Welcoming the Sun: the changing of the seasons

Imagine a time before electricity when the waking hours were determined by the length of the day. Darkness would fall and it would be difficult to conduct much business or continue work without the aid of a strong fire. As the day closes with a shorter period of light, it is common for people to spend more time inside; plants and animals begin to conserve energy, hibernate or migrate. The winter solstice heralds in the sun as each day becomes slightly longer in light. This was a time of celebration marked with lighting candles and fires so as to welcome the sun and the growing period for many ancient cultures. Consider some of your own holiday and religious traditions where lights, candles,or fires are lit to celebrate.

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The Earth as it rotates around the sun is on a tilt. This tilt is slight, but makes all the difference. Gail Gibbons in her book The Reasons for the Seasons outlines this very nicely. Although focused towards a youthful audience it gives a clear and well illustrated depiction of the seasonal changes that occur. “As the Earth circles the sun, different parts of the Earth are closer to the sun than others. This affects the amount of light and heat they receive,” Gibbons explains. Currently, the North Pole is pointed away from the sun causing us in Billings, Montana to experience winter. Transversely, Montana experiences summer when the North Pole is tilted towards the sun.

The seasons are divided by the position of the globe and its tilt in relation to the sun.

December 21: the winter solstice is a day with the longest period of darkness.

March 21: the vernal equinox is a day of equal lengths of day and night

September 21: the autumnal equinox is a day of equal lengths of day and night

June 21: the summer solstice is a day with the longest period of light

Our spring and fall equinox, as the name would suggest, is when the sun is hitting most directly at the equator. The summer and winter solstice occur when the sun is most directly over the Tropic of Cancer and the Tropic of Capricorn, respectively.

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Slowly each day will peel back with a little more light as the winter solstice just passed a week ago today. The winter solstice is a time to welcome the light and the lengthening of days. If you would like to be more aware of these seasonal changes consider: noting in the local newspaper the times of the sunrise and sunset; taking a walk outside and observing any changes in the temperature, the budding of plants, the movement of animals; or even attempting to do a particular activity at the same time each day and gauge how much light you have. These activities will make the subtle change in light become more apparent as we approach the vernal equinox.

Mattie Clark
Big Sky Watershed Corps and AmeriCorps member

Not a creature was stirring

Out for an afternoon walk yesterday, I marveled at the intensity of the silence and apparent inactivity in the animal world. We are less than a week away from the winter solstice, the shortest and darkest day of the year. The solstice occurs because the tilt of the earth on its axis causes the northern and southern hemispheres to receive varying intensities and exposure to the sun over the course of a year. While we experience our darkest day, the southern hemisphere experiences their longest day. The opposite occurs in June when we celebrate the summer solstice.

This is the time of year when many animals have migrated south or burrowed underground to hibernate. But if you tune into the world with your eyes, signs of life appear around every corner. Even though I didn't see any animals (other than one flock of noisy geese overhead), I knew it hadn't been long since they'd been here. Where mud had dried on the trail, I saw the split-hoofed track of an ungulate. Size and location led me to believe it belonged to a white-tail deer.

Further along I spotted the "C" shaped gait of a wild canine running on the frozen pond. The presence of four toes and an overall oval shape to the print hinted that the tracks were those of a red fox. They are year-round residents; We often see them in winter when they are far easier to spot against a barren snowy backdrop than in the summer when the grasses are tall and lush.

Even the animals that have departed or hibernated leave signs of their presence from the summer months. Old tent caterpillar nests are visible in several trees, especially the choke cherry bushes that they favor. Bird nests of various sizes and shapes can be spotted in tree branches, far more visible now than when the leaves protect them and the baby birds in the spring.

They are reminders of the cycles of life and the seasons. As we circle around the sun, so too do we circle through birth, life, and death, continuously and endlessly through the years. At the darkest day of the year, we celebrate the cycles and revel in the knowledge that the light and life will return once more.


Posted by Heather Ristow, Education Director

Sunning Salamander

It is late November, and most days have brought the cold air of winter, light snow fall, and the smell of wood fires, of decaying leaves, of fall. But today feels marvelously closer to spring; snow has melted off the trails, and there is a freshness in the air that we usually associate with springtime. It is sunny and 64 degrees here in Billings today!

