Saturday, May 19, 2012

Western Pondhawk: The Dragonfly With The Groucho Marx Moustache

Yesterday, Betsy and I visited Wild Horse Pass, a very nice birding and dragonflying area.  Here's what it looks like as you enter the area.



Notice the running water in the background on the right.  The whole Wild Horse Pass area consists of a stream with water sometimes running over rapids, and sometimes running so slow as to look stationary.

One of the most common dragonflies in the area yesterday were the Western Pondhawks, a beautiful blue dragonfly that looks a lot like a Blue Dasher.  Probably the most prominent difference is that the Western Pondhawk has a green face and the Blue Dasher has a white face.  Here's a look at a male Western Pondhawk.


Notice the dark blue eyes, and the green face.  When you get a better look at the face, you'll see that the Western Pondhawk has a nice black moustache.  Here it is:


Perhaps I shouldn't mention it, but the female – who is all green – also has a moustache.

Shortly before we left we noticed a Western Pondhawk eating a damselfly, probably a Familiar Bluet.  It was enjoying an obviously juicy meal.

Thursday, May 17, 2012

The Blue Dashers Are Back

Dragonfly season is in full swing now here in Arizona.  Betsy and I went to the Gilbert Water Ranch a few days ago, and dragonflies were everywhere.  One of the most common dragonflies there were the Blue Dashers, which are also one of the most photogenic of dragonflies.  Here are a couple pictures from our visit to the Water Ranch.




Not only are these dragonflies great for photography, they are also incredibly widespread.  We've seen them everywhere we've gone dragonflying, including Washington, Oregon, California, Arizona, Texas, and Florida.

Sunday, May 6, 2012

Forktail Interaction

Western Forktails differ from many other damselflies in an interesting way.

If you go to a nice pond in the summer in Washington state, you are quite likely to see female Western Forktails.  They are pruinose blue overall, and quite easy to spot as they move along the shore laying eggs in one location and then another.  You don't see male Western Forktails, however.  It can be quite tough to spot a male.  What's going on?

Apparently, most female Western Forktails mate just once in their lives; after that they fend off other males who attempt to mate with them. A good example is shown in the slow-motion video below.  The video starts with a female Western Forktail minding her own business.  Suddenly a male races in to grab her and attempt to mate – not really much in the way or courtship, I'd say.  The female resists, and eventually the male moves on.  After getting this kind of treatment from the females, the males apparently move off into the bushes to forage and thus are not encountered very often.

video

According to Dennis Paulson in Dragonflies and Damselflies of the West, female Western Forktails are "very effective at repelling attention of male forktails and bluets by fluttering wings and curling abdomen tip down."  Here's a good example of that.

The Unexpected Pleasures Of Dragonflying: Encountering A Water Scorpion

Several days ago Betsy and I were visiting the Boyce Thompson Arboretum.  As we sat on the shore of Ayer Lake, a fairly large insect suddenly flew in and splashed down in the water in front of us.  I looked to see what was going on, and saw a water scorpion folding its wings and submerging itself into the waters of the lake.  Here are a few pictures I took of this interesting beast:





The water scorpion is in the order Hemiptera – thus it's one of the true "bugs" of the insect world.  It is called a water scorpion, but this guy is in the genus Ranatra – whose species are long and slender.  To me it looks more like a "water stick insect" or a "water praying mantis."  On the other hand, species in the genus Nepa are broad, and look a bit more like a scorpion.  The reason species in either genus are called "scorpions" is because of their long thin "tail," which is really a breathing tube and does not carry a stinger.  Thus, their common name is truly a misnomer.

Water scorpions generally eat invertebrates, but may occasionally take a small fish or tadpole.  I hope they're not eating the endangered pupfish in Ayer Lake.

They are supposedly docile when handled carefully – though I didn't put that to the test.  They are also noted for delivering a very painful bite.  Fortunately, I didn't put that to the test, either.

Tuesday, May 1, 2012

The Whisperer Speaks

I'll be giving a talk this weekend at the Boyce Thompson Arboretum.  Here's an ad for the talk:


Our good friend Paul Wolterbeek at the Arboretum also placed ads in local newspapers, like the following:


It will be interesting to see how many attend.  Updates to come.

Update:  The talk was very enjoyable.  What a nice crowd.  I think we all had a good time – I know Betsy and I did.  Thanks for attending!