Category: Birds

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Why Do Birds Stand on One Leg?

Black-Necked Stilt
Himantopus mexicanus
Copyright © 2011 Holly Strand

Hi I’m Holly Strand.

On a recent Saturday my family and I visited Tracy Aviary in Salt Lake City. Walking through the wetland exhibit we saw a couple of black-necked stilts—a common Utah shorebird–snoozing near the boardwalk. They stood at the exhibit shoreline, each one balancing on a single, long, skinny, leg—the other leg drawn into the plumage underneath their bodies. Rotated almost 180 degrees, their heads and bills were tucked snugly under folded wings.

Why do birds choose to stand on just one leg? Wouldn’t it be more comfortable to distribute one’s weight on two? I’ve tried standing on one foot during yoga practice. It doesn’t feel like a good position for rest or sleep.

Over the years, several theories have emerged about this behavior in birds. One is that standing on one leg will reduce fatigue in the other leg. Then, if threatened, the bird could escape more quickly by using the rested leg to initiate motion.

Another theory is camouflage. Two parallel legs may look suspicious to ground level or aquatic prey. In contrast, one leg might resemble a reed or branch.

Perhaps the most common speculation is that birds are conserving heat via one-leggedness.

I wanted to test this last theory by standing barefoot in last weekend’s snow. First on one leg–and then on two for comparison. But I had a bad cold. I asked my biologist husband to do it for me, thinking he would be happy to support rational scientific thinking in the household. Alas, he rolled his eyes and made a noise that I’ve learned to translate as “You’ve got to be kidding me.”

Giving up on him, I dug deeper into the scientific literature.

At last I found a recent study conducted by Matthew Anderson and Sarah Williams of St. Joseph’s University. By observing Carribbean flamingoes these researchers showed that more birds stand on one foot at lower temperatures than at higher temperatures. Further, we know that loss of body heat to water is significantly greater than to air. So it would make sense to see more birds standing on one foot in the water than on land. And indeed this was the case. 80% of birds in water stood on one leg. On land, significantly less did so. Thus it does seem that temperature regulation is at least one reason for standing around on one leg.

In Utah look for one legged roosting among stilts, American avocets, night herons, double-breasted cormorants, and storks. Ducks, magpies and pigeons also stand on one foot for several minutes at a time
–it’s just harder to notice it in them because of their short legs.

For Wild About Utah, I’m Holly Strand.

Credits:

Table: Courtesy & Copyright © 2011 Holly Strand
Text: Holly Strand

Sources & Additional Reading:

Anderson, Mathew and Sarah A. Williams. 2010. Why do flamingos stand on one leg? Zoo Biology. Volume 29, Issue 3, pages 365–374, May/June 2010

Clark Jr., GA. 1973. Unipedal postures in birds. Bird-Banding, 44:22–26.

Tracy Aviary in Salt Lake City https://www.tracyaviary.org/

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Nature’s Recyclers

Fungi Decomposing Fall
Leaves Outside the
Stokes Nature Center
Courtesy & © 2011 Andrea Liberatore
Stokes Nature Center


Redworms Eisenia fetida
from Stokes Nature Center’s
vermicomposting system
Courtesy & © 2011 Andrea Liberatore
Stokes Nature Center

On Tuesday, November 15th, our nation celebrates America Recycles Day. While the day itself tends to focus on human recycling activity, I thought we should also give a nod to nature’s recyclers. Worms, maggots, fungi, beetles, and bacteria – it sounds like a list of leftover Halloween horrors. But in reality, we should be more afraid of what our world would look like without these creepy-crawlies, for these are nature’s recyclers. Scientists call these organisms saprophytes, and as important as their role in life is, they are more likely to evoke a shudder than any feeling of gratitude.

What decomposers actually do is break dead things down into smaller and smaller pieces, until all that is left are the basic molecular components that make up all living things such as nitrogen, phosphorous, carbon, and potassium. Once broken down, this material is then free to be taken up again by plants and animals that use them to live and grow. This cycle of nutrients is vital to life on Earth, and our saprophytic friends make it all possible.

