Monthly Themed Articles

June 2022:Songbirds Need Pollinators Too!

Photo by Kirsten Carlson

By Kirsten Carlson,

“One Carolina chickadee breeding pair requires between 6,240 to 9,120 caterpillars to feed their brood prior to fledgling in 16 days.”  Unbelievable, I thought as I listened to Doug Tallamy, as the TA Baker Professor of Agriculture and Natural Resources at the University of Delaware, recently at the Cincinnati Zoo & Botanical Garden as part of their Barrows Lecture Series.  There is a lot of information to unfold in that single statement and how it applies to each of us.  Let’s begin the unfolding.

First, the Carolina chickadee is a squirt of a bird; it’s very small, black and white in color, and is a cavity nester (often around woods and our yards).  We see them year-round in our area and they often come to feeders to eat seeds.  Chickadees have a variety of calls and songs; you may be familiar with the chicka-dee-dee-dee call.  If you have heard this call around your home, then you’ve got chickadees and hopefully caterpillars.

Second, who made all those caterpillars?  Lepidopterans of course.  Our friendly neighborhood butterflies and moths can lay up to hundreds of eggs each breeding season.  The number of eggs laid depends upon the species.  Why caterpillars and not worms (a common misconception)?  Caterpillars have soft bodies with a thin exoskeleton, which makes aggressively thrusting down the throat of a nestling a little easier than say, a beetle.  Worms, on the other hand, are quite wriggly, which makes them wriggle right out of the nestling’s mouth.  There went dinner.  But there is something even more special about caterpillars that worms can’t even touch.  Nutrition and necessary molecular compounds.  Caterpillars are loaded with lots of fat and protein, which is needed to get a baby bird from hatchling to fledgling in those 16 days for our chickadee.  You can’t get that nutrition from seeds and fruits alone.  Caterpillars also contain carotenoid pigment molecules, which help with eye development (color perception) and feather color.  Carotenoids are important molecules for our health and well-being too.  Worms have negligible amounts of these molecules such that a bird’s eye development and coloration would be hindered.

Third, where do birds find all of these caterpillars?  Not necessarily in your pollinator garden unless that garden also includes trees and shrubs!  Tallamy found that trees and shrubs are the keystones in the yard.  Keystone species (or plants) are organisms that affect an ecosystem in an inequivalent way by increasing its species amount.  For example, beavers can be considered a keystone species because they convert a moving water system to a standing water system that would allow organisms that require standing water (or slow-moving water) to have their habitat needs met to complete their life cycle, such as some fish, dragonflies, mayflies, damselflies, mosquitoes, as well as willows, some grasses, various waterfowl, and even more.  If we removed the beaver, then the other organisms’ habitat needs may not be met taking with it their population.  For the more than 90% of songbirds that require caterpillars as their “baby” food, trees and bushes are able to accommodate the caterpillar load to feed not only one brood of Carolina chickadees but also broods of other species. 

What types of trees or shrubs are the keystones and how many butterfly and moth species can each support?  Here are the big winners:  Oak species support over 550 different species of butterflies and moths; Willows support more than 450 species; Maples support about 300 species with pines supporting over 200 species.  And let’s not forget our blueberries, which support over 290 species!!  There are many other species of trees and shrubs that can be planted but these trees are the major keystones for the songbird populations.  Without these important trees, then they would not be able to find enough food to keep their populations going.  And did I mention, that the range of the Carolina chickadee for finding these caterpillars on these trees and shrubs is only about 160 feet in all directions from the nest (and don’t forget that the adults still need to find seeds, fruits, and occasional insects for themselves in this range too)?

Finally, how can you help support the songbird population by providing for the baby birds?  Add some specific trees and shrubs in and around your home and neighborhood.  You can find a printable list of species of trees and shrubs to plant along with the species of caterpillars they support at:  Try to choose native trees and shrubs to the best of your ability as research shows that to support the populations of songbirds in their ranges for food requires them to have at least 70% natives.

Trees and shrubs contain a lot of biomass to support caterpillars large enough to be fed to birds so it doesn’t mean you have to grow one or two of each species of tree or shrub in your own yard.  Share the responsibility with your neighbors, change the mindset of some homeowner associations, businesses, and cities to grow species that support the songbird food web at all life stages.  We also have to change our mindsets about having trees with holes in their leaves; it can be a good thing.  Have you ever seen holes in your tree leaves but not the culprit?  It might be in the “belly” of a baby bird! 

