. The Canadian field-naturalist. 302 The Canadian Field-Naturalist Vol. 114. Figure I. Mountain Goat survey blocks as inventoried during the fall periods of 1996 (C, D, E, F, G, H) and 1997 (J). The 1200-m contour approximates treeline. zones are dominated by coniferous trees that are commercially harvested, including Western Hem- lock {Tsuga heterophylla). Mountain Hemlock (Tsuga mertensiana). Western Redcedar {Thuja pli- cata), and Subalpine Fir (Abies lasiocarpa). In the coastal areas of the CWH, lower elevations receive little snow, and in most of the zone, the soil does not freeze extensi
. The Canadian field-naturalist. 302 The Canadian Field-Naturalist Vol. 114. Figure I. Mountain Goat survey blocks as inventoried during the fall periods of 1996 (C, D, E, F, G, H) and 1997 (J). The 1200-m contour approximates treeline. zones are dominated by coniferous trees that are commercially harvested, including Western Hem- lock {Tsuga heterophylla). Mountain Hemlock (Tsuga mertensiana). Western Redcedar {Thuja pli- cata), and Subalpine Fir (Abies lasiocarpa). In the coastal areas of the CWH, lower elevations receive little snow, and in most of the zone, the soil does not freeze extensively during normal winters. Snow with a high moisture content covers most of the MH zone for 5-9 months of the year. Methods Between 7 September and 7 October 1996, aerial surveys were flown by three observers and a pilot in a Bell 206 Jet-Ranger helicopter. The distance to the mountainside and the ground speed varied with topography, but generally, the helicopter was < 150 m from the mountain and ground speed was < 70 km/h. In most areas, a single pass along the perimeter of a mountain block was sufficient to scan the area above treeline thoroughly. In some areas, especially near the coast, three or four passes were made across some mountain sides in order to ensure adequate coverage. Surveys were not conducted dur- ing days when poor weather compromised safety or impaired visibility. Whenever possible, the sex and age class of the goats was recorded as per Chadwick (1983). However, the timing of the surveys did not coincide with the optimum period to conduct classification counts (Resources Inventory Committee 1997). At the time of year when surveys were conducted, "yearlings" (, = years old) were very similar in body size to subadult Mountain Goats (, years old). Accurate classification of "yearlings" requires that the helicopter approach the animals for close inspection. Such close approaches by a heli- copter can disturb goats and
Size: 1801px × 1388px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorottawafi, bookcentury1900, bookdecade1910, bookyear1919
