a primer to site-level monitoring activities for volunteer coordinators

This publication is part of a Monitoring Your Wetland series available online in pdf format at:wetlandmonitoring.uwex.edu

yourMonitoring

Wetland

Butterflies

Insects rarely charm or elicit sympathy from the general public, but the elegant flutter of florid butterfly wings can grab the attention

of even the most entomologically indifferent observer. A healthy and diverse population of insects is just as important in the functioning of a high-quality wetland as any other animal community and needs to be protected. Butterfly monitor-

ing is a great way to generate appreciation among volunteers for the important role insects play in wetland ecosystems. Monitoring also helps butter-fly experts map species distribution including isolated pockets of rare species.

Wetlands host unique populations of butterflies, some of which have narrow habitat requirements and cannot travel far from pockets of suitable habitat. An orange, black and white butterfly known as the Baltimore checkerspot, for example, deposits its eggs only under the leaves of the turtlehead, a plant that needs wet, sunny conditions to grow. Plant diversity is a key component of butterfly diversity within a wetland, and when a wetland’s plant diversity diminishes its butterfly diversity also declines. Wisconsin

is home to 150 species of butterflies, including 66 species of concern.

Compared to other habitats, wetlands are above average when it comes to hosting species that most interest butterfly experts. Take, for example, the swamp metalmark and Poweshiek skipper-ling, both of which prefer wetland areas and are endangered in Wisconsin. The ochre-winged swamp metalmark lives in wetlands where swamp thistle grows and the golden yellow, silvery gray and brown Poweshiek skipperling

nectars on black-eyed Susan flowers in wet mesic habitats. In the last decade, observations of these two species have been limited in Wisconsin and in

some years no one has reported seeing them anywhere

in the state.

EXPERTIS

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RES

OURCES

HIGHHIGH

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(Lepidoptera)

. . . . . . . . . .

Plant diversity is a key component of butterfly diversity within a wetland.”

“

Peck’s skipper

©Ann Thering, www.annthering.com

About Wetland Butterfly Surveys

Butterfly monitoring is a good project to engage volunteers in if you are interested

in raising volunteer awareness about wetland ecosystems and expanding what you know about your wetland with inventories of the wildlife it supports. There are a number of possible approaches to surveying butterflies in a wetland. This manual will introduce two approaches — surveying to create a basic inven-tory of all species and surveying to establish relative abundance and track population trends for a limited number of targeted species. When surveying to create a basic inventory, volunteers document all of the butterfly species they encounter in the wetland. Documenting all encountered species can help you evaluate the wetland’s butterfly diversity, but requires a high level of identification skill.

A survey documenting just a few target species, on the other hand, will provide little data about a wetland’s overall butterfly pop-ulation diversity, but can be more easily con-ducted using the methods that establish relative abun dance and track population trends. Also, a targeted-species survey can be com plet ed by volunteers with limited identification skills.

Detailed data about a handful of species may be more valuable than a less complete inventory of all observed species, particularly if your wetland supports butterflies listed as species of con cern or uniquely adapted to your wetland type. Many bogs,

for example, support butterfly species found in no other habitat. Establishing relative abundance and tracking population trends, however, requires about ten years of data collected using consistent survey methods. If you are uncertain as to whether your monitoring group can sustain a consistent surveying effort for a long period of time, or you are more interested in collecting data on the diversity of your wetland’s butterfly population, then it is probably best to conduct a basic inventory.

When conducting a basic inventory, long-term data collection will likely result in a more complete inventory, but is not imperative. Additionally, for surveys conducted to establish relative abundance and population trends, volunteers must document not only what species they observed, but how many of each species were observed. While this information adds value to data collected for a basic inventory, it is not absolutely necessary.

In this manual, we discuss survey methods that maximize volunteers’ ability to detect and

identify butterfly species, whether they are docu-menting all observed species or just target species. We’ll also intro-duce you to resources that can provide you with additional and, in some cases, more advanced survey methods. No volun-teer protocols have been developed for monitoring butterflies in Wisconsin wetlands. There are, how-ever, two protocol manuals that have been developed Atlantis fritillary on Joe-Pye weed

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Monitoring Your Wetland – Butterflies

2

The equipment needed to

monitor butterflies is minimal.

Butterfly monitoring volunteers

can get by with as little as a

butterfly identification guide­book, writing utensil and

notebook. However, volunteers

can enhance their ability to detect

and identify butterfly species if

they also use binoculars, rubber boots and a camera.

