RED-BREASTED NUTHATCH. Sitta canadensis Linnaeus

Field characters.—Half size of Junco; tail about half length of body. Top and sides of head, black in male, slaty in female; a white stripe over eye in both sexes; back slate gray; under surface of body reddish brown. (See pl. 10g). "Hitches" about in all directions on bark of trees. Voice: A piping nasal na, uttered singly or in measured series.

Occurrence.—Common in summer in Canadian Zone (less plentiful in Transition and Hudsonian zones) on west flank of Sierra Nevada. Recorded in that season from Smith Creek (at 3000 feet altitude east of Coulterville), and from near Chinquapin, eastward to Tuolumne Meadows. Found on east slope of mountains (Walker Lake) in September. In Yosemite Valley practically throughout the year. Lives on trunks and branches of conifers, usually in the upper halves of the trees. Solitary.

Often when the traveler is following a trail through a forest there comes to his ear from the lofty tree tops the quaint nasal call of the Red-breasted Nuthatch, sounding like the blast of an elfin horn. With careful search he may locate a small form moving about the trunk and branches at the tiptop of a tree. If luck favors and the observer is patient the bird may eventually come low enough so that the black on its head, the white stripe over the eye, the bluish gray back, the reddish brown under surface, and the very short, squared tail will all be seen and the identification rendered certain.

The center of abundance of the Red-breasted Nuthatch lies within the Canadian Zone, but some of the birds are to be found in the zone above and in that below. The seasonal status of the species is not fully known. In Yosemite Valley, which is in the Transition Zone, it is present continually at least from April to the last of December, and it seems likely that a few of the birds stay there throughout the whole winter. On December 30, 1914, four Red-breasted Nuthatches were heard near Gentrys (6000 feet), which suggests that some of the birds may remain even higher in the mountains throughout the year. The species is known to visit the foothills and valleys in other parts of California during some winters, but we did not see it, winter or summer, at any station below the Transition Zone, in the Yosemite section.

The Red-breasted Nuthatch is of about the size of the Pigmy Nuthatch and but half the bulk of the Slender-billed. It has a conspicuous stripe over the eye which is the best single mark by which it may be recognized. (See pl. 10g). The Red-breasted Nuthatch is a solitary bird and so is not likely to be confounded with the Pigmy Nuthatch which is emphatically of flocking habit.

The call note of the Red-breasted Nuthatch is a nasal na or weh, reminding some people of the tooting of a child's penny trumpet. Sometimes the note is given singly or, if repeated, with very long intervals between calls, while on other occasions five to nine calls are given close together with measured timing. When the birds are disturbed or excited the na-na-na, etc., comes with a more rapid and continued production, even for several minutes at a time. The nature of the call is such that it carries for long distances; the hearer is frequently deceived into believing that the bird is close by. This one call seems to be the only vocal achievement of which this nuthatch is capable.

Even among the three species of nuthatches, which as a group are bark dwellers, there seems to be mutual agreement with respect to forage range, by which each is allotted a separate precinct. The Slender-bill keeps to the smaller trees or around the bases of the larger ones, the Pigmy forages out toward the ends of the branches and amid the needle tufts, while the Red-breasted, although sometimes coming close to the ground, spends most of its time up near the tops of the loftiest trees where it inspects the main shaft and larger branches. Were it not for the bird's far-carrying note, the last-named species would often be passed unnoticed even by the careful observer. Although a nuthatch may be calling constantly the observer often has great difficulty in discerning the 4-inch bird at the top of a tree a hundred feet or more in height.

At Hazel Green on May 14, 1919, a pair of these nuthatches was seen foraging close together and within a few feet of the ground. One of the birds (the male?) kept its tail slightly spread so that the white band showed at each side. Presumably this was a courting display somewhat of the nature to be noticed among fox sparrows, juncos, and other birds at this season, and it is likely that nesting commenced soon afterward.

The Red-breasted Nuthatch probably nests as a rule well up in the trees at about the level at which the birds spend most of their time. On June 14, 1915, near Chinquapin, the mobbing of two Blue-fronted Jays by a pair of nuthatches led to the discovery of the latter's nest site. After the jays had quit the vicinity one of the nuthatches was seen to enter a little round hole in the trunk of a slender and very brittle, dead silver fir. Since the hole was about fifty feet above the ground, the tenants were perfectly safe there from any human intrusion.

Of the nuthatches collected during June, 1915, males predominated, a fact which would suggest that at this season the females were engaged in incubation or in caring for the young. On August 3, 1920, at Smith Creek, 6 miles east of Coulterville, a juvenal bird which was molting into the first winter plumage was taken. The birds collected in August, 1915, at Merced Lake and on Mount Clark (at 8800 feet) were all immatures of the current season; probably the adults were molting and so, as is often the case with birds at that season, were keeping themselves in seclusion.

Once a Red-breasted Nuthatch fell victim to a mouse trap, baited with rolled oats, which had been set beside a log in the forest. Whether the bird had sought the material as food (for some nuthatches do take nuts and seeds) or whether it was led to investigate the trap out of curiosity was not evident. All nuthatches have a more or less well marked trait of curiosity, as have their relatives, the tits and chickadees.

The flight of the Red-breasted Nuthatch is slow and hesitating, the wings beating a few rapid strokes and then being held closed for a short interval. Perhaps this peculiarity of flight is due partly to the extreme shortness of the tail (fig. 58b). The shortness of the tail is a striking feature of the silhouette of the bird in flight.

But little seems to be known concerning the food habits of this species. Its regular patrol of the bark of trunks and branches of trees probably means that insects and their eggs and larvae contribute extensively to the diet of the bird. A freshly captured bird gives off a curious odor quite distinctive of the species, possibly due to its regularly feeding upon some particular sort of insect.

At Aspen Valley one day in October one of these nuthatches was watched as it came down to drink. The bird descended from the trees to the vertical surface of a rock about three feet above the water and then by short flights moved to a twig two inches above a little pool. There it leaned down and drank ten or twelve sips at intervals of three or four seconds. Its bill was in the water less than a second for each drink; the rest of the time the bird spent in looking cautiously about. At this same locality a Red-breasted Nuthatch came several times to a white fir near our camp and drank some of the sap which was oozing from a gash in the bark near the base of the tree.