While decomposition would occur even without the help of the decomposers, it would take much, much longer. In some landfills, newspapers have been unearthed that are more than 20 years old, and still quite readable. This is because landfills often create anaerobic environments, where oxygen-loving insects, fungi, and bacteria cannot live and therefore cannot aid decomposition. If without decomposers, a newspaper can last 20 years, what would happen to much larger and hardier items such as tree trunks and roadkill? I shudder to think about it.

Did you know that the U.S. throws more than 33 million tons of food waste into landfills each year? This organic material goes to waste there – taking up valuable space and taking longer than normal break down. So this year, celebrate America Recycles Day by employing some of nature’s recyclers in your yard. Consider starting a compost pile where your fall leaves and food scraps can get broken down into nutrient-rich all-natural fertilizer for next year’s garden.

If you’re in Cache Valley and are looking for a way to mark America Recycles Day, please join the Stokes Nature Center for a tour of the Logan landfill to find out what happens to your garbage and how recycling programs ensure there is less of it. This free tour will be held at 4:30pm on Tuesday, November 15th. For details, visit the Stokes Nature Center website at www.logannature.org.

For composting tips and more information about nature’s recyclers, visit Wild About Utah online at www.wildaboututah.org. Thank you to the Rocky Mountain Power Foundation for the research and development of this Wild About Utah topic. For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.

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

Credits:

Photos: Courtesy & © 2011 Andrea Liberatore, https://logannature.org/
Text:    Andrea Liberatore, Stokes Nature Center, logannature.org

Composting Tips & Information:

Farrell-Poe, K. and Koenig, R. (2010) Backyard Composting in Utah. Utah State University Cooperative Extension. https://extension.usu.edu/files/publications/factsheet/HG-Compost-01.pdf

U.S. Environmental Protection Agency: Composting. https://www.epa.gov/epawaste/conserve/rrr/composting/index.htm

Additional Reading:

Fogel, R. (2002) Waste Not, Want Not: Fungi as Decomposers. Utah State University Herbarium. https://utahpests.usu.edu/ipm/ornamental-pest-guide/diseases/wood-decay-fungi

Hoff, M. (2009) Young Naturalists: Nature’s Recyclers. Minnesota Conservation Volunteer Newsletter. July-August 2009. https://files.dnr.state.mn.us/publications/volunteer/young_naturalists/natures_recyclers/natures_recyclers.pdf

U.S. Environmental Protection Agency (2011) Basic Information About Food Waste. https://www.epa.gov/osw/conserve/materials/organics/food/fd-basic.htm

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Lewis and Clark’s Taxonomic Legacy

Clark’s Nutcracker
Courtesy US FWS
Dave Menke, Photographer
Lewis’s Woodpecker
Courtesy US FWS
Dave Menke, Photographer

Thomas Jefferson will forever be remembered as our third president and author of the Declaration of Independence. Jefferson oversaw the acquisition of the vast Louisiana Purchase and soon thereafter initiated planning for an expedition that would be named the “Corps of Discovery”. That bold adventure was led by Meriwether Lewis and William Clark. These two frontiersmen are immortalized by the plants and animals that taxonomists named in their honor.

The arduous 3-year expedition route passed far north of what would become Utah, ascending the tributaries of the Missouri River and later following down the Columbia River to the Pacific Ocean. Jefferson, being an avid naturalist, instructed the explorers to observe and make record of the geography, plants and animals that they encountered and to return with those specimens which they could carry. Hopes for discovery of a navigable inland passage to the Pacific were not realized, but in all other ways, the expedition was a singular success.

Lewis and Clark made collections of pressed plants along the way. These eventually went to Frederick Pursh, a German botanist in Philadelphia. One new genus of plant he named Lewisia. These are the bitteroots, one of which is the spectacular state flower of Montana. Another genus new to science he named Clarkia . Many species names of plants immortalize the men too, such as the blue-flowered flax, Linum lewisii, commonly used today for seeding following wildfire.

Bird names honoring the discoveries of Lewis and Clark include Clark’s nutcracker and Lewis’ woodpecker. Clark’s nutcracker is a big black and gray relative of crows. [https://wildstore.wildsanctuary.com/collections/special-collections, https://wildstore.wildsanctuary.com/collections/special-collections] This noisy resident of Utah’s mountains is notable for its habit of caching seeds of pine trees to be remembered and found months later.

