dragonfly evolution Archives - Following Deer Creek

Dragonflies have been around longer than dinosaurs. Except for size, they’ve changed little through time. They’ve gone from a wingspan about the size of an adult shin (between knee and ankle), to palm-sized (stretching between a fully extended thumb and pinky).

Evolutionary biologists believe that size reduction is connected with decreased oxygen levels in the atmosphere.

Dragonflies are fierce hunters, expert flyers, and the subject of artificial intelligence and robot developers.

Recent dragonfly brain studies can now explain the mechanisms behind the aerial acrobatics. Like the human brain, dragonflies have target-detecting neurons that track moving objects and predict where it will go.

Dragonfly Super Skills

Approximately 80% of the dragonfly brain devoted to the visual processing
Some species can see prey up to 30 feet away
Movement detection up to 60 feet away
Almost 360⁰ range of vision
Hunt capture rate in the high 90% range
Seizes prey with feet and eats while flying

Swarm Behavior Studies

Swarm behavior is still not fully understood, but puzzle pieces are falling into place as scientists amass data.

Biologists know there are static (food source) and migratory swarms. The two types may be related.

Generally, both swarm types follow these patterns;

They occur more in the midwestern states
Take place before a storm that follows a hot, dry spell
Happen between July – October with September being the peak
They follow coastlines and lakeshores
Dragonfly migrations appear to match bird migration patterns

Life Cycle – Up to 5 Years – Most of it Under Water

Mating – Mid to late summer.

Egg-laying – Females lay eggs in still waters on submerged aquatic plants or in shallow areas. In cooler zones, like Nevada County, dragonfly eggs wait until spring to hatch.

Nymph – Molts up to twelve times and can live for as many as four years in the water.

Nymph Diet

Nymphs are voracious eaters, happily dining on;

mosquito larvae
tadpoles
small fish
each other

All dragonflies must have clean, fresh water to live.

Adult – The final molt is completed above the water’s surface in late spring or early summer. They live only two to four months before dying.

Adult Dragonfly Diet

horseflies
mosquitoes
bees
wasps
termites
deerflies
blackflies
midges

Features for Dragonfly Friendly Water Gardens

Dragonflies breed in water. To encourage dragonflies and damselflies, include these features in your pond, trough, or marsh area;

water free of pesticides & fertilizers
protected from wind
well oxygenated
receives 5-6 hours of the midday sun
flat rocks near pond edges for sunbathing
shallow areas (but not so shallow it dries up)
aquatic vegetation, especially reeds and lilies
cover for final molting safety
tall above water plants for perching

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Cultural Symbolism

Websites devoted to dragonfly symbolism are diverse! The meaning that cultures apply to dragonflies seems to be as diverse as the people who observe them. Below are a few examples.

Change, Transformation & Adaptability – Worldwide
Swiftness, Activity & Purity – Native Americans
Good Luck, Harmony & Prosperity |Instability & Weakness – Chinese
Light & New Joy| Irresponsibility & Unreliability – Japanese
A dragonfly will lead you to fairies – Ireland & Europe
Horse possessed by the devil – Romania
Eye Pokers – Norway