Pollinator Study

Monday, September 21, 2009

Autumn Meadowhawks

Yesterday was the last day of summer. This string of endless sunny days has been a phenomenal opportunity to go out and watch animals that love the sun. For us, right now, that means dragonflies.

So my friend Jay and I went out to McLane Creek beaver pond once again. We decided to go out a little earlier this time; females and males use the pond differently at different times of day, and we wanted to see if we could observe these shifts in the daily use of the beaver pond.

When we got to McLane around 1:00 pm, it was about 60 degrees, and the sun was shining fully on the pond. It was very quiet, dragonfly-wise. We watched a few drab-colored female dragonflies whisking around the surface of the pond, occasionally dipping their abdomens into the water, most likely dropping off eggs. From my reading, female dragonflies tend to avoid the ponds (and the herds of sexually eager males), so those that are ready to lay eggs (oviposition) show up early and later in the day, when the males are less likely to be around.

As the afternoon warmed up, we started to see Shadow Darners (see previous blog) and Jay made a skilled swing with her net and caught one. Here is a photo of her gently extracting him from the green net bag, holding two wings on one side to prevent his escape. We took a few quick pictures, then let him go on his way, watching as he seemed to shake off the indignity of capture, then return to his previous circuit of the pond.

Around 2:00 pm we were surprised when several tandem pairs of red Autumn Meadowhawk dragonflies started to appear. In reading Dennis Paulson's book on Dragonflies of the West, it appears that when some Meadowhawks are ready to mate, they "hook up" with their partners near their night roost sites in the woods, then fly in tandem to the ponds, where the male flies the female low over the water, where she then curves her abdomen down and deposits her eggs.

The male has a special pair of claspers at the end of his abdomen, which are readily seen in this photo. When he makes hopeful ventures to a possible perched female, he is said to flutter and do a kind of courtship dance. If she is duly impressed, she cooperates, by allowing him to hook his claspers on her prothorax, a kind of narrow neck area behind her eyes ( it gives a whole new meaning to the phrase "hooked up"). This is called the tandem position.

If she is willing to mate, she then curves her abdomen up and touches the tip to the second segment of his abdomen, which is the genital bump. He then transfers sperm to her to fertilize her eggs. This is called the wheel position. They may then return to the tandem position, where he flies her to the pond to lay eggs, ensuring that HIS sperm are the ones that fertilize her eggs.

We saw many pairs in tandem, and watched a few hovering over the pond, no doubt laying eggs. It was amazing to see. Even though we were not able to net many dragonflies that day, we saw a lot of interesting dragonfly behavior that was new to us. For nature watchers, this is nirvana.

As the afternoon wore on, we saw more male Autumn Meadowhawks, by themselves. There was a lot of basking going on (perhaps post-coital). They were sunning themselves on the railing of the dock, on nearby cattails, even on my knee, briefly. September is late for dragonflies to be out and mating. I have read that the Meadowhawks who flourish in northern climes do so in part by spending a lot of time basking in the available sun. We certainly saw signs of that on this field trip.

By 3:30, activity was slowing down a great deal, and it was time for us to head home. That night my sleep was deep, drugged as I was with hours of sun and fresh air. Through my dreams, red dragonflies danced and wheeled in the last sunny hours of summer.

Janet

Thursday, September 17, 2009

A Passion for Dragonflies

One of the best things about being a nature watcher is that there is so much to see and so much to learn, that it would take a lifetime to learn all the things out in nature. This could be considered discouraging, but in fact, it means that there are always new things to focus on. Which I love.

A few weeks ago, Glen and I signed up for the Northwest Naturalists' weekend workshop at North Cascades Institute, on Diablo lake in the North Cascades. This is a yearly event; for this year they brought in two of my favorite expert naturalists: Bob Pyle (butterflies) and Dennis Paulson (dragonflies). We followed Dennis around on an all day field trip to Lake Campbell and Pipestone canyon in the Okanogan, to explore dragonflies. These were pretty new to us. We were astounded by the variety, the colors, the behaviors. We decided that when we got home, we would seriously pursue dragonflies. Which we have been doing.

I say "we" loosely. Since I am in recovery from hip surgery, my contribution is to strain my brain for good places to go to watch these amazing animals. Glen is the chauffeur, the tracker, the stalker, and ultimately the catcher (and yes, these insects are HARD to catch). We have also had our friend J come along; she has studied these animals for some time, and is a dab hand at catching them.

So we have been to various areas on the Black river, to Scatter Creek and to McLane creek. Here are some photos of some of our first successful catches (we catch them for a few minutes, take a photo and then release them). We then go home with our pictures and I spend several days pouring over books and photos, to identify them. It's been a lot of fun.

Enjoy!

This is a male Paddle-tailed Darner Aeshna palmata. Dennis caught it at Lake Campbell on August 14th. Look at that striking green face and the HUGE blue-black eyes. Darners are the biggest and most visible dragonfly species, and my personal favorites.







