City Creek Nature Notes – Salt Lake City

June 14, 2017

June 10th

Sego Lilies and Cheat Grass

6:30 p.m. The jet stream has reconnected over the Intermountain west to its usual spring route, and this has brought back strong, cooling breezes. This evening, I drive to the end of the road at North Terrace Hills Drive to walk up the trail from the Avenues to the south ridgeline of the Salt Lake salient that looks down into City Creek Canyon. I am looking for the Sego lily which blooms this time of year. One-quarter mile below where the trail intersects the road, I find patches of this Utah state flower (November 30th) among the parched Cheat grass. It is a bulb flower that rises from the hard ground sometimes without any leaves, and its four inch blossoms have delicate cream petals that are yellow at the base surrounded by splashes of dark red-purple. Against this central yellow backdrop, contrasting thick, white-colored stamens rise. I estimate about 80 lilies along are within a 100 feet along the trail for one-half mile below the ridgeline. Like most native desert wildflowers, it is a metaphor for beauty under adversity.

Also along the road are blossoming Canadian thistles (Cirsium arvense). Although a weed, its three inch light purple blossoms are a visually pleasing example of complexity in nature. Hundreds of small, spike like petals surround a central circular whirl of about 150 short, cylindrical, vertical stamens. The whirl pattern in its stamens betrays two counter-spirals of stamens that are arranged in left and right spiraling Fibonacci series.

Near the Sego lilies, there is a 10-inch diameter coyote burrow in the road bank to the west of the trail. That it sits along a heavily traveled mountain biking trail – perhaps between 50 to 100 people traverse this route each day – is unusual. It is not clear whether the burrow is currently occupied. The mouth of the burrow shows no recent signs of entry or exit, but there is contrasting excavated soil radiating below the entrance.

Below the ridgeline back over a mile to the trailhead, Gambel’s oak forest covers most of the land to the west of the trail, but the oaks only cover patches of ground to the east. Birds sing from their hiding places. I see Black-billed magpies at the trailhead and a Green-tailed towhee within the first quarter-mile. Near the ridge, Song sparrows, Black-headed grosbeaks, a hummingbird, and chukars are heard. From their calls within one-third of a mile of the ridgeline, I estimate 150 birds are present. None appear to be flying.

I reach the east-west running ridgeline and begin to climb another 150 feet to a small peak to the east of the intersection of trail and ridge. As with my last visit to this peak (January 5th), wind is blowing strongly from the north. The reason for the song bird’s grounding becomes apparent: in the steady wind, an avian farmer, a Cooper’s Hawk, hovers motionless about 20 feet above the ridge. The low Sun is filtered through clouds to the north, and its light sets the yellow molted breast feathers blazing. The hawk continues for hover for another minute, turns and glides off to the east just below the ridgeline.

From the peak, which bears a concrete and metal Salt Lake City survey corner marker indicating an altitude of 4,905 feet, or about 900 feet above the valley floor, there is a clear view down 20 miles of Wasatch Front Mountain Range from Grandview Peak and Little Black Mountain on the north, to Lone Peak on the south. In the evening light, the two sandstone geologic “U”‘s synclines that define Red Butte Canyon, Emigration Canyon, and part of Parleys Canyon are easily seen (January 9th). These sit on top of a larger deeper “U” shaped syncline of limestone that stretches from City Creek Canyon on the north and emerges again in Millcreek Canyon on the south. Perhaps this geology also explains why the streams in Red Butte and Emigration canyons reduce to trickle. Unlike City Creek and Millcreek with their limestone upper canyons, the surface bedrock of Red Butte and Emigration are porous sandstone. (Parleys Canyon contains two dams that hold back the stream.) Underground water may not be trapped along limestone layers. This is speculation, and another possibility is that Red Butte and Emigration canyons, unlike City Creek, were never reforested after the foresting and mining eras of the last half of the 19th century. Summer surface water may simply evaporate. To the west, the jet stream is marked by a fast moving line of clouds that extends from the southwest to the northeast.

