Month: December 2013

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Tracking Wildlife in Winter

Jumping Mouse Tracks
Photo Courtesy & Copyright 2011
Mark Larese-Casanova

Moose Tracks in Snow
Photo Courtesy & Copyright 2011
Mark Larese-Casanova

Cottontail Rabbit Browse & Scat
Photo Courtesy & Copyright 2011
Mark Larese-Casanova

Hi, this is Mark Larese-Casanova from the Utah Master Naturalist Program at Utah State University Extension.

The cold depth of winter is a time when many animals are hiding- either hibernating until the thaw of spring, or finding shelter and warmth in burrows, under logs, or in the tangled branches of evergreen trees.

However, snow falls in much of Utah, and even a dusting can reveal the stories of wildlife in winter. It’s a bit like solving a mystery. By reading the clues of animal tracks, we can know not only the type of animal that made them, but also where they were going and what they were doing.

The most obvious clue is the size of a track. Smaller animals make smaller tracks, and also sets of tracks that are generally closer together.

The shape of an animal track is also very revealing. Members of the canine family, including domestic dogs, coyotes, and fox, show four toes in front, each with a visible claw. Felines, including bobcats and mountain lions, also show four toes, but no claws. Tracks from members of the weasel family, such as mink, ermine, and skunks, show five toes, each with a claw. Raccoon, squirrel, and mouse tracks almost look like they were made by tiny human hands. The long tails of some animals, including deer mice, jumping mice, and weasels, often leave a characteristic line through the center of a set of tracks.

Combining the size and shape of tracks reveals further details about wildlife. The three inch long cloven hoof print of a mule deer is easily recognizable. An elk track looks almost identical, but is about four inches long. A similar moose track is even larger at six inches long.

Figuring out which animal made a track is only half of the story. If we follow tracks, we’ll surely find clues about an animal’s daily life. Wildlife often gather around sources of water that aren’t frozen, which are critical to winter survival. Perhaps rabbit tracks lead under a spruce tree where browsed branches and droppings indicate a frequent feeding spot. Maybe mouse tracks lead from tree to rock to log as it avoids owls and hawks.

While we are much more likely to see wildlife during the warmer months, winter gives us a chance to unravel the story of daily survival during the most difficult time of the year in Utah.

For Wild About Utah, I’m Mark Larese-Casanova.

Credits:
Images: Courtesy and Copyright Mark Larese-Casanova
Text:     Mark Larese-Casanova

Additional Reading:

Canadian Wildlife Federation: Tracking Down Winter Wildlife. https://www.cwf-fcf.org/en/action/how-to/outside/tracking-down-winter-wildlife.html

Murie, O. J. (1982). Animal Tracks. Peterson Field Guides. New York, NY: Houghton Mifflin. https://www.amazon.com/Peterson-Field-Guide-Animal-Tracks/dp/061851743X

Vermont Nature and Outdoors: Tracking Winter Wildlife. https://www.ruralvermont.com/vermontweathervane/issues/winter/97012/vins97012_tracking.shtml

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Small birds in cold temperatures

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Black-Capped Chickadee, Copyright Stephen Peterson, Photographer
Black-Capped Chickadee
Copyright Stephen Peterson, Photographer

Hi, I’m Holly Strand from Utah State University’s Quinney College of Natural Resources.

There is a biological principle that states that species or populations that live near the poles tend to be bigger than those closer to the equator. Called Bergmann’s rule, this principle seems to work pretty well for some animal groups. Consider the size of polar bears, walruses, or penguins. An explanation behind Bergman’s rule is that large animals have a lower surface-to-volume ratio. Therefore they lose less body heart per unit of body mass. Furthermore, the larger you are, the more fat reserves you can carry around with you. Fat reserves represent potential energy, which is pretty useful to have in severe environments.

Large size could come in handy when dealing with Utah’s cold winter. But what about our little creatures? Like the small birds that forego a winter vacation in Arizona or Central America? Without the advantage of large size, how do they keep from icing over when the temperature drops?

