Monday, June 28, 2010

Weather Folklore

Susan Thurn,
CNHM Director of Education

“Wait a day and the weather will change.” Although a common saying in northern Wisconsin, it hasn’t been true lately. Although we have been the lucky recipients of some long-awaited, much-needed rain, cabin fever is setting in to my brain. Also, with several education programs at the Museum this past week, I’ve been looking upwards a lot to find out if we are doing outdoor or indoor explorations, I also have been interested in how to tell if it’s going to rain, and interested in how people can know this without going to the local television forecast, or the Doppler radar on the internet. People have been forecasting the weather for centuries. They have looked to plants and animals – are ants moving to higher ground, do the frogs croak more frequently, is a sheep’s’ wool uncurled? Are there signs we can use to tell us if it is soon going to rain?

First, I go to the Museum’s Naturalist, Cully Shelton, as he always seems to know when it’s going to rain in the next few minutes. Cully recently told me, “When the clouds seem so low you could touch them…when the clouds are touching the trees, then it’s likely that there is going to moisture precipitating out of them in a short length of time. Another favorite observation I use is when you see puffy, white cumulus clouds, which means that within a 12 hour period there should be rainfall.”
What about some of the folklore we all know? "When the glass is low on a ship, the sailors get ready for a storm,” or "When your joints hurt, a storm is coming," are common occurrences we often hear. Both of these folklore statements refer to low air pressure systems which do often mean storms are on their way.

"Red Sky at night, sailor's delight. Red sky in the morning, sailor take warning." It turns out there is some truth to this saying. When our western sky is clear, we often get a red sunset because as the sun sets, its light shines through the lower atmosphere containing more dust, smoke, or pollution. With these clear skies and high air pressure, the air sinks, causing the contaminants to be held closer to the earth surface. These particles scatter the shorter wavelengths of light, leaving longer wavelengths that create orange and red colors, creating the sky that brings weather delight to the sailor. If the sky is red in the morning eastern sky, the high pressure may have already passed, and a low pressure period may follow, usually bringing clouds, rain and storms.

Another favorite folklore statement is, "Mare's tails and mackerel scales make tall ships take in their sails." These mackerel fish scale looking clouds make reference to cirrocumulus clouds, and mare’s tails represent cirrus clouds. Both types of clouds can indicate a warm front that is approaching where two air masses meet, bringing changing winds and precipitation. This prediction of high winds would make it necessary for boats to reef their sails.

"When the stars begin to huddle, the earth will soon become a puddle" is another clue that can be used to forecast weather. As clouds increase, large areas of stars are hidden, while a burst of stars can seem to be huddled together in a section of clear sky. As this sign means the clouds are increasing, the chance of rain is definitely possible.

There are also some clues we can also learn from nature. Some flowers close up as humidity levels rise so their pollen doesn’t get washed away. Cicadas cannot vibrate their wings in high humidity, so can be silent with approaching rain. Swallows sometimes fly lower when there is dropping air pressure. Crows and geese have been known to call more frequently with falling air pressure. Flying insects are more active when air pressure is dropping, staying closer to the ground so that it might seem like they are swarming. With all of these clues, who needs a television or computer?

Nature Watch is brought to you by the Cable Natural History Museum. For 40 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 and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Tuesday, June 22, 2010

Clean Air

Susan Thurn,
CNHM Director of Education

Breath Deep

Take a deep breath. And again. I just spent a week’s honeymoon in New York City, and I learned one incredibly important thing this past week. I love New York, but I love clean air even better. I learned how much I take our northern Wisconsin’s clean air for granted. The cultural and architectural sights, the Broadway shows, the food, and the 10 million working people of New York City were all amazing, but I missed the air of the north woods. I missed waking up and knowing the weather outside, sunny or cloudy, without having to try and figure it out through the smog. It was a fresh breath of air coming home again!

Air – we breathe and expose our lungs to about 35 pounds of it every day and 2 gallons every minute. This air is made up of gases – nitrogen, oxygen, argon and other natural ingredients. Smaller amounts other naturally occurring gases are found on earth such as water vapor, carbon dioxide, methane, nitrogen dioxide and sulfur dioxide. Tiny particles, bits of earth, sea salts, pollen, and microscopic microbes, are blown into the air. These substances play an important role in regulating and sustaining life on our planet.