Looking at the lands around the peak, they are one-third green oak forest, one-third dried brown Cheat grass, and one-third still green native brome. It must have been an impressive spring sight of green meadows before the invasive grasses arrived. The peak itself is covered in Cheat grass about six inches deep, and because of this year’s heavy winter snow, an acquaintance reports stands several feet in height along the Bonneville Shoreline Trail below this peak. The cheat grass is read to burn, and within the last week across the state, six large cheat grass wild fires of over 1,000 acres have burned. Several smaller cheat grass fires of a few acres in size also occurred in Salt Lake Valley over the last week, but those were quickly suppressed. Although overgrazing immediately after the Euro-american colonization of the valley in 1847 quickly converted fire resistant native bromes and bunch grasses to non-native adventive grasses spotted with sagebrush (March 13th), cheat grass was not present in the valley or on the Avenues ridgeline. This weed grass was introduced in California in 1870 (id), and the grass followed along the railroads lines east (Monson and Kitchen, 1992, p. 24), but may have also traveled as a contaminant in feed grain (id at 33). Cheat grass was first collected in Utah in 1894 by M. E. Jones on Provo, Utah (Barbour and Billings, p. 264; Monson and Kitchen). How fast it overtook native grasses statewide is unclear, but in 1932, Pickford of the Intermountain Forest and Range Experiment Station noted that while Cheat grass, which he called Downy brome, was found in all areas of the north half of the state, it was only dominate in the Great Salt Lake area (Pickford, 1932; Monson and Kitchen, 24). Pickford found that Cheat grass was most dense (11 percent coverage) on plots that had been both grazed and then subjected to a grass fire, but it was absent from plots that had never been grazed or subjected to a burn. What makes Cheat grass different is the higher frequency of its burn cycle and the higher temperatures at which it burns (Monson and Kitchen, 24). There is a direct relationship between the level of the prior winter’s precipitation and cheat grass fires in the following summer (Monson and Kitchen, 24). One-hundred and twenty-three years later, this hot burning grass covers the Avenues ridgeline, more than half of the City Creek canyon walls of the Salt Lake salient, and much of the State. The state and federal agencies spend about 83 million USD per year fighting wildfires in Utah (Stambro et al, 2014, Chap. 9), and much of that total is related to cheat grass fires.

The peak is also covered in unidentified, one-half inch nymph crickets. When walking forward, every step raises five or six nymphs that jump forward to avoid being crushed. They are marvels of camouflage, and their dark brown, light brown, dusky yellow and dirty white colors perfectly match the surrounding dried grass. They move at the slightest provocation and it takes several attempts to locate one for a photograph. Even knowing where it is, I have to stare at the brown grass for fifteen seconds before I can make out the cricket’s outline.

Despite the invasives, the expansive view of the surrounding hills and mountains is inspiring, and I return home a happy and contented person.

* * * *

In Thoreau’s “Journal” on June 10th, 1853, he notes honey locust, black willows and blackberries are in bloom. He hears a robin. On June 10th, 1856, he watches a huckleberry bird and finds a pigeon woodpecker nest with young. On June 10, 1857, he sees a snake. On June 10, 1860, he examines a bat suspended in the daytime forest.

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The Fibonacci series seen in the whirls of the center of a bull thistle plant reappears in many plant contexts, including how seeds are distributed around a pine cone (Klar, 2002) and how branches are radially distributed around on tree (Nelson 2004). The study of the arrangement of leaves on a plant is called phyllotaxis. There are several competing hypotheses for how leaves self-assemble themselves themselves in a Fibonacci series, and the prevailing theory is that these spatial patterns are the result of most-efficient packing solutions (Klar). Hormonal diffusion is also theorized but the actual mechanisms are unknown (id). Limited progress has been made in defining the theoretical mathematics of how a circle of undiffentiated meristem plant stem-cell tissue can transform into a spiral pattern and on identifying candidate biochemicals that control the process (Flemming, 2002).