Inactivity conserves energy so these little birds go to bed early and get up late in winter. That’s why your feeder looks so deserted on cold mornings. For a roosting spot, birds choose locations that offer protection from both the elements and from predators. The thick branches near the trunk of a conifer work nicely. And some species will seek out tree cavities or nest boxes. While roosting, birds may huddle together to create additional warmth.

Shivering helps a bird to increase its metabolic rate and generate heat when roosting. The drawback is that shivering requires a lot of calories.
An alternative approach that requires less energy is to simply reduce the core temperature of your body. The diminutive black-capped chickadee is well-known for surviving the cold using this adaptive form of self-induced hypothermia.

Good insulation is critical for survival. Some birds–like juncos and finches– put on extra fat. But all birds have feathers which are great for insulation. You’ve probably seen a bird fluff itself out, looking like a chubby feather ball. The bird does this to trap air next to its body to creating a nice warm down coat.

Bird parts not covered with feathers are more vulnerable to cold. So birds will bury their bills into their plumage and will tuck in their feet underneath.

During the shortened, active daytime hours little birds need to consume as many calories as possible. We can help them most by providing high energy food items such as oil sunflower and suet. For more information on what you can do to help Utah birds survive the winter chill, go to www.wildaboututah.org.

For Wild About Utah, I’m Holly Strand.

Credits:
Image: Courtesy Bridgerland Audubon Society, Copyright Stephen Peterson, Photographer
Text: Holly Strand

Sources & Additional Reading

Cooper, Sheldon J. and James A. Gessaman. 2005. Nocturnal Hypothermia in Seasonally Acclimatized Mountain Chickadees and Juniper Titmice. The Condor 107:151–15 https://www.uwosh.edu/faculty_staff/cooper/articles/Condor%20107%20151-155.pdf

Elkins, Norman. 1983. Weather and Bird Behavior. Calton, England: T& AD Poyser. https://www.amazon.com/Weather-Bird-Behaviour-Norman-Elkins/dp/0856610356

Kress, Steve. 2010. Audubon Guide to Winter Bird-Feeding. Audubon Magazine Published: November-December 2010
https://www.audubonmagazine.org/articles/living/audubon-guide-winter-bird-feeding

Marsh, R. L., and W. R. Dawson. 1989. Avian adjustments to cold. In: Advances in Comparative and Environmental Physiology, vol. 4, edited by L. C. H. Wang. Berlin Heidelberg: Springer‐Verlag, p. 205–253. Citation

Smith, Susan. 1991. The Black-Capped Chickadee: Behavioral Ecology and Natural History. Comstock Publishing
https://www.amazon.com/The-Black-Capped-Chickadee-Behavioral-Comstock/dp/0801497930

Yuhas, Daisy. 2013. How Birds Cope With Cold in Winter. Audubon Magazine Published: 12/12/2013 https://www.audubonmagazine.org/articles/birds/how-birds-cope-cold-winter

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Snowflakes

A free-falling snow crystal photographed as it fell on Alta Ski Area on March 6, 2011, Photo Courtesy & Copyright Tim Garrett, University of Utah
A free-falling snow crystal
photographed as it fell
Alta Ski Area on March 6, 2011
Photo Courtesy & Copyright 2011
Tim Garrett, University of Utah
Alta Snowflake Showcase

As winter draws to a close, I’d like to take a moment to reflect on the amazing weather phenomenon that is a snowflake. When winter weather dumps inches of snow on us, it’s easy to overlook the tiny works of art, those intricate and delicate snowflakes, which make up the storm.

Snowflakes – or to use a more scientific term, snow crystals – come in a variety of different shapes including long, thin needles, flat hexagonal plates, columns, and irregularly-shaped pellets called graupel. The International Snow Classification System recognizes ten different shapes in all, only one of which is the traditional snowflake image. The classic six-armed snowflake shape is called a ‘stellar dendrite’ by scientists.

