Abstract

Return to Conservation Biology Research on Spiders

Ehmann, W.J., and B.E. Boyd. 1998. Surveys for proposed Special Concern jumping spiders of Minnesota. Final report submitted to the Minnesota Department of Natural Resources. 17 pp.

Abstract:

We surveyed 87 sites in 16 counties across Minnesota to assess the occurrence of eight special concern jumping spider species at protected natural areas, typically containing remnants of prairie plant communities. Overall, 526 jumping spiders were collected, primarily by sweep netting, including at least 19 species previously collected in MN and four of the species of special concern (Marpissa grata (Gertsch, 1936), Paradamoetas fontana (Levi, 1951), Pelegrina arizonensis (Peckham & Peckham, 1901), and Sassacus papenhoei Peckham & Peckham, 1895). None of these species exceeded 5% of the total identified catch. Three jumping spiders were represented by only a single specimen (Habronattus viridipes (Hentz, 1846), S. papenhoei, and Sitticus palustris (Peckham & Peckham, 1883). Two species were very common, comprising 63% of the total identified catch: Pelagrina insignis (Banks, 1892) and Phidippus clarus Keyserling, 1884. Significant range extensions are reported for M. grata and Marpissa pikei (Peckham & Peckham, 1901). Special concern species that were not collected may not have been present or may have been missed due to sampling protocols (methods, seasonal timing, or site selection).

This study is the first to use a geopositioning system (GPS) for a spider survey in the state, which facilitated establishment of relocatable sample sites within target areas. At many sites, sampling effort and areal coverage was substantially increased from earlier reconnaissance work. These established sites introduce a more systematic approach to acquiring census data and can now be used to monitor spider populations over time.

Although results from any one study in one portion of a season should be interpreted cautiously, we found good correspondence between our data and previous accounts of spider abundance and habitat associations (most by B. Cutler). Areas of high conservation value for listed special concern jumping spiders appear to include Stearns, Swift, Washington, and Winona Cos., including a high diversity site (Lake Elmo County Nature Reserve) not presently designated as a State Natural Area or managed by The Nature Conservancy.

We suggest continued field work at known sites in search of the four uncollected special concern species and for monitoring jumping spider populations at specific high-interest sites. We also suggest that such information be placed within a larger, landscape context by adding survey data from new sites on public lands that may not presently be managed for invertebrate conservation. In particular, large gaps in species range maps should be explored, as well as the northern tier of counties that remains unsampled to date.

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