City Creek Nature Notes – Salt Lake City

June 23, 2017

June 16th

Partial Success in Treating Starthistle

3:00 p.m. The field at lower Pleasant Valley (mile 1.2) where the Utah Conservation Corps and the city watershed officials have done Starthistle abatement (May 17th, May 21st, October 16th) has both succeeded and failed. The horizontal field at Pleasant Valley has filled in with new native grass, Wild bunchgrass (Poa secunda), many smaller wildflowers and also the invasive Western salisfy. The lower field is an idyllic scene, but because the field has been sprayed with Milestone herbicide (Aminopyralid), the Peregrine falcons are not hunting here for Rocky Mountain deer mice as in prior years.

The green of the lower field climbs up the hillside, and this is also an area where the Utah Conservation Corps manually pulled starthistle weeds. I cross the field to the slope to take a better look, and to my surprise, the treated vertical slopes have three or four times the density of starthistle plants as compared to the slope’s pre-treatment state last year. Other treated steep slopes to the west of Pleasant Valley are in a similar condition. Limited to steep slopes, the abatement project is a failure. Probably only a burning with reseeding can rehabilitate such slopes, but citizens in nearby residential areas rejected a burn control approach proposed in 2010 (see Salt Lake City Department of Public Utilities 2010). Conversely, expensive manual pulling in conjunction with Aminopyralid spraying worked on horizontal fields (see Utah Watershed Restoration Initiative at May 21st).

I am also concerned that the use of Aminopyralid might be detrimental to the Peregrine falcons, Cooper’s hawks or Western screech-owls that utilize this field. Earlier this year, while with the Tracey Aviary bird count team (May 6th), I saw a Peregrine falcon hunting above this area, and in spring of 2015, a pair of peregrines would regularly sit on the power line wires above the field. One afternoon, one of the pair dived on the field, and then slowly rose beating its wings while grasping a fat deer mouse in its talons. The second falcon left its perch, swooped up from below of the first falcon and extended its talons. This startled the upper falcon and caused it to release its catch. The lower falcon, while flying inverted, expertly caught the mouse and flew off with its prize. Research later in this evening locates a 2007 United States Forest Service sponsored assessment of the effect of this herbicide on birds, principally by literature review (Durkin 2007). Since birds have a short-life span (Peregrines and Cooper’s hawks both live about twelve years), testing consists of applying a variety of doses of the chemical to test species. In the instant of Durkin’s review, a 2003 prior study force fed quail with a 50 percent lethal dose of Aminopyralid (id, pp. 96-97 and 4-1 to 4-6). The quail grew disoriented in the short term, but survived. In another study using high doses on hatchlings, success to viability declined up to 30 percent. Other lower dose studies did not find any significant effects. The consultant recommended exposure levels for humans, birds, and mammals based on prior works. Based on this limited study, my concern about using Aminopyralid around Peregrines and Cooper’s hawks were assuaged. Aminopyralid is not another DDT.

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Per Thoreau’s “Journal” on June 16th, 1852, he records a morning fog with singing birds, and he remarks on how evening mornings are now hot. In the night, he sees an aurora borealis to the north. On the morning of Per Thoreau’s “Journal” on June 16th, 1853, he hears robins, birds, other birds, and crickets. He sees sunlight reflecting off a stream that makes the stream appear as silver metal (compare Dec. 26th, in main text, above). He extracts a red squirrel from its underground nest. Per Thoreau’s “Journal” on June 16th, 1854, he sees fleabane. The Utah version is Utah fleabane, Eigeron utahensis. He sees white lily and two variants of wild rose. He hears a cherry bird. Per Thoreau’s “Journal” on June 16th, 1855, he sees young squirrels. Per Thoreau’s “Journal” on June 16th, 1858, he smells blackberry blossoms, and on June 16th, 1860, he notes summer thunderstorms are now a common occurrence.

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On June 16th, 1997, the U.S. Forest Service revives the Anschutz Ranch East Pipeline Environmental Impact Analysis after a consultation disputes Chevron’s claim that an existing pipeline has sufficient capacity to handle all loads for the next fifty years (Salt Lake Tribune). On June 16th, 1919, there was a large grass fire in City Creek Canyon (Salt Lake Herald). On June 16th, 1915, bids were opened for the construction of the reservoir at Pleasant Valley (Salt Lake Telegram). On June 16, 1910, the Little Giant Mine petitioned the City council to open a mine in City Creek Canyon (Salt Lake Herald). On June 16, 1904, a bear destroyed a camp at the forks in City Creek Canyon, and Ben D. Luce and party hunted the bear (Salt Lake Telegram). On June 16, 1881, J.J. Branch, a former L.D.S. Church member who was present at Joseph Smith’s death, now turned evangelist, held a revival at a tent in Salt Lake City, at which he predicted that God would send a great flood from City Creek Canyon and destroy the City in retribution in retribution for the “wickedness and lying and blasphemy and abomination” of the L.D.S. church (Salt Lake Tribune). On June 16, 1897, George Crimson, a still living 1847 pioneer, relates his biography (Salt Lake Herald). In the spring of 1848, Crimson and his father built the first grist mill in City Creek Canyon, and sold the same to Brigham Young (id). He left for the California gold rush in 1849.