This next one is a Blue-eyed Darner Rhionaeschna multicolor. Dennis also caught this one at Lake Campbell in August, but we recently saw this same dragonfly flying at McLane Creek beaver pond. This one is very easy to identify: of the ten species of darners in Thurston County, this is the only one with huge blue eyes and lots of blue splashed everywhere.






This next dragonfly is one of the group of the medium-sized red meadowhawks. It is called the White-faced Meadowhawk Sympetrum obtrusum. It was perched on some low vegetation along the Black River. J did a fabulous sneaky stalk on this dragonfly, dropping her net on it from behind. It has the bright red abdomen of all meadowhawks, and a distinctive pattern of black triangles edging that abdomen. And of course, a white face. Unmistakable.

Glen and I saw a lot of this species of dragonfly at McLane creek a few days ago. We were walking along a shaded path on the wooded edge of the beaver pond, when suddenly in front of him he saw and caught this dragonfly. It is a Shadow Darner Aeshna umbrosa. I struggled to identify this one, but with the help of Dennis Paulson's fabulous field guide to dragonflies, was finally able to figure it out. Shadow Darners tend to be quite dark, with limited blue splashes on the abdomen. They also prefer to hang out in shadowy edges of slow-moving streams, and this is exactly what we saw with this darner.

Finally, we did not catch this dragonfly, but we saw several big males flying over the pond at McLane Creek. This is the Common Green Darner Anax junius: the biggest dragonfly we have in our county, it has an unmistakable olive-green head and bright blue abdomen. We watched a few of these patrolling the pond, no doubt looking for females ready to mate.








Janet

Resources:
Dragonflies and Damselflies of the West by Dennis Paulson
Dragonflies through Binoculars by Sidney Dunkle
North Cascades Environmental Learning Center - wonderful nature classes on many topics

Friday, September 11, 2009

Alligator Lizards

Three weeks ago I had hip replacement surgery. It has required me to take it easy, to allow healing to take place, to limit my activities. And in general, in this time of beautiful Indian summer, it has been a real pain. And boring, too.

So when Glen stumbled upon this Northern Alligator lizard sunning herself on the back porch, I was wildly enthusiastic. Well, I probably would have been pretty enthused anyway: I love all the "herps" ( lizards, amphibians, frogs, snakes, turtles). Twenty years ago I was a volunteer zookeeper assistant at Point Defiance zoo, and worked in the building that housed these animals. I got to see and work with some amazing snakes, tortoises, geckos, etc. These are animals that truly are from another planet.

But my fondness for herps was planted even earlier. In 1955 my parents moved to the outskirts of Olympia, near what is now Olympia High School. From our place looking east, all you could see was abandoned cow pasture and a few cow-chewed Douglas firs. This was the playground for me, my six siblings and all the neighborhood kids.
We saw Pacific chorus frogs in our apple trees, and chased after garter snakes. Nearby Hazard lake had salamanders and bullfrogs. All in all, it was a wonderful haven for herps and children alike.

One time we caught a huge bullfrog roughly the size of a dinner plate. I took it into the house to show my mom, and was surprised to see my normally unflappable mother become unglued when the bullfrog jumped out of the shoebox onto my arm. My surprise turned to a calculated glee as I stalked closer to her, menacing her with the bullfrog, despite her freaked out attempts to assert parental authority and get me to back off. It remains one of my better memories.

Anyway, back to alligator lizards.

Lizards are cold-blooded animals, so they especially like heat and sun, both of which are generally in short supply in western Washington. What this means is that lizards are also in short supply here; only the Northern Alligator lizard is considered widespread and common. It likes damp Douglas fir and Hemlock forests with sunny edges, where it can sun itself, and also catch its insect prey. If you, like us, find a lizard in your back yard, chances are very very good that it is this lizard.

They are active in the day, but tend to be secretive, so it's not common to find them. As I talked with a couple of friends who had seen them, I was told that they like houses with high exposed foundations, especially if those foundations are sunny. These flat concrete surfaces act as a rock face against which the lizards can soak in sunshine, but also pick up the stored heat the in "rock". Since our house is built on a high foundation, this probably helps bring in lizards.

The other factor is Schneider creek. I have written about this creek and its proximity to our house in previous blogs. Schneider creek emerges into a deeply forested ravine about one block from our backyard. This may provide the wet woodlands that Alligator lizards like; I speculate that these lizards use the forest edges of Schneider ravine, and venture into connected sunny backyards.

This particular individual is a fat female. Females bear live young as late as early September, and it is possible she is pregnant. Or not; she has clearly had a prosperous summer, and laid down lots of fat stores, which will help sustain her as she goes into an underground den to hibernate in October, slowing her body metabolism down to get through the winter months. Come next March she will re-emerge from her den, eat voraciously and find a mate. And so the cycle begins again.

Janet


Resources:
• Washington Herp Atlas: www1.dnr.wa.gov/nhp/refdesk/herp/
• The Reptiles of British Columbi: www.bcreptiles.ca/lizards/alligator.htm
• Reptiles of Washington and Oregon; authors Storm, Leonard, et al
• Many thanks to Bill Leonard for answering my questions.