Bird migration watches on Crown Lease 17, Alberta, fall 1984

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  • Migration watches were conducted from 21 August to 15 October 1984 near the site of Syncrude Canada Ltd.' s bitumen mining, extraction and upgrading development north of Fort McMurray, Alberta. These watches were undertaken to complement studies of birds using the waterbodies in the area of the development. Watches were conducted each morning and evening from a blind overlooking the Athabasca River valley. Morning watches began at first light and ended two hours after sunrise. Evening watches began two hours before sunset and lasted until it was too dark to see birds. In all, there were 49 morning watches and 51 evening watches. During each watch, migrating or potentially migrating birds were recorded. Birds making obviously local flights were not recorded. For each observation the following information was recorded: the time of the observation, number and species (or species group) of the birds seen, direction of flight, altitude, and distance from the blind at the point of closest approach. Non-systematic observations of swans, geese and cranes were also recorded during off-watch hours. Comparison of data from migration watches in 1984 with data from 1975 shows that patterns of migration over the study area have not changed appreciably. Both timing of migration and the diel pattern of passage were comparable in the two years for all species and species groups observed. Although large numbers of geese and lesser numbers of tundra swans and sandhill cranes passed over in both 1975 and 1980, few landed in the study area. Waterfowl, cranes, gulls and ravens were the groups most commonly observed during migration watches. Small numbers of several hawk and eagle species were also seen but few of them appeared to be migrating. Including observations both during watches and during off-watch hours, a total of 46 tundra swans were seen. All were flying in a generally southerly direction and most were between 75 m and 500 m above the Athabasca River. Swans appeared to pass over the area in two waves, one in the second week of September and one in the second week of October. Few swans, however, landed in the study area. Three species of geese, greater white-fronted goose, snow goose and Canada goose pass over the study area during migration but, like swans, few land. A total of 18, 399 geese were observed: 6,157 were recorded during watches and 12,242 were recorded during off-watch hours. The Canada goose was by far the most abundant species and comprised 67.4% of the total. Snow geese and white-fronted geese comprised 3.5% and 5.2% of the total, respectively. The remainder of the geese recorded were not identified to species but the majority were probably Canada geese. Geese were seen flying in all directions. However, over 80% of the geese seen were flying south through southwest, both during watches and during off-watch hours. Most geese were between 100 m and 300 m above the Athabasca River. Geese were seen fairly regularly until 2 October but the peak dates of migration were 30 August, 7 September and 25 September; the movement on 7 September alone accounted for 47% (8650 geese) of all the geese recorded. Each of these migration peaks followed the passage of a cold front through the study area, a situation consistent with observations of goose migration in other areas. The largest numbers of geese were seen during the second hour after sunrise, probably reflecting a dawn departure from the Peace-Athabasca Delta staging area. Although large numbers of ducks were recorded during water body surveys in fall 1984, relatively few were seen during migration watches. A total of only 440 ducks was recorded and some of these were probably engaged in local movements. Few ducks were identified to species. Two large flocks of ducks (170 and 66 birds) were, however, seen on two of the days when goose migration was highest. Moderate numbers of ducks also moved southwards on 13 and 14 October just before a major winter storm swept the area. Many ducks migrating through the area may have remained undetected because they migrated at night. Daily counts of ducks on Horseshoe Lake, adjacent to the blind, support this hypothesis. Numbers of ducks on Horseshoe Lake were consistently lower in the morning than in the evening, suggesting an overnight departure. A total of 21 sandhill cranes were seen during watches and 132 cranes were seen during off-watch hours. Most were moving in a generally southerly direction at less than 100 m altitude. No cranes were seen after 18 September. Although whooping cranes have been recorded in the study area, none were seen during this study. Although substantial numbers of gulls (6137 birds) were seen during migration watches, the majority were engaged in local movements to and from a roost on Mildred Lake. Gulls involved in these movements included ringbilled gulls, herring gulls and possibly California gulls but, because of the similarity of plumage of these three species, few were identified to species. Gulls were first detected flying toward the roost on Mildred Lake on 6 September and substantial numbers were seen regularly from 14 September until the end of the study. Based on the maximum count during a watch, the roost was used by at least 617 gulls in late September. Observations suggest that many of these gulls probably followed the Athabasca River northwards before turning northwest toward the roost. Al though ravens are not strongly migratory, some do move southwards in winter. There was some suggestion of migration through the study area in 1984. We saw larger numbers in October (0.7 ravens/h of observation) than in August or September (0.2/h) and a larger proportion of the ravens seen were moving south or southwest than were moving in other directions.

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    Conditions of Use McLaren, M.A. and P.L. McLaren, 1985. Bird migration watches on Crown Lease 17, Alberta, fall 1984. Syncrude Canada Ltd., Edmonton, Alberta. Environmental Research Monograph 1985-2. 57 pp. Permission for non-commercial use, publication or presentation of excerpts or figures is granted, provided appropriate attribution (as above) is cited. Commercial reproduction, in whole or in part, is not permitted without prior written consent. The use of these materials by the end user is done without any affiliation with or endorsement by Syncrude Canada Ltd. Reliance upon the end user's use of these materials is at the sole risk of the end user.