December 6, 2016

December 6th

Filed under: Bald-Faced Hornets, Gambel's Oak, Nests, Starthistle, Weather — canopus56 @ 8:07 pm

Orange Lichens

1:30 p.m. The cold pocket of arctic air has dropped temperatures into the low twenties and with canyon winds down into the teens. The flood retention pond at Bonneville Drive has started to freeze over, and the effect on the cattail patch that grows in the pond is immediate. Previously, the dried cattails stood erect, and now they have fallen over.

As I jog up canyon, the sky is overcast with the cloud bottoms only a few hundred feet overhead, there is a wind driving light snow out of the north. By the time I reach milepost 1.0, this changes and the snow drops vertically. This kind of overcast with falling snow and cold changes perception of the canyon; it makes the canyon seem more dramatic. A buttress that sticks out on the north-west canyon wall at mile 1.1 normally looks insignificant. In the diffuse overcast light, falling snow and severe cold, it looks like a grand mountain. Four mule deer are seen on the high on the south canyon wall; three more are seen back at mile 0.2.

Between mile 1.2 and mile 1.6, lichens (Xanthomendozaon species.) growing on the Gambel’s oaks have turned from green to a dull and bright orange. With the falling snow and overcast light, this orange contrasts greatly with their host tree trunks. This color change can occur when lichens are exposed to nitrogen rich, polluted air, and such changes are used to track air pollution over time in over cities. Salt Lake City has some of the worst air quality in the nation, and the U.S. Forest Service surveys lichens at 128 plots throughout Utah, including one plot in upper City Creek Canyon. But Werstack et al (2016, pp. 43-44), researchers with the U.S. Forest Service Rocky Mountain Research Station, conclude that Utah’s lichens probably overstate air pollution. This is because orange-turning lichens are also correlated with drought tolerance (id). The lichens may be turning orange because they are in a drier climate and not because the air contains more nitrogen dioxide. The Rocky Mountain Research Station is currently conducting studies to calibrate the density of orange lichens by precipitation, thus allowing western researchers to use these epiphytes to monitor air pollution.

At mile 1.6, the snow on the north-west hillside emphasizes yellow star-thistles. Dried tall grasses and the star-thistles have the same hue, and I do not ordinarily perceive them in the meadows. But the ground snow makes for a differing background that allows one to distinguish between hills that are covered in grass and those that are covered in these invasive thistles. It was undesirable plants that the Utah Conservation Corps are trying to eradicate from the meadow one-quarter mile down canyon from here (October 16th).

I take my time jogging back down the canyon. I have been inventorying bird and insect nests in the canyon since December 2nd, and today I am marking each nest’s location using the global positioning system. Hornet’s nests are temporary constructions meant to last a single season. On December 2nd, I find and photograph the largest in the lower canyon between picnic sites 4 and 5. It is twice the size of a basketball, and it precariously sits intertwined with the smallest upper branches at the top of a 100 foot tall Rocky Mountain cottonwood. After three days of snow, rain, and freezing temperatures, I cannot find it again. Apparently, winds have blown it out of the tree or ice formed on it, and the weight of the ice pulled the nest from the heights.

October 16, 2016

October 16th

“C” is for Conservation

5 p.m. There was a wind storm last night and the temperature dropped 25 degrees Fahrenheit in the early morning hours. Even so, the canyon is again packed with walkers, runners and bicyclists. The wind-tunnel up to mile 0.9 has stripped even more leaves from the trees and the fallen leaves now cover even more of the road. At mile 1.3, Pleasant Valley opens into a sea of dark golden brown. All of the Gambel’s oaks have turned and they are set off against similar dark red-brown groves on the south canyon slope.

Here, back on October 12th, students from the Utah Conservation Corps, a project of the Utah State University Logan, are resting after working on a starthistle restoration project in the meadow on the north side of the road. The yellow star-thistle (Centaurea solstitialis) is a roadside weed that produces small quarter-inch burrs. It was into starthistles and burdock that “burr boy” wandered into on September 5th. As an experiment, the Corps have cleared nearly a football field sized plot in the meadow and continuing up onto the north canyon slope. They hope to re-seed the plot with native plants and determine if the star-thistles can be abated. Over fifteen years, students in the Corps have restored over 40,000 acres of habitat and 3,300 miles of trails.

These undergraduate and future biologists, range managers, and foresters complain that while clearing the meadow, they were attacked by Western Yellowjacket wasps. The yellowjacket wasps, unlike the Bald-faced hornets whose nest is here in a tree on the south side of the road (Sept. 16th), build an almost identical paper nest underground, often in the abandoned burrows of rodents. But the door of the yellowjacket nest is at the top, and not on the side as with their tree-dwelling Bald-faced cousins. Disturbed by the clearing of the meadow, the yellowjackets came out in force to defend their home. Today, I unsuccessfully search the scoured plot for the entrance to their lair.

At the flood retention pond where the canyon road meets Bonneville Drive, the cattail grove and the surrounding tamarisk are turning brown and yellow, respectively.

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