EFFECTIVENESS OF SEARCH PATTERNS FOR RECOVERY OF ANIMAL CARCASSES IN RELATION TO POCKET GOPHER INFESTATION CONTROL

We tested four search patterns to identify one or more that consistent ly resulted in the location of a high percentage of above ground carca sses. Searchers found only 25 . 4% of placed carcasses. The random sea rch pattern exhibited the lowest search efficiency (i.e. percent carca ss recovery), 26%. This differed significantly from the other three se arch patterns (E/W transects; E/W transects followed by N/S transects; five randomly placed, 0 . 027 ha circular plots), which ranged in sea rch efficiency from 24 . 5 to 36 . 2%. No significant difference in se arch efficiency over time was noted and recovery rates were comparable in the morning and afternoon. Searchers did not differ in mean time s pent searching or in carcass recovery efficiency. Carcass density did not influence search efficiency, but searchers found proportionally mo ve carcasses on high carcass density plots. Starlings, the largest and least cryptically colored of the three carcass types, were recovered in the greatest proportion. Carcass degradation by various animals was confirmed To be an important contributor to rapid carcass deteriorati on. Selecting the best overall search pattern requires careful conside ration of a number of factors. Because search efficiency was low regar dless of search pattern, a substantial correction factor should be use d to estimate the number of carcasses occurring on the surface after a baiting operation.