Paradoxes of Poweshiek Skipperling (Oarisma poweshiek) (Lepidoptera: Hesperiidae): Abundance Patterns and Management of a Highly Imperiled Prairie Species
Table 1
Number of O. poweshiek individuals itemized by site, for sites where we found >50 individuals, with expected O. poweshiek based on proportion of survey effort (km) at each site. For statistical testing, the sites are grouped into three categories (chi-square = 2800.7 and ).
Year preserved
Site and state
individuals
% individuals
Survey km
% effort
Expected individuals
Top five sites
1978
*Hole-in-the
1990
Mountain, MN
1057
44.0
46.47
19.7
473.0
1986
Prairie Coteau, MN
477
20.0
21.97
9.3
223.5
1972
Staffanson, MN
354
15.0
15.61
6.6
159.0
Unknown
*Prairie Marshes, MN
146
6.0
9.98
4.2
101.0
Unknown
*Hartleben, ND
54
2.0
4.30
1.8
43.0
Subtotal
2088
87.0
98.33
41.6
999.5
Intermediate three sites
1975
Bluestem, MN
113
5.0
19.32
8.2
197.0
1971
Chippewa, MN
89
3.5
17.10
7.2
173.0
1970s
Ordway, MN
62
2.5
16.33
6.9
166.0
Subtotal
264
11.0
52.75
22.3
536.0
Lowest twelve sites
Various
Remaining 12 sites
51
2.0
85.37
36.1
867.5
Total
2403
100.0
236.45
100.0
2403.0
Long or never-fire managed area of occupied habitat in site throughout study period. MN: Minnesota; ND: North Dakota.