Binoculars will allow volunteers

to observe and identify difficult-

to-approach butterflies and

rubber boots will enable them to

cover more of the wetland. Ideally,

the binoculars you choose should

be able to focus on objects within

a relatively close range and

should have a lower power.

Binoculars in about the 7- 8 power

class work better for observing

butterflies than high-powered

binoculars, which make it difficult

to track butterflies. With a camera,

volunteers can recruit the help of

butterfly experts by taking

photographs of butterflies not

identified in the field and sending

them to experts for identification

assistance. Photographs are also

useful as a record of project

observations that can be used as

new volunteers replace retiring

volunteers over time. Most popular

point-and-shoot digital cameras

have macro features sufficient for

taking the close-up pictures need-

ed for identification.

With respect to butterfly

identifica tion guidebooks, no

Wisconsin butterfly identification

guidebook has been published

since 1970. Instead of using this

out dated guidebook, local

butterfly experts recom mend the

following three guide books

written for identifying butterflies

within the Midwestern region:

Butterflies Through Binoculars

by Jeffrey Glassberg, Michigan

Butterflies by Mogens Neilsen

and Kaufman Field Guide to

Butterflies of North America by

Jim P. Brock and Kenn Kaufman

(see Informational Resources on

back page). A Wisconsin butterfly

guidebook is currently being

written by butterfly expert Mike

Reese.

In addition to guidebooks, you

might also want to provide

volunteers with identification flow charts. Wisconsin butterfly

expert Ann Swengel has

developed a series of flow charts

for several groups of Wisconsin

butterfly species, which can

greatly assist volunteers identify-

ing species in the field. Each flow

chart is designed to help

observers distinguish species

within a group of similar looking

butterflies. You can request

copies of Swengel’s flow charts,

by contacting her directly (see

Informational Resources).

Finally, although butterfly

watching is often associated with

butterfly nets, many local experts

discourage butterfly observers

from using them since they can

irreparably damage butterflies.

Instead, these experts encourage

butterfly monitoring volunteers

to follow in the footsteps of their

avian counterparts and rely on

binoculars to identify difficult-to-

approach species.

Supplies and Equipment

for long-term butterfly monitoring programs elsewhere in the Midwest that can serve as rich informational resources for volunteer butterfly monitoring groups in Wisconsin.

The two manuals — The Ohio Lepidopterists Long-Term Monitoring of Butterflies Instructions for Recorders and the Illinois Butterfly Monitoring Network Guidelines — were developed for monitoring programs in Ohio and Illinois.

Although not designed for site-level monitoring projects in Wisconsin wetlands, these manuals offer many informative examples of possible protocols that will be useful as you determine the best approach for butterfly monitoring in your particular wetland. These manuals are listed in the Informational Resources on the back page and will be referred to as we discuss some of the basics of butterfly monitoring.

Monitoring Your Wetland – Butterflies

3

Ideally, a volunteer group creating a wetland butterfly inventory should have members

with at least basic identification skills and a leader with relatively strong butterfly identification skills. A volunteer with strong identification skills knows between 80 and 120 species. Volunteers should endeavor to develop at least a minimal level of identification proficiency. You can help new volunteers develop this proficiency by providing them with a beginner’s checklist of species they are most likely to encounter in your wetland. It is not crucial that all volunteers be able to identify

Well-timed surveys will ensure volunteers encounter as many of the species present

in your wetland or as many specimens of a survey’s target species as possible. Although the total lifespan of a butterfly may be much longer, the flight stage of a butterfly’s lifespan can be less than a month.

Luckily, determining when to monitor butterflies is easier in wetlands than in other habitats. In most wetlands, July is over-whelmingly the best time to monitor butterflies, with the peak flight period for many wetland species occurring between July 10 and July 30, and nearly every species flying spontaneously on July 15. In many wetlands, just two or three surveys, including a mid-July survey, may be sufficient. Bogs are a bit of an exception, with the peak flight periods scattered within a

Survey Participants

Surveying – When, Where & How

large numbers of species, but they will contri-bute more to an inventory with greater species knowledge.

As mentioned earlier, less advanced identification skills will be required if you pursue a monitoring project in which volun-teers conduct surveys establishing relative abundance and tracking population trends for a limited number of targeted species. This approach, however, will require a greater level of training in executing the surveys, which must be conducted using rigorously consistent methods.

period extending from May to the end of July. In other habitats, peak flight periods for butterflies are more scattered and surveys must be repeated more frequently.

