Dragonflies

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Western Pondhawk
Erythemis collocata
Copyright © 2006 Nicky Davis

Eight-spotted Skimmer, Female
Libellulidae Libellula forensis
Copyright © 2006 Nicky Davis
Carboniferous ancestor of dragonflies,
fossil Meganeuridae indet.
from Commentry in France,
Museum des Sciences Naturelles,
Brussels, Belgium. The griffenfly belonged to the genus Meganeura.
Courtesy WikiMedia
Ghedoghedo, Contributor

Available under the GNU Free Documentation License

Twelve spot skimmer, Courtesy US FWS, Rick L. Hansen, Photographer Twelve spot skimmer, Courtesy US FWS, Rick L. Hansen, Photographer

Hi I’m Holly Strand.

Have you noticed there are a lot more dragonflies this year? It’s a banner year for them. The combination of a rainy spring and plentiful snowmelt created excellent nursery conditions for dragonfly eggs and emerging larvae. Any kind of freshwater habitat will do—streams, rivers, lakes, canals, and farm ponds, and– this year– temporary wetlands left by floodwaters.

After the final molt by larvae, newly minted adult dragonflies leave the water to go forage. Depending upon the species, they may fly several miles in search of food. That’s why we’re seeing these colorful aviators aloft in forests and fields far from water.

Dragonflies are among the most ancient of winged insects. The fossil record shows evidence of ancestors in the carboniferous period –over 300 million years ago! That’s way before the dinosaurs came to be.

By the end of the Paleaozoic, a dragonfly relative called the griffenfly patrolled the airways. The griffenfly –like the modern dragonfly–was a voracious predator with enormous compound eyes, large toothed mandibles and superb flight cabilities. The wingspan of this insect behemoth was 28 inches! In fact there were lots of giant insects during this period. Nowadays, the oxygen delivery system in insects prevents them from getting very large. But back then, expansion of land plants produced huge volumes of oxygen through photosynthesis. Levels greatly exceeded the amount in the atmosphere today. Because of their unique physiology—insects could take advantage of this oxygen surplus –and grew extremley large.

But once the oxygen levels dropped, the griffenfly and other giants disappeared. I’m seriously glad they aren’t still around. Imagine having to swat at a pesky 2 ½ foot wide dragonfly!

True dragonflies (not just relatives) made their first appearance in the late Paleozoic. The number of species soared quickly. Today, we know of approximately 3000 dragonfly species worldwide.

Thus the dragonfly is a premier example of evolutionary success. Many other living creatures that date back 100s of millions of years aren’t doing so well now. Take, for example, gingkos, horseshoe crabs, or coelacanths. They are mere relicts of past lifeforms –evolutionary stubs if you will. But dragonflies were successful in the past and remain highly competitive in the present. You can bet they will be here for a long time to come.

For pictures and sources go to www.wildaboututah.org

For Wild About Utah, I’m Holly Strand.

Credits:

Photos: Courtesy & copyright © 2006 Nicky Davis,
Courtesy WikiMedia, Ghedoghedo, contributor
Courtesy US FWS, Rick L. Hansen, Photographer
Text: Holly Strand

Sources & Additional Reading:

Corbet, Philip S. 1999. Dragonflies : behavior and ecology of Odonata. Cornell University Press.

Grimaldi, David, A and Michael S. Engel. 2005. Evolution of the insects. Cambridge University Press.

Harrison, Jon F., Alexander Kaiser and John M. VandenBrooks. 2010. Atmospheric oxygen level and the evolution of insect body size in Proc. R. Soc. B (2010) 277, 1937–1946.

Links:

OdonataCentral, Texas Natural Science Center, The University of Texas at Austin, https://www.odonatacentral.org/

Slater Museum of Natural History (Puget Sound) https://www.pugetsound.edu/academics/academic-resources/slater-museum/biodiversity-resources/dragonflies/

Digital Atlas of Idaho. Dragonflies and Damselflies https://imnh.isu.edu/digitalatlas/bio/insects/drgnfly/dragfrm.htm

Go to the Wild Utah website for more amazing images of Utah Dragonflies & Damselflies by Nicky Davis:
https://www.wildutah.us/index_dragon.html

Wind, Hold on to Your Hat!

Graphical Forecasts – Central Rockies
NOAA National Weather Service
Western Regional Headquarters

Hi I’m Holly Strand.

On a recent camping trip on Utah’s Colorado Plateau, my brother and I were buffeted by strong sand-blasting winds for two days straight. Setting up camp was nearly impossible. Strong gusts ripped the tent away from us. Catching only the guylines, we flew the big green tent like a kite through the sagebrush. Eventually we pulled it down and got stakes in the ground. Unable to make a fire, we ate a cold dinner and tried to sleep –until the tent collapsed under the persistent onslaught of meteorological Furies. The next day, the sand-infused wind whipped us painfully as we descended into Horseshoe Canyon. Dust devils pursued us along the canyon floor.

