| Summary: | Farmfields located in the vicinity of wetlands are often visited by wintering waterfowl.
The selection of individual fields could be affected by a number of factors, including the crop
cover type and the accumulation of surface water on the field, as well as by other factors
related to the location of the field.
This research investigated the possible relation between locational factors (size and
shape of the field, distance to the coast, presence of trees, roads and buildings in the
surroundings) and the observed presence/absence of ducks (mallard, Anas platyrynchos,
pintail, Anas acuta, wigeon, Anas americana) in a group of fields in the Fraser River delta.
Maps of the fields were obtained by interpretation of aerial photographs. Bird data
came from previous surveys. Maps and associated attribute data were integrated in a
Geographic Information System that also provided analysis tools.
Regression analysis was undertaken in order to relate the presence of ducks in the fields
with the geographic (locational) factors. Day and night situations were considered, and fields
were grouped into two cover type classes for the analysis.
Results of the analysis indicated that the consideration of just locational variables could
not predict the presence of ducks in fields, although some factors, particularly the distance to
the coast and the vegetation in the perimeter were found to be correlated with duck presence.
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