Northern Prairie Wildlife Research Center
Distribution and Abundance of Predators that Affect
Duck Production: Prairie Pothole Region
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|
| Nc|| Oddsd|| Associatione||Homogeneityf|
|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|
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.