Saturday, April 21, 2012


What are the signs of spring that you watch for each year? Birds returning and flowers blooming, insects hatching, frogs calling, chipmunks scurrying…these are all milestones on the way to our brief summer of warmth and sun.

One of my favorite early-birds is the Eastern Phoebe. These dusky brown flycatchers spend the winter in the southern U.S. or Mexico, and they are one of the earliest of our feathered friends to return each spring. They have learned to tolerate a human-altered landscape quite well, and often build their moss and mud nests on bridges, barns, and homes.

The first time I noticed a Phoebe as a beginning birder I was completely baffled. They do not have striking markings or colors to make them stand out in the bird book.  As I have become a better birder, I have realized that it is their call and their behavior not their looks that are helpfully distinctive.

Phoebes often perch low in trees or on fence lines, where their plump body and large flat-topped head give them a distinctive silhouette. Not only is their shape distinctive, but they also wag their tails down and up frequently as they watch for flying insects. Then they zip out to catch the bug, and often return to the same perch.

Their shape and behavior is similar to other flycatchers. In northern Wisconsin, we have about eight species of flycatchers, including Least and Great-Crested Flycatchers, Eastern Kingbirds, and Wood-Pewees. Some flycatchers look so similar to each other that voice is the primary field mark. However, none of these commonly nest on your porch!

Phoebes are very helpful to folks who are learning to “bird by ear,” because they say their own name. The song is a raspy, two-parted “fee-bee,” or a variation on that with a stutter in the second half. Like most birds, males are more vocal than females.

Other songbirds will spend one period of brain development memorizing songs of adults, and the next phase trying to match them. If a songbird does not grow up with adults of its own species, or is deaf, it does not develop a normal song. Phoebes do not need to do either! They do not need to hear other adults in order to produce the typical Phoebe song, and they do not even need to hear themselves to know that they are pronouncing their name correctly.

We have two lovely Phoebe nests in a display at the Museum.  It is sometimes tempting to collect Phoebe nests on your own because bird nests are fun to examine, and Phoebe nests are easy to find.  However, Phoebes often reuse their nests within the same season, or even the next year. In addition, it is illegal for you to possess bird nests without the proper permits. There would be no way for you to prove that you did not dump the babies of a protected species on the ground when you collected the nest.  It is best to admire them in nature where you find them.

With my neighborhood Phoebes calling cheerfully, darting out to catch insects, and building a nest, it feels like a great start to the spring.  Let me know what is happening in your yard!

Salamanders and the Sun

I just love spring.  It is so exciting to watch everything wake up and start growing.  

I can’t imagine that I will ever stop being amazed that things can take carbon dioxide from the air, water from the soil, energy from the Sun, and make sugar. This time of year it seems like everything is doing it: pine trees, lilac bushes, evergreen woodferns, spring beauties, algae, and salamanders.

Recently, I took a nature walk (which takes twice as long as a hike) up the St. Peter’s Dome trail. Spring beauties, wild ginger, leatherwood, honeysuckle, and cut-leaved toothwort were in bloom. Wood anemone, Dutchman’s Breeches, and several others were close. These plants are taking advantage of the sunlight before leaf-out shades them out.  They complete their entire annual cycle in just a month or two. By midsummer, sugars produced through photosynthesis are stored safely in their roots, flowers have spread their seeds, and leaves have withered back into the soil. Their short appearance above ground is what earns them the title “spring ephemerals.”

Vernal pools are another ephemeral spring phenomenon. Puddles of snowmelt and spring rains form in low areas, and may last a few days, or a few months.  The key is that they dry up eventually, which makes them poor habitat for fish.  Amphibians, like frogs and salamanders, take advantage of this lack of predators, and lay their eggs in the relatively safe, warm water. Their young then feed on mosquito larvae and other insects who also use the pools to breed.

One vernal pool, near the old quarry at St. Peter’s Dome, has several jelly-covered clusters of spotted salamander eggs! Spotted salamanders are common throughout the eastern U.S. Their large size, blue-black skin, and bright yellow spots make them a charismatic critter.  Adults mostly live in moist leaf-litter and under rotting logs. In the spring, they journey by the hundreds to vernal pools to mate and lay eggs.

