In the News

Friends Alaska Trip 2017

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Fourteen members of the Friends of Retzer Nature Center recently flew to Alaska on a fourteen day natural history tour of the state. The trip was led by Board member David Block, who has organized travel programs in Alaska many times.

The trip included overnight stays at Sitka, Juneau, Skagway, Denali National Park, Valdez and Seward. Our first stop was Sitka, where we visited Sitka National Historic Park, toured the historic Russian Bishop’s House, learned about the Tlingit culture and their famed totem pole heritage, and hiked a bit in the Tongass National Forest.

We then traveled by “blue canoe” ferry to Juneau and on to Skagway, where we enjoyed whale watching and photographing beautiful scenery along the Inside Passage waterway. While in Skagway, we strolled the restored 1890’s gold rush era town and traveled across White Pass into the rugged interior of British Columbia and the Yukon.

The first half of our trip ended in the capital city of Juneau, where we toured parts of the historic downtown area and visited the Mendenhall Glacier nearby. We then flew from Juneau to Anchorage to begin the second half of our journey in Anchorage. The remainder of our itinerary included a knowledgeable local driver, Steve Helgeson, and use of his customized tour minibus.

Our trek through southcentral Alaska began with a drive north to Denali National Park. Along the way, we stopped at the Iditarod National Headquarters in Wasilla, and learned about the history of the famed dogsled race. We all had a chance to nuzzle sled dog puppies, and some took a dogsled ride pulled by an Iditarod husky team. Then, nearing Denali National Park, we were wowed by cloud-free views of the massive Denali summit, and enjoyed spending a night in cabins along a scenic creek. The next day, our bus tour of the national park included nice sightings of grizzly bears, caribou, and a moose with babies; Polychrome Pass and views of Mt. Denali and the Alaska Range were memorable highlights of the park’s geology.

After leaving Denali, we headed back south to the oil pipeline port town of Valdez, stopping along the way for lunch in the scenic Matanuska glacier valley. Later, we viewed the Wrangell-St. Elias Range, crossed the rugged Chugach Mountains, and photographed the intriguing Alaska pipeline, the receding Worthington Glacier and the impressive Keystone Canyon waterfalls. We overnighted in Valdez before taking our final ferry ride through Prince William Sound to the Kenai Peninsula.

Our lodging destination on the Kenai Peninsula was coastal Seward, home of the Alaska Sea Life Center gateway to Kenai Fjords National Park. At the sea life center, we were able to view puffins, sea lions, harbor seals, and other marine critters.  A newly rescued baby walrus drew a lot of viewer attention. Near Seward, the group was able to witness a sockeye salmon run up a local river and several enjoyed a hike up to Exit Glacier. The final day of the trip included a boat tour of tidewater glaciers in Prince William Sound. The highlight was Beloit Glacier, which calved four times into the sea as our boat idled nearby.

Filled with fine memories and a bit of travel fatigue, the Retzer group arrived back in Wisconsin on the Fourth of July… a patriotic end to a tour of America’s grandest frontier.

Here is a link to a photo album from the trip.

Friends of Retzer Receive Donation From Local High School

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In December 2016 we received a wonderful donation to the Friends of Retzer Nature Center from Waukesha West’s Interact Club. They held a fundraiser and we were chosen as their recipient. A check for $1280 was presented to the Friends from Patty Corrao (advisor) and Waukesha West students. We were very surprised at such a generous donation and will be put to great use with continuing support of Retzer Nature Center.

Also pictured are Friends Board members: Jerry Strom, Lyle Drier and MK Kelly.

Planetarium Premiers New Video System

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For 39 years, the School District of Waukesha’s Charles Horwitz Planetarium has been using slides for its basic form of media projection.  This fall, at Retzer Nature Center’s Apple Harvest Festival, the planetarium will celebrate the beginning of its 40 year with the premier of a completely new digital sound and video technology.

