City Creek Nature Notes – Salt Lake City

March 16, 2017

March 16th

The Character of Light

1:30 p.m. It is another warm clear workday, but again the pre-spring canyon is full. There is palpable change in the character of the warming light: it is overwhelmingly bright. I feel as if I am moving through a substance and not that I am viewing the reflected particles. This is another sign of the coming of spring. In the first one and one-half miles of the canyon, the west side contains a sprinkling of a compressed white-chalk rock. They are the remnants of polished boulders from the streams of an ancient now vanished mountain range to the west. On the west hillsides above milepost 1.5, this white rocks now shine brilliantly against the wall’s green grass. The last three days have been what valley residents would call prefect spring days. The air is warm, clear and pollution free, and the high peaks of the Wasatch Mountains are frosted with snow. In the canyon, so too are Scott’s Hill and Black Mountain covered with snow that intensely reflects the new light. Today, Black Mountain’s snow pack has begun to dissipate, the mountain’s flank is beginning show a patchwork of white and brown.

As I jog, two Mourning Cloak butterflies do a mating dance a few feet away. They do tight aerobatic turns and loops, and then together they fly high up into the trees. On the road, there is small rust-brown caterpillar with a black rectangle on the side of segment that is surrounded by a white bar. The first large beetle appears, and it has a body plan similar to a Consperse Stink Bug, but this beetle has a brownish back and a gold strip at the end of its wings.

It occurs to me why earlier in the month the City decimated the cattail field at flood retention pond (March 5th). The pond is now a mathematically pure bowl, but devoid of life. There will be no summer hummingbirds there and a kingfisher who annual visits will not be returning. February and March have had record warmth, and the City probably feared that the canyon might flood. But there was never any risk. The water level at the exit pipe of the flood retention ponds has risen only a foot or so, and is indicates that stream flow is still below 30 cubic feet per second. There is four more feet of exit pipe to fill. The City has also forgotten lessons from the past. In the 1890s and 1900s, City Creek maintenance meant removing the many dead and overhanging trees from stream (Salt Lake Tribune, January 4, 1908; Salt Lake Herald, January 31st, 1894). In the 1983 flood, snags and overhanging limbs were swept down City Creek and where log jams formed, the road was washed out. The flood down State Street started when logs jammed the underground City Creek conduit (Personal recollection). The first two-miles from the gate to above Pleasant Valley contains many fallen limbs, and the stream bed has not been cleared of trees since the 1990s.

In Thoreau’s “Journal” on March 16th, 1840, he sees a flock of ducks. On March 16th, 1854, he notes that trees are filled with singing robins, blackbirds and song sparrows. he observes shelddrakes. On March 16th, 1855, he finds a woodchuck burrow and follows several woodchuck tracks. March 16th, 1859, he notes that the ground is a bare brown and winter snow is gone. This is a marker of spring. On March 16th, 1860, he sees a flock of shelddrakes and two gulls.

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October 10, 2016

October 10th

A Stinky Supporting Cast

Daytime weather has warmed and this has arrested the turning of leaves. It is almost the end of insect season: a few flying moths and small insects are seen, the crickets have recovered to full song, but a few notable ground-dwelling insects, not previously mentioned, are all but gone due to the low overnight temperatures. These supporting characters are commonly seen on the road when walking up the first mile of the canyon.

Stink Beetles (Eleodes obscurus): Stink beetles are a large (2cm) black beetle with ridged wing plates. They are usually seen, as one is today, kneeling with their abdomens sticking up. Their defense is a smelly oil shot from the rear. At summer’s peak, up to fifteen of these stink bugs can be seen along the first mile.

Eastern Boxelder Bug (Boisea trivittata): In this city, mature boxelder bugs are a plague. In droves they infiltrate any small opening in a home to breed, but in the canyon, strangely, there are few mature boxelders can be found. Almost the entire population is made up of immatures, and this is probably the result of heavy predation. The immature boxelder is about 4mm long, has two prominent red back wings flanked by grey side bars, and a noticeable white spot at the apex of its abdomen. In the summer, up to five hundred small immature boxelder bugs can be found in the first mile of the canyon road. Two days ago, wherever an insect carcass fell, a small red, round rosettes of about fifty immature boxelder bugs would form to devour the meal.

Consperse Stink Bug (Euschistus conspersus): This is a small beetle with an armored back plate and small head. It is similar in appearance to the green stink bug, but the body is grey, not green. At summer’s peak, up to 100 can be found on the roadside of the first canyon mile.

Brown Marmorated Stink Bug (Halyomorpha halys): The Brown Marmorated Stink Bug (BMSB) is a small beetle with camouflaged grey-brown back plates and an extended head. It is an invasive species. They are usually found on trees, picnic benches, and on leave litter along the road.

All of these stinky supporting cast members in the canyon’s ecology feed on insect carrion. When a dragonfly or cricket falters, its corpse will be covered with a immature boxelders and quickly removed. Since these carrion eaters no longer active between mile 1.1 and 1.4, there are two cricket carcasses on the road that have remained undisturbed for two days.

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