Impact of Red Fox Predation on the Sex Ratio of Prairie Mallards

Table 19: Apportionment of Mallard Remians Found at Red Fox Dens

Table 19. Apportionment of mallard remains found at red fox dens to fox predation and to accumulation of scavenged birds.

Case	Sex	Percent of birds found at dens killed by foxes	Predation rate per fox family	Accumulation rate per fox family	"Other" spring mortality rate^a	Spring sex ratio
0	Male	100	0.96	0.0	0.0	126:100
0	Female	100	3.60	0.0	0.0	126:100
I	Male	50	0.48	0.48	2.52	118:100
I	Female	75	2.70	0.90	4.54	118:100
II	Male	50	0.48	0.48	2.52	117:100
II	Female	87	3.12	0.48	2.35	117:100

^a Added to rate of "other" summer mortality.

Previous Section-- Table 18: Sex Composition of Adult Ducks Found at Mink Dens
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Next Section-- Table 20: Parameters of Distributions Used to Generate Random Variates