EVALUATION OF THE VAMPIRE BAT CONTROL PROGRAM

THIS STUDY IS THE FIRST SOCIOECONOMIC EVALUATION OF DIPHACINONE VAMPIRE BAT CONTROL. DATA WERE OBTAINED IN SURVEYS OF 178 NICARAGUAN CATTLEOWNERS. PERSONNEL OF THE DENVER WILDLIFE RESEARCH CENTER (DWRC) HAVE BEEN SUCCESSFUL IN DEVELOPING CONTROL METHODS. THE TOPICAL METHOD CONSISTS OF CAPTURING BATS, PLACING AN ANTICOAGULANT PASTE ON THE BACKS OF THE CAPTURED BATS, AND RELEASING THEM. THE BATS RETURN TO THEIR ROOSTS WHERE GROOMING AMONG THE BATS RESULTS IN INGESTION OF THE PASTE AND SUBSEQUENT DEATH BY HEMORRHAGING. THE SYSTEMIC METHOD INVOLVES THE INTRARUMENAL INJECTION OF THE ANTICOAGULANT INTO THE BLOODSTREAM OF THE BOVINE. WHEN THE BOVINE IS FED UPON BY VAMPIRE BATS, THE INGESTED ANTICOAGULANT CAUSES FATAL HEMORRHAGING IN THE BATS. THE ECONOMIC LOSS OF CATTLE TO BAT-TRANSMITTED PARALYTIC RABIES IN THE FIRST YEAR FOLLOWING CONTROL DECREASED FROM $31,388 (209 HEAD) TO ZERO IN THE 1,918 HERDS TREATED. THE ANNUAL LOSS IN PRODUCTION OF BEEF AND MILK DUE TO VAMPIRE BAT FEEDING AND HARRASSMENT WAS REDUCED BY $2,382,770 IN THE YEAR FOLLOWING CONTROL. THUS, THE TOTAL ANNUAL BENEFITS OF THE PROGRAM IN NICARAGUA ARE AN ESTIMATED $2,414,158. A COMPARISON OF THE BENEFITS AND COSTS RESULTS IN A BENEFIT-COST RATIO OF 18.61. THE ESTIMATED BENEFITS TO THE CATTLEOWNERS WERE DISTRIBUTED 0.3% TO SMALL HERDOWNERS ($280 PER HERD), 22.6% TO INTERMEDIATE HERDOWNERS ($3,782 PER HERD), AND 77.1% TO LARGE HERDOWNERS ($16,632 PER HERD). THE USE OF DIPHACINONE METHODS IN THE CONTROL PROGRAM HAD OVERALL POSITIVE IMPACT ON ENVIRONMENTAL QUALITY. THE OVERALL IMPACT IS FAVORABLE, WITH NO NEGATIVE ASPECTS OTHER THAN THE INCOME DISTRIBUTION ASPECT AMONG SMALL PRODUCERS, AND A POTENTIAL HAZARD TO FOOD QUALITY SHOULD THE CHEMICAL BE MISAPPLIED.