Author: Andrea Liberatore

Andrea Liberatore was the Director of Education at the Stokes Nature Center from 2010 - 2013. She loves spending time outdoors in just about all ecosystems, terrains, continents, and weather conditions. Learning about the intricacies and wonders of nature, and sharing them with others, is her lifelong passion.
Posted on

Water Properties

Water Properties
Water as frost on a window
Courtesy and © Andrea Liberatore

Water PropertiesSurface tension – water drops
on a quarter
Courtesy and © Andrea Liberatore

Water PropertiesWater as snowflakes
Courtesy and © Andrea Liberatore

In our winter wonderland, water is all around. It piles upon the landscape in great white drifts. It is a substance life is completely dependent upon and as ordinary as it seems, this tasteless, odorless substance is actually quite amazing. Up to 60% of our body mass is due to water, and life as we know it would not exist if not for water’s unique physical properties.

Properties of Water

When most known liquids get colder they contract – shrinking around 10 percent in total volume. Water contracts too, but only until it reaches its freezing point, at which time it reverses course and begins to expand. This molecular marvel does wonderful things for life on earth. As water freezes and expands, the resulting ice becomes lighter than its liquid form, causing it to float. If ice contracted as other liquids do, it would sink, and lakes would freeze from the bottom up – and freeze quickly, meaning big changes for aquatic life. Water in all forms happens to be a very good insulator, meaning that it doesn’t change temperature very quickly. Ice floating on top of a pond insulates the water underneath, keeping it warmer, and therefore liquid, longer than it normally would. Obviously, this is beneficial for local creatures like fish and beavers not to mention the penguins, whales and seals that thrive in the colder parts of our planet.

Another critical property of water is its stickiness. Individual molecules are generally more attracted to each other than to other substances such as air or soil. This ‘stickiness’, or cohesion, creates surface tension, which allow puddles, rivers, and raindrops to form, and also enables water striders to glide on the water’s surface and rocks to skip across a lake. Water tension is also responsible for a tree’s ability to siphon water from the soil and transport it to the very topmost leaf. However, water’s bonds aren’t so strong as to be unable to break when a fish swims through or when you cannonball into the deep end. You can observe surface tension at home by dripping water onto the head of a coin, and watching it ball up into a surprisingly large mound.

Water is also one of the only known substances that naturally occurs in three phases – solid, liquid, and gas. This is important to many facets of life including the proper functioning of the weather system as we know it. Thankfully, there is a lot of water here on earth – about 320 million cubic miles of it. However, only four tenths of a percent of that comes in the form of freshwater lakes & rivers. Most of the rest is locked up in glaciers and oceans. It’s also important to realize that this is all of the water that Earth has ever had, and all the water we’re ever going to get, which can lead to some interesting thoughts about where that water you are about to drink has previously been. Perhaps it was once part of Lake Bonneville, in the snow that fell on the back of a wooly mammoth, or in a puddle slurped up by a brachiosaurus. If only water could talk…

For more sources and to calculate your water-use footprint, visit our website at www.wildaboututah.org.

For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.

Credits:
Images:  Andrea Liberatore, Stokes Nature Center in Logan Canyon.
Text:     Andrea Liberatore, Stokes Nature Center in Logan Canyon.

Additional Reading:

Bryson, Bill (2004) A Short History of Nearly Everything. Broadway (Random House): New York.

U.S. Geological Survey (2013) The USGS Water Science School. Accessible online at: https://ga.water.usgs.gov/edu/

United Nations: Water. Accessible online at https://www.unwater.org/

Calculate your water footprint:
https://www.waterfootprint.org/?page=files/YourWaterFootprint

Posted on

Wily Coyotes

Coyote Canis latrans
Photo Courtesy & Copyright © 1991
Eric Gese, Photographer

Coyote Canis latrans
Photo Courtesy & Copyright © 1991
Eric Gese, Photographer

In many of the diverse Native American storytelling traditions, the wily coyote plays the same role over and over: that of the smart, sly trickster. For those who study coyote behavior, this characterization is well deserved. Coyotes are incredibly adaptable creatures – intelligent, observant, curious and well, wily.

