April 1933

Volume XII April 1933 Number 4

THE PUBLICATION OF THE YOSEMITE EDUCATIONAL DEPARTMENT AND THE YOSEMITE NATURAL HISTORY ASSOCIATION

Published Monthly Volume XII April 1933 Number 4

Altitude Records By C. A. Harwell, Park Naturalist

The naturalist staff on all of their trips here and there through the park make careful notes of birds and animals observed. By the accumulation of these data we are constantly gaining new knowledge of the occurrence, habits and range of the species in this region. The following observations may help to establish new altitude records for some of our birds and animals:

PACIFIC HORNED OWL — On our glacier measuring trip, October 1932, we were camped on the Lyell Fork of the Tuolumne near timberline at 10,500 feet elevation. I was attracted by the familiar "hooting" song of this owl very close to our camp. As is my habit when hearing birds singing, I discovered him call for call. It was 6 p.m. I left camp and started in the direction of the singing bird and certainly got closer than 100 yards to him. The song was distinctly that of the horned owl. Perhaps a young male, because the ending "hoot" of the usual male's song was either left off entirely or given faintly. I stood in his singing range for 20 minutes. This bird is usually thought of as belonging in Canadian Zone or lower in our mountains. Here he was at the very upper limits of Hudsonian Zone.

AMERICAN PIPIT — On each of our glacier measuring survey trips made during October, 1931-32, we have noted this bird actually foraging on the ice fields and about the moraines and lakes just below the glaciers. We had previously listed this bird as extending up to timberline. These observations indicate that he is also quite at home in our Arctic-Alpine Zone. October 6, 1932, I observed several of these birds at the 12,000-foot level on Mount Lyell Glacier.

EARED GREBE — On October 6, 1932, I observed an eared grebe at home in the highest lake of Yosemite National Park. This lake is 12,000 feet in altitude, is not more than 200 feet across. It nestles close up to the westerly lobe of the Lyell Glacier; in fact, one of our glacier measuring stations is at its very edge, where ice definitely protrudes from under the crest frontal moraine at its shores. We worked at this station for three-fourths of an hour so the grebe was practically in sight all the time. It would not trust to flight, but in characteristic grebe fashion chose rather to remain at the far side of the lake, diving below the surface of the glacially turbid water whenever we seemed to pay too much attention to it.

WESTERN MEADOW LARK — In late fall this bird has been observed at several high stations in the park, such as Tuolumne Meadows, Ten Lakes and Booth Lake. This October 12, while crossing Parker Pass I observed a pair of them at rather close range, seemingly quite at home in the stunted white-barked pine in that wind-swept region. The altitude here was 11,000 feet, which seems to be the highest record of observation for this bird to date. Mr. Presnall and I were making the trip over this pass to measure and photograph the Knip and Kuna glaciers. We were interested in the numerous tracks of deer along the trail. All tracks were pointed in the direction we were traveling, from Tuolumne Meadows toward Parker Peak. We therefore assumed these animals were crossing over this high pass to find suitable winter range on the eastern side of the Sierra.

WESTERN ROBIN — On a trip to the Mount Goddard glacier, November 10, Ranger Sam King, Stephen Tripp and I flushed two robins from a seeming hiding place among the rocks just at the outlet of a lake whose altitude is 10,800 feet. Once flushed, the robins flew to the slope of North Peak above us, settling in the white-barked pine. This seems to be the highest record of this bird in the Yosemite region.

WESTERN BLUEBIRD — The western bluebird is thought of as commonly nesting in the foothill region of the Sierra. There are no nesting records on the floor of Yosemite Valley. They are commonly present throughout the winter in the valley, feeding on the berries of mistletoe in the black oaks. June 26, a group of our naturalist staff were out with Dr. Francois E. Matthes of the United States Geological Survey, studying under his direction the interesting glacial story written in the great series of moraines about Moraine Dome in Little Yosemite Valley. During our lunch hour we discovered a pair of these bluebirds carrying feathers and other nesting material into a woodpecker hole in a limb of a Jeffrey pine, situated at the very summit of this dome, whose altitude is 8000 feet. Violet-green swallows were seemingly using a cavity in the same tree as a nest site. Both species seemed perfectly at home in this setting. This is the first nesting record for the western bluebird at such a high altitude in this region.

DIPPER — During the summer of 1927, while leading a party around the circuit of our high Sierra camps, I spent several hours on the afternoon of July 28, fishing up Alkali Creek above the Glen Aulin camp. At 8400 feet elevation I discovered a nest of dippers or water ouzels just at the brink of a 15-foot fall under which I was fishing. One baby dipper was still being fed at the nest entrance and a second one was being fed on the stream bank at the edge of the pool under the fall. This finding of an occupied nest seems to establish not only an altitude nesting record for the species in the Yosemite Park region, but also a late seasonal record.

