Echoes of a Silent Night

Senior ecologist Jim Steffen describes his close encounters with curious and beautiful bats.

Jim Steffen —  October 29, 2014 — Leave a comment

A few years ago, in early spring, I was traveling through McDonald Woods at the Chicago Botanic Garden, searching for some of the flat-bodied crab spiders (Philodromus) that typically spend the winter in communal groupings under the loose bark of dead trees. Upon reaching a small stand of dead American elm trees, I began to lift the loose remaining bark away from one of the trees to see if any spiders were present.

As I gently pulled the bark away from the trunk, a tiny black hand reached up over the top edge of the bark. It quickly became obvious that there were more than spiders under this bark!

Although I was a little startled to have this hand slowly reach out in front of my face, I immediately realized that this piece of loose bark was the day roost of a silver-haired bat. The silver-haired bat is a medium-sized bat that is a dark chocolate brown or black with white hairs scattered among the dark hairs on its back. I gently released the bark so as not to disturb the napping bat any more than I already had. This is just one example of why it is important to maintain at least some dead standing trees in our woodland communities.

PHOTO: Silver-haired bat.

A silver-haired bat curls up tightly on a tree in McDonald woods. Photo by Jim Steffen

Even though bats are fairly common mammals in our area, since they are almost totally nocturnal, we don’t get to see them all that often—especially at close range, when we would be able to admire their delicate form and attractive appearance. Bats are in the order Chiroptera, roughly translated as “hand wing,” and are the only mammals that are actually capable of true flight (unlike flying squirrels—which we also have at the Garden). 

You might be familiar with another group of small mammals known as shrews. Shrews are mouse-like animals that are actually carnivores that feed heavily on invertebrate populations. Although bats may have varied diets around the world, here they are primarily insect eaters, much like shrews with wings.

When I was in college studying mammology, we used to go out at night and look for streetlights where there were large numbers of moths and other flying insects attracted to the lights. We would then take out our car keys and jangle them around to make high-pitched sounds with the keys clinking together. These high-pitched sounds would simulate the high-pitched sounds produced by the echolocation sounds produced by hunting bats to locate their prey. (Unless we are equipped with special listening devices, we are not able to hear the sound of bat echolocation.) Often times, many of the moths would begin flying erratically, or drop out of the air as though they had been struck with a stupefying charm from Harry Potter’s wand. These moths have evolved defensive tactics to help them avoid being eaten by bats by flying in erratic patterns or closing their wings and dropping if they heard the sounds of an approaching bat. 

PHOTO: Eastern Red Bat

An eastern red bat (Lasiurus borealis) clings to black landscape fabric at the back of one of the buildings here at the Garden. Photo by Jim Steffen

Many years later, while removing invasive garlic mustard from our oak woodland a few summers ago, I came upon an oak tree with a broken branch. All of the leaves on the branch had turned a bright reddish-brown that stood out against the backdrop of all the other green foliage. On closer examination of the branch, I spotted a female eastern red bat hanging upside down, in typical bat fashion, with its single offspring clinging to it. I don’t know if the bat was aware of it, but this dead branch provided the perfect camouflage for her rich color.

This made me think about how these mammals perceive the world. Do bats have color vision, and was this red bat able to tell that the dead branch would be such a good match for its own color? Most nocturnal animals tend not to have color vision, since color does them little good in the dark. Most bats are various shades of brown, black, or gray. (It is a different story for birds that are mostly active during the day and use bright colors as a means of attracting mates or advertising territories.)

PHOTO: Lasiurus cinereus (hoary bat).

Hoary bat (Lasiurus cinereus by Daniel Neal [CC-BY-2.0], via Wikimedia Commons

We have five species of bats that are likely to be seen at the Garden. Some of them are summer residents, like the little brown, big brown, and eastern red bat, while others are mostly migratory species, like the silver-haired and hoary bats that show up during their spring and fall migrations. Years ago, in the late fall, while using fine nets at night to capture owls for attaching U.S. Fish and Wildlife Service bird bands, I often caught many of the large, hoary bats migrating south for the winter. These large bats have an attractive frosted appearance with a mix of white and reddish hairs all over their bodies.

