UBC Theses and Dissertations
Avian ecology as it relates to the bird hazard problem at Vancouver Airport Halladay, Delbert Raymond
A general survey and analysis of the avian ecology and control problem of Vancouver International Airport was attempted. The approach followed in this study entailed consideration of as many bioenvironmental factors as possible to permit a broad understanding of bird activity in the area. Important aspects of weather, soils, drainage, flora and fauna were considered as objectively as possible. Records of bird occurrence, activities (including behavior) and food habits were made by making regular count surveys, observations and collections respectively. The information gathered during the study period and from earlier work in the "study area" enabled the writer to designate each bird as either a problem or non-problem type. The latter types are not discussed in this thesis but the results of the food analysis for collected species is given in the form of an appendix. Problem bird species are discussed individually with information for most consisting of seasonal occurrence nesting and breeding activity, sex and age, daily activity, food habits, hazard to aircraft and possible control. General observations on daily activity of eleven problem bird species were also supported by a simple correlation analysis. One problem bird species, the American Widgeon, was studied experimentally. Live birds were encouraged to indicate their grazing preferences for five experimental ground cover plants. Unfortunately these experiments were met with a series of set backs which eventually forced their termination. Very little information gathered on grazing was considered worthwhile. However, there was some indication that birds preferred the grasses to the forbs used in the experiment. An analysis was made of experimental techniques used and suggestions were made for future work of this type. The majority of these suggestions are directed toward limiting the stress on experimental animals in light of the importance of this factor in determining the success of the present work. In addition to the above, field experiments were conducted using ground cover species thought to have features which qualified them for use on Vancouver Airport to reduce attractions for birds. The unattractive, and adaptive features of each species are presented along with the results of the experiments. In all cases the experimental plants were rated for competitive ability and vigour. Generally all plants used were found to be inadequate as an airport ground cover because of their inability to become dominant during the study period. However, there is some indication that future experiments might have different results. If the ground cover species were afforded a more adequate start they might be able to become dominant. Therefore, this approach is still considered valid to help solve the bird hazard problem, particularly if species used can be easily and cheaply propagated over large areas. Generally it is concluded that the bird hazard problem on Vancouver International Airport is complex. The results of the present study indicate possible means of solving the problems associated with certain species but they also serve to indicate how limited an effect control efforts have on others. In a number of cases the means of control for some birds may actually attract other birds. In light of the present study the writer believes the most ideal control measure would be to maintain all of the "study area" as a short well drained turf free of open ditches. It was noted that future efforts should include a more detailed quantitative information for computer analysis on variables found important during the present study, considerations for control of persistant food species and periodic reassessment of changes in bird number and species using the "Airport" zone and "bird strikes" resulting from this use. These efforts may eventually enable control of the bird hazard problem to a tolerable level.
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