Restoring areas contaminated with cheat grass has proven difficult and expensive in terms of both capital and labor (Barbour and Billings, p. 264; Monson and Kitchen). Salt Lake City and Salt Lake County have spent over 150,000 USD since 2008 trying to rehabilitate about 180 acres (0.3 square miles) in City Creek and Parleys Canyons that are contaminated with both Yellow starthistle and Cheat grass (see May 21st). The best strategy for restoration is reseeding following a cheat grass fire, but its effectiveness is limited to level areas (Barbour and Billings, 264-265) and not the steep slopes of City Creek Canyon and the Salt Lake salient. Although the city considered a controlled burn program in City Creek in 2010 (Gray and Harrison, 1999; Salt Lake Dept. of Public Utilities 2010, Salt Lake City Corporation 2010a), it was not pursued, and currently the Utah Conservation Corps is using the labor intensive method of manually denuding and spraying fields in lower Pleasant Valley, including along a steep slope (May 17th and May 21st).

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On June 10th, 2006, students at the Design Workshop recommend daylighting City Creek Canyon stream from the mouth of City Creek, along North Temple, all the way to the Jordan River (Salt Lake Tribune). Daylighting means raising the creek which now traverses the city’s center in underground pipes back to the surface. (Prior U.S. Corps of Engineer and City proposals recommended daylighting City Creek beginning at 700 West.) On June 10th, 1898, the National Guard plan exercises in City Creek Canyon (Deseret Evening News).

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May 9, 2017

May 6th

Wizards of the Canyon Soundscape

7:00 a.m. The entrance to the canyon along Bonneville Drive is closed today for one of the many social 5K runs that occur during the summer. This adds an extra mile jogging along the drive to reach Guardhouse Gate. As I start, the sun line is just beginning to descend the snow capped peaks of the western Qquirrh Mountains and the small sliver of the southern tip of the Great Salt Lake reflects slate blue. The clear western sky shows the last vestiges of dark slate band of the Earth’s shadow retreating from the sun. Along the first stretch of road there are many sage brush bushes that provide cover to chukars. I stop to pick and crush a bracket of this pungent bush to remind myself of what Utah smells like during the heat of summer. About one-half mile from the gate and around a bend, the canyon explodes with the sounds of stream and birds. Although hidden, a male Lazuli bunting peaks from behind some red maple leaves, singing loudly. His colors are muted, since he perches in early morning shadow of the canyon’s east ridge. The sound of the stream is overwhelming, and this indicates the vernal season’s heat is melting the high snowpack. At the gate, the parking lot is full, and includes the enormous truck of the wild turkey bow hunter (May 4th). I must have just missed the race organizer’s closing of the road.

Along the road, the grasses are now twelve to eighteen inches thick, and the first quarter-mile is nearing full leaf out. Near mile 0.3, I look up through the trees to the step slope above, and there a young female mule deer idly grazes on the new grass. I stop to watch and after some minutes, she takes notice of me, stares back, and knowing that it is not hunting season and she is in no immediate danger, she slow walks and disappears into the Gambel’s oak forest. A bird loudly chirps from a nearby tree, and I catch a fleeting glance of black, white and red-brown from below. It is probably a Rufus-sided towhee (Pipilo maculatus). I count about forty or bird separate birds calling the forest thickets in the first mile.

I am not a morning person, most of my daily observations are in the afternoon, and the morning spring canyon is a new place. The warm morning light crawls down the western ridge of the canyon, and makes the thick grasses of spring bathed in an inviting green light. Although it is a pleasant high fifties along the road, one can feel the advancing daytime heat in the seventies approaching. Between mile 0.5 and 1.0, large overhanging trees in partial leaf-out form a series of green tubes through which the rising south-eastern sun penetrates. The lighted end of these tubes with the darkened green leafed foregrounds reminds me of the religious ceiling paintings of European cathedrals. I am overwhelmed by the beauty of it all.

