Common Green Darner - Anax junius
The Green Darner is a common and widespread member of the family Aeshnidae. Darners are among the largest and fastest-flying North American dragonflies, 2 1/4-4 3/4" (57-120 mm) long. Green Darners are found state-wide from the mountians to the prairies with a subspecies in the east and in the western part of the state. Due to the Common Green Darner's highly migratory nature, they can also be seen in a wide variety of non-wetland habitats as well. Green Darners inhabit a variety of well-vegetated lakes, ponds, marshes, and vernal pools, some temporary or even brackish, as well as small streams. This species prefers habitats that lack fish (Nikula et al. 2002, Paulson 2009, Dunkle 2000). Of the darners in Montana, the only one with a fully green thorax and a blue striped abdomen. Associated Wetland Ecological Systems: Western Emergent Marsh, Northern Rocky Mountain Wooded Vernal Pool, Great Plains Open Freshwater Depressional Wetland, Perennial Praire Streams.
Common Green Darners, although a native North American species, are also a wide ranging migrant dragonfly. They occur as far south as Honduras, the West Indies, and Hawaii. They are vagrants to Alaska, eastern Asia, Britain, and France (Dunkle 2000, Paulson 2009).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
Common Green Darners are both migratory and breeders in Montana. Mature adults move north early in spring, long before other resident have emerged. These migratory individuals then breed in appropriate wetlands and the larvae develop, emerge late in summer, and migrate out of the state in the early fall (Paulson 2009).
Common Green Darners inhabit a variety of well-vegetated lakes, ponds, marshes, and vernal pools, some temporary or even brackish, as well as small streams. This species prefers habitats that lack fish. Due to the Common Green Darner's highly migratory nature, they can also be seen in a wide variety of non-wetland habitats as well (Dunkle 2000, Nikula et al. 2002, Paulson 2009).
Ecological Systems Associated with this Species
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
- Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if
point observations were associated with that system.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: http://mtnhp.org/requests/default.asp
) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.
- Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
- Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
- Foresman, K.R. 2012. Mammals of Montana. Second edition. Mountain Press Publishing, Missoula, Montana. 429 pp.
- Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
- Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
- Maxell, B.A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
- Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
Larvae feed on a wide variety of aquatic insects, such as mosquito larvae, other aquatic fly larvae, mayfly larvae, and freshwater shrimp. They will also eat very small fish and tadpoles.
Adult- The dragonfly will eat almost any soft-bodied flying insect including mosquitoes, flies, small moths, mayflies, and flying ants or termites.
Male Common Green Darners patrol irregular territories along open water and shorelines often clashing with other males and searching for females. Copulation is completed away from breeding sites, probably to avoid harassment by other males. Oviposition usually in tandem (unique for darners) on floating or submerged stems and leaves as well as woody branches. Single males often try to dislodge males from tandem pairs (Dunkle 2000, Nikula et al. 2002, Paulson 2009).
- Literature Cited AboveLegend: View Online Publication
- Dunkle, S.W. 2000. Dragonflies through binoculars: A field guide to dragonflies of North America. New York, NY. Oxford University Press. 266 pp.
- Nikula, B., J. Sones, D.W. Stokes, and L.Q. Stokes. 2002. Stokes beginner's guide to dragonflies and damselflies. Boston: Little, Brown. 159 pp.
- Paulson, D.R. 2009. Dragonflies and Damselflies of the West. Princeton University Press, Princeton. 535 pp.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Kohler, Nathan S. Excel spreadsheets of Odonate observations/collections in Montana.
- Additional Sources of Information Related to "Insects"