City Creek Nature Notes – Salt Lake City

May 22, 2017

May 22nd (Revised)

Continental Scale Bird Population Trends – Part I

(Science Section Revised May 28th.)

1:30 p.m. It will be a good day. As I ready to leave for the canyon and before even starting the car, a brilliant red House finch lands on a nearby telephone wire and sings happily for five minutes. Bright sunlight floods the canyon, and spring life explodes. There is too much to see, and I am overwhelmed. The roadside heats up with smells of fresh growth, and it mixes with the crisp cool air that rises from the transparent, chilled water of the swift stream. In the first mile, fifty birds are active, all singing in cacophony. The red ozier dogwood bushes are covered with small one-half inch bees with yellow and black abdomens and similarly miniature wasps with black and white striped abdomens. The first Western Yellowjacket wasp of the season lands. Nine Yellow swallowtail butterflies line the first mile with Mourning cloak, White cabbage, Painted Lady, and Spring Azure butterflies. Two Blue-eyed darner dragonflies fly above the road, and one unceremoniously defecates as it passes.

Immediately past Guardhouse Gate, three Warbling vireos exchange calls from the surrounding trees. Along the road to mile 0.3, I can distinguish about fifteen bird songs and calls, but by sound, I can identify the American robin, a Mountain chickadee, the Black-headed grosbeak, and the Song sparrow. A small Blue-gray gnatcatcher (Polioptilidae Polioptila caerulea) jumps parallel to the road along oak branches. Black-chinned hummingbird wings beat loudly.

At the bend in the road above picnic site 3, there is another riot of bird songs in a small cluster. Songs of the House finch, Mountain chickadee and others blend together. Then a blazing Yellow warbler comes of the screen of trees and lands in a nearby branch. The warbler leaves and finally, a Western scrub jay lands on a another branch. I play a recording of one of its kind squawking, the blue shouldered bird replies. This way we have an odd conversation. There is more, but this is enough.

This is the green explosion that the vernal season (February 16th) has been building to since the first of May.

* * * *

Parrish, Norvell and Howe’s Utah bird study covers one state – Utah (Parrish et al. 2007; Novell, Howe and Parrish 2005), but birds are international travellers. Olsen’s Pacific Flyway data is international but regional (Olsen 2017). Because of their dispersal, bird trends also need analysis on the continental scale. In 1966 in response to DDT’s impact on birds, the U.S.G.S. and the Canadian Wildlife Service began the first North American continental Breeding Bird Survey (BBS). However, design of the BBS did not cover weighted areas of differing habitat types (Bart 2005; Parrish et al. 2007 at 11). All survey sites were along roads, and this introduced a bias that would not allow for the study of how changes in habitat affects bird populations (id). Acknowledgement of the need to have coordinated continental scale non-game, longitudinal bird population data led to the establishment of the Partner-in-Fight Working Group (Bart 2005) to supplement the Breeding Bird Survey, and Parrish, Norvell and Howe’s work on Utah riparian habitats was part of the Partners’ system. Governmental agencies, including Utah, consolidate results into the national Breeding Bird Survey database (Sauer 2017; Pardieck 2016). Both the BBS and the Partners-in-Flight programs focus on professionally trained biologists working for or associated with many governmental agencies collecting high quality data by conducting transect surveys over time at the same sites.

Through 2015, the Breeding Bird Survey shows a declining population at 1.4 percent per year in its Western region (Sauer 2017). Plumbeous vireos decline at 2.3 percent per year.

Since the 1990s, concerns grew over what impact climate warming might have on bird populations and a need was perceived to develop management tools to early identify adversely effected bird species, and a management tool, the Partners-in-Flight the Conservation Concern Index was develop to provide guidance under the conditions of uncertainty in estimating local and global bird populations and their trends. The Partners-in-Flight methodology rates stresses on bird populations for 1,154 bird North American bird species (Panjabi et al 2012) based on five non-dimensional, ascending scales ranging from 1 (least concern) to 5 (most concern). The five indices are global population size, breeding geographical distribution, non-breeding geographical distribution, threats to surviving the summer breeding season, threats to surviving the non-breeding season, and population trends, and the combined indices yield a maximum total score of at most 25 denoted as the “Conservation Concern Index”.

