Episode Archive - Page 177 of 221

January 19, 2012February 12, 2026

Cache and Retrieve

Click for a larger view of the Clark's Nutcracker, Nucifraga columbiana, Image licensed through the noted CCL. Stephen Pavlov, Photographer — Clark’s Nutcracker
*Nucifraga columbiana*
Courtesy Steven Pavlov
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license

Common Raven
*Corvus corax*
Courtesy US FWS
Gary M. Stolz, Photographer

Click for a larger view of Common Raven, Corvus corax, Photo taken in Utah by Gary M. Stolz, Courtesy US FWS — Clark’s Nutcracker
*Nucifraga columbiana*
Courtesy Steven Pavlov
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license

Common Raven
*Corvus corax*
Courtesy US FWS
Gary M. Stolz, Photographer

Hi I’m Holly Strand.

Every year, just before Christmas, I comb through the house looking for presents hidden earlier in the year. I check inside old shoes, unfold towels in the closet, and peer way back into the dark recesses of seldomly-used cabinets. With a child in the house, you have to be tricky! The problem with this complex gift stashing behavior is that sometimes I forget where I hid the present when it’s time to wrap it! And once in awhile I forget that I bought something at all! Out of sight—out of mind!

You wouldn’t make a very good magpie, I have been told. For magpies– along with jays, crows and ravens, are masters at hiding–or caching as it’s called– and then retrieving. Of course, what they cache is not Christmas presents but food.

One Utah bird that is much admired for its caching and retrieving skills is Clark’s nutcracker . This large jay lives in mountainous areas throughout the west. Experts say that Clark’s nutcracker can cache 10s of thousands of pinyon, whitebark or limber pine seeds in a single season. Starting in August, the bird will hide 1-15 seeds at a time, often distributing them several kilometers and at much different elevations from the original tree. Caches lie 1-3 centimeters deep in forest litter, bare soil, under bark, in holes, in logs or stumps.

As winter wears on, the nutcracker will retrieve its caches with the help of visual landmarks such as rocks, trees or logs. Using these visual cues, the nutcracker will retrieve the seeds through summer of the following year. Forgotten or abandoned seed caches often germinate, growing into trees that produce more food.

Just as I worry about prying eyes when I hide Christmas presents, birds who cache must be careful to notice who is watching. The common raven is notorious for its spying and thieving behavior. One raven will covertly observe while another caches scraps of meat, eggs, bones or seeds. The observer will then shamelessly raid the cache usually within a couple of days. But having probably raided someone else at some point, the caching raven is on the lookout too. If the caching raven senses the presence of a would-be looter, it might wait for the other bird to become preoccupied. Or it may move the food to a different site altogether. Caching ravens will also hide behind some structure to avoid being seen.

Interestingly, these sly birds will even engage in fake caching. Ravens will cache inedible or low value food items in plain view of other ravens but then stash the good stuff in secret. Fake caching seems designed to throw looters off track, . But perhaps it’s also a character test for fellow ravens? Or maybe—for the intelligent raven—it’s all just an amusing shell game?

For sources and pictures for this and past stories, go to www.wildaboututah.org

For Wild About Utah, I’m Holly Strand.

Credits:

Theme: Courtesy & Copyright Don Anderson as performed by Leaping Lulu
Images: Courtesy Wikimedia/ Steven Pavlov, Photographer
and Courtesy US FWS, Gary M. Stolz, Photographer
Text & Voice: Holly Strand

Sources & Additional Reading:

Balda, R.P. & Kamil, A.C. 1989. A comparative study of cache recovery by three corvid species. Animal Behaviour 37: 486-495. https://doi.org/10.1016/S0003-3472(89)80041-7

Boarman, W. I. and B. Heinrich (2020). Common Raven (Corvus corax), version 1.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.comrav.01 or https://birdsoftheworld.org/bow/species/comrav/cur/introduction

Bugnyarf, Thomas and Kurt Kotrschal. 2001. Observational learning and the raiding of food caches in ravens,Corvus corax: is it ‘tactical’ deception? Animal Behavior, Volume 64, Issue 2, August 2002, Pages 185–195. https://doi.org/10.1006/anbe.2002.3056

