A SURVEY OF THE EXTANT DRAGONFLY FAUNA OF THE LEE AND ROSE WARNER NATURE CENTER AND SURROUNDING HABITATS

Ron Lawrenz, Lee and Rose Warner Nature Center

The author has been conducting a survey of the dragonfly fauna of the Lee and Rose Warner Nature Center (WNC) and surrounding habitats since 2007. This work was initially prompted by collections made during a BioBlitz conducted at the site in June of 2007. Subsequent observations and collecting indicated that the dragonfly fauna was unusually diverse, and included several uncommon or rare species. Work in 2009 and 2010 established the presence of a breeding population of Rhionaeschna mutata (the Spatterdock Darner), previously unknown in Minnesota, significantly extending its range west and north. A review of existing collections at WNC revealed that another new species for the state, Libellula incesta (the Slaty Skimmer), had been collected on the site in the 1990s. It is likely that the ongoing efforts of this survey will uncover additional species records in eastern Minnesota given the fact that the dragonfly fauna of the state is poorly understood, that several species unknown in the state have been recorded in several western Wisconsin counties, and that Minnesota is situated at the east to west, and west to east maximum ranges for numerous species. More than two dozen new records for Washington County have been found at WNC since 2007. Data from this project is being included in the Minnesota Odonata Survey Project (MOSP).

To date, 51 species of dragonflies have been collected on WNC lands and adjoining properties. Recorded sightings, known specie ranges, and habitat availability would indicate that we are likely to find an additional 15 to 20 species on site. The WNC fauna potentially includes almost three quarters of the dragonfly species currently recorded for the northern tier of states and Canada. Since there are no permanent streams within the WNC land base, our records include few of the species found in flowing water. However, the WNC fauna does include approximately 95% of the species found in lake and wetland habitats for this region.

The author surmises that the rich diversity of the dragonfly fauna at WNC is an extension of the limnologically diverse array of relatively undisturbed aquatic habitats found on site. These include lakes, bogs, fens, and a continuum of temporary pools to permanent wetlands.

Suggestions for Reading

Mead, Kurt. 2009. Dragonflies of the North Woods (second edition). Kollath+Stensaas Publishing. 194 pp.