Of the five indices, the global breeding population size is the most sensitive. It varies by a geometric growth rate of 10 denoted by a logarithmic index:

5 – World breeding population is less than 50,000 or 5 x 10^4.

4 – World breeding population greater or equal to 50,000 (5 x 10^4) and is less than 500,000 (5 x 10^5).

3 – World breeding population greater or equal to 500,000 (5 x 10^5) and is less than 5,000,000 (5 x 10^6).

2 – World breeding population greater or equal to 5,000,000 (5 x 10^6) and is less than 50,000,000 (5 x 10^7).

1 – World breeding population greater or equal to 500,000,000 (5 x 10^8) (Panjabi et al 2012).

The global breeding distribution index is the second most sensitive. It varies by a geometric growth rate of 3 denoted by a logarithmic index. An index of “5”, or highest concern, corresponds to 80,000 square kilometers or a U.S. state size of about 300 kilometers square. A breeding distribution index of “1”, or least concern, corresponds to 4,000,000 square kilometers, or a continent-sized 2,000 kilometer square(Panjabi et al 2012).

The Populations growth index is the least sensitive. An annual growth decline rate between 0 and 15 percent is rated “3”. Only crashing populations with a growth rate of greater than 50 percent are have an index of “5”.

Logarithmic risk indices are intended to overcome human compression bias, i.e. – our tendency to misinterpret risk over a large range of outcomes (Adams and Smith). Humans overestimate the risk of rare events, like botulism, and under estimate the risk of common events, like heart attack (id) and many natural processes, for example from our hearing and sight, increase sensitivity by a geometric scale. Thus, a logarithm index is a useful abstraction, but it is still often misperceived. If a risk level is expressed in terms of raw data, e.g. a world population breeding size of 50,000 to 500,000,000, this lends to unwarranted accusations of overstating for conservation. Conversely, when confronted with a logarithmic index, the natural human tendency is to erroneously interpret risk as an arithmetic sum. The earthquake Richter scale is a useful, common analogy. An earthquake of 5.0 on the Richter scale will shake the picture frames on your walls, but an earthquake of 7.5, will turn your home into a pile of sticks. The effects are perceived as additive, but in reality the effects are exponential.

To supplement the governmental North American Breeding Bird Survey by applying the Panjabi et al criteria on a global scale, private groups and industry from the North American Bird Conservation Initiative (NABCI). NABCI analyses are reported in annual glossy “North American State of the Bird” reports, – e.g. North American Bird Conservation Initiative (2009) and North American Bird Conservation Initiative (2016a). Another useful form of the their results is the annual NABCI Assessment Database, a spreadsheet that allows the user to sort and select birds by risk and habitat North American Bird Conservation Initiative (2016b). The mean of the index is 11.5, and a Conservation Concern Index higher than 13.5 suggests a high level of concern for which further study and action should be taken. A Conservation Concern Index (CCI) of 8.5 to 13.5 denotes moderate concern. This continental scale study provides insights into future threats that might change the currently stable bird diversity and populations totals seen in the canyon. But again, the CCI is a management tool and it does not report additive risk. Because its two key component scales, global breeding size and global breeding area, are logarithmic, the CCI scale conveys an expert opinion of a geometrically or exponentially increasing risk.

Two spring species that are regularly seen in the canyon (May 6th, May 20th) have CCI’s of 13 at the borderline of high concern: Virginia’s warbler and Plumbeous vireo. Others in the moderate concern category and their concern indices are: Broad-tailed Hummingbird (12), Steller’s Jay (11), Dusky Flycatcher (10), American Dipper (10), Black-chinned Hummingbird (10), Mountain Chickadee (10), Townsend’s Solitaire (10), Lazuli Bunting (9), Northwestern Crow (9), Orange-crowned Warbler (9), Western Scrub-Jay (9), and the Western Tanager (9). One commonality between these 13 species of 149 known to visit the canyon are that their non-breeding season ranges are in the southern Mexican highlands or the Pacific Coast lowlands. In short, land development in distant places might reduce their annual appearance in the canyon. But these results should be read in context. The NABCI indices for species found in the canyon generally indicate there is low concern of immediate threats to most species. The diversity of bird species in the canyon is stable. The NABCI “State of Birds” reports are not a trend-based forecast, although their short annual narrative report incorporates conclusions from Christmas Bird Count trend studies by the Audubon Society and governmental Breeding Bird Surveys.

