Northern Prairie Wildlife Research Center

# Factors Associated with Duck Nest Success

in the Prairie Pothole Region of Canada

*Components of Mallard Production*

Data were available for 49 of the 56 half-area-years studied during 1983-85. The
west half of the Yorkton Study Area in 1985 was omitted because pairs were counted
on only part of the area; the 6 others were excluded because no hatched nests
were found on them. Correlations between log(Hatched Nests) and the 4 variables
on the right-hand side of equation (4) were as follows:

log(Wetlands)
*r* = 0.27 (*P* = 0.06),
log(Pairs/Wetland)
*r* = 0.13 (*P* = 0.38),
log(Nests/Pair)
*r* = 0.37 (*P* = 0.01),
log(Hatched nests/Nest)
*r* = 0.57 (*P* = 0.0001).

Thus, of these 4 variables, the one that most closely correlated with the number
of hatched nests was the nest success rate, followed by a measure of the nesting
effort, and then by the number of wet wetlands. The density of mallard pairs per
wetland was not significantly correlated with Hatched Nests.
If the alternate model described by equation (5) is fitted, correlations between
log(Hatched Nests) and the constituent variables are as follows:

log(Pairs)
*r* = 0.47 (*P* = 0.0007),
log(Nests/Pair)
*r* = 0.37 (*P* = 0.01),
log(Hatched nests/Nest)
*r* = 0.57 (*P* = 0.0001).

In this formulation, the nest success rate is still the most influential, but
is followed closely by the number of pairs, and then by the measure of nesting
effort.

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