This entire $330,000 project was made possible by the generous donations of the Friends of Retzer Nature Center, the School District of Waukesha and the supportive public and private fund-raising activities promoted by the “Friends of the Charles Horwitz Planetarium.”

The planetarium’s new equipment called Digistar-6, will be combined with a new 7.1 surround sound system to transform the planetarium dome into an incredible immersive experience for visitors. Digistar-6 consists of a high-powered “host” computer and four, high-resolution “graphic processing” computers.  The 4,000 pixel presentation is made possible by sending the rendered graphic images through two new laser-phosphor video projectors.

Without leaving their seats, audiences can now trek through a rain forest, climb the heights of Mt. Everest, explore the depths of the world’s oceans or experience the weightlessness of space.  Beginning in September, a new library of school and public programs will be available.  For a complete list of programs, please see Waukesha County’s Environmental Guide, or visit the Charles Horwitz Planetarium website:

Parents, Tell Your Children: Fluttering, Flirtations, Fairies

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(Excerpts below are from an article on butterflies entitled, “Parents, Tell Your Children: Fluttering, Flirtations, Fairies” which was authored by Retzer naturalist Karen Mann and first appeared 30 years ago in the May/June 1992 “Center Line” issue. In this article, she aptly describes in detail the morphology, physiology, adaptation, reproduction and life cycle of butterflies.)

On behalf of Retzer Nature Center, I would like to acknowledge our appreciation to six families for their age old contribution. Most of us anxiously await their arrival: the Hesperiidae, Papilionidae, Pieridae, Nymphalidae, Rionidae and Lycaenidae, known together as the Order Lepidoptera (from the Latin “lepis” meaning scale and “pteron” which means wing). It is the scales, covering the wings of butterflies, which contain the pigments that give them their dazzling colors. Arrangement of the colored scales produces the distinct patterns used to tell individual species apart. These six families of butterflies account for roughly 18,200 species, including swallow-tails, sulphurs, skippers, metalmarks, angelwings, checkerspots, commas, and the gossamer wings such as hairstreaks, elfins and blues. Their secret to success (evidenced by their abundance and diversity) is their wings. The mobility afforded these animals allows them to establish large territories and breeding areas. This puts them in contact with the needed resources which provide them with food, cover and space.

Migration of butterflies offers an additional strategy for success. Flight allows butterflies to cover as many as 1100 miles in only a few days.

There is more to this success story. Numerous adaptations offer further points of study and observation. We can look further at wings. Butterflies communicate by means of their colored, patterned wings. Bright colors warn predators of the ill-effects associated with consumption of the butterfly’s sometimes poisonous body. (Many butterflies mimic the colors and patterns of poisonous or foul-tasting relatives to avoid predation themselves, however palatable they may be). Patterns such as owl spots or eye spots may frighten some predators away. Other patterns deflect a predator’s attack from vulnerable body parts to modified scales which appear antennae or tail-like.

Some butterflies confuse predators by folding up bicolored wings, hiding the brightly colored upper surface and exposing a camouflaged lower surface. These camouflage patterns blend with the host plants the butterflies often associate with. A bird may be attracted to butterflies’ bright colors. By folding up their wings many butterflies can quickly “disappear”, confusing the predators and saving their own lives. Another technique of camouflage is that of having transparent wings. Transparency allows the butterfly to blend completely with any background, since the background shows through.

Wings also function as a furnace. Butterflies bask in the sun on leaves, on the ground or on tree trunks. The colored scales absorb heat, warming muscles and nerves before flight. As the seasons change, successive generations of offspring produce varying shades of color. Lighter color in summer helps the summer-hatched; the wings reflect sunlight, which keeps them from heating up. In cooler weather, those hatched are darker, absorb more sunlight, and keep warmer. Some wing pigments are undetectable to humans (and other predators). These pigments reflect ultraviolet light which other insects can detect. This offers a mode of species-to-species communication, something like the flashing of mirrors used long ago.

Energy. A butterfly is a perfect example of what would appear to be a never-ending bundle of energy. Constantly moving, searching, fleeing, it burns energy, but from what source?

