Ecology & Wildlife – Page 8 – My Chicago Botanic Garden

Looking for some good grub

While checking the perimeter fence around McDonald Woods to see if there was any damage to the fence after a windy day, I discovered a large red oak that had lost its foothold in the frozen soil and had toppled over against a white oak. Since the tree was threatening to push the other oak over into the fence, I decided to cut the red oak down to save the white oak and the fence.

When trying to remove a leaning tree, you have to start at the base and work your way to the top as each section falls away. The base of the tree was good and solid, sending a shower of sour-smelling oak shavings flying from the chainsaw. When I got about halfway up the trunk, the saw began spewing dark brown flakes of rotting wood, and the sawing became easier. After a few more cuts, the trunk became mostly hollow and the top of the tree crashed to the ground.

Looking back at one of the middle sections of trunk, where the center was a rich dark brown from the rotting wood, I noticed a thick, white object shaped like the letter “C”.

A closer look showed the object to be a large grub from a beetle. These grubs are similar to the white grubs of Junebugs and Japanese beetles that you find in your gardens and lawns, but much larger. Although the rotten wood was frozen, I was able to split open the log, revealing a whole colony of 30 to 40 beetle grubs about 2 inches long and about a half inch in diameter. Each grub was cradled in a smooth-surfaced cell in the rotted wood. Even at temperatures well bellow freezing, the grubs were able to move enough to show they were alive.

As it turned out, these grubs were the larvae of one of our largest woodland beetles, known as the stag beetle or stag-horn beetle. These beetles are one of the myriad invertebrates active year-round, doing the important work of reducing fallen trees to rich organic soil that will help other trees grow and support the next generation of plants.

These beetles are members of the Coleoptera (beetles) and get their name from the large antlerlike mandibles (jaws) found on the front of the head of the males. The females also have mandibles, but they not as impressive as those of the males. The large mandibles are used for territorial defense and also to protect the beetles from any birds or other animals that might try to eat them. The impressive “antlers” can look threatening to people when they first encounter them; however, they are not a serious threat to people and will only give you a pinch if you handle them roughly. It is not uncommon to find the large brown stag beetles around buildings near woodlands at night, when they are sometimes attracted to the lights.

These critters are fascinating, not only because they are social in the larval stage and can take several years to mature, but they can also produce an assortment of sounds that are thought to help with communication between the grubs. The grubs have a striated structure on the leg that allows them to produce sound (called stridulation), kind of like rubbing a spoon on a washboard. If you notice the dark-colored segment that looks distended on the end of the grub, it is the digestive chamber, where the wood the grub consumes is digested with the aid of microorganisms. If you give one of these guys a gentle squeeze, you will notice a stream of liquified, dark brown wood coming from the tail-end of the critter.

One last item of interest about these wood-grubbing dynamos is that they often carry a large population of mites around, clinging to their bodies. When I took a closer look at the grubs, I found dozens of whitish-colored tiny mites attached to each of their legs.

This observation lead me to recall the verse by the Victorian mathematician, Augustus De Morgan:

Great fleas have little fleas upon their backs to bite ’em,

And little fleas have lesser fleas, and so ad infinitum.

And the great fleas themselves, in turn, have greater fleas to go on,

While these again have greater still, and greater still, and so on.

These mites do neither the beetles nor the grubs any harm; they are just along for the ride and probably snacking on any choice fecal pellets deposited by the beetles. If you find yourself sitting on a log out in the woods, you just might be perched above a nest of developing stag beetles.

Stories in the Snow

When a coyote pirouettes in the snow, you start to wonder. Where was it going? And what made it turn?

After a big snow, I love looking for wildlife tracks and the stories they tell. The paw prints and other tracks in the snow are among the small wonders of winter.

In a recent blog, we talked about finding awe on winter walks—turning attention outside yourself for emotional well-being. By following animal tracks, you lose yourself in a different world and take a fresh look at the nature that surrounds you. You can do so in your neighborhood or at places including the Chicago Botanic Garden, where I’m director of youth education.

One winter, after a snowstorm, I decided to look for evidence of wildlife near the Garden’s Regenstein Learning Campus. My first sighting was the tracks of at least one coyote running through the snow.

The individual track was not a clear footprint, but it was the right general shape and size to be a coyote.

PHOTO: the single track of a coyote is seen in the snow. — The coyote track looks like that of a medium-sized dog, with padded feet making toe impressions in the snow.

The tracks formed a few paths across the Campus.