In this half-lit morning reflected light, the canyon has a different character. I have misjudged the Starry solomon’s seal. In the afternoon, I have found two or three open out of an estimated 20,000 plants (May 4th). This morning, most are open, and I easily count 200 open blossoms in the solomon grove surrounding the seep below picnic site 5. The number of active birds is astounding, and a multiple of several times over my afternoon encounters.

At the entrance to Pleasant Valley, I run into the Tracey Aviary sponsored birding, a course directed by and led today by aviary biologists Bryant Olsen and Cooper Farr. I am happy to find the group; I have followed their Cornell birding logs in the canyon for some years; and in the spring, they regularly return to the canyon. Other seasons draw them to other habitats. Traveling down canyon, there seven group members including the leaders, and their five students are a diverse group that range from their thirties to eighties. They allow me to tag along as they proceed down the Pipeline Trail for the one mile walk back to the parking lot. Since I have been frustrated for some years in identifying the thicket hidden birds by sound, and I hope to gain some insight into the process by watching and learning. I quickly learn that I am in the presence of masters. Many birding skills quickly become apparent that explain the large number of birds that they record each week in the Cornell University E-bird log system (Cornell Ornithology Laboratory 2016).

First, birding in groups greatly increases detection. I first encountered this in amateur astronomy. Looking for detail in nature, which involves rare events, is more likely with more eyeballs that can cover the whole sky. In addition to the chance of making a sighting, the ability to perceive rare events also differs greatly by both the ability to perceive and by the knowledge to understand what one is seeing or hearing. The seven of the birders stare intently towards a sound coming from a clump of leaves, and one or two of the seven will first detect the bird, and then direct the others to it. Seven sets of eyes scanning the sky’s dome catch fleeting glances of bird movements in opposite directions, and this greatly increases the number of exclamations that one or another of some species has been seen.

Second, time explains the groups many sightings. As we descend the trail, younger runners and bikers wisk by at six to fifteen miles per hour. They traverse the mile of Pipeline trail in five to ten minutes. When I was younger, I has one of these. They smile as they pass, confident in their belief that in their superiority that their youthful ability to exercise makes them the most important denizens of the canyon. My slow jogging takes twenty minutes, but the birding group takes about one and one-half hours to walk this mile. Perception and time are inversely related. The slow see more; much more. Chance visual sightings reveal common sightings such as the cliff-soaring Red-tailed hawks. In this way, the group quickly seeings a Peregrine falcon resting on the top of the western massif at the entrance to Pleasant Valley and a brood of cliff dwelling Violet-green swallow (Tachycineta thalassina) living nearby in the crumbling deposits of Van Horn and Crittenden’s Triassic conglomerate No 2. sandstone. Are these the peregrine’s prey? Peregrines prey on many of the plentiful birds and mammals in the canyon, including mallads, swallows, Mourning doves, Northern flickers, starlings, American robins, Black-billed magpies, American crow, hummingbirds, owls, mice and Rock squirrels. Thoreau used the Peregrine’s historical name – the duck hawk – and Audubon memorialized this predator-prey relationship in a noted 1827 oil painting (Audubon 1827). The peregrines are in turn fed upon by larger birds of prey like Bald eagles and Red-tailed hawks. The birding group has great interest in following the falcon back to its nest, since these birds, although removed from the United States endangered species list in 1999, remain popular and are known to raise young near Pleasant Valley.