Kirsten Carlson is a biology teacher at Ivy Tech Community College and the Education and Outreach Coordinator for Oak Heritage Conservancy. Oak Heritage is a nonprofit that protects over 1,100 acres of habitat in southeast Indiana, including old growth forests, native wildflower meadows, creeks, and wetlands. They host hands-on nature programs for the public. Their work is possible because of support from their members, donations, and grants.  Find more about Oak Heritage Conservancy at

All photos by Kirsten Carlson

May 2022: Spring’s Migratory Stories

Photo by Kirsten Carlson

By Kirsten Carlson,

If you ask a fourth-grade classroom to describe a bird, expect to hover for 30 minutes in excitement.  If you ask six more fourth-grade classrooms, you’ll discover patterns emerge in their responses.  One such pattern that emerged across all classes was the migration of birds.  Students know that birds migrate.  When asked if all birds migrate or the reasons for migration, then we’ve got a little bit of silence that we need to fill with the stories of migratory birds.

The latest edition (Spring 2022) of the magazine, Audubon, writer Lauren Leffer wrote, “at least 40% of bird species migrate in some form.”  And that 40% makes for some interesting stories during the spring and fall in our area.  During these times, we can witness many transient travelers and wonder why they take such distant voyages.  A simple answer is that in general, birds migrate to satisfy one or more habitat need.

Habitat needs are those “things” in an organism’s environment required for survival and maintenance of its population.  These needs could be the ability to find food, shelter or nesting areas, water for drinking or bathing, space or territory to obtain other needs, and to find a mate to reproduce.  In our area, if a bird is not adapted to survive our winter’s temperatures or find appropriate shelter or food, it must travel to areas to find temperatures and food conducive to their needs.  For some birds that means they must fly south to the southern United States or further to the forests of South America.  For other birds from the far northern regions, migration to our area for the winter is all they require to meet their winter habitat needs.

If they fly south, they are sure to return as they journey back north.  There are many obstacles birds face as they migrate back and forth.  Those that make the return trip, often to the same area from the previous summer, have navigated predators and storms, avoided deadly window strikes, found appropriate shelter and food, and a mate to raise the next generation of world travelers. 

There are various ways that we can support their journeys as the birds pass through.  We can help by providing natural shelter areas through plantings of native bushes and trees or by leaving snags at safe heights.  We can also place feeders out with a variety of food choices to support the diverse bird populations that migrate.  To avoid window strikes we can place our feeders less than three feet or more than 30 feet from our dwellings.  Additionally, I like to make paper snowflakes to tape on my windows so that birds see the flakes and avoid a collision with the window.  I keep them up year-round and the number of collisions have decreased significantly.  The website,, provides more tips and tricks that we can use to help birds on their journeys as they continue telling their stories. 

If you are interested in tracking some of your migratory favorites, think about joining eBird to contribute to their research and data base for birds.  You can find more about eBird at  Finally, the organization Journey North,,  would also invite individuals to contribute to their data collection to track a variety of migratory organisms across the United States.  Regardless of how you would like to contribute your talents to these migratory wonders, remember that all organisms require habitat needs, just like you and me.  It is through finding habitat needs and navigating obstacles that their stories can continue for generations to come.  Perhaps a migratory songbird, such as the American Robin, will allow you to share its home with you.  Oh the stories you could share.

April 2022: Spring’s Ephemerals

Virginia Bluebells (Martensia virginica)

By Kirsten Carlson,

Ephemeral, what a cool word!  It is an adjective used to describe things with a short-lived nature, such as certain insects, bodies of water, some plants, or perhaps even relationships.   There are many ephemerals that come to mind in spring.  Mayflies (relatives of dragonflies and damselflies) belong to the taxonomic order, Ephemeroptera.  By definition, mayflies could not be more aptly described as they live for a very short time, some for only a few minutes and others for a few days.  Mayflies emerge from their freshwater aquatic stage from spring through summer (depending upon the species). 

But mayflies are not the only short-lived organisms we see in spring.  There are many plants that emerge in spring to complete their life cycles in such a short time as well.  Indiana native spring ephemeral plants require conditions that are cooler, typically moist (due to spring rains), and sheltered sunlight.  Many of our spring ephemerals are woodland species that take advantage of the short length of time they have access to sunlight before the leaves on the trees begin to shade them out.  By June, they may have already died back to the underground to wait out the warm, dry summers and autumns before emerging again the following spring.  A hiker exploring one of Oak Heritage’s preserves in the early spring might be rewarded by one or more ephemeral wildflowers common to southeast Indiana including Virginia Bluebells (Martensia virginica), Dutchman’s Breeches (Arisaema triphyllum), Toadshade (Trillium sessile) and Cutleaf Toothwort (Dentaria laciniata).