Heinrich, Bernd and John W. Pepper. 1998. Influence of competitors on caching behaviour in the common raven, Corvus corax . Animal Behaviour. Vol. 56, 1083–1090, https://doi.org/10.1006/anbe.1998.0906

Marzluff, John and Tony Angell. 2005. In the Company of Crows and Ravens. Yale University Press. https://yalepress.yale.edu/yupbooks/book.asp?isbn=0300100760

Schaming, T. D., D. F. Tomback, and T. J. Lorenz (2024). Clark’s Nutcracker (Nucifraga columbiana), version 2.0. In Birds of the World (N. D. Sly, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.clanut.02 or https://birdsoftheworld.org/bow/species/clanut/cur/introduction

[Page Updated February 12, 2026]

January 12, 2012January 31, 2026

Dark-eyed Juncos

Click for a larger view of a Dark-eyed 'Oregon' Junco Male, Junco hyemalis montanus, Courtesy and copyright 2008 Ryan P. O'Donnell — Dark-eyed Junco “Oregon” Male
*Junco hyemalis montanus*
Courtesy & © 2008 Ryan P. O’Donnell

Dark-eyed Junco “Oregon” Female
*Junco hyemalis montanus*
Courtesy & © 2011 Ryan P. O’Donnell

Dark-eyed Junco “Pink Sided”
*Junco hyemalis mearnsi*
Courtesy & © 2011 Ryan P. O’Donnell

Dark-eyed Junco “Cassiar”
*Junco hyemalis cismontanus*
Courtesy & © 2011 Ryan P. O’Donnell

Dark-eyed Junco “Gray-headed”
*Junco hyemalis caniceps*
Courtesy & © 2011 Ryan P. O’Donnell

Click for a larger view of a Dark-eyed 'Oregon' Junco Female, Junco hyemalis montanus, Courtesy and copyright 2011 Ryan P. O'Donnell — Dark-eyed Junco “Oregon” Male
*Junco hyemalis montanus*
Courtesy & © 2008 Ryan P. O’Donnell

Dark-eyed Junco “Oregon” Female
*Junco hyemalis montanus*
Courtesy & © 2011 Ryan P. O’Donnell

Dark-eyed Junco “Pink Sided”
*Junco hyemalis mearnsi*
Courtesy & © 2011 Ryan P. O’Donnell

Dark-eyed Junco “Cassiar”
*Junco hyemalis cismontanus*
Courtesy & © 2011 Ryan P. O’Donnell

Dark-eyed Junco “Gray-headed”
*Junco hyemalis caniceps*
Courtesy & © 2011 Ryan P. O’Donnell

My backyard bird feeders are a busy place this time of year. I enjoy keeping track of who visits – especially as a relative newcomer to the Utah bird scene. Last winter, however, I was baffled by the identity of what turned out to be a fairly ordinary bird.

Dark-eyed juncos are a common sight throughout the United States, but as it turns out, they exhibit an incredible geographic variation in plumage colors. There is a ‘slate-colored race’ which I was used to seeing in the Midwest – uniformly gray above with a white underbody. During Utah winters, the ‘Oregon race’ is common, with its black hood, brown back and peachy sides. Another ‘gray-headed race’ sports varying shades of gray with a distinct reddish brown patch on its back.

Depending on who you ask, there are up to fifteen different races, also called sub-species, of dark-eyed junco – all quite visually distinct, but all considered to be the same species. It wasn’t always this way, however. In the late 1950’s what we now call dark-eyed juncos were recognized as four different species, and in the 1890’s there were six.

These changes beg the question, at what point does speciation occur? And the answer lies in the ability of these birds to interbreed. One scientific definition of a species is those organisms or populations of organisms that are “potentially capable of interbreeding.”

Unique plumage patterns have evolved in a number of geographic locations across the junco’s range, however all of the dark-eyed junco variants could potentially interbreed if they happened to meet. Indeed in places where these geographic territories overlap inter-breeding does take place resulting in blends of the usually-distinct color patterns.