Third, these are the wizards of the canyon’s bird soundscape. Raw knowledge, expertise, and practice allows the group to identify many birds by sound alone or first by sound and then by sight. A member will hear a call of interest, and all will stop intently listening while leaning in one direction; some cup hands around their ears. Someone will call out a name, there is a discussion, and then a final determination is made as to the species. Sometimes, this is accompanied by a pointing figure and the exclamation “There it is!”, and all binoculars are raised in unison. I humbly learn the calls of one or two common canyon residents, like the chirping of the Rufus-sided towhee, and can notice distinct obvious sounds, like the wing-beat of a passing Broad-tailed hummingbird (Selasphorus platycercus) and the obnoxious squawking of the Red-breasted nuthatch (Sitta canadensis). But the group’s ability to identify unseen colorful birds by sound alone is astounding. They hear a Green tailed towhee (Pipilo chlorurus), an Orange-crowned warbler (Vermivora celata), and a Western tanager (Piranga ludoviciana).

The group’s ability is distinguish between similar calls is uncanny. I have a particular interest in the rapid chirping call of the Rufous towhee. Later at home, I compare audio recordings and spectrographs of several species found along the trail that all include to my uneducated ears, subtle variations on a series of four to six rapid fire trill chirps, preceded or followed by two tones. The songs of the Rufous-sided towhee, the Green-tailed towhee, and Orange-crowned warbler, are all variations on a theme.

The group continues down the trail as the bright line of sunlight engulfs them. The celebrity bird of the afternoon are many Lazuli buntings. On the western brightly lit slopes, perching on a Gambel’s oak, several of these buntings are seen. They males are aflame in their cloaks of brilliant iridescent blue. Bryant notes that a bird’s coloring are the result of their feathers refracting sunlight. The explains why colorful birds have dulled colors in diffused light, but radiant colors in full sun. Near trail mile 0.5, a Black-chinned hummingbird (Archilochus alexandri) sits on a powerline and obligingly ignores the birders as they take photographs. In the last third of trail mile, the sun and temperature has risen, the birds are less active, and the group quickly exits back to the road. A mallard rests in the flood retention pond.

I point out the cliff nest site that I followed last spring near mile 1.0 (Dec. 9th, 40°48.227 N, 111°52.204 W), but only about one-half of the group can see the nest. I had previously thought it was built by Peregrine falcons or Cooper’s hawks, but Bryant notes I am mistaken. Peregrines and Cooper’s hawks do not build stick nests, he says, a point supported in literature (Utah Legacy Raptor 2011). A later search on the internet returns many photographs of peregrines nesting in nearly identical stick nests. A probably resolution of the difference is found elsewhere: peregrine falcons sometimes will take over the stick nests of other raptors like eagles (White et al 2002).

Comparing the group’s Cornell Ornithology Lab birding logs for the canyon since April 30th reveals the arrival of many small migratory song birds with the abrupt rise in temperatures and the arrival of the vernal season (April 29th and May 1st). Common canyon birds in their logs in April through May 6th include mallards, European starlings, American robins, House finches, Song sparrows, Dark-eyed Juncos, Black-billed magpies, Mourning doves, Ravens, American crows, Red-tailed hawks, and Cooper’s hawks. New spring heat-seeking migrants that arrived just as the temperature switch tripped two or three days ago include the Peregrine falcons, Plumbeous vireo (Vireo plumbeus), Warbling vireo (Vireo gilvus), Orange-crowned warbler, Yellow warbler, Virginia’s warbler, Chipping sparrow (Spizella passerina), Green-tailed towhee, the Western tanager (Piranga ludoviciana), Broad-tailed hummingbird (Archilochus alexandri), Black-chinned hummingbird, Lazuli bunting, the Lesser Goldfinch (Spinus psaltria). These new colorful arrivals have followed the north running heat wave from the southern states and Mexico for a thousand miles to this northern canyon, and now that they have arrived, their next tasks will be mating and beginning the construction of nests.