While I was studying birds in the tropical rain forest of Central America, I often encountered small colonies of bats hanging at eye-level, under the broad leaves of Heliconia plants. I think these wide, tent-like leaves were chosen mostly for the protection they gave the bats from the torrential downpours that occurred every day. However, the bats we find here are either solitary animals, like the red, silver-haired, and hoary bats that live solitary lives in the woodlands and forests, or they are colony-forming bats, like the little and big brown bats, that search out attics, barns, or large hollow trees where they gather in groups to raise their young.

Some of the bat species also search out caves or old mine shafts during the wintertime, where the subterranean habitat provides moist, stable conditions with above-freezing temperatures suitable for hibernation. It is possible to construct bat houses that, if placed in the proper locations, can attract and support colony-forming bats during the summer.

We have several of these bat house installed on buildings around the Garden. This summer, one of those houses contained half a dozen bats—probably little browns. It is best to place bat houses in full sunlight, since the bats have high body metabolisms and prefer very warm conditions for roosting during the summer. Think you’d like to build a bat house? Construction details can be found at the Bat Conservation International website at batcon.org.

PHOTO: Flying squirrel.

Another local flier, this very tame flying squirrel enjoyed a snack of walnut with his photo op. Photo by Jim Steffen

Bats are more than curious and beautiful creatures; they are also tremendously important components of a healthy environment. They are extremely important control agents of insect populations. Many of the insect species they eat are harmful crop pests, like army cutworm, or irritating or disease-carrying species like mosquitoes. Some bats can consume more than 1,000 mosquitoes in a single night! Bats are in trouble now for many reasons—not the least of which are climate change, exotic diseases like white-nose syndrome, and habitat loss.

Although bats are seldom seen and often have scary, erroneous wives-tales associated with them, we should be working hard to correct the problems that might lead to a truly silent night.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

Parents! Here’s a kid-friendly, fun-to-make idea from Kasey Bersett Eaves, who “talked squash” with fall-minded visitors at the Regenstein Fruit & Vegetable Garden on a gorgeous fall weekend.

With winter squash and pumpkins readily available at grocery stores and farmers’ markets, a nicely spiced fruit leather is a great way to use a post-Halloween pumpkin (uncarved) or extra can of purée—and to get kids to eat their vegetables in a new and tasty way. Super simple to assemble, it’s a whole lot healthier than candy!

Kids AND adults love the cinnamon-y pumpkin flavor.

Kids and adults love the cinnamon-y pumpkin flavor.

Pumpkin-spiced Snack Leather

  • 1 can of plain pumpkin or 3½ cups of cooked pumpkin pulp*
  • 1 cup of unsweetened applesauce
  • Cinnamon, nutmeg, cloves, and honey according to taste

Purée all ingredients together by hand or in a blender or food processor.

Spread purée on a foil-lined or greased cookie sheet, and smooth until just a little more than ¼-inch thick. Bake on your oven’s lowest setting (around 150 degrees) until no longer sticky to the touch (this takes close to eight hours).

Remove and cool until you can lift the edges and corners of the pumpkin leather off the foil or cookie sheet. Peel off and cut into strips. Roll each strip into plastic wrap and refrigerate until ready to eat.

If you have a food dehydrator, it’s even simpler. Spread the purée on the plastic sheeting provided with your dehydrator—or wax paper—and dehydrate until no longer sticky. Roll, refrigerate, and snack away!

It's a kid-friendly process: first, blend puree with applesauce and spices to taste.

It’s a kid-friendly process: first, blend purée with applesauce and spices to taste.

A tin foil base rolls up easily.

A tin foil lining makes cleanup easy.

*Basic Technique for Cooked Squash

Fresh-cut pumpkin (which is actually a squash) has a much higher water content than canned pumpkin. You will need to cook your pumpkin first, and use more fresh pulp. Cut your squash in half and remove the seeds. Place the squash skinside down on a baking dish, and bake at 350 degrees until the flesh is tender and the cut edges have caramelized. Remove the squash from the oven and let it rest until cool. Scoop out the pulp and discard the cooked skins.