According to a New York City Community Air Survey, wintertime air quality across the city, found results that Manhattan and the more developed, high-traffic locations in five of the studied boroughs have the city's highest particulate levels. The beautiful Manhattan skyline has certainly been changed by the smog and air particulates. This is just one part of our planet, however. According to the Environmental Protection Agency (EPA,) 50 million Americans live with ozone levels above the current national standard. Worldwide, 1.4 billion people breathe polluted air every day.

None of this information about our air is a surprise to us, and there is good news. According to EPA estimates, the Clean Air Act has helped significantly through a savings of $22 billion in health costs, material damage, and more. Here at home in northwestern Wisconsin, we have an air quality index that is marked as “Good.” In comparison to other places, perhaps it should be marked excellent.

In spite of this good news, my recent city experience was a strong reminder of what daily life could be like in other places. Wisconsin, like all other states and countries fights their battles with growing carbon dioxide emissions, ozone, mercury, and a host of other air quality issues. This past week brought about a renewed sense of commitment to decreasing my personal global footprint. Let us all be reminded of the air that we breathe daily and all take for granted. Let us stop what we are all doing for a moment, breathe, and appreciate what we take in every day, every moment of our north woods lives, and enjoy it!

Nature Watch is brought to you by the Cable Natural History Museum. For 40 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 and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Monday, June 14, 2010

Turtle Crossing

Susan Thurn,
CNHM Director of Education

Beware! It’s turtle crossing time! Over the weekend, I was saddened to find a 20+ year-old snapping turtle dead on the side of the road. Phone call questions have also come into the Museum asking about turtles and how to cope with their change in lifestyle that impacts ours this time of year. Motorists are likely to see turtles crossing roads near lakes, rivers and wetlands right now because the roads separate the aquatic habitat, from the drier soils in upland habitats that female turtles prefer for egg-laying. Their nests also end up in our backyards and driveways, making for an exciting experience!

All Wisconsin turtles lay their eggs on land, usually in a nest that they dig. Painted turtles may nest twice in the same season, but other species only once. Most turtle species begin their nesting around dusk or dawn, although it can occur throughout the day. Snapping turtles can lay 30-80 eggs, while smaller turtles lay up to five eggs. Once the eggs are laid, the female departs, allowing the eggs to hatch on their own. There is great danger in making a roadside nest. The mortality from automobiles is significant because turtles are very slow to mature, taking up to 20 years to reach sexual maturity. This makes it important for motorists to drive with caution in wetland areas in order to protect our female turtles.

Although the danger is over once the female adult turtles have left the nest, the danger has just begun for the eggs. Turtle eggs can take 60-90 days to incubate, and so are often uncovered and eaten by predators such as raccoons, foxes, skunks and crows. With cooler summer temperatures incubation can take longer. Turtles that hatch in the fall overwinter in the nest, using a glycol/sugar antifreeze to keep the eggs or hatchlings from freezing. Summer temperatures actually determine the sex of many Wisconsin turtles. Blanding’s, painted, box, and snapping turtles produce more females at higher temperatures, while more males are produced at lower temperatures.

For those who might find a turtle who has laid eggs in their yards or driveways, and are looking for a way to protect the nest from their pets, or predators, resources suggest placing an object over the nest site such as a oven shelf or plastic egg crate that might prevent predators from digging to get the eggs. This past week’s rain might also help erase the scent that many turtles leave behind, making it more difficult for predators to smell the eggs.

Help a turtle by allowing them time to cross roads, while keeping safety in mind. Road mortality is especially significant for our rare and endangered Blanding’s and wood turtles. However, even our more common snappers or painted turtles can experience mortality rates that cause populations to decline and suffer. Almost half of Wisconsin’s turtles are experiencing declines. Giving turtles the time to move out of the way or occasionally using a stick to help them move to safety can truly help an animal that is a fascinating part of a diverse northern Wisconsin.

