The Smell of Rain

Electron micrograph showing
the filamentous structure of
actinomycetes
Photo Courtesy:
Soil Science Society of America

Spring is my favorite season. I love watching our landscape turn from brown to green, the first butterfly sighting, and the rain. During a recent April shower, I stepped outside and inhaled that magical springtime scent – the smell of rain. Which got me thinking – what is that smell, anyway?

What seems like a simple question, begs a complicated answer. That smell, however, does have a name – petrichor – and there are many things that contribute to its scent. One of the biggest culprits may actually be soil bacteria – mostly from the genus actinomycetes – which grow in unfathomable concentrations in soils all around the world. These bacteria play an important role in decomposition and soil health. Periods of relative dryness trigger their reproductive cycle, causing the production of spores, which are considerably more drought-tolerant. When rain finally does fall, the spores are launched into the air, where they may eventually reach our nose. Scientists have identified the chemical compound responsible for the spore’s odor and have named it geosmin, which literally translates to ‘earth smell.’

Humans noses are particularly sensitive to geosmin, but we’re not the only ones. Camels, too, are sensitive to its smell and some scientists believe this helps them find oases in the desert. Our ability to detect this odor might be a throwback to our nomadic ancestors for whom finding water in a vast landscape was of utmost importance.

But the scent trail doesn’t end with geosmin. The chemical compound ozone may also be a part of petrichor especially after a thunderstorm, as ozone is produced by lightning. Another aroma is provided by chemicals called volatile oils which are produced by all plants, and which collect on the ground during dry periods. With rain, they evaporate into the air, contributing to the musty, earthy odor. Acidic rain has also been shown to create scents by reacting with chemicals on the ground such as spilled gasoline. And further complicating the matter is the fact that rain hitting the earth throws dust and other particles from countless sources into the air.

If all of these smells are around us all the time, why is it that they are distinctly associated with rain? The answer lies in the properties of odors and how they travel. Everything that produces a scent is releasing chemical compounds into the air. The ability to evaporate – or volatility – of these compounds increases with the heat and moisture levels of the air around them. The humid air that produces rain creates ideal conditions for conveying scents to our noses.

In the end, it’s not the rain itself that causes odor, but the interaction of water and a number of chemical and organic compounds. Test this theory at home by throwing a bucket of water on the lawn or a hot driveway to see if you can recreate the smell of rain. Likewise, smell a stick, leaf, or rock when it is dry, then wet it and see how the odor changes. For those seeking answers to the origins of the smell of rain, it’s often best to follow your nose.

Thank you to the Rocky Mountain Power Foundation for supporting the research and development of this topic.

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

Credits:
Images: Photo Courtesy Soil Science Society of America
Text:     Andrea Liberatore, Stokes Nature Center in Logan Canyon.
Special thanks to Joel Martin from the Utah Climate Center

Additional Reading:

National Public Radio (2007) The Sweet Smell of Rain. All Things Considered, August 11 2007. Interview of Dr. Charles Wysocki by Debbie Elliott. Transcript available online at: http://www.npr.org/templates/story/story.php?storyId=12716163

Gerritsen, V.B. (2003) The Earth’s Perfume. Protein Spotlight, Issue 35. Accessible online at: http://web.expasy.org/spotlight/back_issues/035/

Gerber, N.N, and Lechevalier, H. A., (1965) Geosmin, an Earthy-Smelling Substance Isolated from Actinomycetes. Applied Microbiology. 13,6. Accessible online at:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1058374/pdf/applmicro00362-0105.pdf

Live Worldwide Network for Lightning and Thunderstorms in Real Time, Blitzortung, http://en.blitzortung.org/live_lightning_maps.php?map=30

Birds Fitting the Bill

Birds Fitting the Bill

Fitting the Bill: White-winged Crossbill
White-winged Crossbill
Copyright © 2009 Paul Higgins
More photos at pbase.com/phiggins/
and utahbirds.org Photo Gallery

Red Crossbill (female)
Copyright © 2009 Paul Higgins
More photos at pbase.com/phiggins/

Fitting the Bill: Few among us would choose to eat a steak with a spoon or soup with a fork. And in the world of birds, it’s the same story – you need the right tool for the right job – and you can tell a lot about a bird by paying attention to its beak.

Physiologically, beaks are a specialized extension of the skull and are coated in keratin – the same material that makes up our fingernails. And like our fingernails, the cutting edges of the beak can be re-grown as they are worn down by use.

Birds use beaks for a multitude of tasks including preening, weaving nests, and defending territories. However it is the task of eating that seems to dictate beak shape and size. Envision the hummingbird, for instance. Its long, thin beak – and corresponding tongue – is designed to reach deep into flowers to collect the nectar within. A hummingbird beak would not work for a woodpecker or a great horned owl. Likewise an eagle’s beak needs to be sharp and strong for tearing flesh, and wouldn’t suit the lifestyle of an ibis or a sparrow.

