Flight Record for Line 4 by Phil Dumont and Ann Evenden, by 5-minute periods 4-5:15 p.m. Jan. 3, 1970 at Pyle Jr.Hi "Blackbird" Roost, Bethesda, Montgomery Co. Maryland 3477 Time Starlings Species Count Grackles Cowbirds Totals 405 20 0 465 485 410 250 1 1,520 1,771 415 280 0 3,430 3,710 420 495 1 4,510 5,006 425 3,600 0 1,500 5,100 430 5,000 0 3,400 8,400 434-5 (3,400) 435 7,300 50 1,300 8,650 435-6 (2,700) 436-7 (3,300) 440 10,100 0 0 10,100 440-1 (3,700) 445-5 (3,300) 445 17,000 1 0 17,001 450 16,400 2 400 16,802 450-1 (3,200) 455 11,200 0 0 11,200 457-8 (2,000) 500 9,000 10 0 9,010 502-3 (2,200) 505 11,200 10 0 11,210 510 3,550 220 0 3,770 514-5 (150) 515 650 118 0 768 Totals 96,045 413 16,525 112,983 The important thing to note is the early arrival of the cowbirds, and the final rush of arriving grackles. Also note the almost complete absence of grackles on this particular flight line. A similar pattern of "travel time" was ob- served on Line 1. Note the per-minute rate Dumont recorded on certain intervals, time permitting. F.Evenden estimates an even/per-minute arrival rate on the late-flush of grackles, Line 1, greater on other table.