Comparison of helicopter and ground surveys of waterfowl broods in southern Ontario / T. Shane Gabor, Jerry R. Longcore, Henry R. Murkin, and A. Neil Arnason.

Includes bibliographical references (pages 18-19).

Managers often employ aerial survey infonnatiol1 to manage waterfowl.
Results of surveys by heli copt er and from elevated platfonns were compared to
determine the accuracy of helicopters to detect waterfowl broods on beaver ponds in
southern Ontario in 1996 and 1997. Fewer broods were detected from the helicopter than
by observe rs in elevated platforms at wet land ma rgin s. When broods were detected by
helicopter crews, >90% were con cctly enumerated and >80% were correctly aged. A
second heli copter survey, the day following the first survey, did not change the Visibi lity
Correction Factor (VCF) substantially ( 1.79 vs. 1. 53). Data from th e 2 helicopter
surveys combined (without ground counts) resu lted in greater VCFs (2. 17) than when a
s ingle heli copter survey and ground count was used (VCF = 1. 79). In genera l, VCFs for
most waterfowl broods were lower in fores ted or closed (emergent and scrub-shrub)
wetland habitats than on open wetlands. When multiple broods were present on a
wetland, sightability of the additio nal broods (second , th ird, etc.) was lower for the
he lico pter crew than ground crew. Surveys by helicopter are li kely most lI seful to
develop indices for waterfowl broods of diver species in large inaccessible areas. If
3ccurate information is required on dabbler brood densities. age. and number of
duck li ngs, quiet observation by crews in elevated piatfol111S should be used.