Wisconsin Odonata Survey title graphic Wisconsin Odonata Survey graphic Wisconsin Odonata Survey graphic Wisconsin Odonata Survey graphic Wisconsin Odonata Survey graphic

Get Involved with the Wisconsin Odonata Survey

The focus of the Wisconsin Odonata Survey (WOS) is to document populations of dragonflies (Suborder Anisoptera) and damselflies (Suborder Zygoptera) by identifying adults, nymphs, and exuviae (cast skins left behind near shore when the nymph transforms into the adult). In this way we are gaining increasing knowledge of where the 160+ species known to occur in Wisconsin may be found and their required habitats. This information is especially useful for rarer species. Citizen volunteers are greatly appreciated because there are far too many habitats to check for the few professionals who work with Odonata.

The Identification Process

A beginning cooperator should start by learning the common species of Odonata in his/her area before doing much surveying. Purchase a field guide or two and a pair of close-focusing binoculars if possible. The initial focus should be to have fun, learn, and just enjoy the process of discovery and exploration! During this process, visiting the Wisconsin Dragonfly Society (WDS) Facebook group page is likely to be helpful and encouraging. There you can post your photographs to confirm your identifications, ask questions, and learn about coming WDS activities.
Wisconsin has around 160 species of odonata. However, males and females usually differ in appearance, as do immature and mature adults, resulting in much more variation. Most dragonflies and damselflies possess sufficiently distinct characteristics to readily allow their identification in the field. Important characteristics to notice include colors, patterns, sizes, shapes, and even behaviors. The many "easy" species can be readily documented with good quality photographs or even sight records in many circumstances (see acceptance of records page).
Another group of "tougher" species may still be identified in the field, but require capture. Individuals should be netted, their appropriate structural parts examined with a hand-held magnifying lens (10X loupe), and results compared to illustrations in a good field guide. Specimens that are captured and examined in the field can usually be released unharmed.
A very small number of species (or genders of a species) can only be identified by examining them under a microscope. The dichotomous keys and microscopes used for the most difficult identifications are expensive, and much terminology must be learned. For most people, this level of commitment is superfluous and they focus on those species and genders that are more readily identifiable.

What to Survey

The goal of surveying should be to gain as complete a picture as possible of the species that occur at a site. Depending on season, one or more life stages may be present (nymphs, exuviae, or adults). A rule of thumb is to sample whatever life stage is available, preferring mature adults, if they are present, because they are the easiest to identify. However, some species are infrequently seen as adults and are best sampled as nymphs or exuviae.
Dragonflies and damselflies spend most of their lives as nymphs living under water in a variety of aquatic habitats. Nymphs could be at any stage of development, and if only partly grown, may not show the key characteristics needed for their identification. However, nymphs are extremely useful, especially when mature, and are available over a wider time frame than the other stages.
When nymphs are ready to mature, they crawl out onto land and emerge from their nymphal skins, or exuviae. Exuviae have the advantage over adults of firmly indicating a breeding site; adults could have flown to a site from a considerable distance. Identification of exuviae can be easier than for nymphs because exuviae represent the final and most mature molt of the nymph stage where the key characteristics needed for identification are fully developed.
After nymphs emerge as young adults they are called tenerals. Tenerals are soft-bodied, fly weakly, and do not develop full adult coloration until at least a few hours or days after emergence. For this reason, and because they do not preserve well, collecting of tenerals should be minimized. However, the presence of tenerals is important to note because their presence indicates a nearby breeding site, and their appearance marks the time of emergence of the species.
Mature adults are the easiest to identify, making them the most common life stage surveyed. Of these, males are often more conspicuous than females and usually, but certainly not always, easier to identify. You are likely to encounter many more males than females. In some species, females are very reclusive and are rarely seen. However, the ability to identify both genders is useful.