When teaching programs about snow, someone inevitably asks me, “Is it really true that no two snowflakes are alike?” As far as I can tell, the answer is, well, ‘maybe’, and here’s why.

A free-falling snow crystal photographed as it fell, Alta Ski Area, March 6, 2011, Photo Courtesy and Copyright 2011, Tim Garrett, University of Utah, Alta Snowflake Showcase, https://alta.com/pages/snowflakeshowcase.php
A free-falling snow crystal
photographed as it fell
Alta Ski Area
March 6, 2011
Photo Courtesy & Copyright 2011
Tim Garrett, University of Utah
Alta Snowflake Showcase

Three things are needed to form these intricate crystals, and the first two are fairly obvious: water, and temperatures below freezing. The third item is a little more inconspicuous. Water cannot condense and freeze all on its own. Every snowflake needs a piece of atmospheric dust or salt at its core. This particle is referred to as a ‘nucleating agent,’ and it attracts water molecules which then condense and begin to freeze. From there, a snowflake’s overall shape is determined by a number of other variables including the atmospheric temperature, the amount of available moisture, wind speed, and mid-air collisions with other snowflakes.

To add more complexity, consider that each individual snowflake contains somewhere on the order of 10 quintillion water molecules. That’s ten with eighteen zeros behind it. While the way these molecules bind to each other is dictated by the laws of physics, the sheer number of ways in which 10 quintillion water molecules can arrange themselves as they freeze into place is mind boggling. But then again, how many snowflakes do you think fall in the typical March snowstorm in Utah? A lot. One scientist has estimated that the number of individual snowflakes that have fallen on Earth in the planet’s history is ten with 34 zeros behind it. In all of those snowflakes is it possible that two are exactly alike? Yeah, maybe… but good luck finding them!

A stellar dendrite snow crystal, Photo Courtesy and Copyright Kenneth Libbrecht, Caltech University, SnowCrystals.com, https://www.its.caltech.edu/~atomic/snowcrystals/photos/photos.htm
A stellar dendrite snow crystal Photo Courtesy & Copyright
Kenneth Libbrecht, Caltech University
SnowCrystals.com

For more information and some beautiful snowflake photographs, please visit our website at www.wildaboututah.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:

Photos: Courtesy Tim Garrett, University of Utah,
Kenneth Libbrecht, Caltech University
Text: Andrea Liberatore, Stokes Nature Center

Additional Reading:

Halfpenny, J.C and Ozanne, R.D. 1989. Winter: An Ecological Handbook. Boulder, CO: Johnson Books, https://www.amazon.com/Winter-Ecological-Handbook-James-Halfpenny/dp/1555660363

A stellar dendrite snow crystal, Photo Courtesy and Copyright Kenneth Libbrecht, Caltech University, SnowCrystals.com, https://www.its.caltech.edu/~atomic/snowcrystals/photos/photos.htm
A stellar dendrite snow crystal Photo Courtesy & Copyright
Kenneth Libbrecht, Caltech University
SnowCrystals.com

Gosnell, Mariana. 2007. Ice: the Nature, the History, and the Uses of an Astonishing Substance. Chicago, IL: The University of Chicago Press, https://www.amazon.com/Ice-Nature-History-Astonishing-Substance/dp/0679426086

Libbrecht, Kenneth .1999. A Snowflake Primer: the basic facts about snowflakes and snow crystals. https://www.its.caltech.edu/~atomic/snowcrystals/primer
/primer.htm

 

 

 

A hexagonal plate snow crystal, Photo Courtesy and Copyright Kenneth Libbrecht, Caltech University, SnowCrystals.com, https://www.its.caltech.edu/~atomic/snowcrystals/photos/photos.htm
A hexagonal plate snow crystal cite>Photo Courtesy & Copyright
Kenneth Libbrecht, Caltech University
SnowCrystals.com
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Defining the Great Basin

Willow Creek North of Wells, NV. Sagebrush at mid-distance. Route of the California Trail used by pioneers.
Willow Creek north of Wells, NV.
Sagebrush at mid-distance.
Route of the California Trail
used by pioneers.