* * * *

On May 22nd, 1914, the newly completed scenic automobile drive up City Creek and along 11th Avenue to be called Wasatch Boulevard will be opened to the public (Salt Lake Tribune). Other park improvements include the new Thirteenth Street Reservoir Park and adding lawn areas to Liberty Park (id).

May 20, 2017

May 20th

Spring Bird List

3:30 p.m. In the morning I am woken by the cawing of an American crow (Corvus brachyrhynchos) standing outside my window, but then I drift back off to sleep. Around noon, neighbors are buzzing over their photographs of a common Red fox (Vuplus vulpes) hunting mice in the city cemetery about one-third of a mile from my home and on the south-City side of the east-south canyon ridgeline.

In the afternoon, the cold snap of the last few days has ended and the canyon is again warming into the sixties under blue, ideal spring skies. Driving into the canyon along Bonneville Drive, the grasses have reached up to three feet high, but in the canyon they remain between one foot to eighteen inches in height. Along Bonneville Drive, young Curly dock plants rise, but there are none in the fields at mile 1.5. Arrowleaf balsamroot has noticeably disappeared from the surrounding hillsides through mile 1.5, and its yellow color has been replaced by the duller yellow of fields of Dyer’s woad. Along the first mile, where a few days ago there was a single Sticky Wild Geranium, there are now ten, and four blue penstemons are blooming. The other major blossom are the white inflorescences of chokecherry bushes or trees. Blue is the color of canyon near the stream, but at the Pleasant Valley lower field, I scan the surrounding hillsides for a hint of Arrowleaf balsamroot. There is none, only the green of the balsamroot’s wide bases surrounded by wide swaths of Dyer’s woad. A pattern repeats in the many sun-exposed small gullies that lead to the western salient’s ridgeline and below the eastern salient’s cliffs: Groves of green Gambel’s oak or Red Maple fill the damp soil or seeps along side canyon gullies, but where the side canyons begin to flare out, the dryer soils, formerly covered with balsamroot, are now covered in Dyer’s woad. At lower elevations along the western slope above the Pipeline Trail and above Bonneville Drive, some balsamroots remain in bloom, but their numbers are rapidly dwindling from their shriveling flowers.

Butterflies are recovering in the rising heat. Yesterday’s Western tiger swallowtail and Desert Elfin butterflies are joined by a few Spring Azure and White cabbage butterflies. About eight new, small and black unidentified butterflies appear. They move too fast to see any detail. Two examples of a new unidentified small black spider are on the road, and a small black ant is carrying a whole insect pupae, about eight times it size, back to its underground ant lair. Common houseflies are active on the road, and a larger Blue-eyed darner dragonfly patrols up and down the road. Along the Pipeline Trail, I flush out two Mormon crickets. Instead of red underwings (May 8th), they now flash muted orange underwings.

Where the chokecherry bushes are warmed by the sunlight, they are the buffet for the insects. The best of these is along the Pipeline Trail near mile 0.9, and the chokecherry bush is covered in about seventy bees, flies and a American Lady butterfly. The bush sits near a seep in a bend in the trail. It is in a large-tree shaded area, but a single shaft of light penetrates and warms the bush and its nearby air to fifteen degrees more than its surroundings. Another shaded chokecherry bush about fifteen feet away is ignored by these flighted insects. On the chokecherry inflorescences there are also two types of flies, one large and one small, and three types of bees, including a red-rumped worker bumble bee, wild common honey bee (Apis var.) and one of two Utah varieties of the Carpenter bee (Xylocopa californica) (Hodgson and Trina 2008). Near this seep, a tiny unidentified slug, about 1 centimeters by 3 millimeters in diameter crawls up the trail, and I help to the mud next to the seep. Three other chokecherry bushes fifty yards up from Guardhouse Gate and a full chokecherry tree at picnic site 4 are similarly covered, but to a lesser degree. These are also sunbathed.