If you are conducting target-species surveys rather than collecting data for an inventory, surveys should be timed to correspond with the peak flight periods of target species, since you will want volunteers to encounter the greatest number of butter-flies belonging to the target species rather than the greatest number of species overall. From one year to the next, peak flight periods can change depending on weather.

For example, the best butterfly monitoring periods arrived about three weeks earlier in 2010 than they did in 2008. Consequently, it is

In most wetlands, July is overwhelmingly the best time to monitor butterflies, with the peak flight period for many wetland species occurring between July 10 and July 30, and nearly every species flying spontaneously on July 15.”

“

Monitoring Your Wetland – Butterflies

4

good to seek the advice of a butterfly expert with a strong understanding of butterfly phenology in determining when to begin and end butter-fly surveys. Another way to identify shifts in flight periods and ensure appropriate survey timing is to watch sightings post-ed by other observers on the Web site Wisconsin Butterflies, a site maintained by Wisconsin butterfly expert Mike Reese (see Informational Resources on back page). If you notice sightings of your target species posted earlier than usual, then you may need to conduct surveys earlier than planned.

Effective monitoring must also take place during the right time of day, under the right weather conditions and within the right habitats. Butterflies are most active and visible from late morning to early afternoon and when tempera tures are 70°F or warmer and the air is calm. However, monitoring can occur when it is between 60° and 65°F and at least 75 percent sunny or between 65° and 70°F and at least 50 percent sunny. Wind speeds should always be less than 20 miles per hour. Within your wetland, there are likely many habitat variations in soil saturation levels, water depth levels and vegetative cover. A good butterfly survey will cover all of these areas with the exception of deep water areas, which do not attract butterflies.

Aside from covering the wetland as thoroughly as possible, there are no hard-and-fast rules determining where you should survey when collecting data for a basic inven tory. If, on

the other hand, you are surveying to establish relative abundance and track population trends

for targeted species, you will require a permanent survey route. Determining relative abundance and population trends requires long-term data that has been collected using consistent methods and a consistent route. The route you choose should be as represen-tative of the habitat types present in your wetland as possible. Examples of route configura tions and methods of surveying them can be found in the Ohio and Illinois manuals mentioned earlier – The Ohio Lepidopterists Long-Term Monitoring of Butterflies Instructions for Recorders and Illinois Butterfly Monitoring Network Guidelines. Examining the examples in these two resources will provide you with

a starting point as you determine how to create and survey a route that suits your particular wetland type.

An example page from Mike Reese’s Wisconsin Butterflies Web site, which includes a graph and map of target-species sighting dates and locations.

The Ohio and Illinois manuals.

Monitoring Your Wetland – Butterflies

5

Many tools, resources and techniques can be employed to enhance volunteers’

ability to identify the butterfly species in your wetland. Some identification tools – binoculars, guidebooks, identification flow charts and cameras – have already been mentioned briefly. In addition to these tools there are also online resources and local events volunteers can use to boost their butterfly identification skills.

Reese’s Web site, Wisconsin Butterflies, for example, is a ter-rific tool for familiarizing volunteers with Wisconsin butterfly species and their distribution within the state (see Informational Resources on back page). Using this Web site, volunteers can also submit unidentified butterfly photos to solicit expert identification assistance. Taking pictures to document and assist with species identification is encouraged, particularly when collecting data for a basic inventory. Volunteers can also improve their butterfly identi fication skills by attending any of the field trips, lectures and classes listed on the Southern Wisconsin Chapter of the North American Butterfly Association Web site (See Informational Resources).

You can also help new volunteers by providing them with a beginner’s list of butterflies likely to be present in your

Surveying – Identification wetland. The species most likely to be present depends on the location, hydrology and

vegeta tion characterizing your wetland. Once you have identified these three things, you can use butterfly species habitat prefer-ences, host plants and distribution maps found in guidebooks and on the Wisconsin Butterflies Web site to determine which species are most likely to be present in your wetland.

If, instead of creating a basic inventory, you are establishing relative abundance and tracking population trends for targeted species, identification will be more manageable. But it is impor tant to remember that volunteers will need to identify target species look-a-likes. If, for example, a volunteer is documen ting the black dash as a target species they should also know what a byssus skipper and dion skipper look like and know how to distinguish the black dash from these species.

To get started, at left are three short lists of butterflies you might expect to find in your wet-land in addition to other butterfly species common in your area of the state.