PHOTO: two coyote trails are seen very clearly running through the snow, close to the treeline. — A coyote ran through the snow toward the right of the picture, then ran back and rejoined its original trail.

The tracks did not follow the paths that people walk, but instead ran closer to trees. This makes sense for an animal that is trying to stay hidden from other animals. I also found a spot where the coyote seemed to run up, do a little turnaround, and take off in another direction.

PHOTO: The tracks in the snow look like the coyote ran and make a circle in the snow. — The tracks look like a coyote circled around after running out of the woods.

This isn’t the clearest picture, but you can still see that the coyote came from the wooded area toward the front of the picture. Then it turned around and sank down on its front paws, right where you see two clear side-by-side holes in the snow. It turned and ran to the right of the picture frame. You can imagine a spirited puppy, running excitedly as it plays in the new snow and leaves tracks like these. Was the coyote playing? Hunting? Running away? If you’re walking with someone, especially kids, it’s fun to come up with a story.

I was also hoping to find evidence of animals interacting. The closest thing I found was this set of rabbit tracks.

PHOTO: a set of rabbit tracks appears from behind the corner of the building, turns around and goes back in the direction it came from. — The rabbit that left these tracks decided to turn around and go back instead of coming around the corner of the building.

Here, the rabbit hopped to the corner of the building, stopped, and then turned around and went back the way it came. Did it possibly see or smell the coyotes that were running around and decide to go back to hiding?

I also spotted squirrel, bird, and mouse tracks. And then I found these strange marks in the snow.

PHOTO: a nice layer of snow on top of a hedge row has long parallel lines from students dragging their fingers along the hedge as they walked past. — Fingerprints in the snow?

What could these strange lines be? “It’s elementary, Mr. Watson!” These “fingerprints” were left by elementary school students as they dragged their hands along the snow.

Here are some tips on how to look for wildlife stories:

Go out and look when the snow is fresh.
Think about which animals you have actually seen around, and where you have seen them. Look there.
Do a little research on the habits of animals you might see and look for tracks in places where that animal finds food, water, or shelter.
Search around trees and shrubs, especially if there are places a small animal might crawl into for shelter. Watch you head as you duck under branches.
Take photos to compare them to pictures of animal tracks posted online.

And if you don’t spot any animal tracks, no worries. You got in a walk and fresh air and took in the beauty of a winter wonderland.

Snacker, Flapper, Sleeper, Napper

All animals that inhabit this area, including humans, have to cope with the changing of the seasons. There are four basic responses to the cooler temperature and shorter daylight. Which is your favorite strategy for surviving the winter?

Do you eat more food during this time of year, loading up on high calorie goodies? You may be a Snacker. It is a natural instinct. You are like the squirrels, rabbits, and some birds that fatten up and keep going all winter long.

PHOTO: a gray squirrel poses as it feeds on bird seed dropped from a bird feeder. — Squirrels fatten up on seeds and stay active all winter long.

Do you travel to warmer climates during the winter? Wings are not required to be a Flapper. Count yourself in the company of warblers, monarch butterflies, and herons if you leave the area in winter. You may be migrating to escape the cold, but these animals are generally traveling to find more plentiful supplies of food.

Do you become sleepy and hibernate for four or five months every year? Then you are a Sleeper, like a bear, turtle, or frog. These animals undergo physical changes that shut down their respiratory systems and metabolism during the winter. You are probably not a true sleeper, even if it sounds appealing.

PHOTO: This bronze model of a painted turtle on a rock can be seen a Kleinman Family Cove yearround. — This bronze turtle can be seen all year at the Kleinman Family Cove, while the real turtles are hibernating in the mud at the bottom of the lake in winter.

If you are prone to feeling tired and sleeping more in the winter, then it’s more likely that you are a Napper. Animals like skunks and opossum cozy up in burrows or under deep piles of leaves and sleep. Occasionally they emerge, find something to eat, and then go back to bed.

PHOTO: A small skunk is feeding on squirrel corn on a dark winter evening. — A skunk wakes up from its nap and feeds on some seeds during a winter evening.

PHOTO: A baby opossum is seen in the snow surrounded by dormant plant stalks. — Like the skunk, this baby opossum emerged from its nap and is looking for something to eat before it returns to its shelter.

Snacker, Flapper, Sleeper, Napper — try to say that three times fast as you prepare for another midwestern winter!

Squirrel Drey Query

Most people recognize a squirrel nest, called a drey, when they see one. The eastern gray squirrels in our region build dreys in trees for shelter and protection from the elements. What you see as a messy clump of leaves is actually a structure formed from sticks and then lined with leaves and other materials to make it a dry and cozy home.