One Utah native, the aptly-named red crossbill, has one of the most unique beaks around. When closed, its curved top and bottom bills overlap crossways in what looks like an awkward and uncomfortable pose.

French naturalist Count Buffon, first laid eyes on a crossbill in the mid-1700’s. The bird was collected in the Americas, then shipped abroad for examination. Without observing the crossbill in its natural habitat, Buffon labeled its beak “an error and defect of nature, and a useless deformity.” More than 50 years later, Scottish-American naturalist Alexander Wilson observed a crossbill in the wild and determined that its beak ‘deformity’ was in reality a magnificently adapted tool. The crossbill’s diet consists mainly of the seeds of conifer trees, and it turns out that the bird’s curiously crossed beak is perfectly adapted to prying apart the scales of pinecones to get at the seeds within.

Members of the finch family, these birds are often seen in flocks and occasionally visit backyard feeders. They are easily identified by their unique beaks, which serve as a reminder that the right tool for the right job can sometimes seem a bit unconventional.

For more information and photographs of crossbills, visit our website at www.wildaboututah.org. Thank you to 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.
Fitting the Bill-Credits:
Fitting the Bill
Photos: Courtesy & Copyright Paul Higgins(phiggins)www.pbase.com/phiggins
Text:    Andrea Liberatore, Stokes Nature Center, logannature.org

Fitting the Bill-Additional Reading:

Benkman, Craig W. 1987. Crossbill Foraging Behavior, Bill Structure, and Patterns of Food Profitability. The Wilson Bulletin 99(3) p. 351-368 http://www.uwyo.edu/benkman/pdfs%20of%20papers/benkman_1987_wilsonbull.pdf

Conniff, Richard. 2011. The Species Seekers: Heroes, Fools and the Mad Pursuit of Life on Earth. W.W. Norton & Company: NY https://www.amazon.com/Species-Seekers-Heroes-Fools-Pursuit/dp/0393341321

Pearson, T. Gilbert (ed.). 1936. Birds of America. Garden City Publishing Company, Inc. Garden City, NY https://www.amazon.com/T-Gilbert-Pearson/dp/1331531268/ref=pd_lpo_14_t_0/144-1525643-4789824

The Mysterious Salamander

Tiger salamander egg mass, Copyright and courtesy of Jason Jones, Utah Division of Wildlife Resources
Tiger salamander egg mass
Copyright 2009 Jason Jones
Utah Division of Wildlife Resources

Salamanders have long been a source of mystery for humans and their name reflects some of this mystique. The word salamander has its roots in an Arab-Persian word meaning ‘lives in fire’, reflecting an early belief that salamanders could walk through fire unscathed. Mentioned by Aristotle, Aesop, and Shakespeare, this myth likely arose from salamanders that fled the fireplace once their cozy home in the woodpile was disturbed

Utah is home to only one of the world’s more than 500 salamander species. Our tiger salamanders can live in a multitude of different habitats, so long as there is access to fresh water. Because of their need to stay moist, salamanders live a life often hidden from view – spending much of their time underneath rocks, leaves, and other debris. But in early spring, these unique creatures become more active and leave their homes in search of a mate.

Long-toed salamander larvae in an egg, Copyright and courtesy of Jason Jones, Utah Division of Wildlife Resources
Long-toed salamander larvae
in an egg
Copyright 2007 Jason JonesUtah Division of Wildlife Resources

The salamander lifecycle is similar to that of a frog. Eggs are laid in a pond or other source of still water, and hatch into larvae called efts, which look quite like their frog counterpart, the tadpole. After spending a few weeks in the larval stage, individuals metamorphose into an adult.

While modern science has debunked a lot of salamander myths one big mystery still remains. Not all salamanders undergo metamorphosis to become what we recognize as an adult salamander. Some remain in the larval form their entire life, and are even able to reproduce as larvae. This phenomenon, called paedomorphism, has been documented in a number of salamander species, and scientists don’t really understand why or how it happens. Some speculate that the ability to morph or not helps salamanders overcome environmental challenges, such as competition for resources, lack of water, or increased predation.

Tiger salamander eft, Copyright and courtesy of Jason Jones, Utah Division of Wildlife Resources
Tiger salamander eft
Copyright 2007 Jason Jones
Utah Division of Wildlife Resources

Unfortunately, this amazing adaptation has not helped salamanders overcome recent decreases in population that baffled scientists for many years. At one time mysterious, scientists now understand that salamanders are some of the first species to show the effects of pollution in their environment. Now that this particular salamander mystery has been solved, these animals are playing an increasingly important role in determining ecosystem health which may help save many other species.

For more information and photographs of tiger salamanders, 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.

