Wild Birds in City Parks / Being hints on identifying 145 birds, prepared primarily for the spring migration in Lincoln Park, Chicago

by Herbert Eugene Walter; Alice Hall Walter

Explanation of Chart.

The “height of the migration” usually comes during the second or third week in May. This chart makes a comparison of the observations of six years graphic.

For instance, the largest number of different species seen on any one morning in 1903 was 68 (May 12), while in 1901 it was 48 (May 16).

The sudden rise or fall in the migration may also be seen at a glance. May 9, 1899, for example, only 16 different species were observed and May 10 the record was 40. Similarly, in 1901, the number of species seen May 17 dropped from 45 to 15 in three days.

A chart showing the number of different kinds of birds seen in LINCOLN PARK during the HEIGHT OF THE MIGRATION