Property-Based Monitoring for Dragonflies and Damselflies (Odonata)

Bob DuBois

Ecological Inventory & Monitoring

Bureau of Endangered Resources

Dept. of Natural Resources

Superior, WI

Why Bother With Odonates? Because people care about them!

• First, a group of animals captures people’s attention.

• Next, field guides and books become available.• Then over time, the pool of people grows who

are competent in identification of and knowledge about the group

• Odonates are starting to enter this more mature phase of public awareness

Besides, they’re fun to have around!

Decide on what the objectives will be, what life stages to sample, and who will do the

collecting and make the identifications

But you need to know just a little about Odonata life history…

An aquatic larva transforms to a terrestrial adult

New adult Dragonhunter emerging from its exuvia

Shed larval exoskeleton iscalled an “exuvia”

Same individual 20 minutes later

Now called a “teneral”

Mature adult Dragonhunter

Considerations for Sampling Adults

• Are present for several weeks to several months depending on species

• Warning – they could have flown from elsewhere!

• Should be seen mating or ovipositing

• Some species are rarely seen as adults

• Easiest life stage to identify

• May be challenging to sample

Got him!

Lyre-tipped spreadwings layingeggs into a plant stem

Considerations for Sampling Larvae

• Are present for the longest time frame• Indicate a breeding site with certainty• May be very time-consuming to collect• Are the most difficult life stage to identify• Need special equipment and knowledge to

identify• May be part-grown and unidentifiable• Current keys to larvae stink

Empire Bog

Douglas Co., WI

Ebony boghaunter

Williamsonia fletcheri

larva

Empire Bog

Douglas Co., WI

Considerations for Sampling Exuviae

• Are present for the shortest time frame

• Indicate a breeding site with certainty

• Are often easy (time efficient) to collect

• Are difficult to identify as are larvae, except that they are full grown

• Least collecting impact ecologically

Searching for exuviae in a sheltered area

where they will often persist for a longer time

Ophiogomphus exuviae found

at least a month post-emergence

Monitoring recommendations if the goal is a comprehensive species list for a property

• Visit a site at least 4 times during flight season (mid-May through September)

• Sample adults and exuviae each visit• Larval sampling may help (esp. rivers)• Look for evidence of adult breeding• Choose nice weather days to sample• Sample all habitat types on the property• Bring along a competent odonatist

Identification Helps

• Field guides (user-friendly; minimal equipment needed)

• Keys (harder to learn to use; more equipment needed)

• Internet discussion groups and websites (show your photos; ask questions)

• Regional experts (show photos; ask questions; send specimens)

Add the data to the Wisconsin Odonata Survey (WOS) Website

http://WIatri.net/inventory/odonata

Or Google “Wisconsin Odonata Survey”

http://WIatri.net/inventory/odonata

Questions?