Owls & iPods

Audio:  mp3

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
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. http://www.sibleyguides.com/2011/04/the-proper-use-of-playback-in-birding/ [Accessed May 19, 2011]

Recordings:

Soundscapes for Birders by Kevin Colver http://www.7loons.com/

http://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 http://www.ibirdexplorer.com

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

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

Nesting Season

Audio:  mp3

Lark Sparrow Nest, June
Courtesy & © Copyright
Jim Cane, Photographer 

While we swelter in summer’s heat, the southward shorebird migration has begun. But some songbirds find this a perfect time to nest. We think of spring as nesting season and for the majority of birds it is. But there are some birds nesting almost year round in Utah.

Living organisms are impelled to maximize the number of successful offspring they produce. Therefore, they tend to reproduce during times of plenty, because the breeding season is strenuous. Males compete for mates and territory and females produce eggs. Both parents may guard the nest from predators and feed the young. Many birds feed nutrient rich insects to their nestlings so nesting season is timed to coincide with the greatest abundance of insects, usually spring in temperate and arctic climes.

American and Lesser Goldfinches are one example of birds who do things differently. (Lesser Goldfinch. Kevin Colver: Songbirds of the Southwest Canyon Country) Instead of insects, they feed their young a regurgitated milky seed pulp. Therefore, they time their nesting for greatest abundance of seeds, especially sunflower and thistle, which is in the summer.

Other birds prefer one type of nut. These include Pinon Jays and crossbills. Abundant pinon nuts trigger Pinon Jay nesting. (Pinon Jay. Kevin Colver: Songbirds of the Southwest Canyon Country) If they have enough nuts cached from the previous season, they will nest in late winter, even while snow blankets the landscape. In years with a bumper crop of pinon nuts, they will also breed in late summer to take advantage of the plentiful food. Good conifer cone crops determine when and where crossbills nest, which can be almost any time.

Great-horned Owls are one of the first to nest each year. (Great-horned Owl. Kevin Colver: Songbirds of the Southwest Canyon Country) You can hear courting pairs hoot back and forth in midwinter. They may incubate their eggs while covered in snow, and if the temperature is too frigid, the eggs freeze and the young die. Many predatory birds nest early, perhaps to insure that the young learn how to proficiently hunt before winter.

The drive to reproduce is inviolable and birds take advantage of whatever season gives them the greatest chance for success. For every nesting bird there is a season.

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

This is Linda Kervin for Bridgerland Audubon Society and Wild About Utah.

Credits:
Images: Jim Cane, Bridgerland Audubon Society
Audio: Kevin Colver, 7loons.com
Text: Linda Kervin, Bridgerland Audubon Society

Additional Reading:

http://www.allaboutbirds.org/guide/red_crossbill/lifehistory

http://www.birds.cornell.edu/AllAboutBirds/owlp/ghowl

http://birds.audubon.org/birds/american-goldfinch

http://books.simonandschuster.com/Birders-Handbook/Paul-Ehrlich/9780671659899

Insect Mimicry

Audio:  mp3

American Hoverfly, Courtesy National Park Service, nps.gov/long/naturescience/insects.htm

American Hoverfly
Courtesy National Park ServicePeach Tree Borer, Courtesy Cooperative Extension, Copyright 2009 Clemson UniversityPeach Tree Borer
Courtesy USDA Cooperative Extension
© 2009 Clemson University

Katydid, Courtesy Stokes Nature Center, Scott Biggs, Photographer Katydid
Courtesy Stokes Nature Center
Scott Biggs, Photographer

Monarch Butterfly, Courtesy Utah Division of Wildlife Resources, J. Kirk Gardner, Photographer Monarch Butterfly
Courtesy Utah Division of Wildlife Resources
J. Kirk Gardner, Photographer
Licensed Under CCL 3.0

Tiger Swallowtail Butterfly
Courtesy Utah Division of Wildlife Resources
J. Kirk Gardner, Photographer
Licensed Under CCL 3.0

 

Insects are the most diverse class of organisms on earth, with more than 900 thousand known species. With that many different kinds of bugs, it’s no wonder that they take on such a vast array of shapes, sizes, and colors. From Luna moths to fruit flies to millipedes, the diversity of this class of life is immense. Some insects have developed a shape and coloring so deliberate that it’s almost astounding. These insects are mimics – bred to look like something they aren’t, in an attempt to get a leg up on the survival game.

Insects can mimic all kind of things – stick bugs, for example, make such convincing twigs that you’ll never know they’re around until they move. Katydids look just like bright green leaves, and there are some species of caterpillar that in their youngest stages look just like splatters of bird droppings. But the mimics that I find most interesting are those who mimic other insects.

There are two main types of insect-to-insect mimicry. Batesian mimicry occurs when one harmless species mimics another dangerous one. Species that look like something fierce can capitalize on that insect’s dangerous reputation and potentially be safer from predators because of it. A common Utah pest, the peach tree borer, is a moth that very closely resembles a wasp in both its morphology and behavior. Harmless, nectar-eating hoverflies exhibit the black and yellow body stripes of a bee. Apparently, it’s not just humans who want to stay away from the business end of a wasp or a bee – many insect predators, too, give them a wide berth.

