Dee es ea) GN ha. LL eel IN i 
Chicago Lake Front Migration — Fall 1966 
By Bedford P. Brown, Jr. 
SUMMARY — The autumn migration was by far the best that this reporter 
has seen in the last five years. No remarkably large waves of warblers or 
other song birds were noted, but the migration produced almost daily in- 
vasions of varlous species in numbers that occasionally far exceeded the 
normal. 
Major hawk flights occurred during the periods of gales on Sept. 14, 
Oct. 10 and 23. The songbird migration seemed to peak on the week-end of 
Sept. 24 and 25, when many birders were afield. Shorebirds generally were 
early and up in numbers, with Black-bellied Plovers noted the second 
week of July and sandpipers peaking during mid-August. 
Almost all songbirds were up in numbers this autumn, as well as many 
other species. I would consider the following species to be 500% or more 
above their usual numbers: Red-throated Loon, Double-crested Cormorant, 
Greater Scaup, Wood Duck, Broad-winged Hawk, Marsh Hawk, Black- 
bellied Plover, Lesser Yellow-legs, Dowitcher, Western Sandpiper, Stilt 
Sandpiper, Buff-breasted Sandpiper, Red Phalarope, jaegers (mostly un- 
identified), Caspian Tern, Golden-winged Warbler, Black-throated Green 
Warbler, Blackburnian Warbler, Pine Warbler, Ovenbird, Dickcissel, Sharp- 
tailed Sparrow, Harris’s Sparrow and Lapland Longspur. 
WEATHER — July was the fourth warmest on record and the warmest since 
1955, with temperatures averaging 2.7 degrees above normal. August, Sep- 
tember and October, on the other hand, were cooler than normal, with 
departures of 2.5 and 1.1 degrees, respectively. A period of heavy summer 
thundershower activity ended with a five-inch deluge on July 27. This was 
followed by a period of unusual dryness that continued until the middle of 
October, when substantial rains finally broke the drought. 
There was so little discontinuity across many of the cold fronts that 
southward migrating birds tended to overfly the area of northerly winds 
and continued to migrate through areas of southerly winds south of the 
cold fronts. This is unusual along the lake front, as normally migrants 
almost always arrive with tail winds. A major overflight of this nature 
occurred on September 11, when scores of songbirds alighted along the 
lake front after flying some two hundred miles through an area of southerly 
(head) winds. (I might insert here, however, the fact that the pressure 
gradient was much weaker on the south side of the cold front than on the 
north side.) 
East and northeast winds were more prevalent than usual during Sep- 
tember across Canada, possibly contributing to the westward displacement 
of some migrants in the Great Lakes region. It was thought that several 
of the Sharp-tailed Sparrows that appeared along the lake front could 
have been of the James Bay race. 
