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Distribution and Abundance of Predators that Affect
Duck Production: Prairie Pothole Region

Tables

Table 3. P-values and odds rations from Mantel-Haenzel tests (Fleiss 1973) of inter- and intraspecific relations of nest spacing by avian predator species in study areas in the prairie pothole region, 1983-88.^a,b

Species pair or species		P-value
Species pair or species		N^c	Odds^d	Association^e	Homogeneity^f
Interspecific
	American crow-great horned owl	17	0.41	0.193	0.950
	Red-tailed hawk-great horned owl	12	3.38	0.002	<0.001
	Swainson's hawk-great horned owl	18	0	0.252	>0.999
	American crow-red-tailed hawk	19	0.35	0.005	0.992
	Swainson's hawk-red-tailed hawk	11	0.75	0.763	0.988
	American crow-swainson's hawk	20	1.35	0.260	<0.001
Intraspecific
	American crow	25	2.02	<0.001	<0.001
	Swainson's hawk	19	0.46	0.299	>0.999
	Red-tailed hawk	18	0.12	0.002	>0.999

^aAssociation refers to an overall tendency to avoid or aggregate.
^bHomogeneity indicates the consistency of the association across study area-years.
^cNumber of study area-years.
^dOdds < 1 indicates avoidance of nesting near each other; odds > 1 indicates aggregation of nests.
^eP-value based on chi-squared distribution with 1 degree of freedom.
^fP-value based on chi-squared distribution with N-1 degrees of freedom.

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Distribution and Abundance of Predators that AffectDuck Production: Prairie Pothole Region

Tables

Distribution and Abundance of Predators that Affect
Duck Production: Prairie Pothole Region