Ants also have a fierce reputation in the animal world, and so attract a lot of mimics. A number of spider species not only mimic ants in morphology and behavior, but some also give off ant pheromones, making them smell like friend rather than foe. While many ant-mimicking spiders go undercover as a way to hide from their own predators, some do use their disguise as a way to access the nest of their prey.

Batesian mimicry is a delicate balance. Predators need to catch a wasp or two before they associate that color pattern with dangerous prey. If there are too many tasty mimics around, the predators will stop associating black and yellow stripes with a dangerous object and the mimic’s ploy would fail to work.

A slight variation on Batesian mimicry are insects with false faces and false eyes. Tiger swallowtails – those large yellow and black butterflies – have red and blue spots on each of their hind wings at a place farthest from their body. These spots, combined with the skinny black ‘tails’ from which the species gets its common name, are meant to look like the eyes and antennae of another, possibly larger and more fierce, insect. This imagery is meant to frighten off predators, but also in the case of an attack, to spare the most important part of the butterfly’s body.

The second, less common, form of insect-to-insect mimicry is called Müllerian mimicry. This occurs when two equally distasteful insects come to resemble one another. Most of us are familiar with the monarch butterfly. As caterpillars, they feed exclusively on toxic milkweed. The caterpillars take the toxins into their bodies and retain them as adults, making them not only bad-tasting but also poisonous. Predators have learned to associate that distinct orange and black wing pattern with a bad experience, and therefore leave them alone. Viceroy butterflies look incredibly similar to monarchs – the only difference being an extra line of black on the hindwings of a viceroy. While once thought to be Batesian mimics, recent studies have shown that viceroys are equally unpalatable. Their similarity in looks to monarchs, then, serves to reinforce the distasteful nature of both species.

Mimicry is of course, not restricted to the insect kingdom. Some plants have gotten into the mimicry business in order to trick insects. The hammer orchid, which grows in Australia, has a flower that mimics a female bee. Male bees, in mistakenly trying to mate with the flower, collect pollen that they then carry with them to the next, ensuring pollination of this sneaky plant. So this ingenious tactic some insects use to gain a leg up in the game of survival can also be used against them to the advantage of others. Isn’t life amazing…

For more information and photos of some insect mimics, visit our website at www.wildaboututah.org. For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.

Many thanks to Don Viers for his input on this piece.

Credits:

Photos: Courtesy and copyright as marked

Text: Andrea Liberatore, Stokes Nature Center

Additional Reading:

Imes, Rick (1997) Incredible Bugs: The Ultimate Guide to the World of Insects. Barnes & Noble Books. New York, NY

Pyle, Robert Michael (1981) National Audubon Society: Field Guide to Butterflies, North America. Alfred A. Knopf. New York, NY

Viers, Don (2013) Personal conversations

Ritland, David B., Brower, Lincoln P. (1991) The Viceroy butterfly is not a Batesian mimic. Nature, vol. 350, 497-8. Available online at: http://www.nature.com/nature/journal/v350/n6318/abs/350497a0.html

Cushing, Paula E. (2012) Spider-ant associations: An Updated Review of Myrmecomorphy, Myrmecophily, and Myrmecophagy in Spiders. Psyche, vol. 2012. Available online at: http://www.hindawi.com/journals/psyche/2012/151989/

Cryptobiotic Soil Crusts

Audio:  mp3

Cryptobiotic Soil Crust
Photo Courtesy & Copyright 2009
Mark Larese-Casanova

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

Looking out over a Utah desert, we might see relatively few plants- perhaps some sagebrush, maybe a few junipers or Joshua trees, or even some small wildflowers or cacti. What is less noticeable, though, is the living soil crust that holds this entire landscape together. It’s not just sand, but rather an important and vast partnership between bacteria, lichens, algae, and fungi. These soil crusts are often referred to as ‘cryptobiotic’, which means ‘living in suspended animation’. This is a fitting description, considering that water can be so rare in Utah’s deserts.

Cyanobacteria, which is often called blue-green algae, is the backbone of cryptobiotic soil crust. Vast networks of long, microscopic filaments of cyanobacteria and fungi grow in length when they are wet, and leave behind a casing that literally binds the soil together. So, what might otherwise be loose sand not only is less likely to be washed away by water or blown away by wind, but also is able to hold much more water for plants.

Cryptobiotic Soil Crust
Photo Courtesy & Copyright 2009
Mark Larese-Casanova

Cyanobacteria is also extremely useful to desert landscapes for its ability to take Nitrogen out of the air and make it available to plant roots in the soil. Desert soils typically have relatively low nutrients, so this is especially important to desert plants.

In many Utah deserts, cryptobiotic soil crusts can cover up to 70% of the ground surface. Old soil crust can often look like small mountain ranges with black or white peaks inhabited by lichens or mosses. The little valleys in between the tiny mountains of crust are perfect spots for the seeds of desert plants to grow. Over time, the above ground crust can grow up to ten centimeters, or four inches, thick!

