Identification of SGCN
Species of greatest conservation need are limited to aquatic and terrestrial wildlife species that have been documented within Michigan, and that depend on resources available within the State during any life stage or phenological stage (e.g., breeding, migration, wintering). Species documented within the State, but believed to be accidental or infrequent visitors, were excluded.
Species federally or State listed as threatened or endangered or identified by MNFI as 'special concern' (MNFI 2002) have already been recognized through their respective review and listing processes as being in need of conservation. Therefore, each of these 237 species was automatically included in the set of SGCN, even if the species is believed to be extirpated from Michigan. An additional 167 species also were identified as being in greatest need of conservation due to declining populations or other characteristics that may make them vulnerable.
A draft set of SGCN was compiled from suggestions made by DNR and MNFI staff, and from review of: U.S.D.A. Forest Service (USFS) 'sensitive species' for national forests in Michigan (USFS 2004); Michigan species included on the International Union for Conservation of Nature and Natural Resources (IUCN) 'Red List' (IUCN 2003); birds identified as 'primary focus' species in TNC's 'Great Lakes bird ecoregional planning' report (Ewert 1999); birds identified through an analysis of the Partners in Flight's Species Assessment Database (Rocky Mountain Bird Observatory 2002); information available on Nature Serve's web site (Nature Serve 2004); and the Michigan Odonata Survey Master Database (University of Michigan Museum of Zoology 2003).
Individuals who were asked for SGCN recommendations were provided with a set of criteria for identifying species of greatest conservation need, suggested by the IAFWA Teaming with Wildlife Committee. Under the provided criteria, SGCN should include:
- Imperiled species (globally rare)
- Declining species
- Endemic species
- Disjunct species
- Vulnerable species
- Species with small, localized 'at-risk' populations
- Species with limited dispersal
- Species with fragmented or isolated populations
- Species of special (conservation) concern
- Focal species (keystone species, wide-ranging species, species with specific needs)
- Indicator species
- 'Responsibility' species (i.e., species that have the center of their ranges within a State)
- Concentration areas (e.g., migratory stopover sites, bat roosts/maternity sites)
Information was not available to fully address some groups, such as spiders and beetles. The need for further research to fill these and other knowledge gaps is provided in more detail in the Statewide Assessments.
A list of Michigan wildlife species experts was compiled based on recommendations of DNR and MNFI staff and species experts themselves. This list of individuals (Appendix D) continued to grow throughout the action plan development process. These species experts were associated primarily with academic institutions, but also included DNR biologists, Michigan Department of Environmental Quality (MDEQ) employees, USFWS biologists, NGO-affiliated individuals and other non-affiliated individuals. Species experts were consulted throughout the action plan development process.
A revised set of SGCN was developed based on comments received at SGCN Workshops, comments from individual species experts, and information collected at the suggestion of species experts. Species experts were asked to make recommendations based on information from research and projects focused on Michigan wildlife, as well their personal observations and knowledge. Clarifications and additional suggestions were requested when necessary.
The revised set of SGCN was distributed for review and comment. Reviewers included species experts, DNR staff, individuals on the action plan listserve group, 120 Michigan conservation organizations, and attendees at public meetings. Additionally, the set of SGCN has been available for review and comment on the action plan website.
The set of Michigan wildlife species identified as SGCN is expected to change over time. As the action plan is implemented and goes through further review and revision, species will be added or removed when new data indicate changes are warranted. During the development process, several species were added or removed due to availability of new information. An example of a late addition to the list is the evening bat. Until recently, this species had not been documented in Michigan since 1969 and was considered to be extirpated. In August 2004, however, an evening bat maternity colony was discovered in southern Michigan by Dr. Alan Kurta, one of our species experts. Because the evening bat is an edge-of-range species and little is known about its habitat needs in Michigan, it was added to the set of SGCN.
The process of identifying SGCN is not part of the State's official threatened and endangered species listing process; rather, it identifies species and their habitats that will be the focus of funds, conservation actions, research and monitoring associated with implementation of Michigan's WAP. However, information about SGCN acquired during development and implementation of the WAP may be referenced during future reviews and revisions of the State's threatened and endangered species list.
Additional information on each SGCN, including distribution and abundance, is given in the SGCN Summaries. Spatially explicit data were not available for all known locations of SGCN and, therefore, some locations may not be included on distribution maps, even when mentioned in the accompanying text. Available data were of a variety of types, from a variety of sources. Aquatic distribution maps are based completely on documented locations of species, whereas the terrestrial maps are based on a mixture of documented locations and current range, with the data type reflected in the map legend. When location data for a species were limited, historical and more recent locations were combined to create a distribution map that more accurately represents the potential distribution of the species. When the distribution represented on the map differs significantly from the known current locations, this difference is recognized in the accompanying text.