Watching Dragonflies: Eastern Pondhawks

Eastern Pondhawks (Erythemis simplicicollis) are dragonflies that perch when they hunt, usually on low foliage or on the ground.

Female Eastern Pondhawk, perching

Female Eastern Pondhawk, perching

Dragonflies are carnivores. They eat other insects ranging in size from tiny mosquitoes to dragonflies their own size, or for some dragonfly species, even larger.  Dragonflies lay their eggs in or near ponds, streams and lakes.  After the eggs hatch, their larvae develop in the water body, where they eat other aquatic insects, including mosquito larvae. They may even eat tadpoles.

Female Eastern Pondhawk, perching

Female Eastern Pondhawk, perching

Dragonflies have exceptional vision, the best of all insect species. Their large eyes are compound, consisting of thousands of simple eyes, and providing them almost a 360-degree field of vision.  This remarkable ability makes it easy for a dragonfly to spot its next meal, an insect on the wing.  When a dragonfly identifies a likely victim,

Female Eastern Pondhawk, "Whoa, I see a moth! Lunch!"

Female Eastern Pondhawk, “Whoa, I see a moth! Lunch!”

it is able to instantaneously calculate the speed and trajectory of its target’s flight, and determine the necessary speed and path for the dragonfly’s own flight, a calculation that will enable the dragonfly to expeditiously intercept its hapless quarry.  The world’s military forces have spent billions trying to replicate this capability!

Female Eastern Pondhawk, with moth. "Delicious!"

Female Eastern Pondhawk, with moth. “Delicious!”

Dragonflies themselves are prey for other animals, including spiders, tiger beetles, frogs, even fish, and birds such as flycatchers. A dragonfly’s broad range of vision can help alert it to the presence of a predator.  Its only blind spots are below its body and directly behind its head.  Hunting from ground level as Eastern Pondhawks do compensates for one of those blind spots.

A perch on a water lily leaf may leave a dragonfly vulnerable to aquatic predators like frogs or fish.

Male Eastern Pondhawk, perching

Male Eastern Pondhawk, perching

But a rock or other ground surface is usually pretty safe from predators from below.

Male Eastern Pondhawk, perching

Male Eastern Pondhawk, perching

Any of these perches offer a suitable takeoff surface for an Eastern Pondhawk to launch into flight and snag its next meal.

Male Eastern Pondhawk with insect. "Yum! This little critter didn't have a chance."

Male Eastern Pondhawk with insect. “Yum! This little critter didn’t have a chance.”

Look for Eastern Pondhawks in the neighborhood of any vegetated wetland.

Resources

Paulson, Dennis. Dragonflies and Damselflies of the East.  2011.

 

 

4 thoughts on “Watching Dragonflies: Eastern Pondhawks

  1. Dear Mary Anne, I will be on the lookout for these creatures. Thank you for opening my eyes to them. I thoroughly enjoy your photos. Gratefully, Patricia Merkel

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