USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

An Assessment of Predator Barriers and Predator Control to Enhance Duck Nest Success on Peninsulas

Tables

Table 1. Comparisons among percent (%) species composition of ducks nesting on managed and control peninsulas, between both types of peninsulas, and with % species composition of ducks breeding in the Prairie Pothole Region of North Dakota (ND), 1985-1989.
Species % nesting % breeding in ND P-values
Control Managed Control vs. ND Managed vs. ND Control vs. managed
Mallard
 13 15 21 <0.001 <0.001 0.369
Gadwall
 32 42 15 <0.001 <0.001 0.001
Blue-winged teal
 41 18 28 <0.001 <0.001 <0.001
Northern shoveler
 5 6 13 <0.001 <0.001 0.498
Northern pintail
 6 9 9 0.029 0.999 0.088
Lesser scaup
 3 9 4 0.312 <0.001 <0.001
Other
 1 2 10 <0.001 <0.001 0.237

 

Table 2. Numbers of duck nests, nest success (%), and numbers of young hatched/ha on fenced peninsulas with predator control and on paired control peninsulas in central North Dakota, 1985-1989.
Year Peninsula
pairs (n)		 With fence No fence
Nests (n) Nest success Ducks hatched/ha Nests (n) Nest success Ducks hatched/ha
1985 5 111 44 7.8 14 2 0.3
1986 7 165 46 18.7 23 1 1.4
1987 8 265 54 23.5 34 36 4.4
1988 8 280 70 19.4 23 15 1.4
1989 8 281 58 14.9 22 37 1.4
Total 36 1,102     116    
Symbol - Mean x     54 17.6   17 1.9
SE     2 3.2   7 0.7

 

Table 3. Numbers of duck nests, nest success (%), and numbers of young hatched/ha on moated peninsulas with predator control and on paired control peninsulas in central North Dakota, 1985-1989.
Year Peninsula pairs (n) With moat No moat
Nests (n) Nest success Ducks hatched/ha Nests (n) Nest success Ducks hatched/ha
1985 1 6 100 1.5 1 2 0.0
1986 2 222 61 46.3 62 4 0.6
1987 1 135 79 32.4 60 4 3.5
1988 1 68 70 19.6 14 58 2.7
1989 2 145 51 13.6 45 3 0.4
Total 7 576     182    
Symbol - Mean x     75 21.8   14 1.2
SE     4 6.9   16 0.5

 

Table 4. Mean annual construction and maintenance costs ($) on 8 fenced and 2 moated peninsulas in central North Dakota, 1985-1989.
Activity Fenced Moated
Symbol - Mean x total costs Discount rate Annual costs Symbol - Mean x total costs  Discount rate Annual costs
Construction 7,615      ×       0.109          =          830 206,890    ×        0.090         =       18,620
Maintenance    
  Transportation  165        ×       1.000          =          165 124       ×        1.000          =        124
  Labor  225        ×       1.000          =          225 188       ×        1.000          =        188
  Materials  250        ×       0.155          =           39  80        ×        0.155          =         12
Total   1,259   18,944