A flock of four distant raptors circle and glide up canyon. Birds along the first 1.5 miles of road can be divided roughly into seven neighborhoods or groups: at Guardhouse Gate, at road mile 0.4, at road mile 1.0, the lower half of Pleasant Valley, mile 1.1 to 0.9 of the Pipeline Trail, the Trail between mile 0.9 and 0.5, and the Trail between mile 0.5 back to the Gate. There are more calls than yesterday, with between 5 to 10 birds in each neighborhood. By sound alone, I can pick up a few of the easiest out of a chorus of ten different songs: the Lazuli Bunting at the Gate; a Song sparrow and an American Robin near mile 0.5; a near road mile 1.0,; and a Black-chinned hummingbird flying near Trail mile 1.0. I have gathered recordings of about 40 spring birds on my smart telephone, and have begun to replay them constantly in the hopes of building a beginner’s skill for distinguishing their songs. The avian soundscape is being to make more sense to my untrained ear.

As I reach Guardhouse Gate, there is a young woman standing 50 feet from the road, half obscured by blinds made leafed branches of Gambel’s oak, and she is singing gospel and folk songs in a loud but beautiful voice. She has long-black hair, is wearing a short, summer dress of yellow printed ethnic cotton, and is illuminated by that special warm light before dusk. Several strolling couples and myself discreetly walk up to the side of the road for an impromptu concert. For a moment, my mind is momentarily transported back to my adolescence and a similar scene from 1971. After a few minutes, everyone wanders away, leaving her to practice her singing without disturbance, but grateful for a unique moment.

* * * *

The slate of spring canyon birds for this year has sufficiently filled out that a list is timely. The 54 species represented shows the diversity of bird life that is finding living niches in the canyon and making connections between its plants and insects.

List of Spring Birds in City Creek Canyon March through May, 2017 by Order and-or Family (N=54)

Orders Accipitriformes and Falconiformes – Hawks, Eagles and Falcons – Birds that Hunt Other Birds

• Bald Eagle (immature) (Haliaeetus leucocephalus).*

• Cooper’s Hawk (Accipiter cooperii).

• Golden Eagle (Aquila chrysaetos).

• Northern Goshawk (Accipiter gentilis).

• Peregrine Falcon (Falco peregrinus).

• Red-tailed Hawk (Buteo jamaicensis).

• Sharp-Shinned Hawk (Accipiter striatus).

Order Anatidae – Ducks

• Mallard (Anas platyrhynchos).

Order Apodiformes – Swifts and Hummingbirds

• Black-chinned Hummingbird (Archilocus alexandri).

Order Galliformes – Pheasants and Guineafowl

• California Quail (Callipepla californica).

• Chukar (Alectoris chukar).

• Wild Turkey (Meleagris gallopavo).

Orders Piciformes and Coraciiformes – Woodpeckers and Kingfishers

• Belted Kingfisher (Ceryle alcyon).

• Downy Woodpecker (Picoides pubescens).

• Northern Flicker (Colaptes auratus).

Order Strigiformes – Owls

• Western Screech-Owl (Otus kennicottii).*

Order Passeriformes – Larger Perching Birds

Family Corvidae – Crows, Jays and Magpies

• American Crow (Corvus brachyrhynchos).

• Black-billed Magpie (Pica pica)

• Common Raven (Corvus corax).

• Steller’s Jay (Cyanocitta stelleri).*

• Western Scrub-Jay (Aphelocoma californica).

Order Passeriformes – Mid-sized and Smaller Perching Birds

Family Cardinalidae – Cardinals and Grosbeaks

• Black-headed Grosbeak (Pheucticus melanocephalus).

• Lazuli Bunting (Passerina amoena).

• Western Tanager (Piranga ludoviciana).

