iSrORTHERN AND MARYLAND YELLOWTHROATS 555 



recognized, for it is much more definite and distinctive than most 

 warbler songs. 



"The pitch of songs varies from D' ' ' to D' ' ' % or one octave. 

 Single songs commonly have a range of one and one half to two and 

 one half tones, a very few only one tone, and a few others up to three 

 and one half tones. Songs vary in the rapidity of the phrases and 

 range from 1% to 2% seconds in length. Usually about two phrases 

 occuy 1 second of time." 



The song of the northern yellowthroat may be heard throughout the 

 nesting season but in the last weeks of July and the first week of 

 August singing is less general and less spirited. I have never heard 

 the song in Maine after the last week of July, but observers in other 

 sections of its range have heard it throughout the month of August 

 and as late as the second week of September, although this late sing- 

 ing is unusual. M. B. Trautman (1940) in his intensive study of the 

 birds of Buckeye Lake, Ohio, writes : "The song period began with 

 the first male arrivals in the spring, reached its height in mid-May, 

 and continued undiminished until late June. There was less singing 

 in early July, and by August it had ceased almost entirely. A few 

 birds continued to sing throughout summer and fall, especially in the 

 early morning. An individual on Lieb's Island sang during late 

 October and until November 2, 1929, the last day on which it was 

 observed." Others have reported individual birds remaining through- 

 out the winter, as far north as Toronto, Canada, that were heard sing- 

 ing their characteristic song in spite of snow and severe weather 

 conditions. 



Aretas A. Saunders writes that the northern yellowthroat sings 

 until August 1, an average based on 14 seasons in Allegany State 

 Park. The latest date on which the song was heard was August 8, 

 1929. Frank L. Burns (1937) states that the approximate duration 

 of the yellowthroat's song is 87 days, extending from May 5 to July 31. 

 Of this time the two nesting cycles were in progress for a period of 

 77 days. In Arkansas W. J. Baerg (1930) writes that in a 5-year 

 period of study the average singing period extended from April 15 to 

 August 10, or 117 days, about a month longer than the determinations 

 made by Burns in Pennsylvania. 



The northern yellowthroat seems to exhibit some ability in imitating 

 the song of other birds. E. M. S. Dale, of London, Ontario, writes 

 to us: "For several days in early May 1933, we heard a chipping- 

 sparrow-like song coming from the edge of Spettique's Pond (a mile 

 or two south of London) . We were unable to catch a glimpse of the 

 singer until the fifteenth, when we got a good look at it in the very 

 act, and were much surprised to find that it was a northern yellow- 