Arriving home I read up on the cause of our discomfort. In simplest terms wind is caused by air moving from high to low pressure. The steeper the air pressure gradient—that is –the change in air pressure per unit distance–the stronger the resulting wind speed. Differences in air pressure are often caused by localized warming of air temperature. The warm air rises creating a spot of relatively low pressure ; then cooler air from a high pressure region rushes in to replace it.

Wind tends to blow much more forcefully near a frontal boundary. And our camp was located very close to the low pressure center of a stationary front. Although the wind was a nuisance, it was probably only blowing around 35 miles an hour. Meanwhile the record in Utah is 124 miles an hour –a wind gust measured at 11000 feet Snowbird. The strongest wind gust here in Logan was 94 miles an hour. Compare this to the highest wind on record anywhere—a gust measuring 253 miles per hour on Australia’s Barrow Island during a tropical cyclone. The record in the United States is 231 miles per hour on top of Mt. Washington in New Hampshire. Higher wind speeds than these may occur in tornadoes, but anemometers tend to malfunction at extreme speeds .

Luckily, we don’t have to worry much about tornadoes. Utah ranks very low in terms of tornado frequency. We average 2-33 a year with most of them occurring May through August. Utah tornadoes tend to be small and not last very long. Whirlwinds or dust devils are much more common. About 90% of them occur in the West Desert where there is plenty of loose, dry dust and sand to swirl around in the air.

Thanks to Marty Booth of the Utah Climate Center for help in developing this Wild About Utah episode.

For Wild About Utah, I’m Holly Strand.

Credits:

Photos: Courtesy US NOAA
Text: Holly Strand

Sources & Additional Reading:

National Weather Service (NOAA) “Dust Devils” https://www.wrh.noaa.gov/fgz/science/dustdvl.php?wfo=fgz [Accessed June 15, 2011]

National Weather Service (NOAA) Jetstream Online School for Weather. “Origin of Wind” https://www.srh.noaa.gov/srh/jetstream/synoptic/wind.htm [Accessed June 15, 2011]

National Weather Service (NOAA) Daily weather maps https://www.hpc.ncep.noaa.gov/dailywxmap/ [Accessed June 15, 2011]

Utah Climate Center https://climate.usurf.usu.edu/

Pope, Dan and Clayton Brough (eds.) Utah’s Weather and Climate. 1996. Salt Lake City: Publisher’s Press. https://www.amazon.com/Utah-Weather-Climate-D-Pope/dp/1567131743

https://www.photolib.noaa.gov

Owls and iPods

Great Horned Owl and Chick, Courtesy US FWS Digital Library, George Gentry Photographer
Great Horned Owl and Chick
Photographer: George Gentry
US FWS Digital Library

Hi I’m Holly Strand.

In early spring, my friends and I went owling in a northern Utah canyon. We were hoping for modest success—just to see or hear a northern pygmy or great horned owl — both common owls in our area.

To better the odds we brought an iPod with prerecorded owl sounds. We played the northern pygmy call for 20-30 second intervals and listened intently in between intervals.

After 10 minutes of off-and-on playbacks we heard an answering call from a nearby conifer grove. We were ecstatic that we had made contact with an actual owl. But wait! Was it an owl we heard or just another iPod user?

Pygmy Owl, Courtesy US FWS Digital Library, Bob Miles Photographer
Pygmy Owl
Photographer: Bob Miles
US FWS Digital Library

According to David Sibley, author of the Sibley Guide to Birds, the proliferation of digital audio devices and recorders among birders has both pluses and minuses. On the plus side, you can often entice certain birds out of hiding using playbacks. For example, if a territorial male thinks a rival bird is threatening to encroach on its territory, he may come out to confront the intruder. Or he may sing his “I’m Here, So Stay Away” song. A female bird might approach the recording source as a potential date. Using playbacks, you can target specific species to see or hear without disturbing others.

On the flip side, overuse of these playback devices can cause unnecessary stress and distraction in the target birds—and annoyance among other birders. In one study, the use of playbacks upset the avian apple cart by causing high-ranking black- capped chickadee males to lose status. The rest of the flock perceived them as losers as they were unable to drive away an unwanted phantom intruder.

Because the widespread use of recorded playbacks is relatively new, proper etiquette is still evolving. But here are some key points.

  • Keep the volume low and use only occasional snippets of sound—less than 30 seconds at a time. Leave a long pause between snippets. Definitely do not broadcast loud or continuous sound.
  • It is illegal to disturb endangered or threatened species. And these recordings can be interpreted as disturbance. So stick with sounds of non-threatened species.
  • Finally, check the rules at your birding location. The use of playback is prohibited in some parks and refuges.

