USGS - science for a changing world

Northern Prairie Wildlife Research Center

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

Evidence for Edge Effects on Multiple Levels in Tallgrass Prairie

Tables


TABLE 1.  Prairie fragments in southwestern Missouri and the types of study done in each indicated by an "X".
Prairie fragment Size (ha) Artificial nests
(1995)
Natural nests
(1995-1997)
Mammals
(1996-1997)
Pawhuska
31.0 X X X
Little Osage
32.0 X    
Mon-Shon
32.4 X X X
Catlin
43.7   X X
Gay Feather
47.0 X   X
Treaty Line
64.0   X  
Clear Creek
77.7 X   X
Cook Memorial Meadow
113.0 X    
Mo-No-I
122.0 X X X
Niawathe
130.0 X X X
Stony Point
259.0   X  
Osage
506.0 X X X
Prairie State Park
1,084.0   X  

 

TABLE 2.  Tests of effects of distance to edge, fragment size, and vegetation structure on nesting success and its correlates. Presented are results from stepwise logistic regression or repeated-measures ANCOVA (animal track data only). In the logistic regressions, the dependent variables were log (ln) fragment size and three principal components describing vegetation structure at the nest. In repeated-measures ANCOVA, distance to edge (categorical) and ln fragment size were the explanatory variables.
Logistic regression n Variables entered Slope ± SEa P
Artificial nest survival
193 PC1 -0.50 ± 0.12 18.5 <0.001
Nest success
  Dickcisselb 
111 ln fragment size -0.44 ± 0.004 8.5 <0.01
PC1 -0.34 ± 0.13 6.5 0.01
  Henslow's Sparrowb
49 Distance to edge -0.25 ± 0.11 5.6 <0.03
Brood parasitismb
111 Distance to edge 1.14 ± 0.14 4.8 0.01
Depredation of artificial nests by all mammals
169 PC1 0.38 ± 0.12 9.6 <0.01
PC3 -0.31 ± 0.15 4.5 <0.05
  mid-sized carnivores
169 Distance to edge 0.74 ± 0.37 4.1 <0.05
  small mammals
169 PC1 0.40 ± 0.13 9.2 <0.01
PC3 -0.41 ± 0.16 6.5 0.01
 
Repeated-measures ANCOVA
n Variables in model Slope ± SE F P
  all mammals
48 Distance to edgec   11.0 <0.001
ln fragment size -0.03 ± 0.01 5.8 0.05
  mid-sized carnivores
48 Distance to edgec   7.7 0.001
ln fragment size 0.001 ± 0.007 0.0 0.83
  small mammals
48 ln fragment size -0.01 ± 0.001 6.5 <0.01
Distance to edgec   5.3 0.06
a Logistic regression calculated the probability that a nest fails or that a nest is parasitized. Thus a negative parameter indicates that the probability that a nest fails or gets parasitized decreases with increasing fragment size or vegetation variable.
b The analysis includes nests in proximity to shrubby edge only.
c Slopes are presented graphically in Figure 2.

 

TABLE 3.  Percent of total Dickcissel and Henslow's Sparrow nests found at different edge types and within different distance intervals, estimates of daily Mayfield nest survival (±SE), and percent cowbird parasitism within three distance intervals from edge habitats in southwestern Missouri, 1995-1997.
Edge Type Variable Dickcissel (na = 225) Henslow's Sparrow (n = 50)
50 m 50-100 m >100 m 50 m 50-100 m >100 m
Agricultural
Nests found (%) 0.04 0.09 1.7 0 0 2
Nesting success 1.00 ± 0.00 0.95 ± 0.05 1.00 ± 0.00 -- -- 1.00 ± 0.00
Brood parasitism (%) 0 0 0 -- -- 0
Forest
Nests found (%) 1.3 4 5.8 4 2 8
Nesting success 0.96 ± 0.03 0.95 ± 0.03 0.93 ± 0.02 0.96 ± 0.04 -- 0.96 ± 0.04
Brood parasitism (%) 0.08 0 1.6 0 -- 0
Road
Nests found (%) 12 8.4 12 0 4 8
Nesting success 0.95 ± 0.01 0.90 ± 0.03 0.91 ± 0.02 1.00 ± 0.00 1.00 ± 0.00 1.00 ± 0.00
Brood parasitism (%) 1.6 0.04 1 0 0 0
Shrubland
Nests found (%) 13.4 16.7 24.5 16 26 30
Nesting success 0.93 ± 0.01 0.94 ± 0.02 0.95 ± 0.01 0.88 ± 0.04 0.95 ± 0.03 0.98 ± 0.01
Brood parasitism (%) 7.5 2.7 2.4 1 1 1
a Number of nests for which distance to edge was recorded.

 

TABLE 4.  Effects of fragment size on artificial nests, natural nests, and nest predator distribution in southwestern Missouri prairie fragments.
Variable Fragments
used
Slope ± SEa R2 F P
Artificial nest survival 9 0.20 ± 0.24 0.09 0.7 0.43
Nesting success:
  Dickcissel 16b 0.02 ± 0.01 0.22 4.3 0.05
  Henslow's Sparrow 9 0.01 ± 0.02 0.07 0.6 0.45
Cowbird parasitism of Dickcissel nests 9 -0.06 ± 0.11 0.04 0.3 0.59
Predators at artificial nests
  All mammals 9 -0.45 ± 0.20 0.38 4.9 0.06
  Mid-sized carnivores 9 -0.12 ± 0.05 0.46 6.0 <0.05
  Small mammals 9 -0.15 ± 0.15 0.13 1.0 0.35
  Birds 9 -0.04 ± 0.06 0.06 0.5 0.51
  Snakes 9 0.05 ± 0.09 0.03 0.3 0.60
Visitors at track plates
  All mammals 8 -0.03 ± 0.01 0.56 7.6 0.03
  Mid-sized carnivores 8 -0.001 ± 0.007 0.01 0.03 0.87
  Small mammals 8 -0.03 ± 0.02 0.44 3.9 0.10
a Positive slopes indicate an increase of nesting success, cowbird parasitism, or predator occurrence with fragment size.
b n is larger than the number of prairie fragments used in the study, because data from several years were combined.

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/birds/edgeffct/tables.htm
Page Contact Information: Webmaster
Page Last Modified: Friday, 01-Feb-2013 19:19:58 EST
Sioux Falls, SD [sdww55]