Butterflies are equipped with a long mouth structure called a proboscis. Usually coiled up under the head, this can be extended into flowers to probe for and extract the sweet nectar deep within. Few butterflies incorporate any form of protein into their diet. A few tropical species extract amino acids and proteins from seeds. Most burn the easily used carbohydrates derived from nectar. The proboscis is also used to apply saliva to dry surfaces. This dissolves salts left after evaporation, which are then consumed.

Reproduction in butterflies is as varied as are the species. The most significant communication between butterflies is that which is done for attracting a mate. Color is important in this. Males also have specialized scales (androconia) on their wings which dispense scent from glands within the wings. This scent rather intoxicates the female during courtship and mating.

When food is available and fat reserves are ample, the females produce eggs of varying, odd shapes and sizes. Over the course of their lives, females lay 100 – 500 of these unusual eggs. Patterns in which eggs are laid are just as diverse. Eggs hatch, and larvae emerge, more familiarly known as caterpillars. They proceed to gorge themselves, first by eating their egg shells and then by eating the leaves of the host plants they live on. As they grow, their skin tightens. They swallow air to puff themselves up. This causes the skin to split, and the caterpillar emerges. This process, called molting, repeats about four times. Caterpillars between molts are called instars. The final molt produces a hard outer layer, the chrysalis, Inside, the caterpillar changes to a butterfly. Although temperature and moisture trigger development, it is hormones that regulate this miracle of metamorphosis.

Adults emerge fresh, moist and crumpled. Soon after stretching and drying, they take to the air. They flutter about in search of a mate and a place to lay their eggs. They eat, do their best to escape predators, and, eventually, they die.

At least one Wisconsin butterfly species has already become extinct, the Xerxes Blue. Others appear on the Wisconsin Endangered and Threatened Species List, (endangered – Powesheik Skipper; threatened – Swamp Metalmark, Frosted Elfin, Regal Fritillary). As other animals are affected by destruction and manipulation of habitat, so are butterflies. Forests, fields, prairies, wetlands; butterflies have found a place in most habitats all over the world. These areas must be monitored and preserved, not only for butterflies but to maintain the balance of nature (with which we too are interconnected).

Our plans at Retzer include development of a butterfly garden in the area outside the existing greenhouse. The Waukesha Public Library has books available for those interested in starting their own butterfly garden. One of the most important factors to consider is to provide plants (for food and cover) for both caterpillars and butterflies. These might include pussy willow, lilac, phlox, butterfly weed, fernleaf yarrow, black-eyed susan, creeping St. Johns wort, cinquefoil, coreopsis, cherry, plum, dill and carrot. Planning is required to determine which species of butterflies are native to your area and which plants are used by them.

I invite you and your family to come and enjoy the company of these butterfly families.

Karen Mann

Bird Sightings (June 16, 2017)

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The following 36 species were seen during the bird hike on June 16th at Retzer Nature Center:

Orchard Oriole

American Robin

Red-winged Blackbird


Song Sparrow

Field Sparrow

Eastern Bluebird

American Goldfinch

American Crow

Eastern Kingbird

Northern Cardinal

Brown-headed Cowbird

Black-capped Chickadee

Northern Flicker

Sandhill Crane

Barn Swallow

House Wren

Tree Swallow

Clay Colored Sparrow

Chipping Sparrow

Savannah Sparrow

Henslow’s Sparrow


Blue Jay

White-breasted Nuthatch

Eastern Wood-Pewee

Indigo Bunting

Orchard Oriole male and female

Ruby Throated Hummingbird

Yellow Warbler

Gray Catbird

Common Yellowthroat

Rose-breasted Grosbeak

Turkey Vulture



Eastern Phoebe

Woodside at Retzer

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Shared by Woodside Elementary Teacher, Peter Dargatz.

The 2016-2017 school year marked the beginning of a creative collaboration between the staff and volunteers of the Retzer Nature Center and the nature kindergarten program at Woodside Elementary in Sussex. Over the school year,  eight experiences were split between the nature center grounds and the elementary school’s outdoor learning area.