If you are interested in adding some spring ephemerals to your home garden, please refer to this quick reference guide:  Native Spring Ephemerals | Illinois-Indiana Sea Grant ( (  It includes some companion plants as well.  If you would like to make your ephemeral flowers last a little longer, consider pressing the flowers to create notecards, gift tags, bookmarks, or framed art.  You can easily make a press or just use cardboard, newsprint, and those old heavy textbooks or encyclopedias you may still have.  If you plan to press flowers, just take what you need so that you leave enough to maintain or increase the population naturally.  A good rule of thumb is to take only a flower or two if you can find ten other plants nearby.

Take walks this spring into the woods to witness nature’s progression of ephemerals.  Make haste as they soon disappear back underground.  If you are unsure where to venture, remember that Oak Heritage has many wooded preserves you can walk from dawn to dusk. 

March 2022: Spring Reveals Nature’s Symphony of Resilience and Renewal

By Kirsten Carlson,

Resilience, that’s a big word.  In general, it can be defined as the ability to recover, or spring back from change (typically difficult ones).  Nature demonstrates resiliency when we take part in her symphony of resilience and renewal.  Each season, likened to a movement in a symphony, has a different melody that reflects its theme.  The first movement, spring, is that of resilience and renewal.  During spring, we notice the ways in which organisms, communities, and ecosystems awaken in response to winter’s harshness.  Part of nature’s ability to recover or spring back from winter (movement four) is in its preparations during autumn (movement three). 

This first movement of Nature’s Symphony is a time when we also demonstrate resilience and renewal when we “spring back” from winter’s cold and darkness.  As the daylight lengthens, we begin to see trees budding out, grass greening, birds singing, flowers emerging, and bees buzzing.  The warmed soil giving rise to the awakened metabolisms of microbes and other soil organisms, adds to the distinct scent of spring.  This organic symphony lights the senses giving us feelings of peace and renewal in much the same way as the neurotransmitter, serotonin, provides the runner’s “high.”  As we become those “busy little bees” in spring, we cannot help but think and feel a sense of rejuvenation in our new spring moods and thoughts.  We tap our toes in tempo to nature’s resilient masterpiece.

Italian composer Antonio Vivaldi, composed four concertos, called The Four Seasons.  The proceedings of the events during each season inspired Vivaldi to write these concertos.  Spring is the first of his four concertos.  Why did Vivaldi start with spring?  Life begins anew in spring.  As you listen to Spring, you cannot help but feel his symbolism of nature’s renewal in musical form.  Keep listening and close your eyes, imagining the melodic events as spring progresses to summer.  You transform as you become a part of his concerto and the first movement of Nature’s Symphony. 

This spring, find a place outside in nature, where you can become a part of Nature’s Symphony of Resilience and Renewal.  Close your eyes as you quietly listen to Vivaldi’s Spring concerto.  Let your senses take in the surroundings as you bathe in the aura of spring.  Following Vivaldi’s concerto, listen to the  movement of Nature’s Symphony and ponder your own resilience and renewal.  Write your own spring concerto as you “spring back” from winter’s bleakness.  See where it takes you.


February 2022: Spring is just a peep away

By Kirsten Carlson,

And I’m not referring to the sugary sweet treat (but they too will be coming to a shelf near you).  There are some rituals in February that many of us look forward to as a signal that spring will momentarily arrive.  One that brings excitement to my heart is the sound of the spring peeper!  A little frog no larger than an inch; its trill of a call can be heard in mass when you pass by a watery area, such as a vernal pool or roadside ditch.  Try to walk up to the pool or ditch to spy the little ones and you hear the stop of the calling.  You can’t sneak up on those sly peepers. 

Spring peepers are ubiquitous throughout Indiana.  You can find them in upland forests, meadows, wetlands, and even in the suburbs if there is a source of water to lay their eggs and that persists long enough to allow the tadpoles to become froglets or adults.  Frogs and toads are unique in their dietary requirements.  As tadpoles they are herbivores (eating leaf litter, algae, and other plant matter), but as they continue to develop limbs and other body parts indicative of a frog, they require a diet higher in protein and fat, consequently, they enter the omnivore stage of life (adding tiny little aquatic insects or pieces of “meat” they find in the water).  Then as an adult on land, they are carnivores (finding small insects, worms, spiders, snails, mites, etc.) to dine upon.  If you were shrunk down to an inch, what could you find to please your palette?  Considering that these little frogs are active when temperatures a just above freezing, their prey also must be active above freezing as well.  Spiders, mites, and snails are a good choice for a warm Valentine’s Day dinner.