The jelly around the eggs keeps them from drying out, but it also inhibits oxygen diffusion into the egg. Scientists have known for a while that the salamanders have a symbiotic relationship with algae to help address this issue. Algae on the jelly use the carbon dioxide and nitrogen-rich waste emitted by the developing embryo.  In return, the photosynthesizing algae give off oxygen that the salamander embryo can use. The algae form a natural oxygen mask!

Recently, scientists have discovered that spotted salamanders actually have a much closer relationship with algae. These algae are, in fact, located inside cells all over the spotted salamander's body. There are even signs that algae may be directly providing oxygen and sugars to the salamander cells that encapsulate them. An electron microscope allowed researchers to see salamander mitochondria (the powerhouses of cells) gathered around alga like it’s the dining room table! This is the first ever documentation of photosynthetic algae inside the cells of a vertebrate animal.

Somehow, the salamanders have convinced their immune system to not kill these foreign algae cells.  Scientists think that salamanders’ ability to regrow their limbs may have something to do with their ability to host foreign algae cells within their bodies. Scientists even found algae in the oviducts of adult female spotted salamanders, suggesting that the algae can be passed from mother to offspring.

Now salamanders can harness those little photons from the Sun even more efficiently!

Life will never cease to amaze me.

Friday, April 6, 2012

Leaf it to me, Buddy!

While we celebrate fall colors in Wisconsin for their variety and vibrancy, spring colors will also impress the attentive observer. After the snow melts and we enter another round of “stick season,” the drab woods can be a little discouraging. Grass and weeds green up first, since many of them are immigrants from the Russian steppe. To survive in this cold grassland, the plants have adapted to breaking dormancy at much lower temperatures than our locals.

Many leafy things that are green now – Tartarian honeysuckle, common speedwell, lilacs, and dandelions – are not native here. The few evergreen natives, like wintergreen, partridge berry, clubmoss, and pipsissewa, have thick, waxy leaves to protect from frost and desiccation.

If we are patient, color rises slowly in the trees, and soon the forests are washed with the soft greens and pinks of bursting buds and fresh new leaves. Those buds formed months ago, during the steamy days of late summer. At that time, the plant organized the basic cells for shoots, leaves, and flowers, and encased them in protective scales or thick fur.

All winter, tiny and important, they waited for the right cue. Some did not survive. Grouse, purple finches, deer, squirrels, moose, rabbits, and hares all know what a fine winter food source those little packets are. Bright red basswood buds are sweet enough for me to nibble, too.

But what is the right cue? Naturalists have pondered this for many years, and struggle to design experiments that can control all the variables and provide answers that we can generalize across species and locations. The best explanation is that bud-break is determined by a complex interplay of factors involving genetics, day length, cold exposure, and warmth.

Once bud-break happens, there are still more mysteries to ponder. Ever since I can remember, miniature spring leaves have fascinated me. Oak leaves in particular start out wonderfully red and fuzzy, with all their little lobes and wrinkly veins. The rich color is a result of anthocyanin, the same pigment that protects leaves in the fall. Before a leaf has filled with chlorophyll, excess sunlight can be damaging. Anthocyanin acts as a sunscreen and anti-oxidant. The fuzz protects tend young leaves from frost the same way a wool sweater keeps you warm – by trapping warmer air next to the surface.

Leaf growth is another natural mystery. A leaf's size is determined by a combination of cell number, cell size, and intercellular space. Leaf cells within the bud are pre-programed to grow with a certain pattern, and emerging leaves use the plant’s built-in orientation system to determine their axis of growth.

Just like scientists have developed a computer model to simulate birds and fish moving in flocks or schools, they have created a computer model that uses simple rules of leaf growth to grow an accurate “virtual” leaf.

Cells at the leaf margins and on the leaf’s surface layer are especially important in determining leaf and petal size. They are genetically programmed to secrete growth hormones that encourage leaf cells to divide. Once the hormone is diluted to a certain point, growth stops. Animals use this same principal of dilution (although with different hormones) to determine size (like on the wings of a fly, for example). This uneven cell growth results in leaves and flowers with characteristic sizes and shapes that we recognize.