COYOTE — During our trips to the Lyell Glacier, October 1931-32, we were interested in the observation of numerous coyote tracks on these ice masses. A week or so before each of these trips a new snow, the first of the year, had fallen to cover the ice an inch or so with soft snow, which made these tracks quite easily read. On one trip, Ranger Adrey Borell and I spent some time exploring the surface of the Lyell Glacier, noting the great width and depth of the crevasses and bergschrund, which were of great size due to this very dry year. A coyote or more than one had seemingly been searching for food at this extreme altitude. The tracks seemed to indicate that the animals might have been hunting rosy finches. At the very highest ice of the glacier at an altitude of 12,900 feet, coyote tracks were quite numerous. During the October survey of 1932 we discovered tracks which seemed quite definitely to indicate that a coyote had been chasing a white-tailed rabbit across the lower portion of the main Lyell Glacier.

ALPINE CHIPMUNK — While on the Koip Glacier at an altitude of 11,800 feet, Assistant Park Naturalist Presnall watched several alpine chipmunks scampering across the ice of the glacier and the rocks of the frontal moraine, certainly 400 feet away from any source of food supply. He couldn't figure out why any of these tiny animals should choose to be out on the ice.

The Granites of Yosemite By Ranger-Naturalist Carl Sharsmith

To the observer standing on the floor of the Yosemite Valley, the granites making up the walls look very much alike. However, the rocks of either end of the valley, often of opposite sides, are quite different and distinctive in character; so much so in fact, that specimens obtained along various points are characteristic of their location and so have been named accordingly. Thus the fine-grained granites of the cliffs of Bridal Veil Fall are distinctive — the "Bridalveil Granite" — and, after one becomes acquainted with it, is unmistakable from any other in the valley. Just opposite this locality are the quite different granites of El Capitan. In great contrast to these two are the rocks making up the North Dome and Half Dome section of the valley. Their medium grain matrix, in which are embedded comparatively large and well-formed biotite and hornblende crystals, sets them distinctively apart from any of the other rocks.

It was of great interest as a part of my studies with the Yosemite Field School of Natural History, in 1930, to make observations concerning the variations of the valley granites. In order to properly examine them, and to obtain fresh surfaces, it was necessary in each instance to climb to the top of the talus slopes at the foot of the walls — a task which was well repaid by being able to stand directly beneath many of the flawless facades, thus gaining a new appreciation of Yosemite magnitudes. A summary of many such observations served to impress the salient fact of the distinctive character of the different types of granite, forms which one would naturally identify with the place at which they were found. Perhaps the most striking contrasts in general were the differences between the rocks of the upper end of the valley with those of the middle and lower. Not only are they somewhat different in texture and appearance, but also the uniformity which prevails in the rocks of the upper end of the valley is in striking comparison to the extreme variability of the rocks forming the valley walls farther down.

PERPLEXING VARIETY

As the granites and other closely related rocks all came from a more or less common origin deep within the earth, it is difficult to account for such wide variations in so short a distance as the length of the Yosemite Valley. Questions as puzzling as this have been greatly cleared up by the timely appearance of Dr. F. C. Calkins' splendid paper, "The Granitic Rocks of the Yosemite Region," in U. S. G. S. Professional Paper 160, which is available for sale at the Yosemite Museum. The great masses of molten rock-matter which eons ago came to form the igneous rocks of the Sierra did not all appear at once. Not only were there lapses of time in between successive upwellings of molten matter, but also, according to Calkins, each of the masses differed slightly in mineral composition from that of its neighbors. It so happens that Yosemite Valley is a cross-section of outjutting masses of several of these ancient granitic bodies.

INTERLOPERS FOUND

The water-worn boulders and gravels of the streams running into the valley, as well as the material composing the moraines in the El Capitan section, and near Clark's Bridge above the junction of Tenaya Creek and the Merced River, show still other granitic rocks clearly not those of the Yosemite Valley area. Among them are to be found Cathedral Granites with their great feldspar crystals like "plums in a pudding" — a type of rock which is unique in the whole Sierra — also the fine-grained Johnson Granite, which when freshly broken looks like very pale-colored, brown sugar. These rocks, transported here by streams and glaciers, represent samples from outlying granitic masses, the two just mentioned making up the bulk of the rocks of the Tuolumne Meadows region. Their difference further emphasizes the fact that Yosemite granites are not all alike, but that many are so completely distinct.

It becomes a growing pleasure to be able to identify the various Yosemite rocks, and once they are known they afford as keen a satisfaction in their identification as does knowledge of the plants and animals along the trail.

Bear Trails By George H. Merrihew, Field School, 1932

In the Yosemite Park region, one of the larger animals who often amuses or discomforts the visitor is the bear. Now, bears are like human beings in several respects: that is, they follow regular trails; they prefer using a ready-made trail to breaking a new one, and they like to post their signs at various places. In the event that there is not a man-made trail handy, a bear will follow that of another bear, the latter putting his feet in the prints made by an earlier arrival. This process continues until, in the leafy covering of the forest floor, there usually results a series of depressions about six to 10 inches in diameter, an inch deep and from 20 to 30 inches apart. Often, somewhere near this trail may be found what is called a "bear biting tree." In Yosemite Valley it is usually an incense cedar whose bark has deep tooth and claw marks to a level as high as the bear can reach. This is really the bear's "register."