Courtesy & Copyright
Jim Cane, Photographer

Lupines amid sagebrush north of Wells, NV. Ruby Mountains in backgroundLupines amid sagebrush
north of Wells, NV.
Ruby Mountains in background
Courtesy & Copyright
Jim Cane, Photographer

Map delineating the Great basinMap delineating the Great basin
Courtesy Wikimedia, KMusser, Artist
Ref: wikipedia.org/wiki/Great_Basin


The Great Basin is aptly named.  Twice the size of Kansas, it stretches from the watersheds of the Columbia and Snake rivers south to that of the Colorado, and from the crests of the Sierra Nevada and southern Cascades eastward to the Wasatch front.  The Western explorer John Fremont coined its name in 1845.  The rivers and streams of the region that Fremont had seen all ended in sinks, marshes or lakes. None flowed to the Pacific Ocean.  He confirmed this on meeting Joseph Walker at Mountain Meadows in Utah.  Walker had traveled more of the basin’s western margins, dispelling  rumors of a river traversing the Sierra Nevada.  Precipitation that falls in the Great Basin stays in the Great Basin; water leaves only as vapor.  This is the hydrographic Great Basin.

How else to view the vast region between the Rockies and the Sierra Nevada? Geologists speak of the “Basin and Range Province”, so named for its valleys and the towering ranks of north-south mountain ranges that march across the landscapes of Nevada and edges of adjacent states. Unlike the upthrust Rockies and Sierra Nevada, Earth’s crust in the Great Basin appears to be spreading, to be pulling apart. The tilted escarpments of the Wasatch front are the easternmost evidence of this crustal deformation that has built the Basin and Range Province.

Botanists delimit the Great Basin by the hardy flora that clothes this rugged landscape. Great Basin plants tolerate freezing winters and parched summers, and in the valleys, soils of varying salinity.  The so-called Sagebrush Ocean fills many of the basins, as do other shrubs, such as shadscale and greasewood.  Upslope, these give way to juniper woodlands, often mixed with piñon pine.  This floristic Great Basin reaches eastward to central Utah and the Wasatch front, beyond which trees and other plants of the Rockies make their appearance.

The boundaries of all three concepts for the Great Basin — hydrographic, geologic and floristic — largely coincide.  Each recognizes the distinctive attributes of the Great Basin that set it apart from neighboring regions.  The Great Basin is readily recognizable to the trained eye, whether looking at satellite images, river courses, or the native plant communities encountered on a simple walk.

Credits:
Images: Jim Cane
Map: Courtesy Wikimedia, KMusser, Artist, licensed under Creative Commons Attribution-Share Alike 3.0 Unported
Text: Jim Cane

Additional Reading

Frémont, John Charles. 1845. Report of the exploring expedition to the Rocky Mountains in the year 1842 and to Oregon and North California in the years 1843 – 44. Printed by order of the Senate of the United States , Gales & Seaton, 693 pages. –available as a Google eBook scanned from the original published book Grayson, Donald K. 1999. The desert’s past : a natural prehistory of the Great Basin. Smithsonian Institution Press, Washington D.C., 356 pages. –an exceptionally readable, thorough and authoritative overview of the Great Basin, with many maps, photographs and illustrations.https://books.google.com/books?id=W8ICAAAAMAAJ

Intermountain Regional Herbarium Network. searchable plant database representing multiple holdings of herbaria at universities in Utah and Nevada, with maps, images and more https://swbiodiversity.org/seinet/projects/index.php?proj=10

McPhee, John. 1981. Basin and Range. Farrar, Straus, Giroux, New York. 215 pages. –the first of the author’s many engaging books about geology. https://www.amazon.com/Basin-Range-John-McPhee/dp/0374516901