I ask a question about what some of the most common canyon birds eat. I am interested in not only the simple phenological list of what bird species arrives when (this is what Thoreau did), but also how the web of insects, plants, and birds link together. The aviary experts’ answers are general and unsatisfying. “Seeds” (there are none), “grass” (they have not developed grains), and “insects” (there are still few, given the newly higher temperatures). The same vague discussions are found in my various paper and internet birding guides. I have witnessed a few instances in which canyon birds actually eating something over an entire year. A scrub jay ate acorns in the fall (Oct. 6th); wild turkeys ate winter acorns (Dec. 29th); chickadees ate winter fruit; spring kingfishers fish along the ponds and stream, although I have never seen them catch anything (March 19, April 6, 11, and 18); in the mallards eat spring algae from the stream; hummingbirds and dragonflies feasted on summer gnats (August 1st and August 11th), and a few days later, cliff swallows gorged on the dragonflies (August 22nd). In the spring of 2015, two falcons ate a mouse. But what are they, in particular the new arrivals, eating now? After this morning with the soundscape wizards and a subsequent literature search, I am struck both about how much science knows about the birds and how little science knows about birds. All things cannot be known, and I suspect there is little grant money available to fully construct and quantify the ecological relationships of even close natural areas, since minerals, logs, and skiers only have economic value and iridescent sheen of the Lazuli buntings do not.

A lone mallard sleeps near the shore of the flood retention pond. Jogging out of the canyon, the social-cause, 5k fun-run has begun, and three or four-hundred joggers are going towards milepost 0.5, along the opposite western leg along Bonneville Drive. A loudspeaker blares out popular music. Groups of racing bicyclists stopped by the police to allow the race to pass joke about blindly coming around a curve into such a mass of humanity. Their focus on life is different from mine, and neither, as they go about their respective enjoyment of the canyon, will perceive the dazzling blue of the Lazuli buntings seen by the wizards of the canyon soundscape.

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Iridescence in birds is caused by both pigments and the refracting structure of their feathers (Doucet and Meadows 2009; Rajchard 2009), and many birds also perceive light, including the iridescent refraction, in the ultra-violet spectrum (id). The view that humans see of birds is not what they see of each other. The blue feathers of birds, like the Lazuli bunting, may be hint that a bird can see ultra-violet light (see Doucet and Meadows, S118). Falcons use the ultra-violet reflection of mole and mouse urine to determine the density of their mammalian prey in fields (Rajchard). Fruit seeking birds like crows better see mature fruits because the ripe fruit better reflect ultra-violet light (id). Blue tits switch to the ultra-violet spectrum to see insects against non-contrasting backgrounds (id). The iridescent patches also help birds to distinguish their sexes, just as human birders do, but in some birds, the ultra-violet spectrum of their iridescent patches enhance the sex difference of their pigments seen in the human visual spectrum (id). Another study suggests that in the ultra-violet spectrum, some birds find it easier to distinguish eggs (id). Iridescence can also be an indicator of fitness to breed. Male birds lose iridescence as they age and when they are sick (Doucet and Meadows, S120-S121).

The iridescent patches of birds involve a trade-off. Iridescent patches, like those of the front-chin of the Broad-tailed Hummingbird and the side-neck of the Black-chinned hummingbird seen today, may be more visible to their predators, but they are also more visible to their potential mates (Doucet and Meadows). To reduce the predation cost of these patches, some patches are directional. A bird living in a diffusely, dark lit forest can perch in a ray of sunlight and send a narrow beam “flash” to other members of its own species and to potential mates (id). Predators circling above will not see this visual chatter. Conversely, the bright Lazuli bunting simply shines like a beacon. What do the hawks and falcons circling above see of these beautiful song birds in the shorter-bands of light that we human birders are unaware of?

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On May 6th, 1899, work to replace the City Creek water main with a larger diameter pipe was underway (Salt Lake Herald), although a suit seeking an injunction against the construction had been filed. On May 6th, 1888, Z. Jacobs canvassed citizens for suggestions on how to increase the city’s water supply, including Fire Chief Ottinger (Salt Lake Herald). Jacobs argued against building a dam in City Creek Canyon, since failure of the dam would destroy the downtown (id).

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