Radioisotopes in amphibian research

[glen_kruse_at_con084p2@dnrmail.state.il.us]

     I work for the Illinois Department of Natural Resources.  We are 
     trying to design a research project that will let us determine the 
     home range of the Illinois chorus frog, a threatened species in our 
     state.  Chorus frogs breed in temporary ponds in early spring, then 
     move away from the ponds where they burrow into sandy soils and remain 
     underground for the rest of the year.  Our problem is to determine how 
     far the frogs move from the ponds so we can attempt to protect 
     adequate areas of habitat for the frogs' entire life cycle.
     
     I am looking for information that will help us determine what isotope 
     may be appropriate for this research.  We need something that can be 
     injected into a 40-mm frog, will not cause serious injury to the frog, 
     and can be detected with readily available equipment when the frog is 
     several inches below the ground surface.  We would like to be able to 
     locate the frogs for a period of about 2 weeks after they have been 
     injected.
     
     If any subscribers have experience in this type of research or know of 
     someone I can contact, I would very much appreciate hearing from you.
     
                                gkruse@dnrmail.state.il.us