Family Columbidae – Pigeons and Doves

• Eurasian-collared Dove (Streptopelia decaocto) (invasive).

• Mourning Dove (Zenaida macroura).

Family Emberizidae – Sparrows and Buntings

• Chipping Sparrow (Spizella passerina).

• Dark-eyed Junco, Slate type (Junco hyemalis).*

• Green-tailed Towhee (Pipilo chlorurus).

• House Sparrow aka European Sparrow (Passer domesticus) (invasive).

• Rufous-sided Towhee (Pipilo erythrophthalmus).

• Song Sparrow (Melospiza melodia).

• Spotted Towhee (Pipilo maculatus).

Family Fringillidae – Finches

• House Finch (Carpodacus mexicanus).

• Lesser Goldfinch (Carduelis psaltria).

Family Hirundinidae – Swallows

• Bank Swallow (Riparia riparia).

• Cliff Swallow (Petrochelidon pyrrhonota).

• Northern Rough-winged Swallow (Stelgidopteryx serripennis).

• Violet-green Swallow (Tachycineta thalassina).

Family Paridae – Chickadees

• Black-capped Chickadee (Poecile atricapillus).

• Mountain Chickadee (Poecile gambeli).

Family Parulidae – Wood-Warblers

• Orange-crowned Warbler (Oreothylpis celata).

• Virginia’s Warbler (Oreothylpis virginiae).

• Yellow Warbler (Dendroica petechia).

Family Turdidae – Thrushes

• American Robin (Turdus migratorius).

• Townsend’s Solitaire (Myadestes townsendi).

Family Tyrannidae – Tyrant Flycatchers

• Dusky Flycatcher (Empidonax oberholseri).

• Olive-sided Flycatcher (Contopus cooperi).

Family Vireonidae – Vireos

• Plumbeous Vireo (Vireo plumbeus).

• Warbling Vireo (Vireo gilvus).

Family – Other with Family Name

• Blue-gray Gnatcatcher (Polioptilidae Polioptila caerulea).

• European Starling (Sturnidae Sturnus vulgaris) (invasive).

• Red-breasted Nuthatch (Sittidae Sitta canadensis).

• Ruby-crowned Kinglet (Regulidae Regulus calendula).

Sources: Cornell Lab. 2017 Ebird Observation Lists by Bryant Olsen with Joshua Hunt; Author’s Observations. * – Author only sighting claimed.

* * * *

The Wasatch Front Mountain Range has not seen a decline in the number of avian species since the Euroamerican arrival, but no opinion is expressed on any decline in the population of these birds. As noted before (March 4th), ornithologist Robert Ridgeway conducted a survey of birds in Parley’s Park at the summit of Parley’s canyon about ten miles from City Creek Canyon between June 23rd and August 16th, 1869 (Rawley, 69-79). He found 116 bird species. Comparing Ridgeway’s list with Cornell Ornithology Laboratory’s Ebird List for City Creek Canyon for 1900 through 2017 shows 149 species (Cornell Ornithology Lab. 2016, Cornell Ornithology Lab. 2017). For the years 2000 to 2017, 147 species are listed, and for 2012 to 2017, Cornell totals 143 species (id). There are some minor non-duplicates between the historical and modern lists. The Yellow-bellied sapsucker is not currently found in City Creek, and the range of other birds has changed. Birds such as sandpipers and Sandhill Cranes do not presently frequent City Creek but can still be found at the Great Salt Lake’s beaches and marshes. But essentially, the avian diversity of Ridgeway’s 1869 mountain birds is still intact at City Creek Canyon after 148 years.

That the diversity of Utah’s many migrant birds is stable is also shown by Parrish, Norvell, and Howe of the Utah Division of Wildlife Resources in a multi-year study from 1992 to 2005 (Parrish et al. 2007; Norvell, Howe and Parrish 2005). Examining 202 statewide bird species over 12 years at 37 Utah sites, Parrish and colleagues found no significant trend in mean annual species richness (id, p. 27, Fig. 4).

