Today I attended a volunteer training workshop at the Urban Ecology Center (UEC) at Riverside Park. We learned a bit about identifying dragonflies and damselflies so that we can come back on specified survey days to identify and count species. We have at least 30 varieties of odonates in our area. These are dragonfly exuvia, or the cast off shells of the nymphs’ last stage before becoming the familiar and beautiful insects we are used to seeing skimming over water or meadow on a summer day. Dragonflies can live up to four years in water as nymphs, but only live 2-6 weeks on land as adults. (all facts are taken from the handout the UEC provided at the workshop) “The Milwaukee Rotary Centennial Arboretum is an urban oasis that combines Riverside Park and Milwaukee River frontage with reclaimed post-industrial land into a public green space, natural habitat, and outdoor classroom for experiential learning and growing, right in the heart of the city!” (from their website) Here our group heads off, nets and magnifiers in tow, to see if we can find any odonates. It was warm enough, but it is early in the season and a bit windy, which were two counts against our success. We were really there to learn, not formally count today, but if we found something it would be a bonus. This turtle collage/sculpture is found along the trail near the Milwaukee River. While walking near the river, one of our group noticed a Butler’s garter snake by the side of the trail. Turns out it was stuck in some erosion netting that was in place to stabilize new growth on the side of a hill. Ironically, the EPA (Environmental Protection Agency) had required the UEC to install the netting. Luckily someone had a knife and the snake was carefully cut free. Jennifer Callaghan, the UEC’s Research and Citizen Science Coordinator, could tell this Butler’s garter snake is a pregnant female! Our small heroic moment of the day. Chop me down. Graffiti, even in the woods! (or maybe a note to staff to take this tree down, which someone did) Reflections on the Milwaukee River, which flows past Riverside Park and the UEC. Not sure what this is, but it was along the trail so I took a photo. Here we’re heading back up and away from the river, toward the meadow. It’s so pretty in here. There were a number of people out enjoying the park today, several of them walking dogs and/or pushing strollers or riding bikes. The Oak Leaf Trail runs roughly parallel to the river and bisects the UEC. Bikes stay on that paved trail, but strollers and dog-walkers were seen throughout the park. I even saw a schnauzer, which made me happy. Best dogs ever! Just another beautiful area. I love it here. I’m usually at the back of the pack since I can’t stop taking pictures. Go figure! Jennifer holds our only catch and release of the day, a teneral damselfly, or a newly emerged adult. Tenerals are fragile, their bodies still soft and their wings especially shiny. She handled it very carefully and made sure it found a safe place to further dry out when we were done looking at it.
This was an awesome day. I look forward to the formal surveys as they happen over the summer at the three branches of the UEC: Riverside Park, Washington Park, and Menomonee Valley. Each has its own particular habitat and list of odonata species. I’ll have to bring the Nikon with a macro lens and see what I can photograph. All count and species data are shared with the Wisconsin Dragonfly Survey and a National Dragonfly Survey.
I will leave you with a few fun facts from our workshop today, all but the last two taken from the handout they gave us:
- Dragonflies have compound eyes with up to 30,000 facets. Their eyes make up the majority of their head and are positioned to see in a nearly 360 degree radius.
- There are fossil records of odonates dating back some 230 million years.
- Odonates are very agile fliers and can fly forward, backward, during feeding, during egg-laying and even during mating. Aeronautic scientists have studied them to better understand flight physics.
- One adult dragonfly can eat up to several hundred mosquitoes a day!
- The Globe Skimmer dragonfly has the longest migration of any insect at 11,000 miles.
- The fastest recorded speed of a dragonfly was 36 mph.
- Damselflies can detect movement up to 15 meters away.
- Both dragonflies and damselflies are aggressive hunters. They have voracious appetites, will hunt in groups and will even attack prey bigger than themselves.
- Dragonflies are super efficient hunters, catching nearly 95% of the prey they set out to eat. (how do they know this?!)
- Odonates have individual control over each of their four wings.
- Dragonhunter dragonflies (Hegenius brevistylus) are the bad asses of the bunch and a prized find for enthusiasts. They can fly about 30 mph and have no qualms about cannibalizing each other!
- My favorite species name from today’s workshop: Ebony Boghaunter (Williamsonia fletcheri), a small and rather rare dragonfly with a fabulous moniker!