. The Canadian field-naturalist. 1980 Reimchen and Douglas: Loon Observations, Queen Charlotte Islands 399. Figure L Study area. C = center, i = intermediate, p = peripheral. N, S, E, W, NW indicate compass directions. Inset âQueen Charlotte Islands. â = observation platform, â² = observation blind. Depth contours in metres. evening observations. Loon activity, including numbers, positions, movement and diving, was recorded on standardized data cards. For recording positions of loons, the lake was visually divided into 11 areas, according to depth (assessed by lake tran- sects) and compass dir
. The Canadian field-naturalist. 1980 Reimchen and Douglas: Loon Observations, Queen Charlotte Islands 399. Figure L Study area. C = center, i = intermediate, p = peripheral. N, S, E, W, NW indicate compass directions. Inset âQueen Charlotte Islands. â = observation platform, â² = observation blind. Depth contours in metres. evening observations. Loon activity, including numbers, positions, movement and diving, was recorded on standardized data cards. For recording positions of loons, the lake was visually divided into 11 areas, according to depth (assessed by lake tran- sects) and compass direction (Figure 1). Four small floats were anchored in the southeast and northeast areas of the lake to mark the 1-m and 5-m depth contours. The majority of observations were made with a 20- to 45-power spotting scope from an elevated 4-m platform, allowing visual coverage of 97% of the lake surface. In July and August 1979, observations were made from a blind in the southern corner of the lake, adjacent to a nesting pair of Red-throated Loons. To determine age classes of loons, we observed plumage patterns and bill color at close range with the spotting scope and compared these with descriptions by Palmer (1962). Diving durations were timed to the nearest second. Distributions of fish were assessed by standard mesh minnow traps, seine, and gillnets (mesh size 13, 25, and 89 mm) at monthly intervals from April to November. Species and length of captured fish were recorded before they were released. Results Abundance and Description Both loons occurred on the lake from April through August, with similar patterns of abundance during the 3 yr of observation (Figure 2). Red-throated Loons (RT) arrived first (29 March 1978, 27 March 1979), their numbers increasing throughout April, and the- reafter remaining similar (maximum 19) until the middle of August. Individual Common Loons (CO) occurred irregularly throughout April and May. In June, numbers increased sharply, reaching a ma
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