Photo of the Week – September 26, 2013

If found this dragonfly encased in dew a couple weeks ago as I walked through a small prairie here in Aurora.  I’m sure someone reading this will be able to tell me what species it is – I don’t know my dragonflies very well.

Dew-covered dragonfly on pitcher sage.  Lincoln Creek Prairie - Aurora, Nebraska.  September 13, 2013

Dew-covered dragonfly on pitcher sage. Lincoln Creek Prairie – Aurora, Nebraska. September 13, 2013

There were a couple of these in the prairie that morning, but we’ve also been seeing some bigger groups (flocks?  herds? swarms?) of other dragonfly species coming through Nebraska lately on their annual migrations.  Many more insect species migrate than you might expect, including (at least) moths, butterflies, and dragonflies.  I expect we’ll learn a tremendous amount about these phenomena during the next decade as efforts to study those migrations continue to ramp up.  Technology, including tiny radio transmitters, will help, as will volunteer citizen science efforts to gather sightings from across large areas.  It will be exciting to learn more about what seems an improbable but very interesting behavior from insects we don’t give nearly enough credit to.

You can learn more about insect migration from an earlier post I wrote on moths last year, as well as another post on intercontinental insect migrations.

Finally, if you are interested in nature photography or prairie ecology and are within driving distance of Lincoln, you might enjoy the lecture I’m giving tomorrow night for the Nebraska Statewide Arboretum.  More information on the event and ticket information is available here.

Isn’t it a little late to be nesting?

As you might remember, my Photo of the Week last week was an image of a fledgling meadowlark I’d found in mid-September.  At the time, I’d talked about how surprised I was to see such a young bird so late in the season.  Well, last Friday, Eliza Perry, one of our Hubbard Fellows, called me to say she’d just found a nest full of tiny birds – did I want to come take a look?  Of course I did.

American goldfinch chicks sit in a nest about three feet off the ground in a tall thistle (Cirsium altissimum) plant.  Platte River Prairies, Nebraska.

American goldfinch chicks sit in a nest about three feet off the ground in a tall thistle (Cirsium altissimum) plant. Platte River Prairies, Nebraska.

I’m pretty sure what Eliza found was an American goldfinch nest.  The bills and markings on the birds look right, and we spotted an adult goldfinch nearby.  However, the best supporting evidence was that the nest was located in a thistle plant (a native thistle species, by the way) and had thistle down in the nest cup.  There is a strong tie between American goldfinches and thistles.  Unlike most other bird species which feed their young on insects, goldfinches instead feed them regurgitated seeds – especially those of thistle plants.  In fact, they often delay their nesting until those thistle seeds have ripened.  Here is a link to photographer/naturalist Stan Tekiela’s post on this topic, if you’re interested in learning more about the topic.

These birds are even further behind the meadowlark in their development, and it’s already getting pretty cold overnight, so the nestlings’ chances for survival might seem slim.  Of course, the difference between the meadowlark and the goldfinches is that the goldfinches have adults around to help them.  Both have a challenging fall and winter ahead of them, but nothing others of their species haven’t dealt with countless times before, I guess.

A better view of the nest placement within the tall thistle plant.

A better view of the nest placement within the tall thistle plant.

Thanks to Anne Stine, our other Hubbard Fellow, who graciously helped hold equipment for me as we photographed the nest.  Because of the very bright early afternoon sun, I had Anne hold a diffuser near the nest to reduce the harshness of the sunlight while I held a small flash unit to better illuminate the birds.  We worked quickly and got out of the way so the parents could resume their feeding duties.