POOR-WILLS. Phalaenoptilus nuttalli (Audubon)¹⁹

Field characters.—Body size appears nearly that of robin, but tail shorter and legs and feet much smaller; head broad; bill small; eyes large. Throat and band at end of tail below, pure white; rest of plumage a variegated yet blended pattern of black, gray and dark and light browns (pl. 43b); feathers soft, owl-like. Flight, erratic and silent, usually close over ground or brush; squats on ground when at rest. Voice: A mellow yet far-carrying poor-will-o, repeated. Also a soft quirt, uttered mostly in flight.

Occurrence.—Moderately common summer visitant both east and west of the high Sierra Nevada.¹⁹ Life zone, Upper Sonoran on the western side, Transition on the eastern. Rests on ground in shelter of chaparral during daytime, foraging abroad at dusk and during night.

---

¹⁹The Poor-wills at Snelling, Pleasant Valley, Smith Creek, and other west-slope localities belong to a dark-colored subspecies known as Phalaenoptilus nuttalli californicus Ridgway, the Dusky Poor-will, which ranges through the central valleys and southern coast region of California; while the birds at Walker Lake, Williams Butte, Mono Lake Post Office and on Negit Island belong to a paler, and slightly larger, Great Basin form called Phalaenoptilus nuttalli nuttalli (Audubon), the Nuttall Poor-will. Individuals belonging to these two races cannot be distinguished except in hand, but in the Yosemite region neither race is known to invade the range of the other at any season. They are separated by the high Sierras.

---

Poor-wills are essentially birds of the night. Along with nighthawks and bats they replace the swallows, swifts, flycatchers, and other birds that feed upon flying insects during the daytime. Soon after sundown of the long summer days the notes of the poor-will are to be heard coming from the grease-wood or sagebrush-covered slopes of the hills, and a little later the birds themselves begin to take wing low over the chaparral or grass lands in search of their food.

Poor-wills are adapted in many ways for their night-time activities. Their eyes are large, suggesting those of owls. The mouth is broad, extending across the whole width of the head and, when open, forms, with the row of outstanding bristles on either side, a gaping trap into which flying insects can easily be scooped. Their plumage is soft, if anything even more so than that of owls, and so their flight is noiseless, seemingly a necessity in night-foraging birds in general. The wings of the poor-will are relatively long but rounded in outline at their ends, like those of the ground owl. The mottled color pattern of the plumage (pl. 43b) blends well with almost any broken surface, such as gravelly ground, on which the birds may chance to rest, and this may be helpful to them during the daylight hours in making them less easily seen by their enemies when they are resting or sleeping. Certainly the human observer finds difficulty enough in detecting the presence of one of these birds on the ground so long as it remains quiet.

Poor-wills do not usually begin to forage until late dusk, being even more nocturnal in this respect than nighthawks; nor are they seen abroad in the morning as late as are those birds. On the evening of May 20, 1915, at Pleasant Valley, as one of our party was riding along the Baxter Road which winds uphill through the greasewood (Adenostoma), several Dusky Poor-wills were seen along the margin of the chaparral. At the approach of the horse the nearest bird would rise a few feet above the ground, fly a short distance up the road, and then settle down close to the roadway, only to start up again erratically when further disturbed. These birds are active through at least the early hours of the night; for on August 18, 1915, one was heard calling from near Cathedral Spires, in Yosemite Valley, between 9 and 10 o'clock at night.

As regards occurrence in the Yosemite Valley, this last record was made in the season when poor-wills are known to range up the mountains into the lower part of the Transition Zone, where they do not ordinarily occur earlier in the year. We have the statement by Mr. W. O. Emerson (1893, p. 179), however, that the notes of a California Poor-will could be heard "high up on the cliffs above the valley" between June 20 and 25, 1893.

The usual forage range of the poor-will is close to the ground or brush, being thus quite different from that of the high-flying nighthawks. And while actively foraging, the birds pause from time to time and come to rest on the ground or a convenient rock. Indeed they spend much more than half of their forage time at rest. At Mono Lake near the mouth of Rush Creek, on June 3, 1916, three Nuttall Poor-wills were seen foraging on moths about a poplar tree. The birds would fly up and hover about the lower foliage and make short dabs at the insects. At this station the poor-wills were seen to alight lengthwise on old logs rather than on the ground itself.

The mellow two or three-part call of the poor-will is given irregularly, sometimes at long intervals, again in rapid succession. It is heard most persistently at dusk of evening or in the early morning; but near Pleasant Valley on the morning of May 23, 1915, one of these birds suddenly broke out at 10 o'clock and uttered its poor-will'-o 85 times (by count, within 2 or 3) at intervals of two or three seconds. At a distance the third syllable may become inaudible.

Near Williams Butte on June 21, 1916, an adult Nuttall Poor-will was captured alive. Next day the bird was taken out in the open, but seemed reluctant to move. It would sit still for a long time, then suddenly fly a hundred yards or so and alight once more. When disturbed it would spread out its tail and wings, open its cavernous mouth, and emit a hissing sound. Altogether the performance recalled the behavior of a rattlesnake when cornered. The bird objected very much to facing the direct sun-light and usually, after a flight, alighted in a shady spot. When forced to sit in the sun it kept its eyes closed most of the time.

A nesting site of the Dusky Poor-will was found near the head of Smith Creek on August 6, 1920. It was on a cleared side-hill where grew scattering plants of 'mountain misery' and brakes. As the neighborhood was approached an adult bird took wing and alighted on a burnt log near by. Search was rewarded by the discovery of 2 half-grown young birds which were lying side to side on the bare ground both facing in the same direction with eyes closed and wings held apart as if to secure coolness. They were in the partial shade of some brakes about 15 inches high. When the young birds were touched they instantly assumed a fighting attitude and struck out, with their mouths wide open, at the same time giving a peculiar hissing note. A space about 5-1/2 feet in diameter in front of the place where the birds were resting was completely cleared of loose material; it had evidently been used by both old and young as a 'take-off' when leaping to capture passing insects.