The age of the pioneer naturalist in North America closed more than a century ago, but the names of men like Meriwether Lewis and William Clark live on with the plants and animals that bear their names.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Images: Courtesy US FWS images.fws.gov
Audio: Courtesy & Copyright https://wildstore.wildsanctuary.com/collections/special-collections, https://wildstore.wildsanctuary.com/collections/special-collections
Text: Jim Cane, Bridgerland Audubon Society

Additional Reading:

The Lewis and Clark Herbarium, Images of the Plants Collected by Meriwether Lewis and William Clark, 1804-1806, Presented by the University of Maryland and The Academy of Natural Sciences in Philadelphia in cooperation with Cornell University, https://www.plantsystematics.org/reveal/pbio/LnC/LnCpublic.html

Evans, Howard Ensign. 1993. Pioneer naturalists: the discovery and naming of North American plants and animals. Henry Holt & Company, New York. Illustrated by Michael G. Kippenhan. ISBN: 0-8050-2337-2, https://www.amazon.com/Pioneer-Naturalists-Discovery-American-Animals/dp/0805023372

And for a thorough treatment of Clark’s nutcracker:

https://en.wikipedia.org/wiki/Clark%27s_Nutcracker

All About Birds, The Cornell Lab of Ornithology:

https://www.allaboutbirds.org/guide/lewiss_woodpecker/id

https://www.allaboutbirds.org/guide/Clarks_Nutcracker/id

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A Big Year in Utah

Utah Big Year Records
Courtesy Utahbirds.org/records/

Hi I’m Holly Strand.

Birders are flocking to theaters to see the new movie The Big Year. The story is based on a real life competition among birders in which they race around to count the most birds within a particular geographic boundary in a single calendar year.

To do a Big Year, you need to follow some simple rules. To count a bird it must be alive and wild and unrestrained when encountered. You have to see enough or hear enough of the bird to absolutely be sure it’s the species you are claiming to see. And the bird must be within the prescribed area and time period of your particular Big Year competition. For instance if you are doing a Big Year for the state of Utah, you can’t count a bird that you see across the border in Idaho. However, you can be standing in Idaho looking at a bird in Utah, and you can count it.

To be competitive in a Big Year you have to find ALL the usual or common birds in your designated country, state or area. This means hitting all the major birdwatching spots at critical times during the year. In Utah you might want to start in the southwestern corner of the state picking up desert species such as vermillion flycatcher and greater roadrunner . Then head to the high Uintas to see Rocky Mountain alpine and subalpine birds such as the rosy finch and northern goshawk. You’d want to check out the Great Salt Lake in all four seasons and make frequent trips up and down the Wasatch canyons as different elevation zones harbor different species. Whenever possible you should be scouring wetlands and riparian zones for whoever might be perching, wading or fishing.

To push your count up beyond that of your competitors, you would need to spot rare birds, esp. vagrants. Vagrants are birds who have wandered or been blown off course. For example, when setting the Big Year record in Cache County, Ryan O’Donnell saw an Iceland Gull who was obviously terribly lost. And a Mexican Whip-poor-will that had somehow drifted up from Southern Arizona.

Modern communication technology is incredibly useful for locating rare birds and vagrants. Big Year participants monitor chat lists like Birdnet and BirdTalk run by Utahbirds.org. Ebird also helps spread the news of sightings. Email hotlines operate in several Utah regions. It always helps to maintain a network of birding friends who can text you the location of birds you haven’t seen yet.

Thanks to Frank Howe and Ryan O’Donnell of Utah State University’s Dept. of Wildland Resources for their assistance in developing this Wild About Utah story.

For Wild About Utah, I’m Holly Strand.

Credits:

Table: Courtesy utahbirds.org
Text: Holly Strand

Sources & Additional Reading:

American Bird Association https://www.aba.org/

Utah Birds https://utahbirds.org/

Ebird https://ebird.org/content/ebird/

Bridgerland Audubon Society Cache Birders Hotline https://www.bridgerlandaudubon.org/hotline.htm

Official movie site: https://www.thebigyearmovie.com/