Hidden Nature
Discover the Plants, Animals and Natural History of Arches National Park and Canyonlands National Park
Larry Hyslop
Gray Jay Press
Elko, NV
Hidden Nature
Discover the Plants, Animals and Natural History of Arches National Park and Canyonlands National Park
Smashwords Edition
Copyright 2005 Gray Jay Press
All Rights Reserved
This book may not be reproduced in whole or in part by any means without the written permission of the publisher, with the exception of brief passages embodied in critical articles and reviews.
All photos are by the author unless otherwise noted.
For ordering information, contact:
Gray Jay Press
109 Chris Ave.
Elko, NV 89801
hyslop.nvgmail.com
grayjaypress.com
Cover photo: Mesa Arch
Insets: Delicate Arch, desert bighorn ram and sego lily
Back Photo: Claret cut cactus
Smashwords Edition, License Notes
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Dedicated to my grandsons,
I hope they enjoy the canyons and mesas
of southern Utah as much as I do.
Thanks
As always, I need to thank Cindy for waiting. After each hike, she always returns to the pickup before me. Not once, has she left and made me walk back to town.
Thanks to Park Service personnel for reviewing these stories. Thanks to Marilyn Glaser for editing them and for attempting the lost cause of teaching me, proper, comma use.Thanks to Kathy Schwandt for helping with book design.
Contents
Aztec Butte
Desert Bighorn Sheep
Ord’s Kangaroo Rat and Indian Ricegrass
The Arches of Devil's Garden
The Common Raven
Biological Crust
Courthouse Wash and Quicksand
Potholes and Shrimp
An Upheaval in Scientific Thought
Upheaval Dome
Violet-green Swallows, White-throated Swifts
The Plants of Cave Spring
Big Sagebrush
Atlas Mill Tailings
Neck Spring and Drought
Weathering and Landscapes
Dark Angel
List of IDs
Preface
Why did I write this book? My purpose goes beyond wanting to merely describe the natural history of these two desert parks. I want to tell stories that will fill in some gaps. I want to explain, first to myself, then to my readers, how this land fits together. Stories are hidden among the scenic wonders of these two beautiful parks. Many are stories of adaptations and relationships knitting together the natural history of these parks.
This book is meant to enhance a visit to the desert. In my day job, I am a teacher, and therefore, can’t help but use terms like “learn.” Through my stories, I hope the reader will enjoy my descriptions of hikes and sights in these parks. Perhaps the reader will also learn about these environments. Most important, I hope this book adds to their appreciation of the Utah desert.
This is the second book in a series, beginning with Beeplants and Whiptails: the Plants and Animals of Zion National Park. The idea for these books came from what I saw as a lack of information. Area bookstores offer several scholarly books on plants and animals, but each covers only one specific subject. Bookstores also offer several guide books containing only the briefest of descriptions of area plants and animals. The only other available source of information is the simplified (dummified) handouts offered by the Park Service. My hope is this book will fill a niche by providing information not available from these sources. Hopefully, this book will also lead the reader into more detailed sources where they can learn more about natural history subjects interesting them. My basic goal, however, is a book that proves to be a good read.
Aztec Butte
Introduction
As Cindy and I step from our pickup, the colors before us seem fairly simple. Aztec Butte’s sandstone sides are dark red while the sand piled around its base is pink. The area between us and the butte is dotted with the occasional dark green junipers and darker blackbrush. This is all beneath a blue dome of bright sky. But distance fades color detail and soon after we begin walking, details begin coming into view; details sporting a myriad of colors.
Cindy and I chose Aztec Butte for this morning’s hike because of the view from its top. In less than one hundred yards from the trailhead, I am hiking alone. Cindy is my wife of many years and we make good hiking partners, but in a strange way. She is destination-driven, bent on getting there, and my frequent stops drive her nuts. She is quickly out ahead, walking steadily toward the goal. I, on the other hand, am more process-driven. My favorite part of the hike is examining what I find along the way. So the first time I stop to examine the tiny yellow flowers of ricegrass, I am left behind. I know Cindy will be waiting on top of the butte, and if anyone else is up there, I will find them in conversation.
