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AERIAL PHOTO USE IN FIELDS OF WILDLIFE AND RECREATION 
PHOTO INTERPRETATION TECHNIQUES 
There is considerably less literature dealing with the interpretation of aerial 
photographs for wildlife and recreation purposes than with the fact that aerial 
photos are used in these fields. As stated earlier, very few wildlife agencies have 
employees skilled in photo interpretation or assigned to this type of work. 
Photographs used for census work are generally of game concentrations. The 
photographs, usually taken at low altitudes, are enlarged and the game counted 
  
Fıc. 1. Aerial photography is useful in making inventories of wild animals in areas remote or 
difficult of access by other means. This photograph shows a part of the muskox herd on Nunivak 
Wildlife Refuge, Alaska. Note the wool being shed by the animals.—David L. Spencer, Fish and 
Wildlife Service. 
with the aid of magnifying glasses. Rarely, so far as the author has been able to 
determine, are the pictures taken in series and viewed under a stereoscope. Al- 
though many agencies have taken vertical or oblique pictures of special manage- 
ment areas for use as maps, most photographs used for mapping are obtained by 
purchasing from Governmental or commercial sources. ^ 
In censusing waterfowl, particularly large concentrations of ducks, the U. S. 
Fish and Wildlife Service has used aerial photographs to verify or note the 
deviation in visual estimates made from the air or on the ground. Visual esti- 
mates, especially those made at high altitudes, are usually below the actual 
number revealed by aerial photographs. In this connection, Spinner (1949) 
stated that 52 ornithologists who viewed an enlargement of the aerial photo 
mentioned earlier, showing 13,494 geese, gave estimates varying from 3,000 to 
28,000, with an average of 9,000. He also brought out an interesting point re- 
garding two photographs, one of which was taken of geese as the flock rose from 
their feeding grounds and the other as the flock settled on the Bay as a compact 
group. Invariably, Spinner stated, observers overestimated the number in the 
first photograph and underestimated in the second. Thus it is obvious that the