Following the natural cycle of the seasons and connecting to the school’s curriculum, the students engaged in hands on experiential learning opportunities that built on prior lessons, culminating in a special nature celebration event in June where families were invited to the Retzer Nature Center to experience their child’s growth firsthand. Through parent surveys sent out by Woodside’s kindergarten team, the collaboration was very well-received by the families. Both staff at Retzer and Woodside look forward to not only continuing this collaboration, but hopefully expanding it as well.

A Place for Coyote

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(Excerpts below are from an article on coyotes entitled, “A Place for Coyote” which was authored by Retzer volunteer naturalist Maureen Patton-Gross and first appeared 30 years ago in the Mar/Apr 1987 “Center Line” issue. In the article, she clearly distinguished coyotes from other canids based on their size, color, tail, voice, tracks, and scat.)

Evidence of coyotes living in southeastern Wisconsin has been mounting steadily, which logically leads to the question of why the coyote has returned to this area after an apparent long absence. In order to address this issue, the coyote’s needs must be analyzed.

As with other kinds of wildlife, the coyote depends on three basic requirements from the environment. These requirements are water, shelter, and food. The coyote is often associated with arid regions of the West, and has learned very cunning ways to find water in these marginal areas. However, water sources have never been in short supply here. The glaciers left us many lakes, rivers, springs, kettle ponds, and various kinds of wetlands.

Shelter has been a more pronounced problem for the coyote here. In the past when only Native Americans lived here, southeastern Wisconsin was a region where the tall grass prairie met the hardwood forests. This environment supported much wildlife, including both the coyote and timber wolf. The indigenous people of the past lived side by side with the wild canids without conflict. They were intimately familiar with coyote behavior and habits. The ways of the coyote were often woven into their folklore and mythology. The coyote was well respected by Native Americans for his cunning, speed, and intelligence.

When Europeans arrived on the scene, drastic changes took place. The tall grass prairie was viewed as tillable, fertile farmland, and the hardwood forest was viewed as the enemy to be cleared with much labor and sweat. Eventually the landscape changed into a monotonous repetition of farmsteads all with large fields of similar crops. As a result, there was little shelter left for coyotes or prey species. Not only did the European change the landscape, he also referred to the coyote and the timber wolf as “ravenous beasts” which attacked his livestock. Because of this attitude, bounties were established. “Wolf” hunts became a favorite social sport. Unregulated hunting and trapping were the rule. By the turn of the century, southeastern Wisconsin was devoid of much of its former wildlife.

However, as time went on, the landscape again began to change. Residents began to realize the decline in wildlife and recreational land. This resulted in a demand for public land and hunting regulations. Bounties were slowly abolished. Farming practices changed also. The government encouraged farmers to grow wind breaks, to take some fields out of crop production, and to leave erodible land untilled. In addition, some farms were abandoned due to financial stress. The result of these activities has been the creation of thousands of acres of old field and brush habitat ideally suited to the coyote.

This old field and brush habitat also provided shelter for prey species, which leads to the discussion of coyote food requirements. Because small mammals are the mainstay of the coyote, this canid is a predator. The coyote, though, is also an omnivore (eating both plants and animals). The coyote is an opportunist, and this adaptable canid will eat fallen apples or spilled corn from harvest operations. This animal is not a finicky eater, and will eat anything from leather straps and wool rugs to crayfish, pigeons, and deer. Coyote impact on deer is minimal, however, because the canid is not as powerful or as socially organized as the timber wolf. The coyote has few opportunities to kill large game without risking injury or death. While the timber wolf specializes in large mammals, the coyote specializes in small mammals. High on the list of coyote preferences are woodchucks, rabbits and mice of all kinds. Because of these food preferences, the coyote is very beneficial to the crop farmer.

