THE DAWN CHORUS IN ESSEX
269
the results, and it has one disadvantage: it is very difficult to
represent the results graphically. In 1959, in addition to noting
the time when a bird was first heard, a new method was adopted.
One complete hour was divided up into 5-minute intervals, and
every bird heard singing in each 5-minute interval was noted.
This method has enabled results to be shown graphically; and
also indicates the extent of song for each species. It has also
confirmed some conclusions which were suspected. This is men-
tioned later.
TABLE "A"
Habitat
The records were made in mixed oak wood bordering a
secondary road, and fields.