SPECIES GENERALLY SPECIALIZED

TO WETLANDS:

Swamp metalmark

Bronze copper

Purplish copper

Baltimore checkerspot

Eyed brown

Appalachian brown

Mulberry wing

Broad-winged skipper

Dion skipper

Black dash

Two-spotted skipper

Y

SPECIES THAT HEAVILY USE WETLANDS:

Mustard white

Pink-edged sulphur

Silver-bordered fritillary

Common ringlet

Least skipper

European skipper

Peck’s skipper

Long dash

Little glassywing

Dun skipper

Y

BOG SPECIALISTS:

Bog copper

Dorcas copper

Bog fritillary

Frigga fritillary

Freija fritillary

Purplish fritillary

Red-disked alpine

Jutta arctic

Monitoring Your Wetland – Butterflies

6

Peck’s skippers

Eyed brown

BUTTERFLIES

Silver spotted skipper Black dash Baltimore Checkerspot

To document butterfly observations where they can be made publicly accessible and

contribute to a broader understanding of Wisconsin butterflies and their distributions, we recommend volunteers document their observations using the database available on Mike Reese’s Wisconsin Butterflies Web site.

Volunteers who enter their observations are encouraged to include digital photos of

Data Collection & Record Keeping documented species and asked to enter their observations by date and location. If you are collecting data for a long-term monitoring project establishing relative abundance and population trends, you should also keep your own records in addition to those entered into the Wisconsin Butterflies database.

Skippers: ©Molly Fifield Murray; black dash and checkerspot: ©Ann Thering, www.annthering.com

©Ann

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Monitoring Your Wetland – Butterflies

7

INFORMATIONAL RESOURCES

Wisconsin ButterfliesThis Web site offers a comprehensive database of Wisconsin butterfly observations and many other useful resources. Resources include species distribution maps, a descriptive guide to Wisconsin butterflies including phenology, defining characteristics and preferred habitats. Using the Web site, volunteers can also contact the Web site’s creator and Wisconsin butterfly expert, Mike Reese. http://wisconsinbutterflies.org

Illinois Butterfly Monitoring Network This program was designed to promote volunteer monitoring throughout northeastern and central Illinois. The program has developed a guideline manual for butterfly monitoring volunteers. Many of the organization’s recommended guidelines are broadly applicable and can be adapted for use in Wisconsin wetlands. http://www.bfly.org

Ohio LepidopteristsThis non-profit organization’s Web site includes a manual of instructions for butterfly monitoring volunteers. Many of the organization’s recommended instructions are broadly applicable and can be adapted for use in Wisconsin wetlands. http://www.ohiolepidopterists.org

Southern Wisconsin Chapter of the North American Butterfly AssociationThrough this Web site, butterfly enthusiasts can find events and activities that will help them learn more about Wisconsin butterflies including association meetings, field trips, lectures and classes, and how to conserve butterflies and their habitats. Also provides links to many other useful resources. http://www.naba.org/chapters/nabawba

Ann SwengelContact this Wisconsin butterfly expert to receive copies of identification flow charts for groups of Wisconsin butterfly species. swengel@naba.org

Glassberg, Jeffrey. 1999. Butterflies Through Binoculars: The East, Oxford University Press. 242 p.

Neilsen, Mogens C. 1999. Michigan Butterflies & Skippers, MSU Extension, Michigan State University, E. Lansing, MI. 248 p.

Jim P. Brock and Kenn Kaufman 2006. Kaufman Field Guide to Butterflies of North America, Houghton-Mifflin, 392 p.

a primer to site-level monitoring activities for volunteer coordinatorsyourMonitoring

WetlandThe Monitoring Your Wetland series includes 9 sections:

•IntroductiontoWetland Monitoring

•Birds

•SmallMammals

•Dragonflies&Damselflies (Odonata)

•FrogsandToads(Anurans)

Butterflies (Lepidoptera)

•InvasivePlants

•WaterQuality

•Macroinvertebrates

Available online in pdf format at:

wetlandmonitoring.uwex.edu

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . .

Butterflies (Lepidoptera)

March 2011

Project coordination by the Rock River Coalition and Suzanne Wade, UW-Extension Basin Education Initiative.

Researched and written by Patrice Kohl

With editorial contributions from Scott Swengels and Mike Reese, Wisconsin butterfly experts. Editorial assistance by Marie Martinelle and graphic design by Jeffrey J. Strobel, UW-Extension Environmental Resources Center.

Project funded through a DNR Citizen-Based Monitoring Partnership Program Grant with support from University of Wisconsin-Extension.

University of Wisconsin, U.S. Department of Agriculture and Wisconsin counties cooperating. An EEO/AA employer, University of Wisconsin Extension provides equal opportunities in employment and programming, including Title IX and American with Disabilities (ADA) requirements.