This month I was walking around my neighborhood in Chicago, and I noticed that three out of four squirrel dreys on my street were located on branches that reach over the street. I had to ask myself why squirrels would build their homes in such a dangerous place. If the squirrel or its babies fell out, they would not only land on hard concrete but also risk being hit by a car! Are my neighborhood squirrels somehow related to the Three Little Pigs?

Since I know that is not the case, I started to speculate:

Perhaps squirrels are attracted to that particular view. Maybe thermal currents rising from the asphalt make that spot warmer than a branch over a lawn. Could it be that this spot also puts their predators at risk and therefore is actually a safer place to live? I don’t know!

So, I started looking around to see if there was a pattern in locations of squirrel dreys. To date, my findings are inconclusive. While searching for squirrel dreys, I did notice two other interesting things I would like to share.

PHOTO: This close up of a squirrel drey has an arrow pointing to the green plastic sticking out of the bottom of the drey. — Look carefully to see the bit of green plasting in this photo of a drey.

First, there are fewer squirrel dreys on the Learning Campus than there are in my neighborhood. I suspect that is because the Garden is home to our friend the red-tailed hawk (from a previous blog post) and other predators that are more scarce around my home.

Second, I found a squirrel drey at the Garden that was built with something unusual. If you look carefully in the picture, you will see a green material, possibly shredded plastic like Easter basket grass, sticking out of the bottom. Now, I wonder where it found that! This drey is located on the Garden’s entrance road, near the entrance to the Barbara Carr Administrative Center, before you reach the Gatehouse. You will only notice it if you are looking at squirrel dreys as carefully as I am.

PHOTO: The same drey seen from another angle shows the green plastic. — The green plastic is circled in this view of the squirrel drey.

Take a look at the squirrel dreys around your home, nearby parks, and at the Garden. Are the the squirrels building over the road in your area? Have you seen a squirrel enter or leave a drey? What is the strangest material they have used to build it? If you notice any patterns, post a comment in this blog.

Bohemian Waxwing: Lifer

For those birders who keep lists, a Lifer bird is one that you see in the wild for the first time in your life. Always exhilarating, often amazing, and really pretty cool when you think about it.

I love birds. I know a bit about the local ones, and I know enough birders to know when a rare bird is around. Thankfully birders like to share info—a nice trait.

I had heard through the grapevine that a Bohemian waxwing had been seen at the Chicago Botanic Garden for the last two days. This is a bird that spends most of its time in the boreal forests of Canada, and only very rarely visits Illinois in the winter. Similar to the cedar waxwing, which can be found here year round, it is larger, lacks the yellow on the belly, and has lovely reddish markings on the face and under the tail.

_D8A5464 — ©Carol Freeman, all rights reserved.

Birds don’t sit still, and this particular bird had been seen in several different locations at the Garden. No telling where it would be today, or even if I would see it.

Luckily, when I headed toward its last known location near the Enabling Garden, I came upon several birders. They were pointing to the top of a tree. I look up. Yep, there’s a bird about 20 feet up, backlit against a white sky. Hmmm, not the view I was hoping for. But I can just make out the identifying marks of a Bohemian waxwing. Ok, there it is, my Lifer. Hmmm, kinda anticlimactic. In case this is the one and only time I ever see this species, I take a few obligatory shots. I personally don’t count a bird on my list unless I have a photo, and now I have a few. They aren’t going to win any awards, but that’s the way it goes sometimes.

Just after I get my shot, the bird flies to another clump of trees a short distance away. Then it flies out of sight. A few birders go off to see if they can relocate it. I chat with the others who have stayed behind. Some had seen the bird before today. But for many, this is a Lifer for them too.

While waiting for the bird to hopefully make another appearance, I take a moment to photograph the many cedar waxwings that are enjoying the abundant berries nearby. Suddenly I hear shouts from the birders. The Bohemian waxwing has just flown into the trees where the cedar waxwings are feeding, not far from where I’m standing. The bird is a few trees back and blocked by branches. I don’t want to move and scare it off, risking the wrath of the birders, so I just wait. Soon the Bohemian waxwing makes its way toward me. Wow! It’s hopping onto branches, closer and closer to where I’m standing. Oh my! Now it’s right in front of me. Whooo, hoooo! I couldn’t have gotten any closer if I had tried. Click, click, click, wow, wow, wow, amazing! I’m stunned. What an incredible encounter. This is one Lifer experience I’ll never forget. And…I have the photos to prove it!