JA?., I9o2. I THE CONDOR I3 that time that Itook to inquiring into the necessity of birds songs. If they were of no importance to them, as I had hitherto supposed them to be, why did they use them at all? This course of reasoning was interest- ing and opened up a new line of inves- tigation. It was only then that I began to geta faint idea of the true depth of the subject. Bird songs were not use- less. They were the outcome of innum- erable arian needs and necessities and for untold generations of birds' lives they had been used by them as a means of communication, advancement and protection. in short their twitterings and murmurings, so meaningless and disconnected to us, are to all intents and purposes a language, that conveys to the birds in a crude form a great deal of very useful information. I do not mean to say they HAVE a language or even an approach to one, but the system of notes that each species uses is a means whereby ?nv member ?f a fi,?ck cqn eonv:y to the rest of the flock any one of quite a number of ideas. Besides this while the notes of one species are most thoroughly familiar to that spedes, still other kinds of birds, speeifiealty and even generically differ- ent, do at times take advantage of each others notes, especially when there is trouble around. The most prominent instanees of this sort that have come to my attention relate to california jays (?Iphe/ocoma calebmica.) The minute they discover any two or four-legged foe in their domain, they raise their voices in protest, first one, then another joining in the chorus and various other birds of different species and genera, such as the usual run of woodland seed- eattrs, are on the alert at once and re- main so until all danger is over. The idea of birds having even a sub- stitute for a language will seem rather far-fetched to a great many people and this, I remember, was my first impres- sion of it, so in order to make sure of it I began by memorizing the notes of the commonest species of birds, at the same time noting everything I could in regard to each kind of note, as for instance, the occasion of its use; the effects of its use on other birds (of its own species in particular) and also what notes, if any. the other birds gave in reply. This was not as easy as it seemed to be, for at the outset I found it was very hard for a beginner to imitate accurate- ly, mentally or orally, even the common- est bird notes, as the note syllables are not always as defined and distinct as they might be and it takes a long time to get accustomed to this peculiarity. However by frequent repetition of a note ou?' LOUD, while the bird was ut- tering it, I partially overcome this diffi- culty. As an illustration, take the call note of the red-shafted flicker(Co&files caret co[[aris), one of the most wide-spread birds of the state. Some people call the note "chee up" or even "cheer up"; others call it variously "ye up," "kee yik" or "kyee yuk." At times it sounds like t?ne, then like another of these imi- tations, so that it would take an expert's opinion to decide which it is. By mem- orizing the co?nmonest notes of several species of birds, together with keeping a record of the conditions under which they were used, I soon became able to multiply observations on each kind of note and the conditions of its use, and in th:s way could readily compare the notes and their respective causes and effects, in many cases, a number of times over, only to find that each kind of note caused its own particular effedt on the other members of a flock of the same ?ptcias, showing that birds of the same species had a pretty thorough under- standing of their own notes. in quite a good many cases though I could not make these comparisons for I only dimly understood the cause of the note or notes used, so I continued the study by taking up each note in detail, considerin:,? chiefly its cause and effect. While doing this I gradually distin- guished quite a difference between com- mon and special notes, and as it seemed
