SELMA — Like Zorro making his mark, Jim Johnson whipped his long-handled white butterfly net through the air, seemingly at nothing.
"I think I got it," he said, reaching his hand into the net, and coming out with something small and delicate between his fingers. "Yep, it's an eight-spotted skimmer. See the black markings on the wings?"
The eight-spotted skimmer is a type of dragonfly and Johnson is something of a dragonfly expert. He's been studying them — and their cousins the damselfly — for more than 20 years.
Johnson, who lives in Vancouver, Wash., recently brought his expertise to Southern Oregon to teach a pair of classes at the Siskiyou Field Institute.
The beginner class started with a morning classroom session introducing the 19 students to the basics of dragonflies and damselflies. The afternoon was spent at Lake Selmac trying to catch and identify the critters.
"This is a Pacific clubtail," Johnson told the group, holding a dragonfly with its wings pinched between his fingers. "See the yellow spots on its abdomen? And the space between the eyes?"
Dragonflies and damselflies are aquatic insects of the order Odonata and are commonly referred to collectively as odonates.
They are denizens of rivers, streams, lakes, ponds, marshes and other freshwater areas.
The adults are creatures of the sun, they like warmth, and are usually most active in the middle part of the day.
"My wife accuses me of liking odonates because they like to sleep in, too," Johnson said.
Both dragonflies and damselflies have compound eyes, with up to 30,000 "lenses" that cover the top, back, front and sides of the eye, giving them a basically panoramic view.
"They have huge eyes relative to the size of their head," Johnson said. "They are very visual creatures. They find their food visually, they find their mates visually."
Though they appear similar, dragonflies and damselflies have some distinct differences.
Dragonflies are generally larger and more robust; damselflies have smaller, thinner, more delicate bodies.
They both have two pairs of wings, but on dragonflies the forewing and hindwing are different shapes and sizes; damselfly wings are narrow and virtually identical in shape.
Dragonflies are rapid, agile fliers and can even fly backward (as can hummingbirds). Damselflies are slower.
The easiest way to tell the difference, however, is when they are at rest. Dragonflies perch with their wings flat out to the sides; damselflies perch with their wings folded over their back.
Worldwide, Johnson said, there are more than 2,000 species of both dragonflies and damselflies. The Rogue Valley is home to 47 species of dragonflies and 21 species of damselflies.
The afternoon visit to Lake Selmac "netted" 16 different dragonfly species, including a young migratory variegated meadowhawk, a green-faced western pondhawk and a white-faced blue dasher, a pair of bluets flying in tandem, an elusive common whitetail that couldn't be caught, and a cardinal meadowhawk laying her eggs in the water.
Norm Burnett, an odonate enthusiast from Jackson County, spotted a widow skimmer at the end of the dyke.
Sandra Hunt-Von Arb, a wildlife biologist from California, pointed out a young female autumn meadowhawk perched on a cattail.
"A lot of you might think you never see dragonflies," she said. "But after this class, you'll see them everywhere."
Several key characteristics will help with identifying odonates: colors and patterns on face, thorax and abdomen, the size and color of the eyes, the habitat they're found in (lake, stream, pond, marsh, stagnant or moving water), the time of year or season (some species emerge earlier than others), and behavioral differences such as where they perch.
The best way to learn to identify dragonflies and damselflies is to catch them, Johnson said, noting that their seemingly delicate frames are actually quite durable.
"Netting rarely damages them," he said. "You're more likely to hit one with your car than to damage one by netting it."
Reach reporter Kathleen Alaks at 541-474-3815 or firstname.lastname@example.org.