configurations were evaluated in semifield conditions in the Philip-
pines and a design which uses only three electrode wires was selected
for a planned full-scale field evaluation in 1979. Specially designed
activity counters were developed to measure rodent activity and
barrier effectiveness during the field trial.

 34. Several experiments were conducted to evaluate the potential
of "microtaggants" as a promising new wildlife marking agent. These
small plastic particles have properties which make them suitable for
use as an identifying marker in bait formulations or as a topical
(surface) marking agent that could be used for identifying large num-
bers of pest birds (e.g., Quelea quelea).

 35. A better understanding of bird-resistant sorghums is being
acquired through definitive laboratory analysis of their chemical,
biochemical, and physiological characteristics and how these correlate
with bird repellency. A combination of this type of evaluation and
selective plant breeding programs may result in development of a
sorghum that is both resistant to bird damage and high in nutritional
value.

 36. A socio-economic evaluation of the vampire bat control tech-
nology, developed by DWRC scientists, is being conducted under con-
tract by agricultural economists from Oklahoma State University. The
study is scheduled for completion in mid-1979 but evidence accumulated
to date indicates that the technology is effective, economically
beneficial, and appropriate to operational programs in developing
countries.