Tuesday, December 25, 2018

Merry Christmas, 2018!

Merry Christmas 2018, and Happy Holidays!


Special greetings from the Happy-face Dragonfly:


To help us all get in the Christmas spirit, here's a physics problem from Walker Physics involving Santa:


The situation can be visualized as follows:


And now for the calculation:


Here's a bit of insight into the results:


Ah, nothing like a physics calculation to add to the enjoyment of a day.

Merry Christmas!

Wednesday, December 12, 2018

Species Spotlight: Fiery-eyed Dancer

Here's a species of damselfly I don't see very often; the Fiery-eyed Dancer. I've seen it at Lake Patagonia in southern Arizona, near the Mexican border, and at the Hassayampa River, near Wickenburg, Arizona.

For a long time those were the only places I encountered this species—and then, unexpectedly, I found one in late May at the Boyce Thompson Arboretum. It may be more common there later in the year, but we're back in the Pacific Northwest then.

In any case, here it is:



Here's a bit closer look:



The bright red on the eyes makes the origin of the name quite obvious, and the identification very easy. In addition, it's clear this is a dancer by the way it holds its wings well above the abdomen.

I hope I get more opportunities to see this striking damselfly.

Monday, December 3, 2018

Late, Late Season Dragonflies

After the last post about late season dragonflies, I wasn't sure if there would be any additional dragonflies to report on this year—especially since the weather turned gray and wet for several days after our last visit. I thought that might signal the end of the dragonfly season once and for all. Well, it turns out they're still flying.

We went up to Little Cranberry Lake yesterday at noon. Nothing. It was overcast and 44 ˚F. We went back home and had lunch. Then around 1 pm the clouds cleared and the sun came out. We returned to the lake and immediately saw an Autumn Meadowhawk sitting on the bench by the dam. It flew around some, and perched in various places. It seems that we only saw one individual, but one is a lot more than zero. I hadn't brought my camera with me, so I don't have a picture of that one. I thought I might have missed my opportunity for a last photo of a dragonfly this year.

This morning we awoke to a heavy frost outside that looked like snow covering the ground. We thought maybe that was it, for sure. Even so, we went back up to the lake at noon. It was sunny and calm, but only 40 ˚F.

At first, we saw no activity. Then I thought I saw one zip by behind me, but I couldn't be sure. Then, a few minutes later, I saw one perched on the dam. I brought the camera with me this time, so I took some pictures. Here's the male Autumn Meadowhawk we saw today:



This one flew around to various different perches, then Betsy saw another one, and I saw yet another one after that, so there were at least a few flying on this sunny, cold day. The Autumn Meadowhawk is a hardy soul!