Mobbing

Northern Mockingbird mobbing a crow
Photo Courtesy & © William C. Webb
Birding.About.com

Mobs reveal a dark and terrifying side of human nature, whether it be the chaotic urban masses crying for the guillotine during the French Revolution, or a shadowy crime syndicate ruled by a guy named Joe Bananos. Many birds practice a different sort of mobbing, wherein there is rarely an injury and the little guy prevails.

When a predator such as an owl, a hawk or even a large snake ventures into a location, they may be detected by a resident bird. That sentinel will make a noisy, dissonant fuss to recruit reinforcements who will join in harassing that hawk or owl. Just who participates is a matter of size matching and a species’ predilection. Tiny predators such as a screech owl or a merlin will be plagued by tiny birds, with chickadees often leading the charge.

When you hear crows or magpies stirring up a ruckus, chances are that a large hawk such as the red-tail, or perhaps a great horned owl, is at the center of the melee. As the harassment escalates, the hawk will typically take wing in a disgruntled huff, trailed by its fussing mob. By remaining perfectly still, an owl can sometimes become seemingly invisible, its smaller marauders gradually losing interest and dispersing.

Why a predator doesn’t lose its temper and turn on its unwelcome mob I don’t know, but I have not seen it happen.

And the purpose of mobbing? Perhaps in loudly announcing a predator’s presence, the hunter’s advantage for stealth and surprise is lost. Or maybe the mob is just telling the hawk or owl to: “Push off and leave our neighborhood!”

By imitating an owl’s call or by producing the right dissonant “pishing” noise, like this “pishpishpish”, I can sometimes lure a small mob briefly into view, one often led by a valiant chickadee. Soon recognizing my deceit, after a few minutes, the group will quickly disperse, leaving me to smile at just what a frisky mob that was!

Credits:
Photo: Courtesy Birding.about.com: Photo Copyright © William C. Webb
Text: Bridgerland Audubon Society – Jim Cane

Are We in the Rockies?

Snow and the Rocky Mountains in Wyoming, Colorado, and Utah
Courtesy NASA Visible Earth,
Jacques Descloitres,
MODIS Land Rapid Response Team,
NASA/GSFC

Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

For awhile now, I assumed that living on a bench on the eastern edge of Cache Valley, meant that I was living on the very western edge of the Rocky Mountains. But is the Bear River Range really in the Rockies? Are the Wasatch Mountains in general?

Peakbagger.com, which features a hierarchical system of mountain range classification, says that the Utah Rockies are represented by two main mountain massifs the Uintas and the Wasatch.

But according to Halka Chronic, author of Roadside Geology of Utah, we are definitely out: The Wasatch Range, steeply faulted on its western side, was once considered to be part of the Rocky Mountains, formed in the late Cretaceous to early Tertiary period. The Wasatch is now known to be younger than the Rockies and is considered the easternmost part of the Basin and Range region. Chronic identifies Heber Valley as the easternmost basin of the Basin and Range. The Basin and Range is a huge arid region in Utah, Nevada and adjacent states. Within it, narrow north-south oriented mountain ranges alternate with valleys filled with erosional sediment.

I turned to some Utah State University geologists for help. As usual, the answer to what I think is a simple question turns out to be complicated. Sue Morgan considers the Wasatch to be the easternmost edge of the Basin and Range because the mountains were formed by normal faulting characteristic of the Basin and Range. But, she points out, that the Utah Geological Survey considers the Wasatch to be part of the Middle Rockies.

Dave Liddell says the answer to my question is a matter of scale. If you are looking at North America from space those of us on the Wasatch Front could justifiably consider ourselves located on the edge of the continental–scale Rocky Mountain system. However, the closer look, you have to start taking into consideration lots of fine scale variations and categorizations; this makes drawing a boundary between the Rockies and the Basin and Range province extremely complex. Liddell would put Cache Valley in the Basin and Range because of its formation by pull apart tectonics. The rest of the Wasatch Front is Basin and Range for the same reason. But most geologists put Bear Lake in the Rockies. So perhaps the Wasatch is a large transition zone.

Next time the subject comes up—and there’s no guarantee that it will ever come up—I’m probably going to favor the argument that the Wasatch Mountains are outside the Rockies and that most Utahns live in the Basin and Range region. But if some of you Wasatch Front residents really want to live at the foot of the Rockies, that’s fine too–you can cite the Utah Geological Survey. Now that I decided to go with Basin and Range, I’ll want to find out more about the plants and animals that live here. So you can expect to hear more about them in future programs.

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.

Credits:

Photo: Courtesy Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC http://visibleearth.nasa.gov/view.php?id=62272

Text: Stokes Nature Center: Holly Strand

Sources & Additional Reading

Magpies a.k.a. Holstein Pheasants

Magpies a.k.a. Holstein Pheasants: A Dark Black-billed Magpie, Courtesy Bridgerland Audubon Society Library, Stephen Peterson, Photographer
A Dark Black-billed Magpie
Courtesy Bridgerland Audubon Society Library
Stephen Peterson, Photographer

I knew a man who referred to those black and white, long-tailed birds as “Holstein Pheasants.”
He used to say, you can shoot pheasants, can’t you? Magpies are loved or hated. Few are without opinions when it comes to these protected, I remind you protected, birds.
In Asia, they are revered for good luck; while their relatives, the crows, are omens of bad luck.