How to Survey

For adults, as you gain experience you should record the presence of those species that you are sure you can identify in the field, and photograph or collect specimens of those species that you can't identify. Look for subtle differences among species in sizes, shapes, colors, wing patterns, and habits. Make liberal use of your field guides to confirm identifications. Visit all the different habitats at a site. Be aware also that species differ in their behaviors, and that these behaviors can vary with time of day, weather conditions, and season. Many species fly boldly in plain view, but some are secretive and require patient observation to be located. Do not collect a species that you know is federally listed as threatened or endangered.
Net dragonflies while in flight by swinging at them from behind. Many species will fly a predictable route, so you can watch a while to see the pattern and then set up an ambush at a convenient spot, perhaps where you are partially hidden by a tree or shrub. When odonates are perched, approach them with very slow movements, then when you are close enough, swing fast. Once in the net, remove the specimen by the wings holding them together over their back (they don’t bite very hard). Examine it with your hand lens at the appropriate angle to see structures as they are illustrated in your field guide. If you are collecting a specimen, refer to the page on collecting for information and videos on collection and preservation techniques

When to Survey

June and July are "prime time" for odonates, so your most intense efforts should be concentrated then. However, some species fly later in the summer and fall, often well into October. May is an important month as well, because some species, including some of our rarest ones, have short, early flight periods. A few migratory species arrive in Wisconsin as early as mid-April. Regarding time of day, the greatest diversity can often be seen during sunny, warm afternoons. However, some species are most active at other times, so the best time to survey could depend on the species you are looking for. Avoid surveying during inclement weather, as most species perch in trees or other vegetation then and are difficult to find. When collecting exuviae, time your searches to the known emergence periods of the species of interest because exuviae persist in large numbers only briefly (a few weeks at most) before wind and high water levels displace them. Mid-May through mid-June is a crucial time frame for collecting clubtail exuviae along rivers and emerald exuviae in bogs. An excellent goal for cooperators is to thoroughly document the diversity of dragonflies and damselflies at one or a few sites near their home. If this is your goal, visit the site at 10-day to two-week intervals during the entire flight period (late April through October).

Where to Survey

The habitats of focus in recent years have included spring seeps; ephemeral ponds (vernal pools); large rivers; small streams that run through bogs/fens; wooded swamps; acid bog ponds and wetlands with sphagnum mosses; coastal wetlands; and alkaline wetlands. These areas hold species we need to learn more about, and they have not been as well sampled as some other habitats. Presence of sphagnum mosses, in floating mats or with scattered, fishless pools in sedge meadows, are good indicators for a number of rare species of emeralds (Corduliidae). In lakes, diverse shoreline vegetation often provides habitat for many species of odonata. Some species have very specific habitat requirements, whereas others can be found just about anywhere. Aquatic systems differ in a variety of ways including: waterbody size, water chemistry, presence or absence of sunfishes, and types of emergent and submergent vegetation. Moreover, at any aquatic site there will be a variety of smaller habitat areas that differ subtly from others in shading, shelter from wind, and types of vegetation. So, try to check all habitats present at your site. If you are looking for a location to conduct your survey, please reference the information on accessing Wisconsin's properties.

Useful Equipment

  1. Field guides for dragonflies and damselflies (cost about $20 - see Resources).
  2. A lightweight aerial net that you can swing quickly (you can make your own or you can buy one commercially from BioQuip Products [see Resources]).
  3. A quality hand lens (loupe). Many odonatists use a 10X loupe like the Belomo triplett.
  4. A quality pair of close-focusing binoculars.
  5. A digital camera with strong macro-photography capabilities.
  6. Knee-high rubber boots, hip boots, or waders (depending on water depth where you intend to go).
  7. Field clothing and insect repellent as appropriate.
  8. A notebook for recording field notes (optional).
  9. A carrying bag for hauling all this "stuff".
This site is produced in conjunction with the Wisconsin Aquatic and Terrestrial Resources Inventory and sponsored by the Wisconsin Department of Natural Resources. The information presented on this site is subject to the Wisconsin Department of Natural Resources' Legal Notices, Disclaimers, and Terms of Use.