We are not the only creatures fooled by this late November warm spell. Today we found a Tiger Salamander (Ambystoma tigtinum) sunning itself by the nursery here at the Center. In the winter, salamanders hibernate deep underground, below the frost line. In spring, they will emerge and return to their ancestral breeding grounds, usually a pond, glacial pothole, or stock reservoir. Some tiger salamanders will become sexually mature without metamorphosing out of the larval, aquatic form, to the terrestrial adult form. These individuals are called paedomorphs. They breath underwater with three pairs of external gills.

Tiger salamanders are nocturnal, spending the daylight hours underground in burrows or under logs and rocks. At night they hunt for crustaceans such as snails and small crayfish. Some larval forms of the tiger salamander are cannibalistic and feed on other larvae of their species, which can account for up to 80% of their diet!

We felt lucky to watch the salamander amble along the ground in the sunshine today. He provided a good reason to get outside, to marvel at the natural world, and to give thanks for it all.

Posted by Heather Ristow, Education Director


References:
Werner, J.K., B.A. Maxell, P. Hendricks, and D.L. Flath, Eds. (2004) Amphibians and Reptiles of Montana. Mountain Press Publishing Company: Missoula, MT.

Evening adventures

Tonight we went for a hike with 13 young nature adventurers for our Friday Nature Night, which we are hosting once/month for children in 1st - 6th grades. We set out for Norm's Island under a close-to-full moon, in search of owls, bats, beavers, and other nocturnal creatures. Looking behind me, I saw flashlights twinkling like stars, or possibly fireflies, as the children bounced along the trail.

We had just made two brand new bat houses, and were on our way to look at a few older versions. As we crossed Wendell's Bridge to the Island, everyone spoke in hushed tones, in hopes of seeing or hearing wildlife. At the first bat house we approached, even I was surprised to find it occupied. Not by a bat, but by a Northern Flicker (Colaptes auratus). This industrious woodpecker had taken up residence for the night in order to stay warm. It was easily identified by its long, pointed tail feathers, and stripes under its tail. It didn't move an inch as the 13 young explorers each took a turn to peak at it.

Returning to the Audubon Center, we were grateful to have seen some other wild creatures, perhaps not bats and owls as expected, but wildlife none-the-less. Night hikes give us opportunities to explore the little-known night-time world. Even when we are indoors, snuggled under our blankets in bed, the world outside is yet alive.

Icy waters and fresh snow

Friday November 4th when I arrived at the Center I observed a layer of ice on all of the ponds. It was a very thin layer, one that would break if a rock was thrown on it or as soon as the mid-morning sun reached high enough in the sky. But it signals the start of the winter season none-the-less. Soon the open waters will disappear and the ducks will move over to the Yellowstone River, which remains largely ice free during winter.
Today we woke to a fresh coat of snow, nearly one inch by ten AM, and still falling gently. A lone great blue heron (Ardea herodias) stood at the edge of the new beaver lodge in Deep Mill Pond. The great blue heron (affectionately know as a GBH) is one of the few, hardy birds that stay in this part of Montana over the winter. Populations of GBHs over most of the north-central states do migrate south in the winter. However, central and western Montana are host to these stately birds in rain, sleet, and snow.
The great blue heron is an adaptable bird, not only coping with cold weather, but also with a varying diet. They primarily eat fish, but also dine on voles and other small mammals and amphibians as necessary. They are usually seen alone, but may migrate or roost in small flocks. It is the largest heron in the US, and its large size and gray color make for unmistakable identification.

Autumn in Montana

It has been awhile since I've had time to post to the Phenological Field Notes. Our education programs at the Audubon Center have been taking off, and taking all of my time. However, I was inspired today by an email connecting me to the National Phenology Network. This group is dedicated to "taking the pulse of our planet" and monitoring the impacts of climate change on plants and animals. They are looking for volunteers to record their observations of the plant and animal kingdoms across the globe. Visit their website to sign up to help.
It has been a tremendously warm fall. It is October 24th, and we still haven't had a frost here in Billings. I've only lived here three years, but already notice a stark contrast between this fall and my other two here. Both of the last two Octobers have brought 2 - 3 feet of snow in the mountains, and a few inches here in town. This year I am getting concerned that ski season may not happen! It is a la nina year though, which usually brings a wet winter to Montana. I'm still keeping my fingers crossed for a snowy winter! What do you look forward to in winter?