For source material and websites with bird sound recordings, go to www.wildaboututah.org.

For Wild About Utah, I’m Holly Strand.

Credits:

Photos: Courtesy US FSW Digital Media Library
Text: Holly Strand

Sources & Additional Reading:

Sibley, David. 2011. The Proper Use of Playback in Birding. Sibley Guides: Identification of North American birds and trees. https://www.sibleyguides.com/2011/04/the-proper-use-of-playback-in-birding/ [Accessed May 19, 2011]

Recordings:

Soundscapes for Birders by Kevin Colver https://wildstore.wildsanctuary.com/collections/special-collections

https://www.xeno-canto.org/ shared bird sounds from the whole world

Beletsky, Les, editor. 2010. Bird Songs Bible: The Complete, Illustrated Reference for North American Birds Contains digital audio player.

Ipods and mp3 apps:

iBird https://www.ibirdexplorer.com

Audubon Birds Field Guide https://www.audubonguides.com/field-guides/mobile-apps.html

The Sibley eGuide to the Birds of North America https://www.mydigitalearth.com

Dandelions

Dandelions
Copyright © 2002 Roger Banner, Intermountain Herbarium, USU

Hi I’m Holly Strand.

The snow has barely melted yet Dandelions are pushing their way up through the grass. The flowers delight my daughter who eagerly gathers them by the fistful into cheerful but quickly droopy bouquets. However, not everyone shares her enthusiasm. The common dandelion is listed as an invasive and noxious weed by the USDA. Lawnowners spend a lot of time pulling them up and a lot of money on herbicides. There is even a Facebook group called Dandelion Haters United!

The Flora of North America recognizes 15 species of dandelion and four of these occur in Utah. Two native species are found in the mountains. The dandelion that you see in your lawn is an immigrant from Eurasia. If it has olive green seeds it the “Common Dandelion”. If it has brick-red seeds and leaves lobed to the tip it is the so called” Red seeded dandelion. “ This red-seeded dandelion is also common.

The word dandelion comes from the French dent de lion or “lion’s tooth,” referring to the serrated leaves of the plant. The French however, use another name “pissenlit” (pis’seau-li) or bedwetter, referring to the diuretic properties of the plant.

Throughout the ages, people have used dandelions to treat various ailments such as dyspepsia, heartburn, spleen and liver complaints, and hepatitis. Modern pharmacaological studies indicate both dandelion extracts or individual compounds of dandelion leaves or roots really do have significant health-promoting properties. They appear to be especially beneficial for treating digestive disorders, inflammation and as an anti-oxidant.

But the main reason you shouldn’t reach for that pesticide is that dandelions are delicious! The young fresh leaves taste great in a salad, or you can sauté them as you would spinach. You can make dandelion soup or even wine. The greens have 50% more vitamin C than tomatoes, double the protein content of eggplant, and twice the fiber of asparagus. They are also rich in potassium and iron. If harvesting from your yard, just make sure you pick the leaves before the flowers appear.

For information sources and a recipe for dandelion salad go to www.wildaboututah.org

For Wild About Utah, I’m Holly Strand.

Credits:

Photos: Courtesy and Copyright 2002 Roger Banner, Intermountain Herbarium, USU
Text: Holly Strand

Sources & Additional Reading:

Fertig, W. 2011.
Can‘t Beat ‘em? Eat ‘em ! (Sidebar to “Consider the Dandelion Before You Dig”) Sego Lily (newsletter of the Utah native Plant Society. March. Vol. 34, No. 2. P. 8 https://www.unps.org/segolily/Sego2011MarApr.pdf

Lesica, Peter 2011. Consider the Dandelion Before You Dig. Sego Lily (newsletter of the Utah native Plant Society. March. Vol. 34, No. 2. P. 8 https://www.unps.org/segolily/Sego2011MarApr.pdf

Schutz, Katrin, Reinhold Carle, Andreas Schieber Reinhold Carle, Andreas Schieber. 2006. Taraxacum—A review on its phytochemical and pharmacological profile Journal of Ethnopharmacology. Vol. 107, pp. 313–323

Dandelions, Range Plants of Utah, Forbs, Mindy Pratt, Jim Bowns, Roger Banner, Allen Rasmussen, USU Extension, 2002, https://extension.usu.edu/range/forbs/dandelion.htm

Dandelion Salad (from Allrecipes.com)

Ingredients

1/2 pound torn dandelion greens

1/2 red onion, chopped

2 tomatoes, chopped

1/2 teaspoon dried basil

salt and pepper to taste

Directions:

In a medium bowl, toss together dandelion greens, red onion, and tomatoes.

Season with basil, salt, and pepper.