Emergence of Life in a Wetland

After many years of wanting to, we finally installed some solar-powered pumps and livestock water tanks in our family prairie.  (Thanks to the U.S. Fish and Wildlife Service and Nebraska Game and Parks for providing cost-share money!)  Those two water tanks give the cattle nice cool clean water to drink and allow us more flexibility in the way we design our grazing each year.  Most importantly, they allow us to exclude the pond/wetland from grazing so it can start to function as a wetland rather than as a big mud hole for cattle to stand around in.

Because we’ve had good rains this year, the wetland has been pretty full.  That’s nice, but it has also prevented much of the wetland-edge seed I planted from germinating and growing.  Despite that, the recovery of the wetland is well underway.  There is now grass growing right to the water’s edge and arrowhead and other emergent plants are starting to appear in shallow water.  I’ve been spraying the few reed canarygrass plants growing nearby in the hope of preventing that invasive species from taking over the margins of the wetland, and hopefully I can get some more diverse wetland plants to establish there instead.

The pond/wetland at the Helzer family prairie with abundant arrowhead (Sagittaria sp.) in the shallows.

The pond/wetland at the Helzer family prairie with abundant arrowhead (Sagittaria sp.) in the shallows.

My daughter and I went for a walk at the prairie over the weekend and visited the wetland to see what was happening.  As I waded into the shallow water to take the above photo, leopard frogs scattered from my footsteps and red-winged blackbirds scolded me for encroaching upon their territories – very good signs of recovery.  However, looking more closely at the arrowhead plants poking through the water, I found even more evidence of new life.

Abandoned exoskeletons of damselfly nymphs were littered around the wetland.

Abandoned exoskeletons of damselfly nymphs were littered around the wetland.

Adult damselflies fluttered around everywhere, and many of them had apparently just appeared on the scene because the larval exoskeletons they’d just emerged from were stuck to leaves and stems all over the place.

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While I was too late to see the actual emergence of the damselflies, I did manage to find a green darner dragonfly that had just popped out of its larval skeleton and was fluttering its wings and waiting for its body to dry and harden.  I snapped a few pictures of it in place and then carried it over to Anna so she could get a good look at it.

A green darner dragonfly and the larval exoskeleton it had only recently escaped from.

A green darner dragonfly and the larval exoskeleton it had only recently escaped from.

Anna enjoyed getting a close-up view of the dragonfly and even posed for a photo with it.

Anna enjoyed getting a close-up view of the dragonfly and even posed for a photo with it.

After we became a little better acquainted with the new dragonfly, we set it safely on a fence post so it could finish hardening up in the warm sun.  I took a few more quick photos of it on the post and then left it alone.  It was gratifying to see other dragonfly species zipping around nearby too – I’m hoping that’s a sign that a number of other aquatic invertebrates are also colonizing our recovering wetland.  It should be fun to watch the changes in the coming years.

Our new friend on the top of a fence post.

Our new friend on the top of a fence post.

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Frozen Bugs (and Beetles)

My family and I spent some time exploring the frozen pond/wetland at our prairie during the holiday break.  We even got a couple days of great ice skating weather.

My three kids had a great time ice skating on the pond over the holidays.

My kids had a great time ice skating on the pond over the holidays.

While we were on the ice, we found some great patterns (see earlier post), but we also found quite a few frozen insects.  In particular, there seemed to be two species of insects – one bug and one beetle – encased in ice.  The bug was a species of Corixidae, or water boatman.  Its name comes from the fact that two of its legs are extra long and sport hairs that make the legs look and function like the oars on a boat.  Water boatmen suck the juices from algae and plants through their long straw-like beak and are common inhabitants of just about any freshwater body around here.  They are also frequently seen in the ice when those water bodies freeze up in the winter.  Apparently, water boatmen can survive freezing and just start swimming again when the ice thaws.  A pretty neat trick for an aquatic bug that lives in a temperate climate.

A frozen water boatman

A frozen water boatman

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Another one

Another one

We had a two day period over the holidays during which the temperature briefly climbed up to about 60 degrees (Fahrenheit).  The warmth didn’t last long enough to spell an end to our ice skating, but did melt some of ice along the edges of the pond.  Apparently, the warm temperatures also encouraged a number of individuals of one particular beetle species to go exploring.  Unfortunately, it appears quite a few of those beetles wandered out onto the ice and didn’t make it back.  We didn’t see any of them on the ice before the warm spell, but found lots of them afterward.

Here's one of the beetles that froze after (apparently) getting caught out on the ice after a warm day.  I'm hoping one of my entomologically-inclined friends can help me out with identification and/or natural history info?

Here’s one of the beetles that froze after (apparently) getting caught out on the ice after a warm day. I’m hoping one of my entomologically-inclined friends can help me out with identification and/or natural history info?

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This beetle apparently got flipped over before freezing.

This beetle apparently got flipped over before freezing.

I was curious to know whether those frozen beetles could do the same thaw-out-and-re-energize trick as the water boatmen, so I broke off a chunk of ice containing a frozen beetle and brought it home to thaw it.  The beetle has been thawed out for more than a week now, and hasn’t moved, so I’m pretty sure it’s dead…  The next question is: where were those beetles staying during the very cold weather earlier this winter, and how did they prevent themselves from freezing to death then?

Always more questions…

For more information on how water boatmen and other creatures weather the winter, see this earlier post from 2011.