Nature Watch is brought to you by the Cable Natural History Museum. For 40 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 and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Tuesday, June 8, 2010

Whip-Poor-Whil

Susan Thurn,
CNHM Director of Education

It is a bird I have never seen, but hear every night right now, just outside the windows of our house. The song goes on for what seems like forever. It is the sound of a whip-poor-whil, singing “whip-poor-will” with an accent on the first and last syllables. A famous naturalist, John Burroughs, once heard a whip-poor-will make 1,088 vocal repetitions before taking a break. Whip-poor-wills belong to a family of birds called nightjars because their loud songs "jar" the night. They are also called goatsuckers because of a superstition that the birds drink milk from farm livestock at night. The name whip-poor-will and that of many other nightjars is a fairly accurate description of what the bird sings.

The whip-poor-will song begins in the spring. During their courtship, the female will land near a calling male, who then will walk towards her with a fancy gait, head bobbing up and down. When he reaches her, he circles as she bobs, while both continue to sing their songs. He will also approach her from the side and touch her bill while she trembles. The nest is built on the ground on leaf litter in areas where there is little or no undercover. The birds time their egg-laying with the moon, synchronizing it so the usual two eggs hatch about ten days before the full moon. This timing allows the adults to forage all night for food with the greatest amount of moonlight. Both parents feed their young regurgitated food. The chicks hop along the ground very quickly after hatching, using their parents camouflage to hide them. If this fails, the young scatter and freeze while the adults distract the invaders. How unfortunate that we rarely get to observe any of these activities!
Hunting is obviously a part of the whip-poor-whil’s nocturnal lifestyle, and while an owl hunts mostly by sound, the whip-poor-will searches for its prey by sight. As a result, they are most active at twilight, dawn, and on brighter moonlit nights. They will catch insects, ranging from mosquitoes to moths, grasshoppers and beetles. In spite of a small bill, they can open their mouths wide when in flight, foraging while wheeling or circling, even hovering for their prey. They will also make short flights out from the ground or branches to catch prey. They use the silhouette of their prey against the night sky. Such creative strategies for hunting!

Legends of whip-poor-whils include a New England story that the bird can sense a soul departing, and can catch it as it flees. An American belief is that the singing of the birds is a death omen. Stephen King and other movie creators have used the song to help create suspense or other moods.

How can a human be lucky enough to spot a whip-poor-will? Their eyeshine reflects red at night, and sometimes they can be seen in a moth-like flight. The birds can sometimes be seen sitting on roads, with small, weak feet and short legs, as they hop about awkwardly. They usually sit lengthwise on their perch instead of other birds who sit across them. Perhaps someday I will be lucky enough to capture a visual moment of a whip-poor-will. Until then, I will enjoy, as do my neighbors, their nightly song.

Nature Watch is brought to you by the Cable Natural History Museum. For 40 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 and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Wednesday, June 2, 2010

Nest Sanitation

By Susan Thurn,
CNHM Director of Education

A pair of tree swallows has built their nest in the Museum’s bluebird nesting box. The Eastern phoebe is back again on the same nest at my house. The bald eagle is back roosting on the same tree on the Namekagon River, not far from its nest. Imagine the fragility of a nest, which often forces birds to build a new nest every year. However, nests that overwinter can harbor deadly numbers of pathogens or parasites that await the returning birds. What do birds do to cope with these issues?

Nests are often alive with invertebrates that feed on birds, their waste, or on each other. Flies, ticks, mites, fleas, and ticks or bacteria and fungi are discouraged by many different strategies birds use.

One of the most widely used methods is to remove the fecal sacs of the young. Some materials are selected by the parenting birds that help to sanitize the nest. For example, some hawk species continually add fresh leaves that contain pesticides such as hydrocyanic acid, which impacts parasites. Starlings can discriminate between leaves and choose the best to deter lice or bacteria which they include in their nests. Cedar bark is also used for its repellent properties. Nuthatches rub pine pitch and insects around the entrance to their cavity, relying on the defensive chemicals of the pitch and insects to protect them. Some birds of prey’s young defecate outside of the nest or in other birds, outside their nest hole opening. Some bird species put carnivore scat in their nests to repel smaller predators. The great-crested flycatcher puts a snake skin into its nest, which is believed to deter predators such as squirrels.

Birds definitely go to great lengths to protect their young. If heavy parasitism or infestation of a nest begins, birds will desert the nest, and in some cases, entire bird colonies have moved themselves to a new site. It is amazing the ingenuity that the bird world uses to survive!

Nature Watch is brought to you by the Cable Natural History Museum. For 40 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 and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.