Journal for August 20, 2009

Green Darner Dragonflies have been migrating through the farm this week.

Dragonfly migration is a phenomenon that people don’t know much about.  Scientists have been studying dragonfly movements using various methods, including putting tiny radio transmitters on some dragonflies to track where they go.  Their patterns of migration seem to resemble those of birds.  Research at Hawk Ridge, in Duluth, shows that the patterns of Green Darner and American Kestrel migrations are similar, and often happen at the same times.  (In reading about all this, I came across this article about a species of dragonfly that has the longest known migration of any insect – 14,000 km. round trip!)

Green Darners are common dragonflies in Wisconsin in the summer, and part of their population migrates south for the winter.   (The other part stays here, surviving the cold weather as nymphs, under the ice in ponds.)    We often see large groups of Green Darners hunting insects in our valleys in the fall.  Yesterday we noticed many of them flying, and even more resting on the sunlit plants along the side of the path.

Green Darner resting on vegetation

Anax junius

This is the path – the Darners were all resting on the sunny side.

As we walked by, the resting ones flew up in front of us, to join the insect hunters.  Here’s a video of what it was like.  Notice that at first there aren’t many dragonflies.  But as Mike walked ahead on the path in front of me, the resting dragonflies were disturbed, and flew up and across in front of the camera.

Our friend Jan and her friend Mike came to visit this week.  We did a gator tour, and took the traditional picture of them sitting on the bench at Big View Prairie – it was a beautiful day, and we had a great time.

We’ve had some big rainstorms this week – with beautiful clouds and sun afterward.

Storm clouds

Sun after the rain


The wetland after the rain.  I’ve always liked this view – it’s like looking through a window.  It’s actually looking across the place where we jump across a little stream to get to Pat’s Prairie.

A couple more views of the wetland – it’s full of flowers right now.

Tall Sunflower

Tall Sunflower and Cupplant

Jewelweed at the edge of the creek

Impatiens capensis

I walked out to the wetland one evening and sat edge of the culvert that goes under the driveway.  As it got darker, the bats came out, and started skimming over the pond below.  One would swoop over my shoulder, then down and across just above the surface of the water – so that I could see two bats – one real bat, and one reflection.  Then it would swoop up and away, and another one would come over my other shoulder and down to the water.

Now that I know what to look for, I’ve been finding lots of hackberry butterfly caterpillars.  They’re either Hackberry Emperors or Tawny Emperors – both eat hackberry leaves.  The eggs are laid in a large cluster, and the caterpillars stay together for at least the first few instars.

Here’s a cluster of eggs on the underside of a Hackberry leaf.

Asterocampa sp. eggs

And some caterpillars – they seem to be in two different instars

Asterocampa sp. larvae

It’s easy to spot them by looking up through the leaves.

Asterocampa sp. larvae

Here are a few more prairie and flower pictures from this week.

3 Finger Valley

3 Finger Valley

3 Finger Valley looking the other way – back towards the house

3 Finger Valley

Common False Foxglove – a beautiful little annual that grows in the wetland

Agalinis tenuifolia

Evening Primrose – another flower in the wetland

Oenothera biennis

There’s a wet area in 3 Finger Valley, under some Black Walnut trees, that is mostly Giant Ragweed.  We’ve mowed it a few times, and planted some plants that like wet woodlands, and finally some of them are starting to come up.  This is American Bellflower, blooming among the ragweeds.

Campanula americana

American Bellflower – a closer view

Campanula americana

Green-headed Coneflower  in the same stand of ragweed

Rudbeckia laciniata

East Center Valley with Cupplant

East Center Valley

Pat’s Prairie – on the other side of Center Valley

Pat's Prairie

Starflower Opening – a small south-facing opening that I’ve been gradually enlarging

Starflower Opening

Another small opening that I’ve been working on is Ragwort Opening.  One of the edges I cleared last winter has dozens of plants of Western Sunflower.

Helianthus occidentalis

It also has Whorled Milkweed

Asclepias verticillata

I found Rattlesnake Plantain blooming in the woods.  It’s an orchid – not a very showy one.

Goodyera pubescens

But the flowers do look like orchid flowers if you look closely

Goodyera pubescens

And it has lovely patterns on the leaves.

Goodyera pubescens

White Gentian is blooming in all the planted prairies now.

Gentiana alba

Partridge Pea is blooming in Triangle Prairie, next to the house.  There are so many bumble bees feasting on the flowers that in the mornings there’s a constant buzzing sound coming from the prairie.

Chamaecrista fasciculata

I’ve tried shining my light onto the deck to watch for moths this week, but the bats have discovered that it’s an easy food source.  They come swooping by the railing, and I can actually see them catch the moths, they come so close.  I sacrificed a few moths because it was interesting to watch, but then I felt bad and turned off the light.