It is evident that at least some sections of the local environment support the coyote well with the basic requirements of water, shelter, and food. The most ideal situation for a coyote is an area where several different ecosystems merge. For example, looking out over the high hills at Retzer Nature Center, a mosaic of woodlots, old fields, prairies, croplands, wetlands, and streams can be seen. Such diversity provides a habitat rich in large populations of small mammal species. This in turn provides the coyote with a dynamic yet stable food base while also providing the coyote with cover from his primary predator – man.

To the biologist, the coyote is an indicator of a varied and healthy environment. Presently most residents seem to have a curious, neutral, or favorable attitude toward the coyote. It is these very attitudes toward this canid and toward regional land use that will ultimately determine the future status of the coyote.

Elusive Creature Returns

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(Excerpts below are from an article on coyotes entitled, “Elusive Creature Returns” which was authored by Retzer volunteer naturalist Maureen Patton-Gross and first appeared 30 years ago in the Jan/Feb 1987 “Center Line” issue. In the article, she clearly distinguished coyotes from other canids based on their size, color, tail, voice, tracks, and scat.)

“There is an elusive creature living here who is a master at escaping human detection. On moonlit nights his shadow slips silently across the snowy southeastern Wisconsin landscape unnoticed. His nocturnal call is sometimes heard as a distant, mournful requiem causing friends to huddle closer to the campfire. His larger relative – a resident of the Great North Woods – is the majestic timber wolf.  In scientific jargon he is known as Canis latrans but in the vernacular he is known as the coyote.

Though seldom seen, especially during daylight hours, the following description will help identify this animal. The typical adult coyote ranges in weight from 20-35 lbs.  The average height at the shoulders is about 20 inches. The ears are prominent, erect, pointed, and reddish in color. The muzzle is long, narrow and snuff brown to cinnamon brown in color. The forehead and cheeks are paler, mixed with gray and black. The upper parts of the body from the neck to the tail are coarsely mixed with gray and black, with a general tone of gray to cinnamon gray. There is a blackish line down the back. Underparts are buffish.

Often observations of coyotes are brief and the animal can be confused with other canids. However, there are ways to recognize the differences by general size and the tail… A coyote is somewhat larger than a red fox and does not sport a large white tip on the end of the tail. Often the coyote tail has a black tip. Although the gray fox has a black tail tip, it has a noticeable black stripe all the way down the top side of the tail and is considerably smaller than a coyote. Also, red foxes and gray foxes carry their tails straight out while running, as do wolves. The coyote frequently holds its tail down low while running. Because of the great variation in size and color of the domestic dog, it can easily be confused with the coyote. A dog, however, tends to carry its tail curled upward and its tail is much narrower than the bushy tail of a coyote.

Though normally silent, the coyote occasionally communicates audibly. His voice is higher pitched than wolves and many dogs. The characteristic coyote call consists of a vibrant yapping howl that leads into a long, broken, shrill scream. The complete repertoire of coyote vocalization is varied and complex.

Since direct observations of the coyote are infrequent, the best way to detect the presence of a coyote is through certain clues of what might be coyote signs. Coyote tracks are the most common sign found. Typical of canids, the front footprints are larger than the hindprints… Red fox tracks are generally somewhat smaller and, under good tracking conditions, have a ridge impression in the heel of the print. Gray fox tracks are smaller yet and resemble large house cat tracks with claw impressions.

Although some dogs leave prints within the size range of the coyote print, coyote tracks are longer and narrower. For example, a coyote track would typically measure 2 ½ inches long by 1 ¾ inches wide, while a dog track of similar size commonly measures 2 ½ inches by 2 ½ inches. Often the heel pad of a dog is larger and more pronounced.

Scat (droppings) is another kind of wildlife sign that biologists use to confirm an animal’s presence. Coyote scat can be confused with that of a dog. Coyote scat is generally about 4 inches long but size may vary. Dog scat is recognized by the content of dog food, whereas coyote scat often contains fur and bone. At times coyote scat is very dark indicating red meat has been eaten. It may also contain vegetable matter or even insects.”