During the cold temperatures of winter, you might be able to find them in a torpor stage under leaf litter, logs, or holes in trees; a good reason to keep your leaf litter and logs lay throughout the year if you have them near your home.  The adults seek shelter in these moist areas as well during the hot dry spells of summer.  Spring peepers have adaptations that allow them to withstand the cold temperatures in the winter by concentrating sugar in their cells and in the summer, they can also survive with a reduce amount of water in their cells (when water becomes available, they can absorb it).

The scientific name of the spring peeper is, Pseudacris crucifer.  The genus, Pseudacris, means a false locust, referring to the cricket or locust-like call they make.  The species name, crucifer, means cross-bearer, referring to the cross on its back, which we use as a main identifying mark (they can be confused with chorus frogs and cricket frogs).

This February, see if you can’t find the natural signal that spring is around the corner by listening for the call of spring peepers nearby.  Take a walk in the woods, by a pond, or other watering hole, and listen carefully for the sound of the peeper.  If you need some help, check out this website by the Indiana Department of Natural Resources to learn how to identify frogs and toads by their call:  Oak Heritage Conservancy has many preserves in which spring peepers call home.  Feel free to master your frog and toad calls at one of our preserves.  You can find a preserve near you at


January 2022: Finding the Stories in Nature’s Calendar

By Kirsten Carlson,

Tristan Gooley, an expert on natural navigation, wrote in his book, How to Read Nature, “Almost everything that our senses pick out is eager to tell us a story that will help us more vividly read nature” (2017, pg. 101).  Our senses and their meanings lead us to make connections, which Gooley states, “…that these finer connections are out there, everywhere, waiting for us to find them.  The important thing for us to remember is that nature is a set of keys and interlocking connections” (pp. 101-102).  How do we become aware of these keys to unlock the connections?  Perhaps we can observe the smaller parts of nature throughout the course of a year and then think about how the parts connect to unlock natural cause/effect patterns or connections.

For example, each day, the sun rises in the morning and sets in the evening.  But does it always rise and set in the same direction from the same place?  No, it rises and sets just a little bit differently each day when observed from the same focal point.  And if you keep track of this change over the course of a year, you would see a great difference in its time and direction.  During our winter, the sun rises in the southeast and sets in the southwest.  Could you predict its directions of rise and set in six months?  Take a guess.  Then, set out to track the sun’s direction of travel between January and June by observing the little daily changes measured each day or week.  How?  You can mark a window, its sill, or place objects, like stones, outside that won’t get disturbed.  To observe the change, stand in the same place each day or week and make a mark or place a stone that points in the direction of the sunrise or sunset.  After measuring for one year, you have a calendar based upon natural phenomena, not man-made time pieces.

Can we make any connections to nature with our study of the sun?  As you continue to measure the direction of sunrise and/or sunset, make some natural observations.  If you feed birds, do you find a pattern of the species of bird who visit at certain times of the day?  If so, do you think it is related to the sun?  If so, could these behaviors be interrelated to the sun calendar or an effect based upon the sun (such as temperature, amount of light, angle or intensity of light)?  Once you find these interconnections, you’ve got the beginnings of a story and more interconnections!  What about the songs of birds, or the timing of plant emergence or flowering?  Notice anything when you align your senses and observations with your natural sun calendar?

Making a natural calendar allows you to find the keys to unlock their interconnections to create your story of place and time.  Each living kind responds to light (and its effects) in inimitable ways.  And you can uncover these ways with repetition.  If marking the sunrise and/or sunset each day or week is a little daunting, try watching a tree (as it doesn’t move around) over the course of a year. Observe it, take measurements, or pictures.  You actually might make some interconnections to the sun.  Life abounds with numerous opportunities to make a year-long story of discovery.  Choose something that is easy for you to observe and record change.  If you need a little help, take a look at the book, That Tree, by Mark Hirsch (2013).  Hirsch used his phone’s camera to document a bur oak tree out in the middle of a cornfield.  Imagine the story his photos of that tree revealed.  You can learn about that tree’s story at  And if you are interested in bur oaks (or oaks in general), read Aldo Leopold’s essay, “Bur Oak” in the chapter, “April” or “Good Oak” in the chapter, “February” in A Sand County Almanac.  Leopold has stories to tell as well based upon nature’s calendar.

As a final thought from Gooley, “Once we see the way all of nature is interconnected, we have a way of turning time in the fresh air into a richness of experience” (pg. 102) just as Hirsch and Leopold did.  Let this new year of 2022 be one of following nature’s calendar of interconnections to create a story of meaningful interconnections in your place and time.