See Kasey’s summer post, too — “Herbal Mixology


©2014 Chicago Botanic Garden and my.chicagobotanic.org

Windy City Harvest Youth Farm Joins a Growing Community

Farmers' markets are growing in Illinois, and we're working hard to keep the momentum

Laura Erickson —  October 24, 2014 — Leave a comment

Can you remember a time when farmers’ markets were few and far between, and local food was nearly impossible to find, unless you grew it yourself?

Today—October 24, 2014—is National Food Day. Learn more about this initiative by visiting foodday.org, and join the movement with @FoodDayCHI and @FoodDay2014, and #CommitToRealFood.

Now farmers’ markets are popping up all across Illinois—in rural, suburban, and urban landscapes—providing healthy food to many communities.

According to the USDA, the number of farmers’ markets in the United States has grown by 67 percent since 2008, with more than 8,000 markets and counting. Illinois ranks third in the nation for the number of farmers’ markets, with nearly 400 markets.

PHOTO: Juaquita holds up a freshly washed carrot harvest.

Windy City Harvest Youth Farm participant Juaquita holds up part of her freshly-washed carrot harvest.

The Chicago Botanic Garden has been a part of the growth of farmers’ markets in Illinois. With the farmers’ market held at the Garden, along with the farm stand markets hosted at Windy City Harvest Youth Farm sites, we have contributed to the improved access of healthy, local food, especially in underserved neighborhoods of Chicago and North Chicago.

Throughout the summer, the Windy City Harvest Youth Farm program operates three farm stand markets as way to share its fresh, sustainably grown produce with the surrounding neighborhoods. These markets are set up on-site (or nearby) at each of our three Youth Farms. These farms are located in the West Side neighborhood of North Lawndale, the South Side neighborhood of Washington Park, and the community of North Chicago/Waukegan. All of these communities are considered food deserts, as the access to fresh food is extremely limited.

The produce sold at Windy City Harvest Youth Farm markets is grown by the community for the community. Teenagers from local high schools are hired to work at the Youth Farms from May through October. They participate in all aspects of farming, including the growing, cooking, and marketing of the produce. Every week during the summer, the teens set up a farm stand to offer their fresh bounty to the community. The produce is sold at very affordable prices. Our markets accept food stamps and other government assistance benefits, so the food can be accessible to all members of the community.

PHOTO: Happy customer at the first market.

Happy customers enjoy a bounty of fresh vegetables at the first market.

Season after season, the benefits of these markets can be seen in both the teen workers and community. The teens learn business and customer service skills, practice their public speaking, and make positive connections in their community. One of our teen workers, Henry, said that this year’s opening market in North Chicago was the “best day of his life” because the participants nearly tripled their sales goal and broke the previous sales record for an opening day. A former participant of Science First (another wonderful Garden program), Henry was especially proud to host the program at the farm that day and assist with farm stand purchases. He even persuaded a young Science First participant to purchase black currants (later reporting that the Science First participant was eating the tart currants like candy).

We often hear from our market customers how grateful they are to purchase local, sustainably grown produce at an affordable price. They comment on how tasty and fresh our farm produce is compared to the produce available at their local grocery store, and they enjoy the farm tours and recipes provided by our teens. We often hear how our Youth Farms remind them of a farm they grew up on in Mississippi or Mexico. 

PHOTO: Potato harvest success.

Potato harvest success!

Besides impacting the food system and community health at a local level, we also help shape food policy and accessibility statewide. I have had the privilege of representing the Chicago Botanic Garden on the Illinois Farmers Market Task Force and on the board of the Illinois Farmers Market Association. The Task Force—which consists of farmers, market managers, and public health officials—advises the Illinois Department of Public Health on statewide local food regulations. We also provide education to consumers and market managers on food safety at the market. The Illinois Farmers Market Association connects the farmers’ market community to resources and educational tools. Lately we have been training market managers on how to accept food stamps at their markets and working with government agencies to better inform food stamp recipients on the markets that accept those benefits.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

Emerald Ash Borer: Sad But True, Part 3

The invasive insect appears to have spread to a different host.