Adult tiger salamander, Copyright and courtesy of Richard Fridell, Utah Division of Wildlife Resources
Adult tiger salamander
Copyright 2002 Richard Fridell
Utah Division of Wildlife Resources

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

Credits:

Photos:

Courtesy & Copyright Jason Jones, Utah Division of Wildlife Resources
Courtesy & Copyright Richard Fridell, Utah Division of Wildlife Resources
Courtesy & Copyright Krissy Wilson, Utah Division of Wildlife Resources
Text: Andrea Liberatore, Stokes Nature Center

Adult tiger salamander, Copyright and courtesy of Krissy Wilson, Utah Division of Wildlife Resources
Adult tiger salamander,
Copyright 2002 Krissy Wilson
Utah Division of Wildlife Resources

Additional Reading:

Donel, M., Joly, P., Whiteman, H.H. 2005. Evolutionary Ecology of Facultative Paedomorphosis in Newts and Salamanders. Biological Review 80 663-671,

http://onlinelibrary.wiley.com/doi/10.1017
/S1464793105006858/abstract

Grzimek’s Animal Life Encyclopedia, Second Edition. 2003. Volume 6: Amphibians. Farmington Hills, MI: Thompson Gale, http://www.amazon.com/Grzimeks-Animal-Life-Encyclopedia-Amphibians/dp/0787657824

Stebbins, Robert C. 2003. Peterson Field Guides: Western Reptiles and Amphibians, Third Edition. New York: Houghton Mifflin Company., http://www.amazon.com/Field-Western-Reptiles-Amphibians-Peterson/dp/0395982723

Whiteman, Howard H. 1994. Evolution of Facultative Paedomorphosis in Salamanders. The Quarterly Review of Biology 69(2) 205-220, http://www.jstor.org/pss/3037717

Bald Eagles

Bald Eagle Feeding
Copyright © 2011 Bryant Olsen

Bald Eagle in Flight
Copyright © 2011 Bryant Olsen

Juvenile Bald Eagle in Flight
Copyright © 2011 Terry Greene

Flying Immature Bald Eagle
Copyright © 2011 Terry Greene

Flying Immature Bald Eagle

Copyright © 2011 Terry Greene, Photographer

When winter arrives in Utah, a number of our bird species hit the road – some flying thousands of miles to Mexico and Central America in search of a warm winter home.

But there is one notable bird that actually migrates to Utah in the winter – the bald eagle. In general, birds migrate because of seasonal food shortages. Think of the hummingbirds that rely on flower nectar and insects, which Utah cannot provide in winter, but which are abundant other times of the year. The same is true for bald eagles, whose main food source is fish. Winter comes on strong in Alaska and Canada, freezing lakes, ponds, and all but the strongest flowing rivers. So the birds travel to seek out the relatively mild winters found farther south.

One of the largest birds of prey you’ll see in our Utah skies, a mature bald eagle can have a wingspan of 6 to 8 feet and stand almost three feet tall. Only the golden eagle rivals it in size. Pairs are thought to mate for life, and they are also responsible for the largest nests of any bird in North America. One record-setting abode measured 9 feet wide, 20 feet deep, and weighed more than 2 tons.

And to think, we almost lost this incredible species. Since DDT and hunting heavily affected bald eagle numbers in the early half of the 20th century, the birds have made a truly remarkable comeback. From a low point around 4,000 individuals in the lower 48 states, they are now thought to number in the tens of thousands, and have been removed from the Threatened and Endangered Species lists.

Perhaps as their comeback continues, Utah will once again see these majestic animals make their massive nests here, fishing in our many rivers and lakes year round. For now, though, aside from a few rare exceptions, bald eagle enthusiasts will have to make the most of their short winter stay. To observe bald eagles, consider a visit to the Great Salt Lake Nature Center at Farmington Bay. Every year, the Bay plays host to hundreds of eagles, from November to March, and while this milder-than-usual winter has brought in fewer numbers of eagles, you may still be able to catch a glimpse. They will likely be heading north later this month, however, so don’t delay. And be sure to keep your ears tuned into the bald eagle’s haunting song:

[Bald Eagle call from Songbirds of Yellowstone, Kevin Colver]

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.

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

Credits:

Audio: Courtesy & Copyright Kevin Colver
Photos: Courtesy & Copyright Bryant Olsen and
            Courtesy & Copyright Terry Greene
Text:    Andrea Liberatore, Stokes Nature Center, logannature.org

Additional Reading:

Parrish, J. and Walters, B., Editors. (2009) Bald Eagle (Haliaeetus leucocephalus). Utah Division of Wildlife Resources: Wildlife Notebook Series No. 3. http://wildlife.utah.gov/publications/pdf/2010_bald_eagle.pdf

National Geographic Society (2012) Animals: Bald Eagle (Haliaeetus leucocephalus)
http://animals.nationalgeographic.com/animals/birds/bald-eagle/