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.

* * * *

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.

* * * *

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.

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