Tom Tiddens —  October 23, 2014 — 2 Comments

Last week, a college biology professor in Ohio announced he had found evidence that the emerald ash borer (EAB), an invasive insect decimating the continent’s ash trees, is also attacking white fringetrees (Chionanthus virginicus).

PHOTO: White fringetree in bloom.

White fringetree (Chionanthus virginicus) in bloom

In August he found the telltale D-shaped exit holes on a fringetree near his home. When he investigated further by peeling back the bark, he found feeding galleries and live borers. He had the borers positively identified morphologically as well as with DNA tests conducted by the USDA’s Animal and Plant Health Inspection Service (APHIS). He also found evidence of EAB activity on fringetrees in three other locations in Ohio.

The recent discovery marks the first time EAB has been found completing its life cycle on anything other than ash in the United States.

The finding adds an alarming new element to the EAB story:

  • Researchers have been wondering whether the host range for EAB could be wider than just ash. That theory had seemed unlikely up to now but is proven with the fringetree discovery. There has already been a lot of research investigating other possible hosts, and with the new discovery, there will likely to be more.
  • Is the insect adapting? This is a scary thought!
  • Will EAB kill fringetrees as it does ash, or just cause damage? So far the invasive insect appears to only be damaging—not killing—fringetrees.
  • Has EAB moved to fringetrees because EAB populations are locally so high? If the buffet is crowded at the “prime rib station,” it seems logical that “meatloaf station” may get some visits.
  • What will happen when ash tree populations dwindle? Will the EAB population die back, or just move to a secondary host (the meatloaf, as the prime rib is gone) and/or develop a completely new palate?
PHOTO: A D-shaped exit hole left by EAB.

This D-shaped exit hole was left by a mature emerald ash borer as it exited this host tree.

The Ohio professor’s find was not all by luck; he had reason to focus on the white fringetree. Laboratory studies have shown that the adult EAB will feed on the foliage of other tree species in the same family as ash—the olive family, or Oleaceae. Members include ash (Fraxinus), fringe tree (Chionanthus), lilac (Syringa), forsythia, privet (Ligustrum) and swamp privet (Forestiera). Literature from Asia, the homeland of the EAB, indicates other secondary EAB hosts.

The Chicago Botanic Garden has 42 fringetrees; all have been inspected and show no signs of EAB activity. Even a fringetree that is 25 feet from an ash tree that was heavily infested with EAB shows no signs. If you have a fringetree, you should inspect it for signs of EAB. These include dieback starting at the upper limbs of the tree, new growth on the lower trunk, and small, D-shaped holes where the larvae have exited through the bark. Emerald ash borer larvae can kill a mature ash tree in two to three years by destroying the tree’s vascular system.

Find more information on identifying and dealing with EAB on our website, and in our previous posts, Signs of Emerald Ash Borer, and Emerald Ash Borer: Sad But True, Part 2.

As the world has become less fragmented by ease of transportation, more exotic, high-consequence plant pests and pathogens like EAB have entered—and will continue to enter—the country. Other exotic plant pests and pathogens we are watching for at the Garden include the following: viburnum leaf beetle, Asian gypsy moth, brown marmorated stink bug, Asian longhorned beetle, thousand cankers disease, plum pox virus, chrysanthemum white rust, sudden oak death, and so on; most are already in the country. Vigilance and education are the key to managing and slowing the spread of these foreign invaders.

The Garden is a member of the Sentinel Plant Network, a group that unites botanic gardens in monitoring and providing education on exotic plant pests and pathogens, and works in partnership with the National Plant Diagnostic Network (NPDN).

If you are a plant and bug person like me, please consider becoming a NPDN First Detector and help be on the lookout for these exotic plant pests and pathogens. The NPDN offers an online training course to become a First Detector at firstdetector.org. It’s free, and upon completion, you even get a printable certificate!

©2014 Chicago Botanic Garden and my.chicagobotanic.org

Creepy, gooey, stinky, thorny…for some plants, every day is Halloween. Find out more in our Spooky Plants infographic!

Spookygraphic: an infographic about spooky plants

©2014 Chicago Botanic Garden and my.chicagobotanic.org