Archives For Nature in View

Sure, it snowed just three days into spring—it’s Chicago! This week we’re set to hit the magic temperature, 45 degrees Fahrenheit, and here’s what it will trigger in your garden.

ILLUSTRATION: How trees set buds in spring.


©2015 Chicago Botanic Garden and my.chicagobotanic.org

Photographing Orchids

Carol Freeman —  February 18, 2015 — 2 Comments

Compared to photographing flowers outside, photographing in the Greenhouses will be much more challenging and darker than you think.

Photograph the Orchid Show through March 15.
 
Tripods and monopods are allowed in the Orchid Show on Wednesdays during public exhibition hours. Enter your photos in our digital photo contest here.

It may be bright outside, but the light in the greenhouses is being filtered through glass and other plant material; be aware that it will be even darker on overcast days. Most people will be hand-holding cameras, so getting shots that are sharp will take some adjustments. Here are a few things you can try:

Use a shorter lens.

This will be a bit of a compromise, as many of the orchids are up high or hard to reach. It would be nice to use a longer lens to get photographic access to more of the flowers in the Greenhouses. However, a shorter lens—100mm or less—is easier to hand-hold, and has a better chance of capturing sharp images at a slower shutter speed. (Typically, you want to have at least 1/400th of a second for a 400mm lens, or 1/100th of a second for a 100mm lens, etc., so the shorter lens will gain you two stops in this example—a significant benefit when taking hand-held shots.)

PHOTO: Orchid.

With a limited depth of field, I chose to focus on the “face” I saw in this orchid. Photo ©Carol Freeman

Watch for what is in the background.

It is easy to be distracted by the beauty of the orchids and then get home and realize there are many unwanted elements in your photos. One easy option is to move in closer. When you get closer to the flower, you will get less background around the flower. Find flowers that are near the edge of an aisle—you will then be able to move your camera slightly up or down, or left to right, to get a pleasing background. Sometimes just an inch of movement can make all the difference.

PHOTO: Orchid.

Note the distracting window in the background. Photo ©Carol Freeman

PHOTO: Orchid.

By moving just a few inches to my left, I was able to get a more pleasing background for this orchid. Photo ©Carol Freeman

Increase your ISO.

Many of the newer cameras have improved sensors that let you increase the ISO and still get clean images with little noise. I like to do an ISO test before going out to shoot to see just how far I can push the ISO and still get images I find pleasing. It’s best to do this before you are on site so you will be able to review the images on a large screen and know what will be acceptable to you on the day of your visit. Every camera is different, and what may work for me may be too grainy for you. Most cameras will provide nice images in the 400 to 800 ISO range, and some can go much higher.

PHOTO: Orchids.

I was able to get a nice shot of these orchids—in a dark area—by upping my ISO to 1000. Photo ©Carol Freeman

Use your flash.

I much prefer natural lighting, but in the Greenhouses on a cloudy day, there may be no other option for getting that shot of “the most beautiful orchid you have ever seen” that is hiding in the shadows.

PHOTO: Orchids.

When using my flash, I can add some extra depth of field. Here I was able to get most of the flower sharp. Photo ©Carol Freeman

PHOTO: Orchids.

Sometimes using a flash is the only way to get a shot. Here I found orchids that were away from other elements, limiting the distracting effects of the flash. Photo ©Carol Freeman

Increase your depth of field.

Orchids are tricky to photograph, even in ideal conditions. Many of them are deep flowers and require a large depth of field to get a pleasing amount of the flower in focus. Increasing the depth of field, however, comes with a price, as the increased depth will often allow much of the background to be in focus as well. And in the Greenhouses, you may not want what is in the background to be in focus, especially windows, people, or other parts of the building. Hand-in-hand with depth of field is plane of focus. Many orchids have very interesting centers, almost like faces. Be sure to get those features in focus to make the whole photo look sharper.

PHOTO: Orchids.

By moving closer, you can eliminate the distracting elements from your shot. Photo ©Carol Freeman

PHOTO: Orchids.

Here I moved in even closer. I love capturing the intricate details of the orchids. Photo ©Carol Freeman

Have fun, experiment with different apertures, and get creative with composition! There is no right or wrong way to photograph these amazing flowers. They are here for your enjoyment and all that is needed is your appreciation.


©2015 Chicago Botanic Garden and my.chicagobotanic.org

Echoes of a Silent Night

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

Jim Steffen —  October 29, 2014 — 2 Comments

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

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

Fall on the Prairie

Carol Freeman —  October 15, 2014 — 2 Comments

While summer blooms elsewhere are winding down, the Dixon Prairie is still alive with many fall flowers.

PHOTO: Red Admiral butterfly.

Warm fall days bring out the butterflies; this red admiral is enjoying a New England aster. ©Carol Freeman

Asters, sawtooth sunflowers, gaura, and goldenrod are going strong. All of them are abuzz with bees and other insects. Grasshoppers dance from plant to plant. Butterflies fuel up for a last fling or long journey.

Dewy milkweed seeds blow in the wind. ©Carol Freeman

Dewy milkweed seeds blow in the wind. ©Carol Freeman

Grasses, some with tiny fragrant flowers, sway gracefully; many have grown more than 7 feet tall in this one growing season. Early morning dew transforms the seedheads into works of art. Silken strands of unseen spiders glow in the sunlight. Flocks of goldfinches munch on seeds, stocking up for winter, chirping their happy tunes, while shy sparrows occasionally pop up from the shadows, giving us a glimpse of their subtle beauty. Milkweed seeds blow gracefully in the wind.

The prairie truly must be walked to be appreciated. There is so much diversity, and so many stories to tell.

Touch a compass plant leaf on even the hottest day and it will be cool to the touch—with roots going down 14 feet, they pull up water that is chilled underground.

Monarchs live in symbiosis with milkweed plants (as do many other insects). Look closely and you may see a whole world on a milkweed plant.

Surprises can be anywhere—a hummingbird zipping by for a quick sip, a great blue heron flying overhead, drama as a hawk dives down to grab a vole. Fall on the prairie is colorful, alive, and a place of great wonder not to be missed.

Unseen spiders create artwork that catches the early morning dew. ©Carol Freeman

Unseen spiders create artwork that catches the early morning dew. ©Carol Freeman

Seed heads magically transformed with early morning dew. ©Carol Freeman

Seedheads are magically transformed with early morning dew. ©Carol Freeman

Grasshoppers dance from plant to plant. ©Carol Freeman

Grasshoppers dance from plant to plant. ©Carol Freeman

Gaura flowers still attract hover flies. ©Carol Freeman

Gaura flowers still attract hover flies. ©Carol Freeman

Resident Goldfinch stock up on the abundant seeds in the prairie. ©Carol Freeman.

Resident goldfinches stock up on the abundant seeds in the prairie. ©Carol Freeman.


©2014 Chicago Botanic Garden and my.chicagobotanic.org