Once leaves mature, they begin to photosynthesize. Using energy transferred from photons of sunlight to chlorophyll molecules and into a complex photosystem. Then plants can break apart molecules of carbon dioxide and water and re-combine them into sugars. From simple sugars, they make carbohydrates and cellulose, and with those building blocks, they begin the process of forming new buds for next spring.

How quietly, and not with any assignment from us, or even a small hint of understanding, everything that needs to be done is done. -- Mary Oliver, “Luna”

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opens in May 2012. Find us on the web at to learn more about our exhibits and programs. Also discover us on Facebook, or at our blogspot,


It’s that season again. The woods are warming up, the trails are drying out, wildflowers are popping up, birds are coming back, and folks are excited to get out into the woods!

As John Muir, a University of Wisconsin-educated naturalist said, “Walk away quietly in any direction and taste the freedom… Climb the mountains and get their good tidings, Nature's peace will flow into you as sunshine flows into trees. The winds will blow their own freshness into you and the storms their energy...”

Unfortunately, something else may also flow into you after walking quietly off into the woods to get a closer look at a flower or a better glimpse of the warbler. Tick season is upon us, arriving ahead of schedule with the warm weather, and they seem to pose an ever-increasing threat of disease. If you are an avid outdoors person, you have probably already done your research about ticks and Lyme Disease, but I would like to share a few important reminders. Since my job is to encourage people to get outside and enjoy nature, I want to make sure you do it safely!

Wood ticks and the smaller deer ticks both tend to hang out in tall grass and low shrubs, especially where fields meet forests. This is not the only place they are found, but it is where they are most abundant. I also notice them in leaf-litter on the forest floor. Therefore, you may want to avoid walking through tall grass. Ticks do not fall on you from trees, and they do not jump from vegetation. They simply hang on to the top of a blade of grass with a couple of their eight legs, and wave the rest in the air so they can grab whatever warm-blooded animal happens to pass by. Deer, mice, and birds are the primary sources for the blood necessary to develop from each stage in their life cycle to the next. Learn more about their fascinating life cycle at

Wearing light colored clothing and tucking your pants into your socks can help make sure that you find and remove ticks quickly, before they have attached to you. We have a song at the Museum that advises kids to “flick the tick” to get it off you. Just don’t flick it toward your hiking buddy. Instead, as you are walking behind your friend, scan their clothing for small moving dots. You can also apply insect repellent with 20-30% DEET to shoes, socks and pants. There is another chemical known as Permethrin, which reportedly kills ticks on contact with treated clothing. As with any chemicals, there are risks and benefits that you will probably want to research a bit. I personally prefer protective clothing to protective chemicals.

If you do find a tick that has attached to you, don’t panic! A tick must be attached for 12-24 hours for the Lyme or related bacteria to be transmitted. Then, do NOT attempt removal using nail polish, Vaseline, matches or other methods that may traumatize the tick and cause it to regurgitate its gut contents. Yuck! Instead, get a pair of tweezers with good tips, and grasp the tick on its head, as close to your skin as possible. Pull it out slowly and firmly. If you get a little chunk of skin, it means you got the whole tick!

Finally, be aware of your health. If you know you have been bitten, watch the site for signs of infection, or the characteristic bull’s-eye rash. In any case, watch out for symptoms like fever, chills, headache, fatigue, muscle and joint pain, and swollen lymph nodes. If you suspect you may have Lyme or a similar tick-borne disease, see your doctor as soon as possible! Early treatment usually results in 100% recovery, but late-stage infections can have lasting health effects.

As John Muir knew well, there are many health benefits to spending time in nature. Richard Louv documented those benefits well in his books Last Child in the Woods, and The Nature Principle. In my view, the health risks to NOT going outside far outweigh the risk of disease from ticks. With a little care and vigilance, we can make sure that it is only nature’s peace that infects us, and nothing else!

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opens in May 2012. Find us on the web at to learn more about our exhibits and programs. Also discover us on Facebook, or at our blogspot,