Friday, July 1, 2011

Dragonflies in the news

Dragonflies are being noticed by everyone right now - and for good reason. Around this time each year, individuals that have emerged from ponds in the warmer States to the south, push north to find new feeding grounds and new places to rear the next generation. This is a good strategy which is easy to work out; as temperatures soar in the south, ponds start to dry out and adult dragonflies find they have nowhere to lay eggs. The reduction in available water also affects the amount of prey available to the dragonflies. The solution? Head north, where surface water is more plentiful and the season's mosquito crop has yet to peak!

In the interest of research (!) I just popped outside the door at the Northwood Center to see just what is flying right now over Lily Lake and it really is awesome out there! In less than five minutes, I picked out:

Familiar Bluet
Comet Darner
Swamp Darner
Widow Skimmer
Painted Skimmer
Needham's Skimmer
Great Blue Skimmer
Eastern Amberwing
Blue Dasher
Eastern Pondhawk
Spot-winged Glider
Carolina Saddlebags
Black Saddlebags
Four-spotted Pennant
Halloween Pennant

Quite a sight, and I reckon if I walked round the lake and looked harder, there's easily another five or more species to be added. At the point itself, Swamp Darners, Spot-winged Gliders and both Carolina and Black Saddlebags are making up the bulk of the arriving immigrants - and also becoming part of the food chain themselves. For there is something else that demonstrates as good a sense of timing as the movement of dragonflies in response to drying out ponds - the hatching and growth of Purple Martin chicks. Certainly around here, where dragonflies are plentiful, the arrival of Purple Martin chicks and all those extra mouths to feed happens right as the northbound movement of dragonflies starts, providing the birds with a plentiful food supply.

One observation that was recently sent me came from Pat Perkins who spotted something she had read about but never seen before - dragonflies laying eggs on car hoods! This may sound a weird thing but is explained by the fact that dragonflies (along with many other animals) sometimes mistake shiny metal surfaces for water.

These dragonfly eggs were inadvertently laid on a car hood in Cape May Point State Park [photo by Pat Perkins].

Dragonflies are attracting a wider and wider audience; they are colorful, easily-observed and lead interesting lives, making them ideal subjects for closer study or just for sheer enjoyment. If you want to know more, consider joining our dragonfly workshop on July 14th - it's going to be a great day out! Check out the details here or call us for more information. (Pre-registration is required).

To get you all fired up, here's just a few of the many species we can hope to see around Cape May County in July:

Variable Dancer - common in wetlands throughout the county.

Four-spotted Pennant - rare in New Jersey and largely confined to a few locations around Cape May Point.

Widow Skimmer - a real eyecatcher!

Bar-winged Skimmer - localized but fairly widespread.

Twelve-spotted Skimmer - the harlequin of the dragonfly world!

Halloween Pennant - common throughout Cape May County.

Needham's Skimmer - a real dazzler in many of our wetlands.

Calico Pennant - commonly found in grassy meadows away from water.

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