150 
THE CONDOR 
| Voi,. VIII 
The song of the Cassiu vireo ( Vireo solitanus cassi/ii ) is far more striking, tho not 
so continuously littered. It approaches more nearly to articulate human words than 
that of any bird I know. A series of emphatic phrases, each of from one to three 
syllables are uttered alternately with the- rising or falling inflection, and separated 
by a distinct pause. If one had any hope of really guessing "the mind of the 
bright-eyed bird," it would not be hard to translate this song into human words. At 
least it seemed to me that once, when a round-eved little fellow clad in gray came 
to offer his advice to a pair of agitated grosbeaks, who were distressed about my 
presence, he must have meant to use different words from when, in early spring, he 
was excitedly following a coy female from twig to twig, and pouring his passion- 
ate declaration into her unwilling ear. 
I will venture to give a few of the phrases which he seemed to me to utter on 
this first occasion, as they may suggest the song to some one who is familiar with 
it, but does not know the little pale greenish bird from whose throat it comes. 
"Who are yon?” he seemed to say to the intruder; "Watch out!" “Misery!" 
"Phew." This last monosyllable, in a low, rich voice, occurs at rather rare in- 
tervals, and seems to mean a great deal. Often another bird in the distance may 
be heard, answering between these phrases, and using the same series of inflec- 
. tions. The song carries a long way, and a dialogue like this, between two little 
householders on opposite sides of the canyon seems to give them great satisfaction. 
Besides this note they have a soft warble, not often heard (meant only for the 
ear of one) and evidently expressive of extreme happiness, tho not so musical as 
the warble of Vireo gilvus swai nsom ’. By following this note I found on May 10, 
1903, a partly finished nest in a small white oak, which has much the same droop- 
ing habit as the eastern elm, and so offers suitable nesting sites for this bird. 
While I watched, the female alone carried material and built, but the male showed 
no lack of interest. While his mate was away seeking material, he kept a sharp 
watch and drove away all unwelcome bird visitors. When she was seen rapidly 
approaching, he burst into a flood of song and flew with her to the nest, where he 
watched her labors with the greatest excitement. 
The outer layer of the nest was complete and was composed of large tufts of 
white tissue paper, bits of white string and many silky spider’s cocoons woven to- 
gether with a little bark fiber. It was about ten feet up, and was larger in diam- 
eter and much shallower than that of the warbling vireo in the pear tree. The 
female brought fine bleached grasses and always went into the nest with them, to 
adjust them as lining. Then she would reach over the rim and draw out bits of spider 
silk, which she would wrap about the supporting twig and tuck down among the 
grasses. The female only uttered a scolding note which sounded like "zee — tsip, 
tsip, tsip," the first syllable given long and with emphasis, the last rapidly. 
One morning there had been some excitement, and numbers of scolding birds 
of all kinds were heard, in the neighborhood, as I approached. It took half an 
hour for the female to quiet down enough to begin working, tho twice the male 
went to the nest tree and sang a sort of coaxing call. Finally when she came 
near he swelled out his breast and swayed from side to side, seeming to exert all 
his eloquence to reassure her, but she only scolded and flew away. 
The male shares in incubation and even sings on the nest. At Lierlev’s, Men- 
docino County, these birds were very common, apparently more so than the war- 
bling vireo, but the higher I went in the Sierras the less common in proportion the 
Cassin seemed to be. There was hardly a willow or alder thicket near Tahoe with- 
out the cheery song of the warbling vireo. 
Berkeley , Cal. 
