Vertigo bollesiana (Delicate vertigo) - MNFI Rare Species Explorer

Vertigo bollesiana

Delicate vertigo

Key Characteristics

The delicate vertigo is a tiny land snail with an amber-brown cylindrical (beehive-shaped) shell 1.5 mm in height with weak striations on its 4.5 to 5 whorls. The aperture (main opening) has 5 teeth.

Status and Rank

State Status: T - Threatened (legally protected)
State Rank: S2 - Imperiled
Global Rank: G4 - Apparently secure

Occurrences

County Name	Number of Occurrences	Year Last Observed
Chippewa	2	1998
Delta	1	1998
Gogebic	1	1998
Mackinac	5	2009
Ontonagon	1	1998

Updated 05/08/2013. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.

Habitat

This species is found in wooded calcareous or igneous outcrops, limestone/dolomite lakeshore ledges, and algific (cold air producing) talus slopes. The species also reportedly occurs in moist wooded hillsides and marshes. This species is intolerant of disturbance and has only been documented at sites that have been stable for approximately 100 years or more.

Natural Community Types

Management

Land-use activities that remove forest canopy cover and alter critical habitat requirements such as microclimate and moisture availability should be avoided at occupied sites. These include activities such as timber harvesting, residential development, and road building. The species also is sensitive to excessive trampling and ORV use. Use of prescribed fire in occupied sites should be avoided, if possible, or prescribed fire should be applied very conservatively, leaving multiple refugia and using a burn interval of at least 15 years.

Active Period

Active from first week of June to fourth week of September

Survey Methods

Surveys can be conducted anytime during the growing season, but are most successful in spring and fall following rain showers or when the soil is moist, and during higher relative humidity conditions and cooler temperatures. Visual surveys consist of looking for individuals crawling on the ground, in moist leaf litter, and on or under woody debris. Litter sampling consists of collecting soil and leaf litter samples in the field and drying, sifting and looking for snail shells in the litter samples in the laboratory.

Visual surveys
- Survey Period: From first week of June to fourth week of September
  - Humidity: Humid
Litter sampling
- Survey Period: From first week of June to fourth week of September
  - Humidity: Humid

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at http://mnfi.anr.msu.edu/explorer [Accessed Jun 19, 2013]

References

Survey References

Nekola, J.C. 1998. Terrestrial Gastropd Inventory of the Niagaran Escarpment and Keweenaw Volcanic Belt in Michigan's Upper Peninsula. Small Grants Program, 1998 Nongame Wildlife Fund, Natural Heritage Program, Michigan DNR, Lansing. 133pp.

Schilthuizen, M. and H.A. Rutjes. 2001. Land snail diversity in a square kilometer of tropical rainforest in Sabah, Malaysian Borneo. Journal of Molluscan Studies 67:417-423.

Technical References

Nekola, J.C. 1998. Terrestrial Gastropd Inventory of the Niagaran Escarpment and Keweenaw Volcanic Belt in Michigan's Upper Peninsula. Small Grants Program, 1998 Nongame Wildlife Fund, Natural Heritage Program, Michigan DNR, Lansing. 133pp.

Nekola, J.C., T.A. Smith and T.J. Frest. 1996. Land snails of Door Peninsula natural habitats. Final report to the Wisconsin Chapter of The Nature Conservancy. 55pp.