NORTHEBN YELLOW-THEOAT. 



117 



struck the two lighthouses on the same night. Judging by the light- 

 house records, the period of spring migration of the Maryland yellow- 

 throat is one of the most extended. As already noted, the species is 

 a common migrant in March; it is equally common in April, and is one 

 of the few warblers that are common migrants in May in southern 

 Florida. In 1888 it struck the lights at various dates from March 6 

 to May 20, and the next year from March 3 to May 29— the extreme 

 dates for all years and for the Florida lighthouses. The latest of 

 these dates is later than the time when full complements of eggs of the 

 Maryland yellow-throat are laid in nests a thousand miles to the north. 

 The late flights are not merely the passing of accidental laggards. 

 The largest flight noted in spring was on May 8, 1888, when 175 birds 

 struck Sombrero Key light and 37 dead ones were counted. On May 

 20, 1888, 18 birds struck, and on May 29, 1889, five were noted. These 

 records give an idea of the great numbers of Maryland yellow-throats 

 that cross between Florida and Cuba. 



The dates of earliest spring arrival of Maryland yellow-throats at 

 Raleigh, N. C, show the following remarkably even record: March 

 28, 1887, March 28, 1888, April 1, 1889, March 28, 1890, April 1, 

 1891, April 2, 1892, March 27, 1893, March 30, 1899— average March 

 30. Continuing north on the Atlantic slope records of average date 

 of arrival are: Washington, April 22; Philadelphia, April 29; Engle- 

 wood, N. J., May 4; southeastern New York and central Con- 

 necticut, May 5; Boston, May 7; St. Johnsbury, Vt., and southern 

 New Hampshire, May 11; southern Maine, May 14; Quebec, May 17; 

 St. John, New Brunswick, May 18; central Nova Scotia, May 25; 

 southern Ontario, May 8; Ottawa, May 17. 



The following table contains records of first arrivals that presum- 

 ably relate to Tyraclvidactyla. It shows the general dates of movement 

 in the Mississippi Valley, and also how much later the birds migrate 

 on the plains: 



Record of first arrival oj norlhem yellow-throat. 



