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Effects of Grazing and Burning on Densities and
Habitats of Breeding Ducks in North Dakota

Appendices


Appendix 1. Average burn times and grazing periods, grazing rates (animal unit months/ha, AUM/ha), and treatment schedules for each treatment at Lostwood National Wildlife Refuge, North Dakota, 1980-88.

 
Treatment
Spring graze
Spring burn
Summer burn/
spring graze
Control
Burn timing none mid Jun Early Aug none
Grazing period Early May-mid Jun none Early May-mid Jun none
Grazing rate
(AUM/ha)
2.5   2.5-3.1  
Treatment
schedulea
1980 Rest Rest Rest Rest
1981 Rest Rest Rest Rest
1982 Graze Burn Burn Rest
1983 Graze Rest Graze Rest
1984 Graze Burn Rest Rest
1985 Rest Rest Burn Rest
1986 Rest Burn Graze Rest
1987 Rest Rest Rest Rest
1988 Rest Rest Rest Rest
aEach of 3 blocks of fields received the same treatment schedule


Appendix 2. Estimated differences and 95% confidence intervals (CI) for highest and lowest values of nest density and daily nest survival rate (nest success) for cases in which there was no effect of burning and grazing treatments, Lostwood National Wildlife Refuge, North Dakota, 1980-88.

Parameter
Species
Differencea
95% CIa
Total nest density Mallard 0.735 0.006-1.464
Gadwall 0.342 - 0.088-0.772
Blue-winged teal 0.221 - 0.422-0.864
Pintail 0.096 - 0.055-0.247
Lesser scaup 0.090 - 0.429-0.609
Shoveler 0.105 0.048-0.162
American wigeon 0.160 - 0.118-0.438
Annual nest density Mallard 0.077 0.014-0.140
Lesser scaup 0.013 - 0.009-0.022
American wigeon 0.022 - 0.035-0.079
Daily nest survival rate Mallard 0.0014 - 0.0008-0.0036
Gadwall 0.0077 0.0013-0.0141
Blue-winged teal 0.0065 - 0.0009-0.0139
aDifferences and 95% CI for daily nest survival rates are angular transformations. It is not possible to carry out reverse transformations of differences and CI provided by the SAS ESTIMATE procedures. Maximum differences can be computed from data in Table 3.


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