The black-billed magpie of Utah is related to the yellow-billed magpies in California and more distantly to the European magpie and the Korean magpie.
They all have a similar general appearance, black and white with a long black tail.

Our Black-billed magpies mate for life and stay together until one dies. Then the other may find a new mate.

Their home-building skills will not produce awards for neatness on the outside. But are marvels of architecture.
Nests are collections of loose sticks, mud, bark and other available materials, often built on older nests. A hood of loose sticks covers the nest with multiple entrances.
And the inside is lined with soft grasses and other materials.

Once the nest is built, the female lays six or seven eggs. While she sets on the eggs, the male feeds her for up to 18 days. The parents feed their young about two months, even though the young fledge in about a month. Upon independence from their parents, the young flock with other young magpies.

Magpies can be seen harassing hawks, eagles and owls as they perch in trees.
But despite the begrudging landlords, owls and hawks often take up residence in old magpie nests.

Bold and gregarious, magpies are well adapted to man. They are the bane of back yard bird feeders, driving songbirds away and eating everything in sight.
I know at least one local birder, however, who enjoys magpies and attracts them with Cheetos and soft cat food, but on the other side of the house from her regular bird feeders.

Magpies are opportunists and nest raiders. They are despised by hunters because they clean out unprotected and abandoned nests.
And fruit growers fight them with netting, flags and pyrotechnics. But don’t hold that against them.
These Holsteins clean up roadkill, tent caterpillars, grasshoppers and many other things that we’d rather not see or smell.

For Wild About Utah, I’m Dick Hurren.

Credits:

Photos: Courtesy Bridgerland Audubon Society Image Files

Text: Stokes Nature Center: Lyle Bingham and Dick Hurren

Additional Reading:

Cornell Lab of Ornithology: All About Birds, Black-Billed Magpie, http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Black-billed_Magpie_dtl.html, Accessed July 31, 2008

http://www.enature.com/flashcard/show_flash_card.asp?recordNumber=BD0032, Accessed July 31, 2008

http://www.birdweb.org/birdweb/bird_details.aspx?id=315, Accessed July 31, 2008

http://wdfw.wa.gov/wlm/living/magpies.htm, Accessed July 31, 2008

 

Endemic Plants of Utah

Rabbit Valley Gilia or Wonderland Alice-Flower
Courtesy State of Utah:
Utah Division of Wildlife Resources
Ben Franklin, Photographer

Rabbit Valley Gilia or Wonderland Alice-Flower
Photo: Ben Franklin,
Courtesy State of Utah: Utah Division of Wildlife Resources

Other Utah Endemics on DWR pages:
Deseret Milkvetch
San Rafael Cactus
Welsh’s Milkweed

When something is unique to a particular geographic area it is said to be endemic to that area. Not too long ago, while preparing for a lecture on Utah’s biodiversity, I was amazed to discover that Utah ranks sixth in the nation for its number of endemic species. Only Hawaii, California, Texas, Florida and Georgia have more. The Hawaiian islands are totally isolated –a factor that encourages endemics. California and Texas have enormous land area so I’m not surprised they have the space for more species to evolve. And Georgia and Florida are warm and wet states where you would expect biological richness! So what’s Utah doing so high on this list?

It turns out that our unique plants give us this high ranking. Utah has 2602 plants in all plus 393 subspecies or varieties. With 247 endemics Utah has an endemism rate of 8.2%. That’s pretty amazing.

Some areas of Utah have a lot more endemic plants than others. The Colorado Plateau in the south and east of Utah has the most. On the Plateau, erosion has exposed a long succession of different rock layers, and the rock has weathered into a patchwork of locally unique soils. Ecologists have found that isolated or peculiar soil types are like a nursery for endemics. Fine textured soils, saline soils or those that are highly alkaline are associated with highest levels of endemism.

Environmental extremes in the desert such as high temperature or low rainfall prompt evolutionary adaptations that eventually lead to speciation. For example, cushion plants are common on the Plateau—these are compact, low growing, mats often with large and deep tap roots adapted to slow growth in a nutrient- poor and water-restricted environment. In Utah deserts, many different buckwheat and milkvetch species adopted the cushion plant structure thus forming new species.

Variations in elevation can isolate species and create localized versions of widespread plants. High elevation areas can act as islands within the Colorado Plateau separating plants into distinct populations until they diverge over time. The La Sal, Abajo and Henry Mountains form mid-high elevation islands whose resident species are becoming more and more unique, forming endemics such as Chatterly onion, La Sal daisy, Cronquist’s buckwheat, Navajo Mountain penstemon, and Dwarf mountain butterweed.

We all know that Utah is a special place to live, but just knowing that our plants are so unique is another good reason to go out and explore.

Credits:

Photos: Courtesy State of Utah; Division of Wildlife Resources

Text: Stokes Nature Center: Jessica Welsh and Holly Strand

Sources & Additional Reading:

Stein, Bruce A. 2002. States of the Union: Ranking America’s Biodiversity. A NatureServe Report Prepared for The Nature Conservancy. Arlington, Virginia: NatureServe. http://www.natureserve.org/Reports/stateofunions.pdf

Utah Division of Wildlife Resources June 1998. Inventory of sensitive species and ecosystems of Utah: Endemic and rare plants of Utah an overview of their distribution and status.

Utah Native Plant Society. January 2007 Volume 30 No.1 UNPS Annual Members Meeting, Oct 21, 2006, Logan, UT.

Welsh, Stanley L.1993. A Utah Flora (second edition) Provo: Brigham Young University.