After the ricegrass, I find prickly pear cactus in bloom. A clump of cactus on one side of the trail has faint yellow flowers nestled among the many spines, while on the other side of the trail is a cactus clump bearing purple flowers. Both colors have flower petals so fragile, they seem to have been formed from tissue paper. Bent over the cactus are tall stems of larkspur. Their flower petals are light purple while the spur part of the flower is much darker.
What at first seem to be leaves scattered across the loose sand prove to be desert trumpet. Above the sets of round leaves are thin, hard to see, stems. They are bright greens and repeatedly branch into two smaller stems. Directly below each joint, the stem is bulged, with the widest inflations those lowest on the stems. Tiny, yellow flowers cluster at the tip of each stem.
Nearby is a thick mass of green, leafless stems. The only leaves on Mormon tea are small scales near joints in the stems. Among these scales are the plant’s reproductive cones, looking much like tiny pine cones.
Mixed in with these plants are tall stems crowned with bouquets of flowers having bright orange petals and yellow masses of stamens. In May, globemallow offers an orange tint to all of Canyonlands National Park and it is just as common here.
As I wander farther, the trail winds around a shorter butte. As it does, the trail surface changes from soft sand to slickrock. Rain running off the nearby rock has swept away all loose sand, leaving a trail that is much easier walking.
The ground next to the rock offers higher moisture content, and several Fremont’s mahonia crowd the rock face. These shrubs carry spiked leaves looking somewhat like holly. As I brush past the shrubs bearing yellow flowers, a pleasant fragrance envelopes me.
Having circled behind the first butte, the trail turns toward Aztec Butte. The ground is still slickrock, but the rock is a series of thin layers. Each layer’s edge is an intricate, elaborate pattern. The layers look as if a person has ripped several sheets of paper and then stacked the sheets, so each torn edge protrudes slightly from the sheet above it.
As I climb the side of Aztec Butte, more of Island in the Sky Mesa comes into view. Standing at the trailhead, I couldn’t see any way of climbing the butte’s steep sides but now I see the answer. The trail uses an angling line of debris as a natural staircase. It is a steep climb because the debris’s angle is also steep.
Near the top, there is much less debris. However, this part of the mesa’s side is less steep, and the trail angles up its sandstone. The route is marked with rock cairns, but I am too busy watching a turkey vulture and mistake some natural rock piles for cairns. I wander off course and walk around an edge in the mesa side. Very slowly, the slope becomes steeper, and I finally halt in front of a cliff face. Very carefully, I turn and retrace my steps.
The climb’s final scramble is over dark brown sandstone. This rock forms the butte’s top surface, and its edge has weathered into sharp points and recesses. The brown rock is more resistant to weathering and has weathered slower than the lower, lighter color sandstone. Its presence has created this flat-topped butte jutting up from the surface of Island in the Sky Mesa.
When I climb onto the butte’s top, I find a miniature version of the landscape below. The same junipers and blackbrush cover Aztec Butte, but the plants are smaller. Beneath them, the ground is covered with gravel formed from flat pieces of sandstone. The trail winding across the butte is easy to see since the gravel on its surface is lighter colored. The multitude of passing feet has either turned over the pebbles to show their lighter bottoms, or scrubbed the gravel enough to lighten the pebbles.
Stopping to rest, I look out over the surrounding mesa. Bird calls drifts up from below, and I hear the calls of scrub jays coming from the junipers. Softer calls of black-throated sparrows come from the blackbrush. The view includes Whale Rock to the north and Grand View road to the southwest. To the east, the mesa cliffs drop off into Taylor Canyon. But the distance has again swallowed the detail in this grand view. The ground far below is covered with flowers of several colors, but my view has changed from an intimate one to a wide vista.
When I find her, Cindy is enjoying the cool shade of a juniper, sitting next to an Anasazi granary. I join her and we look out at a view that seems to encompass the very essence of both Canyonlands and Arches National Park. It is scenery hiding a multitude of stories about plants and animals superbly adapted to this desert’s harsh conditions.
