EVALUATION OF INFRARED TECHNOLOGY FOR AERIAL MOOSE SURVEYS IN NEW HAMPSHIRE

Abstract

We evaluated the potential of infrared aerial surveys to monitor moose populations in northern New Hampshire during January 1995. Surveys were conducted at 2 sites: near Pittsburg, an area with high moose density (>0.8 moose/km²) and Milan, a region with moderate moose density (<0.8 moose/km²). Both sites contained extensive deciduous and mixed-wood forests and were known moose wintering areas. The surveys were conducted by Airscan Inc. using a Cessna 337G that employed a Westinghouse WesCam Ds 10X infrared sensor.

   Three surveys were conducted at each study site. Surveys I and II were designed to determine the sightability of moose in different cover-types and terrains by surveying 500 hectare subsites under different search intensities in a deciduous and a mixed-wood cover-type, respectively. Analysis of variance was used to determine the influence of terrain, elevation, cover type, and population density on sightability. A sightability correction factor was derived to produce a corrected moose density from the initial search data. Survey III, an intense search of the entire site, was used to compare with the corrected results of Surveys I and II.

Moose were observed in a variety of cover-types, terrains, elevations, and at moderate to high population densities. Search effort averaged 1.0 min/km² during initial searches. The overall sightability was 88% for both sites combined and was influenced by terrain and elevation. The moose densities corrected for sightability at Pittsburg (1.6 moose/km²) and Milan (0.7 moose/km²) were similar (±6%) to those from Survey III. Infrared surveys were cost effective relative to traditional aerial surveys, had greater survey area, and were applicable at least in moderate to high population density areas. This study indicated that this technique can monitor population fluctuations and provide reasonable population estimates of moose in northern New Hampshire.