HOW TO GET THERE

Because of their accessibility, two bear trails which I have discovered, that other nature lovers might wish to see, may be found by taking the Happy Isles Trail from Camp Curry and stopping at the grove of small incense cedars. Here at the right is an older cedar — a bear biting tree. About six feet beyond the tree and parallel to the trail lies the bear trail. Or by taking the bridle path west from the Old Village for 1100 feet, the second bear biting tree may be found, 30 feet from the trail at the left. It is a twin incense cedar from which the bear trail leads to the east.

Curiously enough, men are like bears, for they often follow the bear trails, since once discovered, the trail is easy to follow.

CALIFORNIA WOODPECKERS

NATURE NOTELETS

By M. E. Beatty, Assistant Park Naturalist

ELK DROP ANTLERS

On February 23 two bull elk were observed fighting in a desultory manner and a short time later one of them lost an antler, the second antler falling a day later. This first record compares favorably with former years as our tule elk generally shed their antlers during the last of February and through early March. The mule deer shed their antlers in January.

MARMOT STAYS OUT

Those who believe in the superstition of Ground Hog Day will be relieved to learn that a Sierra marmot, commonly called a woodchuck or ground hog, was observed on February 16 by Charles Michaels on the slope of Mount Watkins. Evidently the marmot failed to see his shadow on February 2 and remained out, hence all signs are for an early spring. Nevertheless we will continue to wear our winter clothes and read the government weather reports carefully.

BIRD TRAGEDY

On February 23 workmen on the grounds of the Ahwahnee Hotel, while cutting up an oak tree that had fallen during a recent storm, brought to light an unusual story. In sawing through one of the main limbs of the tree they discovered three dead California woodpeckers in a hollow cavity. Woodpeckers commonly nest in cavities in dead trunks or branches of black oaks, the entrance hole varying in diameter with the size of the woodpecker. Outside of nesting season several individuals might use the same cavity in seeking shelter from a storm, so it was not surprising to find two males and a female in the same nest. The tree in falling buried the entrance hole deep in the snow and so the three were trapped and probably soon died from suffocation. The tree section showing the entrance hole and nesting cavity will be saved for exhibition at the museum.

SIGNS OF SPRING

That spring is close at hand is shown by the early nesting activities of several birds. Blue-fronted jays were observed on February 23 carrying nesting material at Arch Rock, according to Ranger Bill Reymann.

Water ouzels at El Portal were singing gaily in their mating season during the middle of February and now nest building operations are under way.

Several observations of western robins were reported during the latter part of February in Yosemite Valley.

NEXT MONTH

The May issue of Nature Notes will be a special 30-page number on the Birds of Yosemite National Park. This will include a check list of all birds of the Park together with complete descriptions of all Permanent Residents, Summer Visitants and Winter Visitants to Yosemite Valley.

Due to the greatly increased cost of producing this number, copies will be sent only to those in good standing. If you have delayed renewing your subscription, do so at once to avoid missing this issue.

Subscribers may order extra copies in advance at 25 cents each. Send in your order now.

Sacramento Spotted Towhee By Enid Michael

The spotted towhee (Pipilo maculatus falcinellus) is one of the many handsome birds belonging to the sparrow tribe. There are many geographical races of spotted towhees, all very similar in appearance and habit. The particular spotted towhee found in the Yosemite Valley is known as the Sacramento towhee.

In size, these towhees are about half way between a robin and an English sparrow. Their bodies are rather plump, but a long tail gives them a graceful appearance. When hopping about on the ground, the towhees have a pert way of flicking their tails, and in flight the long rounded, black tail flashes white-tipped feathers. The male Sacramento towhee in full plumage is certainly a dandy. His head is glossy black and a cowl of the same color covers his shoulders. His black back is flecked with white markings, his sides are buff, and his breast is pure white. When seen at close range, his ruby red eye is a mark of distinction. The female of the species is less handsome than the male: she resembles closely the male, but her colors are modestly toned down and her eye is not so ruby red.

OF RETIRING NATURE

The spotted towhees are shy birds and usually keep in the close cover of low-growing bushes, where they scratch for a living. The claw, or spur, on the hind toe is exceptionally long, and is apparently used to advantage in scratching among the leaves.

The towhees nest on the ground, feed on the ground, and spend most of their lives on, or close to, the ground. When moving from place to place, they prefer to move through the bushes, and in hopping or flying through dense bushes, they are expert performers. There is a time, however, when they are likely to be seen up in the highest twigs of their close brush patch, and this time is the mating season. The handsome males take to these perches to sing their love songs. The song is short and simple; a sort of ringing whistle, which is spilled with fervor, and oft repeated.

It has been written that towhees feed principally on worms and insects, but there is evidence which would tend to indicate that this is not the case, at least here in the Yosemite. It has been the writer's observation that adult birds prefer seeds, and about the feeding tables they choose bread stuffs and cracked grain. They never touch the suet that attracts so many other kinds of birds.

Digitized by Yosemite Online Library Dan Anderson