Healthy Herds
Desert Bighorn Sheep
The feeling comes over me as I am looking down, examining the delicate petals of serviceberry flowers. I am no longer alone. Surprise becomes shock when I realize a large animal is nearby. A desert bighorn ram is watching me as it calmly chews on a leafy branch. Protruding from the ram’s mouth, the stick sways about in the air as it is chewed.
ID
Utah serviceberry, Amelanchier utahensis
Shape: 2-13’ high shrub or low tree.
Flowers: white, ½” long petals with gaps between petals.
Berries: purple, seedy.
Leaves: ½-1¼” long, oval or egg-shaped,
finely toothed near tip.
Stems: red.
Habitat: stream sides, slopes and canyons.
The ram is old enough for its horns to carry a ¾ curl. The massive horns rise from the top of its head to curl back and down, slimming as they loop. After curving through ¾ of a circle, the ragged tips face forward. The ram has broomed off, or scraped off, the tips of its horns to shorten the tips and improve its peripheral vision. Large, golden eyes with dark irises are framed inside the arc of horn. Below the eyes is a white muzzle and black, Y-shaped nose.
Desert bighorns are more slender than their northern cousins, the Rocky Mountain bighorns. The horns are smaller and their coat color is lighter brown. Not that this smaller size is important when close to a ram weighing perhaps 200 pounds.
The momentary spell is broken and the ram begins to move away. Park Service policy states that during such an animal encounter, I should immediately turn away. However, the ram is calm and I am left spellbound by the unique experience. Besides, the ram is slowly walking uphill, parallel to the trail. I should turn back but Cindy is somewhere ahead, approaching Delicate Arch. So I ignore park etiquette and continue up the trail.
During pre-Columbian times, tens of thousands of wild sheep inhabited the Southwest. With the arrival of European settlers, sheep populations plummeted. Hunting decimated their numbers, but there were other reasons. All across North America, wild sheep populations have been slaughtered by diseases coming from domestic sheep and cows. These diseases can, and often do, kill off 95% of a bighorn herd. Especially damaging has been a pneumonia-causing Pasteurella bacterium. Livestock and wild (or feral) burros also compete with bighorns for the desert’s limited food supply. As the number of human dwellings, roads and towns increased, their presence kept bighorns away from many food and water sources.
By 1900, Utah’s bighorn population numbers were simply reported as herd “remnants.” Utah banned the hunting of bighorns for almost 70 years, from 1899-1967. Since then, active herd management has raised these population numbers. In 1993, the state-wide population estimate was 2,200 animals. But bighorn populations are also influenced by nature, and the recent drought has reduced this number significantly.
As we continue our mutual stroll, the ram maintains a distance of about 30 feet from me. It stops to bite off the top of a cliff rose and then turns to watch me as it chews. Writers should never anthropomorphize or give animals human characteristics, but the ram’s face looks so content while chewing what must be a succulent snack. After a few more steps, it tilts its head to the side and delicately nips off a yucca’s flower stalk, eliminating the yucca’s reproduction attempt in one bite.
This ram is a member of a herd that lives in Arches National Park. They are normally found in more remote areas such as the frozen dunes. This ram is located in an area having heavy visitor use. When Arches National Park was created in 1971, no sheep were living in this area so this herd was brought in from Canyonlands National Park. By the 1980’s, the herd had grown to 100 sheep. With the drought, the current herd estimate is 60 animals.
ID
Narrowleaf yucca, Yucca angustissima
Flowers: large, cream-colored, bell-shaped, droopy.
Pollinated by yucca moths.
Stalks: up to 5 feet tall.
Leaves: 4-20” long, narrow, sharp, grow from the base.
Habitat: dry slopes.
Canyonland’s Island in the Sky District had a herd of 70-80 animals when the park was created in 1964. With park protection, the number grew to 250-300, while also supplying 200 sheep for transplant to other areas. It is estimated the current drought has reduced this herd by half.
Canyonland’s Needles District also had a native herd, but their numbers crashed in the 1980s, dropping from 200 to 60 animals. They are now slowly rebuilding. The Maze District received sheep from the Needles area in 1986. During the 1990s, this herd prospered, but few animals remain today.
