732 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



tightly until almost stepped upon before they flutter off uttering weak 

 squeaking notes not unUke a mouse." He (1936) writes further: 

 "When they did leave they did not fly, but ran off dragging tail and 

 fluttering the wings as if crippled. If followed they would lead the 

 intruder off about twenty feet from the nest and then fly to some 

 nearby palmetto and begin scolding. Several times the bird would 

 run along the ground within eight feet of me scolding with a weak 

 tik-tik-tik" 



During the incubation period the male spends his time singing and 

 defending the territory, but shows little concern over human intruders. 

 When they appear he simply stops singing and hides in the grass. 

 The actions of both sexes are such that they attract no attention to 

 the nest location. 



The behavior of both male and female changes after the young 

 hatch. One male I observed sang both songs throughout the day 

 his young hatched. The female flushed from the nest but did not 

 feign injury. She flew a short distance, hid in a swath of hay and 

 chipped softly. The male chipped several times, broke into the 

 grasshopper song, fluttered both wings, and then continued to chip 

 vigorously. As I left the area the male sang the sustained song, 

 interrupted it with a grasshopper song, foUowed by the trill (see Voice). 



Young. — Grasshopper sparrows at hatching are blind and covered 

 with grayish-brown down. Walkinshaw (1940) gives the weight of 

 young at hatching as between 1.7 and 2.3 grams. This is approxi- 

 mately the same weight as the egg. At 4 days wing feathers break 

 through the sheath; breast and side feathers still are in the sheath; 

 back, belly, and rump are bare. At 6 to 7 days body feathers emerge 

 from the sheath and appear dark brown to blackish with yellowish 

 buff edge. A distinct buffy crown patch is present; the commissure 

 is bright yellow. By day 9 to 10 the young are well feathered, 

 though the tail feathers are still short. Walkinshaw gives the weight 

 increases as of the second day, 2.9 grams; sixth day, 8.7 to 9.1 grams; 

 and seventh to eighth day, 9.7 to 10.5 grams. Wetherbee (1934) 

 reports the weight of 14 immature birds as ranging between 14.0 

 and 18.3 grams, averaging 16.09. 



Upon my approach to the nest the young invariably gaped for 

 food, but expressed no sign of fear. On June 7, 1944, my dog dis- 

 covered the nest of one pair and threw two of the four out of the nest. 

 As I replaced these, the two in the nest gaped for food. Later in the 

 day, immediately after the female fed the young, one bird gaped and 

 three did not respond. This same pattern was followed at other 

 nests. Recently fed young did not respond in any way; if hungry 

 they gaped when I moved near the nest. 



