Image from the Biodiversity Heritage Library.
Contributed by Smithsonian Institution Archives.
| www.biodiversitylibrary.org
Transcription
20 Squares to the Inch
Bird Densities with latitude along 119 W
Feb. 16 - March 4 1968
Birds/
liner mi.
2
1
30N
25
20
15
10
5
0
5
10
15
20s