A Photographic Technique to Study Tadpole Populations 
C. Kenneth Dodd, Jr. 
Office of Endangered Species , U.S. Fish and Wildlife Service, 
Washington, D. C. 20240 
ABSTRACT . — Although the use of photography to estimate the num- 
bers of vertebrates in wild populations is a well established wildlife man- 
agement technique, it has not been previously used in studies of tad- 
poles in shallow breeding ponds. A pond used by the American toad, 
Bufo americanus , was monitored through the breeding season of 1977 in 
Fairfax County, Virginia. Tadpole clusters were photographed and the 
prints used to evaluate this technique for working with such populations. 
An example of how the technique may be used is provided. While espe- 
cially valuable in certain types of studies (for instance, those involving 
tadpoles in shallow ponds without much vegetation and containing one 
or a few species), photographic analysis is probably of use in many field 
studies. 
INTRODUCTION 
Use of photography to estimate the numbers of vertebrates in wild pop- 
ulations is a well established wildlife management technique (Watson 
1969; also see references in Caughley 1977 and Giles 1969) although it 
has generally been employed in connection with aerial censuses. 
However, photography has not been previously used to estimate the num- 
bers of larval amphibians in breeding ponds. Since many species of 
amphibians breed in shallow ponds where the larvae are readily visible, 
such populations should be amenable to analysis by photographic 
methods. I attempted to determine if photography could be used to study 
one of these populations of tadpoles. 
METHODS AND MATERIALS 
The study area encompassed a shallow (initially 70 mm maximum 
depth) temporary pond, 42.8 m 2 in surface area, located near the con- 
fluence of Indian Run and Back Lick Run, Fairfax County, Virginia. 
Characteristic vegetation in and surrounding the pond included sedges 
(Cyperaceae), Juncus sp., Bidens sp., Aster sp., Lespedeza sp., willow ( Salix 
sp.) and river birch ( Betula nigra)', individual plants often formed clumps 
and were scattered along the bottom and around the edges of the pond. 
The pond was surrounded by a rather well-defined margin consisting of a 
thick growth of vegetation on one side and a mud bank on the other. This 
Brimleyana No. 2: 131-136. November 1979 
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