Unfortunately, this ram’s calm demeanor is not matched by my own. I am frantically trying to retrieve a camera from my backpack, hoping for a photo before this temporary friendship ends. But as I paw through the back pack, I am also gloating. As usual, Cindy has been intent on reaching the arch and, therefore, has missed this encounter. I will happily recount it in full detail during lunch.
Genetic diversity is used to describe the amount of variation carried in a population’s genetic makeup. Animals carrying slightly different genes harbor slightly different characteristics. Diversity is needed to combat change in the environment, when the variation in some may allow them to cope with this change. It also helps fight new diseases, since some individuals may have an immunity to it. Genetic diversity is enhanced when animals have the opportunity to mate with several other individuals, thereby mixing different characteristics throughout the herd.
Low genetic diversity comes from small populations where animals are forced to mate with others carrying much the same genetic code. Such inbreeding makes it easier for the entire population to succumb to a new disease. The time needed to build a population’s genetic diversity is measured in centuries, but it can be lost in only a few generations.
Craig Hauke is a Natural Resources Specialist for the National Park Service. He told me the park service works hard to maintain genetic diversity in their desert bighorn herds. Studies have shown the genetic variety carried by desert bighorns is fairly good, although this diversity may still be a reflection of conditions before European arrival. He and other resource managers are concerned the present conditions are lowering their genetic diversity.
Desert bighorns carry slightly less genetic diversity in their populations than their northern cousins, the Rocky Mountain bighorns. But some of this is natural, since desert bighorn populations have always been smaller. Also, Rocky Mountain bighorns occupy large clumps of habitat. Individual herds have the chance to intermingle with other herds and exchange genetic material. Desert bighorns have always occupied small areas of suitable habitat surrounded by large, unsuitable areas. They live in mountains surrounded by wide, dry valleys containing little vegetation. Historically, individual rams have occasionally crossed these valleys and spread genetic diversity, but the arrival of Europeans has made this more difficult. Human settlements, highways and fences have increased their isolation. Desert bighorns have less chance to intermingle and exchange genetic material. They are also slow colonizers, slow to move into empty favorable habitat, and this also increases their isolation.
Smaller sheep populations have meant less interaction with other herds. This results in more inbreeding, which increases lamb mortality. Several small bands have completely disappeared, and scientists feel a band needs at least 100 members to remain viable.
While I continue walking up the trail, the ram is encountering more boulders, forcing it closer to the trail and obviously making it uneasy. The ram trots ahead and disappears around a rock wall. When I reach this corner, it has disappeared. Although I carefully search the surrounding rocks and junipers, it seems I am alone once again.
Last View of the Ram
The park service encourages herd intermingling by maintaining open paths between them. The bighorns of Island in the Sky make occasional contact with a band along the Colorado River, near Potash Road. In turn, this band occasionally mixes with the Arches National Park herd, which also has bands up river they can reach.
The Needles District animals sporadically mingle with bands farther south. As improbable as it sounds, some individuals even swim the Colorado River between Needles and Island in the Sky. Only the Maze band is effectively isolated. Their closest relatives (other than across the river) are bighorns within the Glen Canyon National Recreation Area to the west.
As I search for the ram, it is hot enough that I stop in the shade of the nearby rock wall. Only when I look at the ground, do I realize this rock’s shadow carries a sheep shadow. When I move into the sunlight and look up, I can see my temporary friend once more. So our mutual stroll continues. The only difference is the ram is now above me, where it probably feels better about my presence.
During each bighorn generation, only one new animal needs to be introduced into a band to maintain a healthy diversity. One way to encourage genetic interchange is through forced migration. Individual animals from one band can be trapped and released near a second band, but such forced migration is approached cautiously. Introducing an animal carries the chance of bringing along a disease. Also complicating matters, new animals can alter the band’s adaptations to local conditions, weakening the band’s fitness.
Fortunately, the chance of introducing diseases by domestic sheep is much less now. The Bureau of Land Management has created a buffer zone around Arches and Canyonlands parks by revoking all nearby domestic sheep grazing permits. Their efforts have been made easier by the virtual elimination of any wool market in today’s economy. No domestic sheep live anywhere close to today’s park animals.