Juncos aren’t the only bird species with recognized color variants. Any raptor enthusiast will be familiar with variations in plumage colors that many birds of prey exhibit, such as merlins and red-tailed hawks. What makes dark-eyed juncos unique is that they are being studied as a possible case of speciation in progress. It turns out that there is more than just a difference in color among dark-eyed juncos. Some sub-species also exhibit variation in song patterns, social behavior, body size, and migration patterns, any of which may eventually cause these groups to stop interbreeding and allow a new species to emerge.

To see pictures of dark-eyed junco subspecies, 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.

Credits:

Photos: Courtesy & © Ryan P. O’Donnell
Text: Andrea Liberatore, Stokes Nature Center, logannature.org

Additional Reading:

Atwell, J.W., O’Neal, D.M, and Ketterson, E.D. (2011) Animal Migration as a Moving Target for Conservation: Intra-species Variation and Responses to Environmental Change, as Illustrated in a Sometimes Migratory Songbird. Environmental Law. Vol. 41:289 p. 289-319, https://www.amazon.com/Animal-migration-moving-target-conservation/dp/B005C29H7I

Alderfer, Jonathan (editor) (2005) National Geographic Complete Book of Birds. National Geographic Press. Dark-eyed junco information available online at: https://animals.nationalgeographic.com/animals/birding/dark-eyed-junco/

Cornell Lab of Ornithology, All About Birds: Dark-eyed Junco. https://www.allaboutbirds.org/guide/Dark-eyed_Junco/id/ac

History of Name Changes for Juncos. Cornell Lab of Ornithology. https://www.birds.cornell.edu/pfw/News/junco_taxonomy.pdf

January 5, 2012February 12, 2026

Peregrine Falcons: Fierce predators rescued from the abyss

What predatory bird can guide a screaming 200 MPH freefall dive to intercept a flying duck, killing it with a blow from a fist of talons? Tornado winds howl at 200MPH. Even flying horizontally, this bird can accelerate to 70MPH. No animal is faster. It must therefore be a falcon, in today’s case, the Peregrine Falcon. This species inhabits all continents but Antarctica. The Peregrine likes cliff ledges for nesting, such as the high basalt walls at the Birds of Prey Refuge along the Snake River near Boise. In such places, listen for its call, which is very similar to this Prairie Falcon:

Kevin Colver recording: Songbirds of the Southwest Canyon Country

Fifty years ago, the Peregrine Falcon was in a different dive, a plunge to extinction. The culprit was DDT. It wasn’t poisoning the birds, but it insidiously interfered with birds’ calcium metabolism, leaving thin-shelled eggs that broke under brooding parents. DDT is persistent. Worse, DDT bioaccumulates in fats of species high on the food chain, birds like falcons, eagles, and pelicans. Robins provided the first persuasive evidence of DDT bioaccumulation.

On December 28, 1973, President Nixon signed the Endangered Species Act into law. The peregrine falcon was immediately listed. DDT use in the United States was banned. Worried wildlife researchers undertook a bold program to rescue intact eggs from cliff-face nests. The captive nestlings were raised up and taught to hunt. Over the years, 1600 peregrines were released into the wild. The peregrine’s population plunge was halted, then reversed. In 1999, it was formally delisted. By 2003, 3000 pairs bred in Canada, the U.S. and Mexico. Peregrines have never been common, but today, you are four times more likely to see a Peregrine Falcon in Utah than 30 years earlier. You can see similar rebounds in Red-tailed Hawks, Brown Pelicans and other predatory birds by going to the website of the National Audubon Christmas bird counts. This is an environmental success story worth celebrating.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Photo: Courtesy & Copyright Kent R. Keller and
Courtesy images.fws.gov
Text: Jim Cane, Bridgerland Audubon Society
Voice: Linda Kervin, Bridgerland Audubon Society
Bird Recordings Courtesy and Copyright Dr. Kevin Colver,https://wildstore.wildsanctuary.com/collections/special-collections & WildSanctuary, Soundscapes, https://www.wildsanctuary.com

Additional Reading:

Peregrine Falcon (Falco peregrinus), U.S. Fish & Wildlife Service, May 2006, https://www.fws.gov/species/american-peregrine-falcon-falco-peregrinus-anatum

