112. The Ornithology of Chester County 
ant, transient. 
Spring arrival—Apr. 9 (1905)—Apr. 28 
(1911); ave. 8 yrs. Apr. 19. 
Spring departure—Apr. 27 (1900)—-May 12 
(1907); ave. 6 yrs. May 4. 
Fall arrival—Sept. 12 (1913)—Oct. 8 (1915); 
ave. 8 yrs. Sept. 26. 
Fall departure—Oct. 9 (1890)—Nov. 14 
(1903); ave. 19 yrs. Oct. 26. 
246. Planesticus migratorius migratorius Robin, 
“redbreast,” ‘‘robin,” “robin-redbreast.’”’ Abundant 
summer resident; occasional resident. Nidification 
usually commences by April 27, and nest is com- 
pleted by April 30. 
Berwyn: 
Arrival—Feb. 7 (1912)—Mar. 17 (1888) ; ave. 
32 yrs. Mar. 2. 
Common—Feb. 21 (1906)—Apr. 5 (1895) ; ave. 
33 yrs. Mar. 14. 
Bulk departure—Oct. 7 (1903)—Nov. 5 
(1907) ; ave. 27 yrs. Oct. 24. 
Last seen—Oct. 27 (1915)—Dec. 3 (1891); 
ave. 33 yrs. Nov. II. 
247. Sialia Sialis sialis Bluebird. ‘Tolerable com- 
mon summer resident; occasional resident. Nidifica- 
tion begins about April 15; complete set April 30. 
Berwyn: 
Arrival—Jan. 17 (1901)—Mar. 25 (1912); 
ave. 33 yrs. Feb. 19. 
Common—Jan. 30 (1892)—Apr. 28 (1911); 
ave. 29 yrs. Mar. 2. 
Bulk departure—Oct. 7 (1915)—Nov. 15 
