COMPARISON OF FIXED-WING AND HELICOPTER SEARCHES FOR MOOSE IN A MID-WINTER HABITAT-BASED SURVEY

Abstract

We conducted a mid-winter habitat-based survey in Terra Nova National Park and an adjacent hunted area (Moose Management Area 27) to compare the reliability and accuracy of using fixed-wing and helicopter aircraft for counting moose. Forest inventory mapping was the primary consideration in defining block boundaries because this readily available information could be easily interpreted by observers during aircraft navigation, and because map classes could be chosen in a way expected to reduce variability in moose distribution. Blocks were also classified from forest inventory mapping as being either open (mean crown closure of all stands < 50%), or dense (mean crown closure of all stands > 50%). We tested the precision of fixed-wing and helicopter aircraft for counting moose in blocks with open and dense crown cover by increasing the time spent during second searches with each aircraft type. More moose were seen in open blocks during second searches with increased flying time in both fixed-wing aircraft (100%) and helicopters (160%) than in dense forest cover blocks (12% and 43%, respectively). We also compared the accuracy of the two aircraft types in each crown cover class by recounting the same blocks at a similar intensity. Verifying the accuracy of fixed-wing counts with helicopter searches of the same 8 blocks (the same crew flew approximately the same time), we found that the helicopter counts were on average 78% higher. We conclude that for highest accuracy and best classification of animals during a moose survey, helicopter counting is superior to fixed wing counting.