2 PHOTOGRAMMETRIC ENGINEERING
and indicating ways of obtaining photographs and of utilizing them more
widely and efficiently in the field of wildlife management, the following uses
were suggested: maps; evaluation and determination of game range; censusing
game animals; locating refuge sites; law enforcement; studying areas damaged
by fire, floods, insects or disease; determining hunting pressure; locating,
mapping, and planning potential dam sites; plotting land-use and wildlife
problem areas; determining changes in vegetative cover and land use over a
period of years; planning the locations of roads, trails, fire lanes, and other
developmental features of newly acquired areas; making special studies of rare
or vanishing species in which permanent records of habitat types are desirable;
conducting lake surveys, including the mapping of emergent and floating
aquatic flora, and possibly the contour mapping of lake bottoms; plotting tax
delinquent lands in connection with acquisition of land for game refuge and
management areas; and recording pictorially the features of breeding grounds
newly discovered in remote areas.
Petrides (1944) pointed out the possibility of applying the principles of
naval aircraft recognition to wildlife study by the split-second projection of
aerial photographs showing deer, for example, as they would appear to ob-
servers in making an aerial census. Spinner (1946) suggested an improved seg-
ment method of estimating the numbers of birds in flocks with large flocks of
birds in the field.
In a later article Spinner (1949) illustrated the usefulness of aerial photo-
graphs in censusing greater snow geese, Chen hyperborea atlantica, in the Dela-
ware Bay area where this species winters. The flock was chased out over Dela-
ware Bay to provide a dark background for photographing the white birds. A
photograph taken by Master Sergeant Robert Livingston, of the 4146 Base
Unit, AMC, USAAF, at an altitude of 500 feet and enlarged to 20 by 24 inches,
permitted each goose to be counted. The entire spring flock shown on one print
totalled 13,494 individuals. As was pointed out by Allen (1951) this figure was
thought to represent the vast majority, if not the entire, Atlantic snow goose
population.
Dr. A. S. Hazzard (in litt. December 19, 1951), Director, Institute for
Fisheries Research, Michigan, reported:
t
. . We have used aerial photography in fisheries work to secure lake outlines and
stream courses. . . . Also we have used aerial photographs of lakes to follow the distribu-
tion of brush shelters. We have used low-level airplane pictures in our stream survey
work to a limited extent, both in making the initial studies and for a record of such con-
ditions as existing bank erosion, presence of riffie areas, extent of streamside cover . . .
and of the location and extent of beaver ponds.”
He stated further:
Ve have also experimented a bit with aerial photography in creel census on a number
of lakes near Ann Arbor. Its use was principally to. check our method of making boat
counts, but it would serve this purpose nicely. Some of the photographs secured were quite
striking and could be interpreted without much difficulty in terms of the number of boats
and the people in them.”
Dobie and Johnson (1951) described a method of making aerial maps of
farm ponds. The method makes use of ground markers, a known distance apart
and projections from photographic negatives, to produce maps of a chosen
scale in spite of variations in plane altitude. They state that if the pond map is
made in the fall when the pond is low, it will show the low water area, high water
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mark, inlets, outlets, aquatic vegetation, upland vegetation, buildings, roads
and trails.
