Improved Techniques for Aerial Wetland Surveys

Abstract

Techniques used in an intensive aerial wetland survey of more than 13,000 square miles of western Minnesota pothole range in 1961-62 are reported. Need for the survey resulted from the accelerated prairie pothole acquisition program of the Fish and Wildlife Service. We used wetland types described by Martin et al. (1953:3-6). Using light aircraft and experienced charter pilots, two men with thorough knowledge of the territory were able to cover the area in two seasons. Flights 1,200-1,300 feet above ground level, averaging 70 miles per hour, proved most satisfactory. Complete coverage of all sections in a township by the 1-mile-wide inspection method took approximately 20-25 minutes. Completed township platsheets with standardized survey information provided a biological basis for systematic negotiation for purchase of fee title and easements of waterfowl marshes. This aerial technique proved to be an economical, rapid, and accurate method to locate and establish acquisition priorities. In 1961 a need arose for a rapid, intensive wetlands survey of the U. S. prairie pothole region (Fig. 1) when the U. S. Fish and Wildlife Service accelerated its prairie pothole acquisition program. This report describes the techniques used in this section-by-section aerial wetland survey of the major waterfowl producing marshes of more than 13,000 square miles of western Minnesota pothole range conducted during 1961-62. Various aerial methods, with different objectives, have been used previously to survey the widely scattered wetland habitat of the prairie pothole region. Lynch (1958) described the aerial waterfowl habitat inventory used to appraise the waterfowl-producing potential of the Canadian prairies in years of normal, abundant, and deficient rainfall. In that method, aerial transects, 24 linear miles apart, were flown across the Canadian prairies of Manitoba, Saskatchewan, and Alberta from their eastern edge to the foothills of the Rockies. Smith (1960) used aerial reconnaissance to locate high-quality marshes of 80 acres and larger with dependable water supplies in he North Dakota pothole area. One of the objectives of his survey was to classify these marshes on the basis of value to waterfowl, particularly diving ducks. Flight AERIAL WETLAND SURVEYS Mann 575 VAN TIENHOVEN, A., R. D. CRAWFORD, AND S. A. DUCHAINE. 1957. The effect of nicarbazin on spermatogenesis and semen quality. Poultry Sci. 36(4):760-762. WAIBEL, P. E., B. S. POMEROY, AND E. L. JOHNSON. 1955. Effect of Arasan-treated corn on laying hens. Science 121(3142):401402. WALLACE, G. J. 1960. Another year of robin losses on a university campus. Audubon Mag. 62(2):66-69. , W. P. NICKELL, AND R. F. BERNARD. 1961. Bird mortality in the Dutch elm disease program in Michigan. Cranbrook Inst. Sci. Bull. 41. 44pp. ZELLER, F. J., W. R. BRENEMAN, AND M. CARMACK. 1958. Action of Lithospermum ruderale on ovulation in the hen. Poultry Sci. 37(2):455-459. ZONDEK, B. 1936. Tumour of the pituitary induced with follicular hormone. Lancet 230: 776-778. Received for publication July 29, 1963. This content downloaded from 207.46.13.13 on Thu, 25 Aug 2016 06:16:41 UTC All use subject to http://about.jstor.org/terms 576 Journal of Wildlife Management, Vol. 28, No. 3, July 1964 SASKATCHEWAN MANITOBA ONTARIO