Eventually, our friendship is over. A group of hikers is approaching, walking down the trail from Delicate Arch. The ram watches them for a moment before turning aside. It easily scales what appears to be a sheer cliff face. The ram pauses where it is silhouetted against the sky, remaining just long enough for me to take a photo before disappearing.
As the hikers pass me, we exchange greetings, but I cannot bring myself to tell them what they missed. For the rest of the day, passing hikers will be unaware of a nearby bighorn ram.
When the noise of the receding hikers fades away, the surrounding sandstone and junipers seem joyless. Since I know what is missing, this rocky spot seems dull. I treasure my brief encounter with the desert bighorn, and I am grateful this animal still roams the desert.
Grassland Partners
Ord’s Kangaroo Rat and Indian Ricegrass
Clumps of Indian ricegrass border the sandy trail. Compared to other grasses, ricegrass seems whimsical in design. After emerging from the main stalk, thin stems branch and branch again. Each new pair separate at right angles with the stems curling and twisting before ending in a single seed. The overall look of the grass is a broad, rounded head dotted with tiny, football-shaped seeds.
Grassland separates the sandstone walls and pillars of Canyonlands National Park. The landscape is sandy, with blackbrush, sagebrush, rabbitbrush, fishhook cactus and clumps of grass. Cattle grazed this area for years before a park was formed.
Squaw Canyon Trail is taking me through this sandy landscape. The route alternates between slickrock and loose sand. On the slickrock, I have to keep track of the rock cairns marking the route. On the loose sand, walking is more difficult, since each step slips slightly. Much of the sandy ground looks orange with globemallow flowers.
ID
Globemallow, Sphaeralcea coccinea
Shape: Stems 12-24” tall.
Flowers: Orange to red 1/2” wide, numerous
Yellow stamens.
Leaves: Long, narrow, 3-5 deep lobes.
Habitat: Sandy area, road sides.
Common, often coloring
entire areas. Small bees spend the night inside
the flowers.
As I walk through sandy stretches, several grass species border the trail. Sand dropseed grasses rising as high as my waist. The main shoot of this grass splits along one side to release numerous branching stems carrying tiny flowers. Each stem looks like a feather. Overall, the plants look vaguely like flimsy fir trees. Ricegrass and dropseed are bunchgrasses, meaning they form dense clumps of grass separated by bare sand. From a distance, they look light green because this spring’s dark green growth is mixed with last year’s tan, dead remains.
Not nearly as tall as dropseed, the heads of galleta grass are dense and fuzzy. By late summer the seed-bearing spikelets have fallen off, and the bare upper stems have a characteristic zigzag. The curled and twisted leaves of this coarse grass are rough to the touch. Galleta is tolerant of trampling and is often planted as ground cover in areas of heavy human use.
In among the galleta heads are blue grama. The flower heads of blue grama look like someone has glued false eye lashes to their stems. The 2-inch long flower head extends from the end of the stem. Its two rows of seed-bearing spikelets grow along the same side of the stem. As this grass dries, the stem curl away from the spikelets, creating an arc-shaped comb looking like false eye lashes.
As tall as dropseed, needle-and-thread is an apt name for this grass. Its seeds end in 4-5” twisted strands. When the seeds fall to the ground, differences in atmospheric moisture cause these long filaments to coil and straighten. These movements help push the seeds into the soil, burying themselves and increasing their chance for germination.
Needle-and-thread provides good forage for wildlife and livestock, but only in spring and fall. The other end of each seed has a sharp point. In spring, the seeds are still green and soft. By fall, the stems can be eaten since the seeds have fallen from them. But when the stems contain dry seeds, the sharp seed points can injure grazers’ eyes, tongues and ears. Seeds can work their way through sheep wool and penetrate the skin.
As I climb over a long finger of sandstone, I pass a group of backpackers. Composed almost equally of adults and children, they have different ideas on the concept of resting. The adults sit and drink from water bottles while the kids climb on boulders.
A partnership in this area is important to the desert ecosystem. The partners are ricegrass and Ord’s kangaroo rats. Ricegrass is important forage and kangaroo rats actively plant this grass.