Christmas Bird Count, National Audubon Society, https://birds.audubon.org/christmas-bird-count

The Birder’s Handbook: a field guide to the natural history of North American birds : including all species that regularly breed north of Mexico [Book] by Paul R. Ehrlich, David S. Dobkin, Darryl Wheye
https://www.amazon.com/Birders-Handbook-Natural-History-American/dp/0671659898

Feathers: The Evolution of a Natural Miracle, Thor Hanson, Illustrated. 336 pages. Basic Books.
https://www.amazon.com/Feathers-Evolution-Natural-Thor-Hanson/dp/0465028780/

Salt Lake City Peregrine Falcon Cameras, Wildlife.utah.gov, See YouTube, https://youtu.be/L9DQW1uBMzY

December 21, 2011July 18, 2020

Utah’s Changing Climate and Weather

Hi, this is Mark Larese-Casanova from the Utah Master Naturalist Program at Utah State University Extension.Utah’s Changing Climate and Weather

When I’m standing in line at the post office on a cold, snowy day, I inevitably hear someone make a sarcastic comment about global warming. The reality is, weather and climate are two distinctly different measures. Weather is the combination of current atmospheric conditions, such as temperature, humidity, precipitation, and wind. It changes from day to day, sometimes from minute to minute. It affects our choices of clothing each day, or whether we carry an umbrella.

Climate, however, is a prediction of future weather conditions based on data that have been collected during at least the past few decades. Climate can change as well, but this occurs more slowly over greater time scales. Climate determines which plants we can grow and how much we insulate our homes.

During the last 500 million years, the earth has experienced several different climates from very warm periods to ice ages. Between about one hundred thousand to ten thousand years ago, the planet was impacted by an Ice Age where 30% of the earth was covered by ice extending from the poles. During part of this time, much of Utah was covered by Lake Bonneville, and was home to several now-extinct mammals, such as mammoths, saber-toothed cats, and ground-sloths.

The modern era has also seen climatic changes. Ocean sediments and polar ice core data show that from 900-1300 A.D., the earth’s climate was warmer than normal. However, between about 1300-1900 A.D., the earth experienced a little ice age. Scientists believe this was caused by a combination of three major, natural events- less solar radiation reaching Earth, five major volcanic eruptions, and the disruption of ocean circulation due to melting polar ice caps.

Even though Utah has the second driest climate in the country, annual precipitation has actually increased 14% since the late 1800’s. Sounds great, right? Well, during this same time period, the average temperature has increased three degrees Fahrenheit. This means that more of Utah’s precipitation is falling as rain rather than snow. Because water is released from snowpack at a slower rate, we are provided with water throughout the year. If more of this water comes from rain, it could result in increased stream flow in winter and spring, but decreased stream flow in summer and fall. Furthermore, it is predicted that Utah will be faced with a reduction in snowpack upwards of 50% by the year 2085.

While those of us who enjoy winter sports might experience a gradually shortening ski season, less snowpack is likely to affect us all throughout the year. With Utah’s population expected to double around the year 2050, we’ll need to find creative solutions to an increased demand on water resources.

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

Credits:
Utah’s Changing Climate and Weather
Images:
Text: Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.
Utah’s Changing Climate and Weather
Additional Reading:

Climate Change and Utah. 1998. US Environmental Protection Agency. EPA 236-F-98-007z. Available at: https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=40000PTI.PDF

Hotter Utah- Not All Bad? 2007. Deseret News. March 18, 2007. Available at: https://www.deseretnews.com/article/660204298/Hotter-Utah–not-all-bad.html

Global Warming: What about Water? 2006. Salt Lake Tribune. October 30, 2006. Available at: https://archive.sltrib.com/article.php?id=4149629&itype=NGPSID

Lindsey, Rebecca and Dahlman, LuAnn, Climate Change: Global Temperature, Climate.gov, NOAA,

Steenburgh, Jim, Wasatch Weather Weenies https://wasatchweatherweenies.blogspot.com/

Weatern Regional Headquarters, National Weather Service, National Oceanographic and Atmospheric Administration(NOAA) https://www.weather.gov/wrh/