336 BULLETIN 195. UNITED STATES NATIONAL MUSEUM 



thick mat of twigs and leaves at one side of the nest, remaining in this posi- 

 tion with the feathers rufflevi for 30 seconds. The nest time she stayed away 

 9 minutes and remmed only to inspect from the rear. Intervals of 6 and 7 

 minutes followed, the bird apparently taking less and less interest in the 

 nest. KeaJizing this, I became anxious for the safety of the eggs and removed 

 the doth. In 3 minutes more she was back in the bush but did not insi)ect 

 the nest. Ten minutes later, however, she returned apparently to stay, 

 inspected the eggs and b^an at once to incubate. 



• * ♦ What light this throws on the narures of the two birds. The one, with 

 changing con'iitions, has been able to adapt itself, the other has remained ever 

 the same. Stirely this foreshadows the future. At present both are among our 

 common birds. The phr>ebe will become more and more so as he copes with new 

 c-onditions, the catbird rarer and rarer as time goes on. 



Voice. — The catbird at its best stands high in the ranks of our 

 American bird singers. Each year one appears in my backyard, and 

 immediatelT upon his arrival his song is the most delightful feature 

 of the chorus of the multitude of bird voices. A good catbird song 

 needs no apology. The bird sits on some tall spray rising above the 

 general tangle of shrubs, its tail depressed and body held low to the 

 perch, and pours forth its medley of song. Phrase follows phrase in 

 rapid succession, and snatches of all the bird songs in the neighbor- 

 hood appear intermixed with occasional hai^her notes, which are 

 given with as much care and finish as the more melodious ones. TThen 

 an intruder is detected approaching, the outpour stops with a sudden 

 squeak, the tail flies up. and the bird comes to attention. Xo matter 

 how many years we may listen to his performance there is always 

 something new and interesting to be learned from his varied rendi- 

 tions. The catbird is individualistic, and while one bird may be un- 

 usually versatile and of prima-donna rank others may be quite 

 ordinary in their ability to imitate and very mediocre in the quality of 

 their voice. 



^The song in general." as analyzed in notes by A. A. Saunders, "is 

 long-continued and of phrases that are greatly varied with pauses 

 between them. It differs from both the mockingbird and the brown 

 thrasher in that phrases very rarely consist of repetitions of certain 

 notes. The quality is not quite so full and rich as that of the mocking- 

 bird or thrasher. In my records pitch ranges three tones more than 

 an octave, from A''' ' to D" "." According to Albert R. Brand (1938), 

 who has determined vibration frequencies of many of the passerine 

 bird songs by recordings on motion-picture film, the song of the catbird 

 has a frequency ranging from the lowest note of 1,100 to the highest 

 of 4,375. The approximate mean of the recordings of the catbird's 

 song was determined to be 3,000 vibrations. 



"Winsor M. Tyler (MS.) describes the usual song of the catbird as 

 a "series of quick, bright widely varying phrases, which is continued 

 sometimes for 5 minutes or more. In form it is like the brown thrash- 

 er's song but is more disjointed and does not run on with the regular 