Ricegrass seeds are brown or black. They are about half the size of a rice grain, thus the name. The large seeds are an important food source for wildlife and livestock, especially during the winter months. Such a good source of food has also been used by man. Native Americans have traditionally ground the seeds into flour to make a nut-flavored mush. Being gluten-free, this flour is used today by people who are gluten intolerant. So important is this range grass species that it is both Utah’s and Nevada’s State Grass.
As a perennial, ricegrass typically has a tough time getting started, but once established, they are robust and throw off seeds for years. The point of new growth is located at or below ground level. If it is grazed off while still green, new growth can quickly rise from the root system. During the hot desert summer, the plant parts above ground die back. But come next season, these growth points will supply new shoots.
I realize I am passing the abode of the other member of this partnership. Beside the trail rises a vague mound of sand. Its surface is punctured by several holes, although each is filled in. This is the home of the Ord’s kangaroo rat. Although 8-11” in length, most of the kangaroo rat is tail. The back legs are long, enabling them to hop like kangaroos. When escaping predators, their long-legged hops can propel them up to six feet while their long tails help balance them. Since each successive hop will likely be in a different direction, they are very difficult to pursue. Kangaroo rats are territorial and advertise their presence to other rats by drumming on the ground with their long back legs. During fights between rats, they strike at each other with these long legs.
Kangaroo Rat,
Photo Courtesy of USDA Agricultural Research Service
They are highly adapted to their desert existence. Solitary animals, each rat occupies a complex arrangement of cool burrows and food caches. Being nocturnal, they spend the hot days underground with the tunnel entrances closed. Finding an open tunnel is usually a sure sign that the mound’s builder is dead. Called granivores, their main diet is seeds. They rarely need to drink water since their bodies are able to metabolize water during the digestion of dry seeds.
The loose skin of their cheeks is folded, creating large fur-lined pouches. These external pouches are found on both sides of the mouth. Rats collect seeds and carry them in these pouches. They are selective in their seed collection, choosing only full seeds and usually the larger ones. They then dig shallow pits in the sand and cache the collected seeds. Such caches may contain over 200 seeds.
Kangaroo rats and their cousins, the pocket mice, are responsible for germinating 90% of the living ricegrass. When ricegrass seeds fall to the ground, ants collect some seeds and either eat them or store them deep underground, making the seeds unavailable for germination. Birds like black-throated sparrows, eat some of the seeds. But most of the seeds are collected by kangaroo rats.
These seeds are stored in shallow “pit caches” to be eaten later. The seeds are cached 1-3 inches underground, which happens to be the perfect depth for ricegrass germination. Many of these seeds are never retrieved from their storage spots, perhaps because the rats forget their locations. In studies using captive kangaroo rats, 50% of the seeds in caches germinated.
Squaw Flats
Ricegrass clumps are often found close to rat mounds. As these germinated seeds begin growth, the seedlings provide valuable green food during kangaroo rat breeding season, but many more seedlings survive to become mature plants.
Ricegrass seeds do not germinate all at the same time. The seeds are encased in tough seed coats and something must scarify or break this seed coat before germination can occur. Some seeds may not germinate for years. This is a strategy used by the plants to hold seeds in reserve in case the first growing season is a poor one. The later germinating seeds may encounter better conditions.
But most seeds in kangaroo rat caches have scarified seed coats. The rats remove the seed coats, hastening germination. Most rat cached seeds germinate the first spring.
Ricegrass is often planted on western rangelands to create ground cover and provide food for wildlife and livestock. It is one of the few plants that can colonize and successfully grow on shifting sand dunes. It is seeded in sandy areas to cover and stabilize dunes. Seeds are treated with acid to help break the seed coat and hasten germination. Planting drills are designed to bury seeds at the proper depth. Such tactics are necessary since seeding is an expensive operation. Ricegrass seed costs from $5-$20/pound and application costs are high. Land managers need to achieve as much germination as possible.
The ricegrass/kangaroo rat partnership has to be taken into account by these land managers. Kangaroo rats are perfectly capable of smelling and digging up planted seeds. One strategy to deal with kangaroo rats is to bury the seed a little deeper and farther apart, hoping the rats will be disinclined to spend the time needed to dig up a majority of the seeds.