SNA Nature Notes - Fall 2014

Minnesota Scientific and Natural Areas header

Fall 2014

What's the Buzz about Native Bees?

Photo of Crystal Boyd conducting survey for bees.

By Crystal Boyd, Minnesota Biological Survey Bee Researcher

In spring 2014, I visited nine SNAs in southwestern Minnesota. It was memorable to see a bobolink singing at Lundblad Prairie SNA and a monarch butterfly soaring at Cottonwood River Prairie SNA. The real treat for me, however, were the native bees that I was there to survey.

I collected bees using small cups of soapy water, as shown in the photo to the right. These specimens will support a DNR grant (see video about the project) to update the state species list of bees. The most recent list was published in 1919 as part of The Hymenoptera of Minnesota, so a more complete version is long overdue. The specimens collected will be preserved at the University of Minnesota Insect Collection, where seven volunteers are helping to catalogue the data.

Native bees are different from honey bees in several ways. First, there are about 350 species of native bees in Minnesota. This contrasts with honey bees, which are just one species—Apis mellifera—and were imported from Europe in the 1600s.

Native bees also have different life strategies than honey bees. Over 90% of native bees are solitary, and only 10% are social. Leaf cutter bees, for example, live alone while bumble bees can nest in hives of a few hundred individuals. This contrasts with honey bees, which are highly social and live in colonies of 50,000 individuals or more.

Approximately 70% of our native bee species nest underground. Usually a solitary female digs a main tunnel connected to several chambers. She provisions the chambers with pollen and lays an egg inside each one. At sites like Compass Prairie SNA and Des Moines River SNA, one of the most common species I found was the Bicolored Agapostemon (Agapostemon virescens). This is a native ground-nesting bee that shimmers bright green in the sunlight.

The other 30% of bee species are cavity-nesters. They use pithy shrubs or hollow grasses to shelter their young. Some bees nest in tunnels that beetles excavate in dead trees. But not all cavity-nesters build their own home: cuckoo bees lay their eggs in the nests of other bees, much like cuckoo birds parasitize the nests of other birds. I found the most cuckoo bees (Nomada sp.) at Prairie Bush Clover SNA. This could indicate that the site’s bee population is healthy enough to sustain parasites.

The specimens from these SNAs are great data points for the state species list of bees, and I hope to survey more SNAs in the future. This research is only possible with the help of SNA staff and volunteers—so I'd like to give a huge "Thank you!" for all your great work and help you provide to this survey!

Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).



Students Survey Rare Thistle

Photo of Hill's thistle bloom

By Jeff Moss, Nicole Ellingson, Isaac Holman, Christina Weeks, Lindsey Forward, and Jack Norland

"There's thistle in them thar hills", or more accurately, there is Hill's Thistle in the hills of Blanket Flower Prairie SNA. The presence of this Minnesota species of special concern on this SNA has given the North Dakota State University Natural Resources Management (NRM) Club, stewards for the site, an opportunity to conduct an annual survey of the thistle. Led by Jack Norland, the group's advisor, nine individuals participated in the 2014 survey.

Hill's thistle is a short stocky thistle with a large flowering head. The stems range from 8 inches to 2 feet in height and usually have only one flowering head. The flower ranges from 2-3 inches in height and are reddish to deep purple in color. The leaves are lobed with wavy edges and can vary in length up to 10 inches with a woolen, whitish appearance. Blanket Flower Prairie SNA is the western most edge of its known range.

Photo of Hill's thistle bloom

After a successful 2013 survey the group was anxious to survey some of the areas not previously covered. A brief discussion on identification was conducted at a known Hill's thistle site, then with GPS and clipboard in hand, the survey crew split into two groups and decided to head into different sections of the SNA. While one of the groups had more of a nature walk, the other group was able to locate and identify 7 different patches of thistle totaling 100 individual rosettes as well as evidence of growth near a prescribed burn site. (NRM Club members are pointing to blooming Hill's thistle on the 2014 survey in the photo above.) The 2013 survey produced 15 different patches with 174 individual rosettes and both years showed evidence of summer blooms, this year however, the group was treated to a rare late blooming plant.

All surveys were promoted as an SNA event open to anyone and are a great opportunity for individuals to come together to enjoy a beautiful natural asset while conducting citizen science. The data gathered will be utilized in further understanding the growth and spread of Hill's thistle as well as formulating future management plans for Blanket Flower Prairie SNA and other prairie landscapes. The experience of a day in one of Minnesota's stunning prairie landscapes is an occasion that shouldn't be missed.



SNA Events

Photo of person cutting buckthorn

Fall is a great time to remove woody invasive species! Help out on one or more volunteer projects to combat aggressive invasives on SNAs. A full list is available on the SNA Events Calendar.



Grey Cloud Dunes SNA

Volunteer Project: Invasive and Trash Removal


Wolsfeld Woods SNA

Volunteer Project: Buckthorn Pull


Seminary Fen SNA

Volunteer Project: Buckthorn Removal, Clean-up and Seed Collection




Site Highlight: Gneiss Outcrops SNA

By Brad Bolduan, SNA Program Management Specialist

Photo of woody removal at Gneiss Outcrops SNA

Over the past half century many areas along the Minnesota River have seen a large-scale invasion of woody vegetation with an especially strong one-two punch of encroaching red cedar and non-native buckthorn. This was, to a degree, the case at Gneiss Outcrops SNA, although not as pervasive as at many locations. The SNA is located southeast of Granite Falls. In the fall 2012 the SNA program solicited bids to cut, treat, and pile the invasive woody vegetation from the majority (150 acres) of this 234 acre SNA. The contracted work was completed in the first half of 2013 leaving the site much more open as seen in the adjacent photo.

Species such as oak, willow, and basswood were left standing. Ongoing management to control remaining woody vegetation and other "weeds" will be required for a few more years. There are still brush piles that will need to be burned over time.

Numerous small trees are still found growing in wetland fringes. Fire and cutting will be used to control these trees. The remaining parts of the SNA are seeing similar treatments. Formerly open areas are being cleared, while buckthorn is being removed in the areas nearest the Minnesota River.

The general appearance of the SNA has changed considerably. Outcrops that were hidden for years are now visible. It is hoped that the native prairie and outcrop species will respond favorably over the long-term. Come take look yourself and see how management is restoring the character of this site.

Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).



Notes from Site Stewards

Photo of photogarpher at prairie photography workshop

Site stewards monitor SNAs across Minnesota. Their observations provide invaluable information to the SNA Program. Here are some interesting notes from reports:

  • Often site stewards help with more than observations, including actively working with SNA staff to manage a site. For example at Whitney Island SNA site steward Virgil Luehrs was shown where a patch of invasive Japanese barberry was growing and he has been working this summer to eradicate it from the Island.
  • Surveying for rare species is another task site stewards can take on. On July 17th site steward Ed Heinen conducted a survey for breeding Louisiana waterthrush at Kettle River SNA.
  • Management isn't the only area where site stewards excel. On June 21st photographer Dale Bohlke offered a prairie photography workshop at Cottonwood River Prairie SNA, where he is steward. He offered a second workshop on August 16th at Joseph A. Tauer Prairie SNA.

Thanks stewards for all the work you do for SNAs!



Nature Notes is the Minnesota Scientific and Natural Areas quarterly e-newsletter. It seeks to increase interest, understanding and support of natural areas while promoting involvement in the protection of these special places. Contact us at


Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).