Their ability to adjust how they live to fit their circumstances can be seen in almost every aspect of the coyote’s life. For starters, coyotes will eat just about anything. As omnivores and opportunistic feeders, coyotes might be found hunting creatures as diverse as small mammals, birds, snakes, mule deer fawns, insects, or fish, and also seek out grasses, berries and seeds. They can hunt alone or in packs, and are not below feasting on carrion, rummaging through your garbage, or raiding the cantaloupe patch.

The environments in which coyotes can be found are similarly diverse. While once restricted to the American West, coyotes are now widespread across all of North America and parts of Central America, and can be found in nearly every ecosystem from deserts to forests to urban areas from Belize to Alaska.

Sometimes called ‘song dogs’ these social creatures are known for their nighttime solos and choruses. Their scientific name, Canis latrans literally means ‘barking dog’, and their many vocalizations help pack members and families bond and communicate over long distances. Coyotes have strong family ties, especially during spring, when puppies are born to monogamous coyote couples.

Coyotes are territorial and defend their space vigorously – especially when breeding and denning. Mating occurs from January through February and after a gestation period of only 60 to 62 days, 3 to 12 pups are born blind and helpless in March or April. Young coyotes are nursed for 4-5 weeks at which point they transition to regurgitated meals brought by both parents. Youngsters tag along on family hunts at 8 weeks old and are able to hunt independently by fall.

Interestingly, studies have shown that even coyote breeding is adaptable – a phenomenon called ‘density dependent reproduction’. In areas where coyote populations are stable, females bear lower numbers of pups. But in areas where there is disturbance to the population – for example through increased predation or hunting – females have larger litters. On average, newborn pups have less than a 50% chance of surviving to adulthood due to threats from disease, predators, and starvation. It therefore makes sense for females to bear more offspring in areas where threats may be even greater.

To learn more about coyote adaptability, join the Stokes Nature Center for a tour of the USDA/National Wildlife Research Center Predator Research Facility on June 16th. For more information visit www.logannature.org. Thank you to the Rocky Mountain Power Foundation for supporting the research and development of this Wild About Utah topic.

For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.

Credits:
Images: Courtesy and Copyright © Eric Gese
            National Wildlife Research Center, Predator Behavior and Ecology
Text:     Andrea Liberatore, Stokes Nature Center in Logan Canyon.


Additional Reading:

Stettler, Brett. 2009. Coyote (Canis latrans). Utah Division of Wildlife Resources Wildlife Notebook Series No. 19. Found online at:
https://wildlife.utah.gov/publications/pdf/2010_coyote.pdf

Video: Coyotes Cruise NYC, Science Friday & Mark Weckel, https://www.sciencefriday.com/videos/watch/10444

Posted on

Turkey Vultures

Swainsons Thrush
Turkey Vulture in flight
Cathartes aura
Courtesy Utah Division of Wildlife Resources
Scott Root, Photographer
Licensed under CCL

Turkey Vulture Kettle above LoganTurkey Vulture Kettle above Logan
Cathartes aura
Courtesy and Copyright
Andrea Liberatore, Photographer

Turkey Vulture Kettle above LoganTurkey Vulture Kettle above Logan
Cathartes aura
Courtesy and Copyright
Andrea Liberatore, Photographer

On certain days in the spring and fall, the sky above my neighborhood looks like a scene from Alfred Hitchcock’s ‘The Birds’. As many as 60 large black birds swarm the sky, circling above the rooftops. On the busiest of days, people will stop their cars in the middle of the road to gawk at the sight. Some give a visible shiver when told that the birds are turkey vultures. But we have nothing to fear from these birds – in fact they should be embraced for the absolutely vital role they play in our environment.

