City Creek Nature Notes – Salt Lake City

June 25, 2017

June 25th

Fishing spiders

5:00 p.m. The first mile of road has turned into a green tube, and the garland of butterflies described on June 15th and June 22nd continues. The sky is clear and the air calm. Trees overhang above and views of the stream are obscured by thick underbrush except at picnic sites. The stream can also be accessed at small breaks made by anglers or at small natural breaks. There about ten of these breaks along the first road mile. I force myself through several of the breaks and look down to enjoy the cool, transparent stream. At each I find various types of spider webs: disordered tangle webs, sheet webs hung low just above the waterline, and the circular webs of Orb weaver spiders (Araneus sp.). Paradoxically, I see no spiders today, but their webs are full of hapless arthropod victims.

Lining the stream banks at these breaks are Bittersweet nightshade plants (Solanum dulcamara) a.k.a. Climbing nightshade with deep blue blossoms. These plants hug the stream’s steep banks and vertical rock retention walls, and they grow just above the waterline. At a few places along the first road mile, they incongruously protrude from the understory of serviceberry bushes (Amelanchier sp.), and there they are noticeable because their colorful blossoms are one of the few flowering plants that are left after the spring flower explosion. The Nightshade’s blossoms are either shriveling or extend vibrant yellow cones surrounded by blue petals. In the fall, these will yield bright red fruit.

Looking up from the stream and into the thick green sub-story, there are butterflies everywhere. They are the usual suspects for a canyon spring and early summer: Cabbage white butterflies, Western tiger swallowtails, Mourning cloaks (Nymphalis antiopa). These are now joined by White Admiral butterflies and by Common whitetail dragonflies patrolling overhead. I am used to seeing this floating butterfly assemblage traveling linearly on their feeding searches along bushes on the road’s sides, but here they fly in their natural setting. The butterflies follow large spiral flight paths broken by and traveling through the dense shrubs. In this setting, their frenetic sharp turns and chaotic shifts are necessary to navigate this complicated scene, and this explains these seemingly purposeless motions on their flights over the road. In this manner, the butterflies explore every possible hiding place in which a flowing blossom might be found.

At each of my stops along the stream, I see about five butterflies, and together with butterflies along the road, I estimate that there about 100 butterflies in the first mile road. Two Painted Lady butterflies (Venessa cardui) are also patrolling the roadside bushes. What flowering plant these butterflies are searching in the shurb understory is a mystery. The daytime flowering blossoms of spring are past, and only a few Foxglove beardtongue flowers remain open producing nectar. The only substantial flowering plant left is Yellow sweet clover. But the stands of this weed that line only the roadsides are fading, and on any one plant only one-third of the blossoms found at their peak are viable.

The fierce post-solistice sun begins to affect tree leaves. One or two Gambel’s oaks and Norway maples have a brace of leaves that are browned and shriveled at the edges. Once damaged, their leafs curl up, and the crabapple tree at the upper end of Pleasant Valley near mile 1.7 shows similar signs of stress. But the deciduous trees’ principal defense against the loss of water from heat and sunlight is a waxy layer on the upper surfaces of trees. This is best seen on the leafs of the western River birch trees. At the right angle to the Sun, their canopy flashes dappled green light for leafs titled away from the light and a blinding silver-white light for those at appropriate angle of reflection. University of Sussex ecologist Hartley notes that the waxy layer provides another benefit: it is some tree’s defense against caterpillars (Hartely 2009). Although caterpillars have evolved specialized feet to grasp leaf surfaces, caterpillars have a hard time walking over the wax layer, they fall off, and the plant is preserved. This may explain the caterpillars sometimes found along the road in the last week. I had supposed the caterpillars had crawled onto the roadway, but perhaps they have slipped and fallen from above.

Returning down canyon from milepost 1.5, insects are backlit by the Sun, and this makes them easier to see. At mile 1.1 near the entrance to lower Pleasant Valley, 30 to 40 Common whitetail dragonflies are circling between 50 and 100 feet above ground. Between the road surface and fifty feet, there are none. In cool places beneath the shade of trees, the prey of the dragonflies, groups of up to 100 gnats float. A small, immature desert tarantula (Aphonopelma chalcodes) scurries into the bushes.

Also mile 1.1, I hear raptor screams, and this repeats my earlier experience of June 21st. They are the unmistakable calls of two Peregrine falcons (Falco peregrinus). This time I travel back up canyon to get a better view, and below the eastern canyon wall near mile 0.8, more than a quarter-mile away, two peregrines are driving a smaller bird away from the canyon sides. There loud screams travel coherently through the calm summer air. This may be where the peregrines are nesting this season, but that side of the canyon does not have the steep cliffs found on its western walls. I note to watch this area closer to see if a nest can be confirmed.

* * * *

Per Thoreau’s “Journal” on June 25th, 1852, he sees a rainbow in the eastern morning sky. He opines that younger birds are duller in color in order to protect them from predators. He hears a bobolink and a golden robin. He sees wild rose and butter-and-eggs. He notes that in cool air, the ridges on distant mountains are more distinctly seen. He describes a moon-light walk. On June 25th, 1853, he finds two bushes of ripe service berries and associated cherry birds. On June 25th, 1854, he sees a bittern. On June 25th, 1858, he sees two or three young squirrels playing. He observes how objects including grass and water skimmers cast lenticular shadows on the bottom of a river. He again notes how the lighter undersides of leaves illuminate dark sprout forests.

