GRASSHOPPER SPARROW 737 



An unusual concentration of grasshopper span'ows is described by 

 Brewster in his Nantucket journal. Here on June 27, 1874, he and 

 Maynard found grasshopper sparrows extremely plentiful. He writes 

 that "they were equally distributed for an extent of three to four 

 miles. Often there were three or four pairs breeding in an area a 

 hundred yards square." This species was fah-ly common on the Islands 

 in the 1920's, but in recent years it has become local and uncommon 

 and appears to have been replaced by the Savannah sparrow (Pas- 

 serculus sandmicliensis) (Griscom and Folger, 1948). Mrs. A. B. 

 Davenport \mtes that the same situation is true on Conanicut Island, 

 off Rhode Island. The bird was formerly abundant on Martha's 

 Vineyard and north to Essex County, Mass.; today it is rare and local, 

 replaced by the Savannah sparrow (Griscom and Snyder, 1955). 



Thus it appears that populations of gi'asshopper sparrows fluctuate 

 sharply at times in spite of the availability of suitable habitat. No 

 reason can be given, but in some areas it appears to be giving way to 

 the Savannah sparrow, a bird that occupies the same fields and is 

 able to maintain its numbers when shrubs invade the area. 



Voice. — The male grasshopper sparrow possesses three primary 

 forms of vocalization, the grasshopper song, the sustained song, and 

 the triU; the female has only one, the trill. 



Of these the most familiar is the grasshopper song from which the 

 bird derives its name. The song consists of one to three introductory 

 notes followed by a long, very high-pitched trill. The length of this 

 song varies from 1 to 2)i seconds, and averages about \)i seconds. 

 The pitch, according to Saunders (MS.), varies from F#' to D^; and 

 the pitch interval varies from 1 to 2>)i tones. The introductory notes 

 "are usually of lower pitch than the triU." The trill is simple and 

 nearly always on the same pitch throughout. 



Brand (1938) determined the pitch of this song to range from 

 9,500 to 7,675 vibrations per second, with a mean of 8,600. By 

 contrast the frequency of a piccilo is 4,608 cycles per second. 



The songs of the other races resemble closely those of pratensis. 

 Zimmer (1913) describes the song of the western grasshopper sparrow 

 as a pit-tuck zee-ee-ee. Simmons (1925) describes it as a "thin, wiry 

 monotonous grasshopper Uke pit-tuck zee-ee-e-e-e-e-e-e-e-e-e or kalsick 

 ha tsee-e-e-e-e-e-e-e-e-e-e-e." 



W. H. Nicholson (1936) describes the song of the Florida grass- 

 hopper sparrow "as sounding like twitile-e-dee repeated several times 

 in rapid succession with a tik-tik-tok-huzzzzzz at the finish. Many 

 times I have heard them sing the latter part of this song without the 

 former, but never the former part alone. The latter part has a 

 distinct insect-like sound." 