There are lots of myths surrounding vultures, which in turn creates a misunderstanding about them. So let’s set the record straight on a few things. Vultures circle for two main reasons, neither of which involves waiting for a sick or wounded animal to die. The first reason is to take advantage of rising columns of air, called thermals, which generally occur in the mornings as the sun warms the air closest to the earth. Vultures are soaring birds and flapping their 6-foot wingspans takes a lot of effort, so they rarely do it. In fact these birds can fly for hours without a single flap. Circling within a thermal helps them travel higher and farther on much less energy.
The second reason vultures circle is to hone in on a food source. Turkey vultures are one of the few birds that have a highly developed sense of smell. Working together with their excellent eyesight, the birds soar and circle to pin down the location of their next meal.

Continue reading “Turkey Vultures”

Posted on

Sphinx Moths

Sphinx Moths: Big Poplar Sphinx, Pachysphinx occidentalis, Courtesy Whitney Cranshaw, Colorado State University, bugwood.org
Big Poplar Sphinx
Pachysphinx occidentalis
Courtesy Whitney Cranshaw
Colorado State University
bugwood.org

White-lined Sphinx
Hyles lineata
Courtesy Whitney Cranshaw
Colorado State University
bugwood.org

White-lined Sphinx Caterpillar
Hyles lineata
Courtesy Whitney Cranshaw
Colorado State University
bugwood.org

I vividly remember the first time I saw one – a small winged creature whirring from flower to flower in the evening light, its long tongue dipping for nectar within tube-shaped blooms. I was mesmerized, and struggled for a closer look.Sphinx Moths

If you’re thinking that I must have seen a hummingbird, you would be making a very common mistake. A mistake, in fact, that has given this critter one of its many nicknames. The winged wonder I saw that summer night was a sphinx moth, also called a hummingbird or hawk moth because of their large size and bird-like characteristics.

In all stages of their life, these insects are large. Caterpillars grow to a robust 4 inches in length and adult wingspans can measure more than 5 inches. Sphinx moths are also some of the fastest insects on earth and have been clocked flying at over 30 miles per hour. Their size, speed, and flying ability reflect those of the hummingbird so closely that they are commonly misidentified.

Sphinx moths are a beloved sight in many Utah gardens. However, they also hold a bit of a devious surprise. The larvae, or caterpillar, of one common species of sphinx moth are well known by vegetable gardeners. They are large and bright green with a distinctive horn near their hind end. Like the adults, these larvae go by many names, the most common being the tomato hornworm. Hornworm caterpillars, unlike their adult counterparts, are not beloved by gardeners. They are voracious beasts with the ability to strip the vegetation off a tomato or pepper plant in one day.

Aside from our garden plants, young hornworms of other species feed on a variety of vegetation including willow, poplar and cottonwood trees. Adult moths rely on a host of flowers such as columbine, honeysuckle, larkspur and evening primrose. Here in Utah you might come across one of a handful of different species in the sphinx moth family including the five-spotted hawk moth and the white-lined sphinx. Look for them in the late summer evenings as daylight begins to fade. But be sure to look twice to avoid mistaking them for something they’re not.

And the next time you find a hornworm on your tomatoes, maybe just relocate the little bugger so that you can enjoy it once metamorphosis changes the beast into a beauty.

For more information and pictures of our native sphinx moths, visit our website at www.wildaboututah.org. Thank you to Rocky Mountain Power Foundation for supporting the research and development of this Wild About Utah topic.

For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.
Credits:

Photos: Courtesy Whitney Cranshaw, Colorado State University, Bugwood.org
            Images licensed under Creative Commons Attribution 3.0 License
Text:    Andrea Liberatore, Stokes Nature Center, logannature.org

Additional Reading:

Cranshaw, W.S. 2007. Hornworms and “Hummingbird” Moths. Colorado State University Fact Sheet 5.517. Found online at: https://www.ext.colostate.edu/pubs/insect/05517.pdf

Buchman, Steve. 2010. Pollinator of the Month: Hawk Moths or Sphinx Moths (Sphingidae). US Forest Service. Found online at: https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/hawk_moths.shtml