Small wonders

Mike Garcia has been taking photos of animals, plants, and all things wild at the Center and Norm's Island. This morning he shared this fantastic photo of a wolf spider. Can you count all the little legs on her back? Those are her young spiderlings, freshly hatched! Wolf spiders carry their egg sacs by attaching them to their spinnerets. After the young spiders emerge, they climb up onto their mother's abdomen, where they will live for a few weeks until they can hunt on their own.

There are more than 2000 species of wolf spiders! Their name derives from their superb hunting ability. Unlike web-weaving spiders, wolf spiders actually chase their prey. They live mostly solitary lives, and hunt alone. Some wolf spiders will defend a territory while others are free-roaming. Like all spiders, they have eight legs, fang-like mouth parts (chelicerae) and two body parts (an abdomen and a cephalothorax). They can be distinguished from other spiders by their stout build and arrangement of their eyes (8 total).

New resident, or a transient?

Yesterday we celebrated the summer solstice, also known as the official first day of summer. This is the longest day of the year, which happens because planet Earth spins on an axis that tips toward and away from the sun over the course of twelve months. On June 21st, the northern hemisphere of the planet is tipped closest to the sun, meanwhile the southern hemisphere is farthest away from the sun. The opposite happens on December 21st, our darkest day of the year and the longest in the southern hemisphere.

With the arrival of summer, we had a new species arrive at the Center! This morning I caught a quick glimpse of a Richardson's Ground Squirrel (Spermophilus richardsonii). This is one mammal that hadn't yet recolonized the restored habitat here at the Center. Ground squirrels are primarily herbivorous, but will occasionally eat insects and carrion. They are a great prey item for our eagle, osprey, and hawk populations. They are 7 - 9 inches long as adults, and are buff-colored overall, with white hairs on the tip of their tail. They are typically found in open fields and prairies that are well-drained. Populations occur in Minnesota to Montana and north into Canada.

We hope the ground squirrel stays, and brings some friends along. They occur in other areas of Billings so it is possible they have finally found their way here to our fields.

Stop on by to welcome this new addition to the Center!

Long days and spring rains bring...

... wildflowers galore! The woods are decorated with splashes of color both above and below this week. Warm, wet weather and longer days have coaxed wildflowers out of their slumber. On a recent bike ride along the Rims I spotted shooting stars (right), spring beauties (below), wild white lilies, and a lovely yellow flower in the pea family. In gardens tulips and daffodils are in full bloom. Lilacs are sure to emerge soon and sweetly scented breezes will blow across town.

At this time of year it is hard not to feel happy and full of life. The songs of birds fill the air as they stake out their territories and call for mates. While we have enjoyed our friends the chickadees and woodpeckers for the past few months, other feathered friends have been to southern climes where warm weather and food were abundant. They have now returned, adding their songs and vivid colors to the canopies. Yellow warblers (right), tree swallows, goldfinches (below), house wrens, mergansers, spotted sandpipers, the list goes on and on! As each species returns, I make note of it in my journal. Next year I can compare the birds' arrival and departure times with the weather and their presence/absence this year. The joy of phenology comes from watching patterns emerge and noting aberations from the norm. Nature is full of many a marvel!

Nesting Owls

Recently one of our dedicated volunteers snapped this photo of a great horned owl that is nesting on Norm's Island. The pair is not shy of people, as they have chosen to build their nest right above a main walking trail!
The great horned owl is one of the most common owls in the Americas. We first noticed the pair nesting on the island about a month ago, in early March. They use a variety of nest sites, and typically won't make their own nest, preferring instead to take over a nest made by another species. They will have one to five eggs at a time, and the young owls hatch in a fairly helpless condition. They are one of the earliest mating and nesting birds; the young owls should be hatching very soon. Meanwhile, other birds are still returning from a winter in the south and haven't began to build nests yet.
Stop by to visit us and see the owls soon!

Several Signs of Spring

There has been a flurry of activity in the Yellowstone River Valley as days become longer and the earth warms up. Recent weeks have brought the return of belted kingfishers, mountain bluebirds, great blue herons, sandhill cranes, and red-winged blackbirds. The painted turtles have woken up out of hibernation in the deep mud beneath Will's Marsh.

