How do our winter birds survive?

North Winds, Freezing Temps
No hats, gloves, nor heated homes.
How do our winter birds survive?

  • In the fall, winter birds add on a layer of fat by increasing their normal intake of food. Some of them also grow more feathers.
  • Because birds have a higher metabolism than we do, they also have a higher body temperature. The average is around 105 degrees.
  • Their feathers equip them with a very effective form of insulation, and fluffing out their feathers enhances the feathers ability to insulate.
  • Birds have an oil gland just above their tail, they use this oil to waterproof their feathers, while adding more insulation.
  • Specialized scales cover their legs and feet, minimizing heat loss.
  • Their ability to constrict blood flow to their extremities, enables them to control the temperature in their legs and feet, without effecting the temperature of the rest of their body.
  • To protect their legs, they will stand on one leg or cover both by crouching down.
  • If it is a sunny day, birds take advantage of it by exposing the largest part of their bodies, their backs, to the sun. Then they raise their feathers just enough to expose both skin and feathers, thus allowing them to absorb the sun’s warmth.
  • During the night, small birds will sometimes share body heat by crowding together.

So don’t be surprised after an especially cold night, to hear bird chatter in the morning.

Reference: Chicago Audubon Society

With all these survival strategies, birds can still use a helping hand. Feed them and provide water, if you can.


A Deer’s Ears: A Natural Satellite Dish

Leisurely wondering the sidewalks and paths of Wolf Road Prairie, you might be lucky and encounter a deer. If the deer is at a safe distance from you, chances are that the deer will hold its ground, steadily staring right at you. Maybe it is sizing you up, perhaps it is just curious. Such an encounter allowed photographer Vito Martinez to capture the beautiful dignity of this Wolf Road Prairie deer. Notice the size of its ears and their taunt alert position. Those attractive looking ears are part of the deer’s defense mechanisms.

The next time you spot a deer at a distance, one that is not paying any attention to you, throw a small object to the left or right of the deer. Standing still, the deer will rotate its flexible ears independently of one another without moving its head. These large funnel shaped ears can effectively scan the air, tuning into sounds all around it. This enables them to pinpoint both the distance and direction of a sound with amazing accuracy. Hunters believe it is the out-of-place sound for which the deer are listening. They will ignore the familiar sound of a squirrel or a raccoon. Field studies have led naturalists to theorize that it is also an effective way for the deer to keep tract of one another. If that is true, then the noises they make while moving around is their own form of Twitter.

Reference: University of Georgia’s Forestry Service 2018.

Amazing Crustaceans . . . on the Prairie?!

Recently, prairie volunteer Greg Jerzyk captured a rare sight with his camera on the prairie–a tower crayfish! Many people don’t know that a prairie contains such creatures. It speaks to the incredible complexity of this now extremely rare and endangered ecosystem. Below is a first time digital reprint of STPS Director Rita McCabe’s article about prairie crayfish. We hope you enjoy!



Prairie Crayfish ( Procambarus gracilis )


Few people who study prairies ever claim to be prairie experts. Years of observation have taught them that the prairie’s complexity is slowly revealed over extended periods of time by close, recorded observations of its flora and fauna as well as through studies of their complex interconnectedness. A good example of this interconnectedness can readily be seen by a close look at Procambarus gracilis, a seldom seen prairie denizen, who nevertheless benefits his habitat.


Since crayfish must keep their gills hydrated, they are usually associated with streams, rivers, and lakes. While it is true that Wolf Road Prairie has wetlands, it is also true that in many years the wetlands shrink or dry by midsummer. Yet our crayfish persist year after year. So how do they avoid dehydration? The answer lies deep below the surface past the water table. Using their pincher-like claws, Procambarus gracilis tunnel down past the groundwater table creating safe burrows or chambers that satisfy their need for water.


The extensive observations and analysis of two University of Illinois at Chicago researchers, Dennis Nyberg and Paul Orlando (2005) have produced significant information about their habits, and effects on prairies – important data for the preservation of remaining populations. As with all long established habitats, the interplay of flora and fauna add to the stability of the ecosystem, and Nyberg and Orlando were able to illustrate a specific benefit the crayfish provide. The digging abilities of prairie crayfish enable them to excavate deeper than ants, worms, and voles, and in doing so bring up to the surface clay soil from depths as far down as 6 feet. Nyberg and Orlando’s analysis of the clay mounds or crowns that often surround their burrows registered soil rich with minerals. These minerals had overtime leached from topsoil as it was percolated downward by the force of heavy rains. Thanks to their study, we now know that by excavating a new home, crayfish return some of these leached minerals to the surface.


