MISSISSIPPI SONG SPARROW 1517 



to a few large splotches irregularly placed, usually the larger part of 

 the pigment being around the large end, sometimes in quite a regular 

 ring. Measurements of 503 eggs ranged from 17.5 to 22.5 mm. in 

 length and from 14 to 17 mm. in width, the median being 19.9 x 15.5. 

 As to weight, 44 fresh eggs varied from 1.8 to 2.85 grams, the average 

 being 2.28, the median 2.23. 



In 211 nests on Interpont sets of 5 eggs were found in 30 percent of 

 the cases, 4 eggs in 50 percent, and 3 eggs in about 20; the average 

 size was 4.1 eggs. In North Carolina in 175 nests D. J. Nicholson 

 discovered only one 5-egg set; 4-egg sets were in the majority, although 

 there were several of 2 eggs and once he collected a single well incubated 

 egg. When a song sparrow's nest is destroyed the first egg of the 

 next set is laid 5 days later. 



The weight of a set was approximately half the weight of the bird 

 that laid it. 



Young. — Incubation, which is performed by the female alone, 

 usually lasts slightly over 12 or 13 days but rarely has taken 14 and 

 15 days with unusually inattentive females. The bird stays on the 

 eggs for 20 to 30 minutes, then leaves for 6 to 8 minutes. The total 

 percentage of daylight hours spent on the nest averages 75 to 80. The 

 male guards his territory, nest, and mate, and does considerable 

 singing. He often calls her off the nest with a sudden loud song. 



The young are brooded by the female for the first 5 or 6 days of 

 nest life. The rate of feeding increases with the age of the nestlings; 

 in 7 broods the rate for the first 5 days averaged 7.2 times an hour, for 

 the second 5 days 17.8; the average for the whole period was 11.1 

 times an hour. The weight of the nestling increases more than ten- 

 fold in the first 10 days of life. Young usually stay in the nest 10 

 days, leaving before they can fly. They become independent of the 

 parents at the age of 28 to 30 days. 



After a nest was destroyed, the young of the replacement nest were 

 usually fledged just 30 days later. Periods between the fledging of 

 two broods successfully raised ranged from 30 to 41 days. M. m. 

 euphonia might be called three-brooded, although Schantz (1937) 

 reports that one pair raised four broods in one nest in one season. 

 D. J. Nicholson writes of a similar observation near Tuxedo, N.C. in 

 1956, his only such record in 56 years of experience. 



Plumages. — Alexander Wetmore (1936b) described euphonia as 

 similar to melodia but distinctly darker above, being grayer, with the 

 dark markings generally more distinct; sides of head grayer, less 

 buffy or brown; tail averaging darker. In common with other races 

 of the song sparrow in the east, many individuals of euphonia show a 

 distinctly rufescent phase. One breeding bird collected has the 



