10 TH E*A'U DU BON? BU Disk 
Report on Spring 1956 Migration 
By Mrs. ISABEL B. WASSON 
THE BirpD MIGRATION this spring in the Chicago area was unusual in several 
ways. First, it practically all took place between May 11 and May 19. 
Second, the birds during those eight days were in phenomenal numbers and 
were seen low or even on the ground. Third, the leaves were small so that 
viewing even in the tree tops was excellent. And lastly, certain species 
usually common were scarce, and others usually scarce were common. 
The Chicago area had a long, cold spring this year. Temperatures stayed 
in the thirties and forties for weeks. Early, hardy migrants: robins, black- 
birds, flickers — came about as usual. On April 14th there was a small 
“wave” of myrtle warblers, ruby-crowned kinglets and hermit thrushes. We 
saw five winter wrens at the Morton Arboretum that day and heard two 
sing, a rare treat in the spring here. White-throated sparrows arrived in 
numbers on April 29th and reached their peak May 6-8. There was no in- 
flux of other warblers besides the Myrtles early in May. 
But on Friday, May 11th, a change took place. The winds swung into 
the south, heavy clouds covered the sky and a tropical downpour with hail 
occurred in the afternoon. I was in Palos Hills on Parker and Bell Roads 
with birding friends and we came upon a fiock of about fifty male indigo 
buntings, twenty male scarlet tanagers and over one hundred goldfinches 
with one dickcissel sitting on clods in a plowed field or on weed stalks 
along the road. 
Saturday, May 12th, it was still warm, with south winds. Marguerite 
Shawvan, Margaret Lehmann and I conducted the field trip as usual at 
the Morton Arboretum for the bird class. Birds were so numerous the groups 
didn’t have to move from the top of Thornhill. The most abundant among 
the warblers were black and white, Tennessee, magnolia, chestnut-sided, bay- 
breasted, ovenbird, Wilson’s, and red-starts. Other abundant birds were 
Baltimore orioles, cowbirds, rose-breasted grosbeaks and indigo buntings. 
Other warblers included one black-throated blue and one Kentucky, the latter 
rare for this area. Vireos were well represented. In the two hours we were 
out, six red-eyed vireos, three blue-headed, one yellow-throated and one Bell’s 
vireo were seen. The last we had never before seen in the Arboretum. 
Sunday, May 13th Marguerite Shawvan and I were in Thatcher Woods. 
The temperature ranged from 80 to 90 degrees; light southerly winds, 
showery. We came upon a shallow pool at the base of the bluff off Edge- 
wood Place where warblers were bathing. In half an hour we counted 
twelve species, several of each, at the pool. In the afternoon we saw twelve 
black-billed cuckoos and two yellow-billed cuckoos in Thatcher Woods. 
On Monday, May 14th the peak in numbers was reached. We met friends 
at Long John Slough and covered the area there and south. Warblers and 
vireos had never been so numerous in the shrubs and weeds. We found six 
Baltimore orioles on the ground along the road at Long John Slough, and 
male tanagers were sitting on dead giant ragweed stalks by Saganashkee 
dam. We had lunch in a grove of honey locust trees, the leaves of which were 
