MIRGATION OF OUR BIRDS 1 63 



show that these species usually arrive in the first week in April 

 and move rarely in the last week in March. On the other hand, 

 the Field Sparrow arrived three years in the last week in March 

 and one year in the first week in April. 



The Chipping Sparrow shows irregularity in the two dates in 

 April — the first and the second weeks; but in March both dates 

 are in the last week. In April, the Sapsucker shows great regularity, 

 arriving three years in the second week; the one irregular date 

 was in the last week in March. 



The Hermit Thrush arrived two years in the first week in 

 April and two years in the second week, 9 days being the difference 

 between the earliest and latest date. The Brown Thrasher shows 

 a little less irregularity, arriving three years in the third week in 

 April, and having 7 days between the earliest and latest date. 



The Purple Finch, in the two )^ears that the bird made its 

 appearance, shows regularity in its dates of arrival; there being 

 but 5 days between the two dates. 



The Towhee presents a case of great irregularity in migrating, 

 there being no two years when the bird arrived in the same week. 

 The greatest difference in the dates was 29 days. 



The Barn Swallow came one year in the second week in April, 

 another year in the third week, and in the remaining two years 

 in the fourth week, the greatest difference between the earliest 

 and latest date being 14 days. 



The Red-headed Woodpecker shows the greatest disparity 

 in its dates of migration of any species under consideration, 39 

 days being the difference between the earliest and latest date of 

 arrival. The four dates are variously distributed in the third 

 week, in March, first, second and fourth weeks in April. 



The Red-winged Blackbird's dates present great differences, 

 but I am sure that the date for 1909 — April 20 — can not have been 

 the correct time of arrival. This species is usually found only in 

 swampy places and unless such a place is visited, the observer 

 may not see the bird until long after its arrival. The true time of 

 migration for the Red-wing must, therefore, be set down as the 

 first or second week in March. 



The dates found in the four years show for the Myrtle Warbler 

 a migration period of 16 days, and make the time of arrival as 

 early as the third week in April and as late as the first week in 

 May. The Ruby crowned Kinglet is still more irregular, with 22 



