Calls of Two Common Owls

Great Horned Owl
Photographer: Ronald Laubenstein
US FWS Digital Library

Societies and peoples the world over have harbored superstitious fears of owls. In truth, only small mammals and other like-sized prey should tremble in the presence of these fierce, stealthy predators. Most owls hunt by night, aided by light-sensitive vision and keen directional hearing. Most owls also call at night, and although not melodic, you can learn to identify owls by their calls. Today I will feature two common owls of the nine species that you can expect in Utah.

The Great Horned Owl is Utah’s largest owl, the size of a Red-tailed hawk. It’s correspondingly loud and booming call is a series of “who’s”.

[Kevin Colver: Great Horned Owl (Private Library)]

Great Horned Owls breed early, so expect to hear their hooting duets on our long winter nights. They hunt at night from a tree perch, swooping down to catch their prey. They primarily feed on rodents, skunks and other mammals.

Western Screech Owl
Copyright © 2007 Lu Giddings

My second choice is the Western Screech Owl, one of our several small owls. Its look-alike eastern relative makes a whinnying cry, far different from the Western Screech Owl’s own call, which sounds like a bouncing ball.

[Kevin Colver: Western Screech Owl (Private Library)]

These smaller owls all feed on mice, voles and large insects. The male calls at dusk.

With persistence and luck, you can see these camouflaged owls roosting in the daytime too. Check out flocks of mobbing birds. Crows commonly raise a ruckus around Great Horned Owls, whereas chickadees will fuss stridently around small owls like the Western Screech Owl. But listening at night remains the best way to meet most of Utah’s owls.

Thank-you to Kevin Colver for the use of his bird recordings.

This is Linda Kervin for Bridgerland Audubon Society.


Bird Recordings: Courtesy & Copyright Kevin Colver, Western Screech Owl & Great Horned Owl (Private Collection), //

Pictures: Great Horned Owl, Ronald Laubenstein, US FWS Digital Library

Western Screech Owl, Courtesy & Copyright 2007 Lu Giddings

Text: Jim Cane, Bridgerland Audubon Society

Additional Reading:

Utah Division of Wildlife Resources, Great Horned Owl,

Utah Division of Wildlife Resources, Western Screech Owl,

Backhouse, Frances, Owls of North America, Firefly Books, 2008,

For Children:

Yolen, Jane, Owl Moon,


Gila Monsters

‘Flower’ Gila Monster
Click for larger view
Copyright Daniel D. Beck
Central Washington University

Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

Turn up your radio and see if you can imagine the Utah creature who makes this sound.

[Sound: Jeff Rice, Gila Monster recorded at Arizona-Sonora Desert Museum]

That was the gasping breathing of a gila monster. It was recorded by Jeff Rice of the University of Utah’s Western Soundscape Archive.

Gila Monsters occur in pockets across the desert southwest. In Utah they are found only in Mojave habitat in the southwest corner of Washington County.

Once you get to know them, gilas are not at all monstrous. They are the largest of all lizards native to the U.S. An average gila might be 14-16 in. in length and would weigh about a pound and a half. They have thick sausage-like tails and large heads. The scales on the backs of these lizards resemble a beadwork pattern of black, orange, pink, and yellow.

Of the nearly4000 lizard species in the entire world only two are venomous. And one of them is the gila monster. But only a small amount of venom is introduced during a bite—not enough to kill a healthy human. Nevertheless, the bites are notoriously painful.

Gila Monster
Click map for larger view
Copyright Daniel D. Beck
Central Washington University

But gilas are reluctant to strike. Victims of bites have usually provoked the lizard in some way. Before biting, the lizard will hiss, and then back away from its would-be attacker. But if these warning efforts fail, it will latch on with frightening speed and tenacity. For gilas are the pitbulls of the lizard world.

A long-held belief has been that the breath of a gila monster is nauseating and toxic. In fact, it was even thought that gilas killed their prey with halitosis. The truth is that like many other animals, a frightened gila may regurgitate a recent meal when molested. Because gilas have such a slow metabolism, that last meal might be pretty old and smelly. Also, excited or reproductively active monsters can transmit a detectable body odor which some people find offensive.

These days, you’d be very lucky to see a gila monster in the wild. For in many areas their numbers are decreasing though collection and habitat loss. Another reason is that gila monsters are homebodies. They spend up to 97% of their lifetime tucked away in burrows or rock crevices.

For sources and pictures of gila monsters, see

Thanks to the Rocky Mountain Power Foundation for support of this Wild About Utah topic.

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.

Images: Courtesy & Copyright Daniel D. Beck, Central Washington University

Text:     Holly Strand, Stokes Nature Center

Sources & Additional Reading

Beck, Daniel D. 2005. Biology of Gila monsters and beaded lizards

Beck, Daniel D.,1990. Ecology and behavior of the Gila Monster in southwestern Utah. Journal of Herpetology 24, pp. 54–68.

Brown, David. E. Carmony, Neil. B. 1999. Gila Monster : Facts and Folklore of America’s Aztec Lizard. Salt Lake City: University of Utah Press.

Rice. Jeff. Western Soundscape Archive. J. Willard Marriott Library at the University of Utah,

State of Utah Natural Resources. Division of Wildlife Resources Species Database. Gila Monster. [Accessed Feb 2, 2010]

For More Information:

National Geographic . Wild Detectives: Gila Monster [Accessed Feb 2, 2010]

Arizona-Sonora Desert Museum [Accessed Feb 2, 2010]

Hot Springs

Utah Hot Springs
Click map for larger view
Map by H. Strand, Data from
Blackett and Wakefield 2002.

Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

Cold weather getting to you? Can’t swing a trip to Hawaii or the Carribean this year?

Fortunately for us, there’s a natural antidote to winter right here in Utah Hot springs abound in the Beehive State. According to a Utah Geological Survey database, there are 106 known springs with waters above 25 degrees Celsius or 77 degrees Fahrenheit. The hottest temperature recorded in a Utah spring is 91 degrees Celsius or 195 degrees Fahrenheit at Crystal Hot Springs in Salt Lake County.

Hot springs develop when rain and melted snow infiltrate into the ground. This ground water then sinks deep enough to be warmed by the heat contained in the earth’s interior. Because hot water is less dense it is pushed back to the surface by the continued sinking of incoming heavier, cold water. Replenishment through surface precipitation creates a continuous cycle.

Why do some areas have hot springs and others do not? While there is heat in the earth beneath any spot on the surface, in some areas, this heat is concentrated closer to the surface. For instance, in and around volcanoes–this is the case in Yellowstone area.

Luckily, we don’t know of any volcanoes lurking beneath us. But we know that the Basin and Range area of western Utah, southeastern Idaho, Nevada and eastern California, is expanding or spreading. This spreading movement leaves a relatively thin crust. And a thinner crust means heat is closer to the surface. Furthermore, crustal movement create surface faults that allow cold water to seep down and warm water to flow out. Thus with few exceptions, the higher temperature geothermal areas in Utah occur either in the Basin and Range Province or within the Basin and Range-Colorado Plateau transition zone.

Geothermal sources have many practical uses. The Blundell power station at the Roosevelt Hot Springs geothermal area near Milford produces commercial energy. There are several greenhouses and aquaculture facilities in Utah using geothermal resources. But my favorite application of geothermal waters would be the hot spring spa or swimming pool. lists 16 of these in Utah. And for those of us in northern Utah there’s at least ten more right across the border in Idaho.

For maps and sources of information on hot springs and spas, see
Thanks to the Lion’s Gate Manor in Lava Hot Springs for supporting research and development of this Wild About Utah topic.

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.

Images: Map by H. Strand, Data from Blackett and Wakefield 2002.

Text:     Holly Strand, Stokes Nature Center

Sources & Additional Reading:

Blackett, R.E., and Wakefield, S.I., 2002, Geothermal resources of Utah, a digital atlas of Utah’s geothermal resources: Utah Geological Survey, OFR-397, CD-ROM. Available online [accessed January 10, 2010]

Blackett, R.E. Utah Geothermal Wells & Springs Interactive Map. 1:500,000. Utah Geological Survey, Cedar City Office. [ accessed January 10, 2010]

DeTar, R.E. Thermal Waters. Digital Atlas of Idaho. [ accessed January 10, 2010]

Oregon Institute of Technology. Geothermal Resources of Utah. Geo-Heat Center Quarterly Bulletin Vol. 25. No. 4. [ accessed January 10, 2010]

Utah Geological Survey. Geothermal Occurrences in Utah.

Lion’s Gate Manor in Lava Hot Springs. (208) 776-5118

Geothermal Springs in Idaho,



Cedar Waxwing US FWS FWS Digital Library, David Menke, Photographer
Cedar Waxwing
US FWS Digital Library
David Menke, Photographer

For the chance to admire a flock of Utah’s most rakishly handsome songbirds, look to the sky or trees when you hear this call:

[Kevin Colver, Cedar Waxwing, Songbirds of Yellowstone and the High Rockies…]

That high, thin whistle indicates waxwings. All winter long, waxwings stick together in dense, cohesive flocks that fluidly fly and forage as one. Like locusts, a flock will swarm over a mountain ash, juniper or hawthorn, quickly stripping it of the small fruits that constitute their diet. They eat a wide variety of small fruits from berries to grapes to cherries. Cedar waxwings are commonly seen throughout Utah all winter long. They are nomadic; traveling to where ever fruit is abundant. Some winters, they are joined here by their northern cousins, the Bohemian waxwings. Both waxwings are debonair, with a sweptback crest and an angular black Zorro mask. The name waxwing refers to a line of scarlet waxy droplets at the tips of specialized wing feathers. More likely you’ll notice the bar of lemon-yellow feather tips across the tail. Both of those colors come from pigments in their fruity diets. The body of the smaller Cedar waxwing is more caramel-colored than the grayer Bohemian waxwing. Bohemian waxwings have a distinct rufus patch of feathers beneath the tail.

Cedar Waxwing feeding on berries
David Menke, US FWS
FWS Digital Library

So remember to pay attention when you hear that high-pitched whistle and look around you for trees decorated with these snazzy-looking waxwings. They will surely put some zing in your drab winter day.

Thanks to Kevin Colver for the use of his bird recordings.

This is Linda Kervin for Bridgerland Audubon Society.


Bohemian Waxwing Copyright © 2006 Stephen Peterson

Bird Recordings: Courtesy & Copyright Kevin Colver, Cedar Waxwing, Songbirds of Yellowstone and the High Rockies… //

Pictures: David Menke, US FWS Digital Library

Courtesy & Copyright 2006 Stephen Peterson

Text: Jim Cane, Bridgerland Audubon Society

Additional Reading:

Bohemian Waxwings Copyright © 2006 Stephen Peterson

Creating Landscapes for Wildlife …A Guide to Backyard Gardens in Utah,