl in its usual roosting tree in Columbus Park. Here’s what the owl looked like yesterday afternoon — the third day in a row we had seen it in exactly the same spot in a White Oak tree:

Great Horned Owl roosting in a White Oak tree, Columbus Park, Chicago, Illinois, December 15, 2009.

Yesterday at 2:15 p.m. the Great Horned Owl was in its usual White Oak roost in Columbus Park.

This morning I looked at the same tree from every angle — and every tree around it — for 10 minutes and couldn’t find the owl. Then five minutes after I gave up a flock of Common Crows flew into the roosting tree and landed in its upper branches. These were tough crows! I had earlier seen them harassing first an American Kestrel and then a Red-tailed Hawk. I figured they knew something I didn’t — after all, crows first found this owl for me on November 24th. So, once the crows flew off, I went back to the roost tree and looked again.

Still, no owl.

I should have been disappointed, but I looked at the bright side. If the owl was in its roost, I would have backed off and left it alone. Since there was no owl to scare off, I could go look for owl pellets under its roost. (Owl pellets are the remains of animals that the owl ate — whole or in really big chunks. The pellet is the regurgitated remains of the owl’s meal, after the flesh and guts have been digested.)

Here’s what I found:

Great Horned Owl pellet, Columbus Park, Chicago, December 16, 2009.

The owl pellets are the fuzzy-looking gray things on top of the leaves. The gray fuzz is fur from whatever the owl ate. The white and yellowish bits embedded in the fur are bones from prey animals.

The more I looked, the more I found:

Great Horned Owl pellet, Columbus Park, Chicago, December 16, 2009.

This pellet -- about two inches across -- had more and bigger bones. When I picked it up, I saw ice crystals among the fur. When the owl spit out the pellet, it was still wet with stomach fluids. After the moist pellet hit the leaves, it froze solid.

The last pellet I found was the biggest and the boniest:

Great Horned Owl pellet, Columbus Park, Chicago, December 16, 2009.

The longest bone in this pellet is about two and a third inches long. It's a humerus, the upper bone from a front leg. I'm guessing it came from an animal bigger than a squirrel, maybe a rabbit or a small opossum or raccoon.

I saw one rodent or rabbit front tooth in a pellet, but the rest of the visible bones were from legs, feet, hips, shoulders, or backs.  I’m not good at identifying animals from their limb bones — I need to see teeth.

I guess we’ll go back at some point and dissect some of the pellets. If we find some jaws or skulls, we’ll know better what our urban owl was eating in Columbus Park.

Then we’ll wash our hands really well. After all, we’ll be handling owl vomit!

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We found more owl pellets on January 31st, including one containing a rabbit jaw. You can see them here.

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Here are links to information and activities about owl pellets:

 

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.