However, cryptobiotic soil crust grows at an alarmingly slow rate of about one millimeter per year. So, any soil crust that is disturbed can take a very long time to recover. Depending on the amount of moisture a desert receives, it can take anywhere between 20 and 250 years for soil crust to grow back.

Next time you’re out in the desert, kneel down and have a close look at the telltale peaks and valleys of cryptobiotic soil crust. If you bring a magnifying glass, you just might be able to see some of the lichens and mosses. Be sure to stay on trail, though, and whatever you do, don’t bust that crust!

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

Credits:

Images: Courtesy and copyright Mark Larese-Casanova
Text:     Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.
Additional Reading:

US Department of Interior. 2001. Biological Soil Crusts: Ecology and Management. Bureau of Land Management Technical Reference 1730-2., http://www.blm.gov/nstc/library/pdf/CrustManual.pdf
Rosentreter, R., M. Bowker, and J. Belnap. 2007. A Field Guide to Biological Soil Crusts of Western U.S. Drylands. U.S. Government Printing Office, Denver, Colorado., http://www.soilcrust.org/

It’s Miller Time – Miller Moths

Audio:  mp3

Miller Moth Adult, Courtesy IPMimages.org, Whitney Cranshaw, Photographer

Miller Moth/Army Cutworm Adult
Euxoa auxiliaris
Courtesy IPMimages.org/bugwood.org
Whitney Cranshaw, Colorado State University, Photographer

Miller Moth Adult, Courtesy IPMimages.org, Whitney Cranshaw, PhotographerMiller Moth/Army Cutworm Adult
Euxoa auxiliaris
Courtesy IPMimages.org/bugwood.org
Whitney Cranshaw, Colorado State University, Photographer

Miller Moth Adult, Courtesy IPMimages.org, Frank Peairs, PhotographerMiller Moth/Army Cutworm Larva(e)
Euxoa auxiliaris
Courtesy IPMimages.org/bugwood.org
Frank Peairs, Colorado State University, Photographer

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

World Cup Colombian soccer player James Rodriguez isn’t the only one with a flying insect problem. For several weeks many Utahns have been coping with a bumper crop of miller moths. These dusty gray nuisances have been mobbing our lights, dive bombing our heads and plopping into our nightstand water glasses. Miller moth annoyance levels seemed highest along the Wasatch Front but other areas experienced high numbers as well.

Miller moths begin their lives as army cutworms. The larvae eat their way through the winter chomping on winter wheat, alfalfa, and many other types of crops and plants. After eating all winter, the army cutworms burrow into the ground to pupate. They emerge six weeks later with a yen for flower nectar. This sets them migrating to the alpine elevations of the Wasatch and Uinta Mountains. However, flowery trees and gardens along the Wasatch front are powerful diversions; thus our yards function as filling stations along the miller moth migration route.

Army cutworm populations soar during relatively warm winters with little snow cover. And that’s what happened this year in the south central counties of Utah. And that’s why we have so many moths now. But to keep this issue in perspective—know that the numbers we see in UT are nothing compared to the annual invasions experienced by populations on the Rocky Mountain front range. In Denver, annual spikes in vehicle crashes, therapist visits and broken light fixtures clearly coincide with the influx of miller moths.

Luckily, the moths are no more than a nuisance – they won’t eat your food or damage clothing or upholstery. And while sometimes it seems as if they are targeting your head, they really aren’t. If they are in your house, it’s because they were seeking shelter from the daytime predators by seeking a dark crack or crevice to crawl into—and then got into your house by mistake.

If you swat these unfortunate moths, they’ll get back at you. They leave a dusty gray, powdery mess. The powdery dust is really the moth’s tiny scales and is what gave the moth its name. For these scales are reminiscent of the dusty flour that covers the clothing of someone who mills grain.

For a clean resolution to the problem, veteran miller moth killers from Colorado suggest you suspend a light bulb over a bucket of soapy water. Moths will flick off the bulb into the water. At our house we catch them with a butterfly net and set them free outside. For I imagine that they will be off to the mountains as quickly as possible after that experience.

In early fall, the moths return to lower elevations to lay their eggs. Enough have died during the summer so we won’t notice them much if at all. But if next winter is also mild, we will be hosting our miller moth friends again.

Thanks to USU biologist Diane Alston for sharing her entomological expertise.

For pictures, sources and tips for living with miller moths, go to www.wildaboututah.org

For Wild About Utah, I’m Holly Strand.

Credits:

Images: Courtesy IPMimages.org/bugwood.org & Colorado State University Extension, Whitney Cranshaw and Frank Peairs, Photographers
Text: Holly Strand

Sources & Additional Reading

Cranshaw, Whitney. Quick Facts about Miller Moths. Colorado State University Extension, Fort Collins, CO http://www.ext.colostate.edu/pubs/insect/05597.html

Cranshaw, Whitney and Frank Peairs, Questions and Answers about Miller Moths Colorado State University Extension http://webdoc.agsci.colostate.edu/bspm/Miller%20Moths-Question%20and%20Answers.pdf