On a recent trip to look at schoolyard wildlife in Pryor, students found several grasshoppers. There are over 400 species of grasshoppers in the 17 western states. Grasshopper embryos suspend growth in the fall and enter a period of diapause (a dormant period). As the earth warms in the spring, the embroys continue growth and hatch out of their eggs. The diapause ends when soil temperatures reach an average of 50 - 55 degrees F. Grasshoppers undergo simple metamorphosis, as opposed to complete metamorphosis seen in butterflies and the majority of other insects. The insect that hatches out of the egg is called a nymph. It looks like the adult except that it is smaller and does not have wings. Young grasshoppers shed their skin as they grow from the nymph stage to adulthood.
Grasshoppers eat primarily grasses, though some species also eat forbs. They can be a destructive force on farmer's crops during years when the population swells. For a complete discussion of this fascinating insect, visit the USDA's online Field Guide to Common Western Grasshoppers.

Signs of spring

The sixty-five degree days in Billings this week have a lot of us fooled into thinking that winter is over. Even the animal world has come alive as if spring were really here. This afternoon we glimpsed the first painted turtle of the year swimming in Will's Marsh. Painted turtles hibernate at the bottom of the pond during winter. When they settle in to hibernate, their respiratory rate and pulse slow down significantly. Their body temperature drops to less than 50% of normal. Since they are not active and are not trying to keep their bodies warm, they don't burn up energy. Therefore they don't need much oxygen at all, and can get by on what they absorb from the water through specialized cells in their tails. They usually warm themselves back up in the spring when the weather is warm and their food supply again becomes plentiful. The turtle that was "awake" this afternoon may have a shock ahead as the temperature drops tomorrow. It is not clear whether the turtle will return to a state of hibernation, or if it will stay active, and try to get enough food to stay warm. Going into hibernation might seem like a better option, but keep in mind that it takes a LOT of energy to warm a body back up out of hibernation; it is energetically stressful. What do you think the turtle will do? We'll keep looking for him as the temperature dips back below freezing in the next few days.


Another surprising sighting on our pond this week was a beautiful male wood duck. This mid-sized duck normally arrives in Billings for the breeding season (though there are populations that live year-round in the western half of Montana). Wood ducks nest in tree cavities or boxes provided by humans. Like mallard ducks, wood ducks are dabbling ducks (as opposed to diving ducks). They feed mainly on seeds and invertebrates, and occupy a wide variety of habitats: creeks, rivers, overflow, bottomlands, swamps, marshes, beaver and farm ponds. For more information, visit the Cornell Lab of Ornithology's website.

Leadership Institute for Nature, Kids, and Stewardship

Are you a high school student in Billings? Interested in nature, kids, and land stewardship? Then apply for LINKS, the Leadership Institute for Nature, Kids, and Stewardship at the Audubon Center. Click HERE for more information.

Awesome Arachnids

Over sixty people participated in a fantastic Weekend Wonders Family Program yesterday at the Audubon Center. The program was led by Amy Weidlich who is working on her Master's degree at MSU-B in the Biological Sciences department. She is studying northern scorpion (Paruroctonus boreus) populations on the rims northwest of Billings for her thesis project, and is a an expert on scorpions. Amy brought several scorpions and spiders with her for the families to look at during the program. In the photo below, her son, Josh, is holding their pet tarantula for kids to see up close. At one of the stations, students of all ages drew and labeled the parts of a spider as they learned about spider anatomy.
In the photo below, one of the scorpions (no longer living) is lit up under a microscope for closer identification. Students also had the opportunity to examine several dead spiders with the microscope in order to identify their body parts. In a dark room at the Center, Amy used a black light to show students how the scorpions light up (fluoresce). Scorpions fluoresce because they have a fluorescent protein in their exoskeleton. This is how Amy finds her study species: she hikes the rims with her black light at night until she sees a scorpion's fluorescence. It is not known why they possess this adaptation; more research is certainly needed on this unique creature.

The most exciting moment of the day was when Amy fed crickets to two live scorpions. The crowds watched in awe as the scorpion grabbed the cricket with its pedipalps (front pinchers) and then lifted its tail to inject venom into the cricket. The venom killed the cricket, and then the scorpion had a feast for lunch. Scorpions only need to eat once every two - three weeks. These scorpions hadn't eaten since the New Year so they were very ready for a meal of crickets!

Northern scorpions can sting humans, but it would not hurt much more than a bee sting. As many as 1,500 species of scorpions have been described worldwide, but only about 30 of these are considered dangerous. The bark scorpion, found in the desert Southwest, has venom strong enough to cause severe symptoms in humans.