* * * *

On May 20th, 2014, Salt Lake Fire Captain Scott Winkler reports that the City has spent $650,000 on six new firetrucks specialized from fighting fires in grass brush areas around luxury homes near Ensign Peak and in City Creek Canyon (Deseret News). On May 20th, 1903, the City Council and Mayor considered issue bonds to construct reservoirs including a 5,000,000 gallon reservoir at Pleasant Valley (Salt Lake Telegram). On May 20th, 1901, an estimated three-hundred people went up City Creek Canyon, one-thousand to Liberty Park, and three-hundred for recreation (Salt Lake Tribune). On May 20, 1896, the City council considered moving the responsibility for maintaining City Creek watershed protection to the health department and the duties of the City Creek Canyon patrolman were described (Salt Lake Tribune). There were five full-time patrolmen. Three men are employed at the lower Brick Tanks keeping the screens clear of debris. Two men are employed for 12 hours per day to service the upper high-line tank screens and to patrol the upper canyon to prevent sheep grazing. Two other men service the Twentieth ward tank and the Capitol Hill Reservoir (id). City Creek has been rip-rapped for two miles above the lower Brick Tanks. On May 20th, 1896, high spring run-off has turned City Creek into muddy water and the water is clearing (Salt Lake Herald).

May 6, 2017

May 3rd

Lazuli Bunting

2:30 p.m. The first day of hot weather and the rest of the week is forecasted with increasing temperatures. For change, I go up the Pipeline Trail. Although it is only three days since the peak of Arrowleaf balsamroot, in the sun drenched fields along the trail, the balsamroot flowers are beginning to wilt. This change in season also brings the first migratory song birds. A small patch of Purple milkvetch flowers, which are usually light purple, are a dark rich purple. A set of powerlines parallels the trail, and small migrating birds like to perch on the lines for the first half-mile. The Gambel oak forest provides excellent cover, it is a favorable locations for building nests, and as the heat of summer approaches, the nearby stream provides relief and food. A male Lazuli bunting (Passerina amoena) perches on a wooden line tower; a second forages from the tallest tree; and both exchange calls with two other unseen pairs. This is sign that true spring has arrived. Two large raptors, probably Red-tailed hawks (Buteo jamaicensis) float above using the cliff updrafts for power. White cabbage, Mourning cloak and Painted lady butterflies feed on dandelions that line the trial. A new bright yellow butterfly, the Common sulphur butterfly (Colias philodice eriphyle), appears. A small unidentified bee also feeds on the dandelions, and then a large black and white bumble bee circles around me. I have a difficult time making an identification, but my guides suggests the Cuckoo bumble bee (Bombus insularis).

Gambel’s oaks have leafed-out with growing two-inch leaves to about mile 0.5 along the Pipeline Trail, but then there is a curious pause. None leaf for the next 100 yards, before oak leaf-out resumes.

Today, I walk with a friend and two dogs, and in the multitude of spring scents the dogs are in constant motion on, off and around the Pipeline Trail. We are a pack of four, and in their mind, they are the leaders. The two dogs look back and aside at us lagging humans with an expression that says we surely are the most stupid of dogs. But their amicable dog nature shines through, and they each occasionally bound up to us, and their infectious enthusiasm encourages us to follow faster.

* * * *

On May 3rd, 2007, the Utah Rivers Council plans to hold a clean-up of City Creek Canyon’s stream bed (Deseret News). On May 3rd, 1994, Utah Partners in Flight plan migratory bird watching in City Creek Canyon (Salt Lake Tribune). On May 3rd, 1919, the road into City Creek was closed for several weeks to allow for repairing the water main (Salt Lake Herald). On May 3rd, 1916, the City commission passed an ordinance for water protection in City Creek Canyon, including prohibiting dogs from running loose, discharging firearms, and speeding in automobiles (Salt Lake Telegram). On May 3rd, 1909, residents were reported enjoying City Creek and other parks during good weather (Salt Lake Tribune). On May 3rd, 1890, the Salt Lake Times, in a travel article, describes City Creek in glowing terms and poetry. On May Day, 1881, University of Deseret students went for an outing to Pleasant Valley in City Creek Canyon (Salt Lake Herald, May 3rd, 1881).

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