* * *


These small rusty brown prairie crayfish were once numerous in the Chicago area. A vivid picture of their abundance was described by one Milton Hans in an interview documented by the Northbrook Historical Society in 1956. In recalling what it was like to grow-up in the early 1900’s, Hans described how as a barefoot boy driving the family cows to pasture, he observed: “After heavy rains, the ground especially the road, would almost be covered with crayfish.” He could not recall what happened to this natural bounty, but only remembered that at sometime he did not see them anymore. We now know that many of the prairie crayfish populations were destroyed by the draining of wetlands and the destruction of prairies. Fortunately, pockets of prairie crayfish still persist in many preserved prairies including Wolf Road Prairie and in suitable undeveloped pockets of land.


Crayfish add to the diet of wading birds, raccoons, snakes, and turtles. Their own diet consists of snails, insects, plants, and scavenged carrion. Growing to a length of 2”to 3”, these crayfish live an average of 3 to 4 years. Each burrow is occupied by a single adult who will spend most of its time there. When they do venture forth, it is usually at night or after a heavy rain.


In the spring of 2012, steward John Banaszak pointed out a female crayfish making her way down a path to a group of volunteers. You can imagine their surprise, when John showed us a living raft of immature crabs ( 20 if counted correctly ) clinging to their mother’s abdomen. John believed that most likely she was taking her young to the wetlands where they could fend for themselves. Upon reaching adulthood, the new generation instinctively searches out a suitable area for the excavation of their own “deep tunnel.”


More recently ( 6/27/14), volunteer Greg Jerzyk, spotted a prairie crayfish aka tower crayfish while working on the prairie. He was quick enough to capture the adjacent picture as the crayfish crossed a prairie sidewalk. If you are out and about on the prairie and observe a grayish-white crown of clay around a small hole, then you have discovered the entrance to a crafyfish chamber. Better yet come after a heavy rain, and you like Milton Hans in the early 1900’s and John and Greg in the early 2000’s, might encounter the excavator.


–R. McCabe

Amazing Moths at Wolf Road Prairie

Our resident photographer Fidencio Marbella has captured yet another amazing sight on Wolf Road Prairie in his beautiful action shots of two different species of moths.

First up is the Hummingbird Clearwing Moth (Hemaris thysbe), named so for its common mistaken identification as a hummingbird.


Next up are Snowberry Clearwing Moths (Hemaris diffinis), with their gold color and black band.


It is always wonderful to see the incredible kind of life inhabiting Wolf Road Prairie. Luckily, avid photographers like Fidencio capture these glimpses into the rare prairie ecosystem for everyone to see!

Learn About Wolf Road Prairie on Earth Day Weekend!

The following is an article written by STPS Director Mary Cray. It has been used for many years as a handout at STPS events but now is online! Please take a look on this Earth day weekend to learn more about the ecosystem STPS has helped conserve for nearly 40 years.

“I have amazing news for you.

Man is not alone on this planet.

He is part of a community, upon which he depends absolutely.

Have you ever had any suspicions to that effect?”



The prairies that exist today on our continent are as endangered as rainforests on other continents, perhaps more so. The Wolf Road Prairie was affected by the same geological history as all North American prairies. Contained here is the most fertile soil on earth. Its black soil was maintained by the decomposition of the deep roots and extensions of its plant life. This could not have been done without the vigorous mixing of earthworms, rodents, and insects. It has adjusted to cold winters, hot summers, periods of ample rainfall, and cyclic droughts.



When visitors enter this area from the south, they encounter a unique savanna ecosystem. Very soon on the path they will encounter a pre-settler burr oak among many other burr oaks of this savanna. This area has its own unique plant life. Its openness contrasts to the closed forest across the street. It is more that just an access to the wonderful mesic prairie down the path. The contrast belies a past struggle to keep its identity as evidenced by its crusty bark and thick taproots, survival adaptions to its neighboring prairie ?res. Nevertheless, it does present a dramatic entrance to the tall grass prairie. Standing on the edge of these two ecosystems, one is struck by the differences in temperature, wind, smells and sights. Each of over 300 species of native plants has its own blooming cycle attracting many species of birds, butter?ies and insects, some of which can be found only on the prairie.


As you travel further down the path, your senses are treated with even more diversity. The wetlands are host to numerous plant and animal species. Among the cattails and sedges are found cover and sustenance for raccoon, deer, red fox, migrating and seasonal birds. This fresh water marsh was formed by an iceberg left by a glacier. The marsh is a complex ecosystem. It serves a myriad of functions: ?ood storage and conveyance; groundwater recharge; erosion reduction and sediment control; pollution control; wildlife habitat; recreation and education.


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When walking through this prairie one is struck with a sense of history, both geological and historical. There is nothing more American that the prairie. All cultures who have lived in this area, whether Native American or settler, were profoundly affected by this prairie. We, the visitors of the 21st century, seeking to keep this land secure, are grateful to be a part of that vision that unites all that went before.


–Mary Cray

Director, STPS