* * * *

On June 25th, 1946, City Water Commissioner D. A. Affleck closed all lands in lower City Creek and above 14th Avenue to entry in order to prevent the possibility of grass fires (Salt Lake Telegram). Campfires were prohibited in upper City Creek Canyon (id). On June 25th, 1913, City officials plan to inspect the headwaters of Salt Lake valley canyons for water purity as part of a plan to develop more water sources (Salt Lake Telegram). On June 25th, 1896, new silver and lead ore bodies were discovered in upper City Creek Canyon about one mile from the old Red Bird Mine on Black Mountain (Salt Lake Herald). Mining work continues at other mines in the Hot Springs mining district, which includes City Creek (id). On June 25th, 1892, an old, destitute woman who had been living in cave in City Creek Canyon was sent to the hospital (Salt Lake Times).

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June 14, 2017

June 9th

First Tarantula and a Fake Bee

7:45 p.m. The jet stream to the northwest has begun to lower temperatures in the eighties and brings cooling evening breezes to the canyon. On this Friday evening, families seeking release from the days of heat fill the first few picnic sites. The heat wave is starting to end, and invasive Yellow sweet clover lines both sides of the road and waves under the wind. But there is no sign of summer’s yellow sunflowers along the road in Pleasant Valley. More soft tufts of pollen float down from the Rocky Mountain cottonwoods and their white down lines the roadside. Evening Black-headed grosbeak calls predominate in the first mile. A 3 inch unidentified dark blue-black dragonfly sails by. A unidentified light brown beetle, that has the shape of a solider beetle, has been seen on the road over the last few weeks. At the rear tip of its shell, there is a diamond shaped darker brown patch. On the road today, the nymph form of this beetle crosses the road. It is bright lime green. A black ant drags a bug twenty times its size to the side of the road.

Planted squarely across the center of a Wood rose blossom near mile 0.3, a member of the Galphyridae family of Bumble bee scarabs. The Bumblee bee scarab is a beetle, not a bee. Its wing shell has four horizontal white strips on the sides and two vertical white stripes on either side of the centerline. Its bee-like features are the abdomen that extends past the wing shell and is covered in fine yellow-white hairs. Its thorax is also covered with these fine hairs. Male Bumblee bee scarabs are sometimes found in flowers, as this oddly behaving one is. This scarab appears almost intoxicated. It is oblivious to my presence and seems to relish feeding on the rose’s pollen. Given its lethargic ways, the scarab’s mimicry of a bee might provide protection from predators, but given that birds eat bees, what predator does the scarab’s mimicry deter?

Near mile 0.4, the season’s first desert tarantula crosses the road. It is only two or three inches across. By mid-summer, it will grow to 5 to 6 inches across (August 17th).

* * * *

In Thoreau’s “Journal” on June 9th, 1850, he notes pitch-pine pollen collected on water. On June 9th, 1851, he observes that signs of the season are grass waving in the wind, new leaves on trees, and increasing louder crickets. On June 9th, 1853, he sees the season’s first lily bud and notes white clover is common. He sees starflowers in a meadow and gathers strawberries. He observes a hawk pair. On June 9th, 1854, he sees a lark and notes that the air has a high density of mayflies. On June 9th, 1857, he sees an indigo bird. On June 9th, 1860, he sees water bugs in a stream.

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On June 9th, 1915, a new reservoir on Fifth South that holds 10,000,000 gallons was inspected, and it will supplemented by a 5,000,000 gallon reservoir at Pleasant Valley (Salt Lake Herald). On June 9th, 1909, the Intermountain Republican reported that a flooding City Creek stream was still carving “numerous erratic channels down North Temple street”. Sandbags and manure was used by crews working under Street Supervisor J. T. Raleigh to create embankments, but this results in large pools of fetid water forming (id). The Tenth South canal overflowed its banks. On June 28th, 1905, the Commercial Club officially turned over the new Wasatch Boulevard to the City (Salt Lake Herald). The boulevard runs up City Creek Canyon, along 11th Avenue to Popperton Place, and then on to Fort Douglas. The boulevard then descends to Liberty Park (id). The Club plans to line the boulevard with trees and stone walls, interspersed with developed parks every few miles (id). On June 3, 1903, as a result of infrastructure improvements, the City had increased its water supply capacity to 28,000,000 gallons per day (Salt Lake Telegram). One hundred and thirty-one miles of water main pipe has been laid in the city, including City Creek Canyon (id). A city ordinance regulates residents sprinkling their lawns. The High line system in City Creek brings water to Popperton Place. On June 9th, 1877, the Salt Lake Tribune recommended City Creek Canyon Road for scenic carriage rides.

September 20, 2016

August 17th

Filed under: Dragonfly, Insects, Meadow Mile 1.3, Pleasant Valley, Tarantula — canopus56 @ 11:05 pm

Tarantula Legs

6:00 p.m. At mile 0.7, A lone tarantula is walking across the roadway. Most spiders move so quickly that the action of their legs cannot be clearly observed. In contrast, this 5 inch diameter specimen walks in slow motion. For its rear 6 legs and counting from the abdomen forward, an even-numbered leg on one side moves forward in concert with an odd-numbered leg on the opposite side. It uses its front two legs like antenna, probing the environment ahead. Its abdomen is covered in one of the tarantula’s defensive mechanisms: urticating hairs or irritating hairs. I spend a few minutes with the tarantula to assure that neither a car or a bicyclist ends it.

The canyon opens up after the first mile and dragonflies are evenly distributed over the meadow between mile 1.1 and 1.5. These are the same fifty or so dragonflies that were hunting in a close knit flock back on August 11th. A U.S.G.S. map describes this area as “Pleasant Valley”.


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