d spots; wings brownish, marked
broadly with white bar; flies close to the water with wings full-spread,
showing white wing-bar; note, penetrating "pee-weet, weet;" walks with
tilting motion. *Solitary Sandpiper.

145. KILLDEER. 10 in.
(Oxyechus vociferus. 273.)

Gray-brown; rump rusty-brown; tail rather long; white below; white collar
followed by a black collar, and a _black band across breast_; forehead,
line over eye and wing-bar, white; bill black; runs very swiftly; note,
loud and persistent "kill-dee" often heard high overhead.

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_

Note to Key.

In response to many demands, the following simple field-key has been
devised, to the end that the beginner may be aided in learning to observe
correctly those points about a bird that appear most conspicuous in the
field or which are particularly distinctive.

Technical analyses and measurements have not been employed, but instead,
the birds are roughly placed in three groups according to size, the Robin
and English Sparrow marking respectively the 10-inch and 6-inch lines of
division.

The first part of the key deals with _general_ differences in color and
markings, while the second seeks to emphasize the most noteworthy
_special_ points which distinguish the different species. Incidentally a
few striking peculiarities of bill, wings and tail have been included.

It will readily be seen that a key embracing so little cannot do more
than reduce wild guessing to a few reasonable chances in identifying a
strange bird. Some practice is of course necessary to enable the student
to use the key readily. Its helpfulnes