For those of you who have been watching Ranger Russ at Meigs Point Nature Center he has his “Favorite Animals Day”…well I get it. Every time I start to think about, or research, a certain animal I find their adaptations so amazing that they become my favorite! Today is no different.
I have always loved dragonflies. When I was small people would tell me don’t let them land on your fingers because they could sew them together. That must have been the green “darner”. This is definitely not true…I had one land on me on the ferry from Bridgeport to Port Jefferson, it stayed on my finger the entire ride over and then flew off! No sewing occurred!!!
For my dinosaur lovers did you know that dragonflies are some of the most ancient insects in the world. Long before dinosaurs even appeared on Earth, giant dragonflies with 2 1/2 feet wingspans soared over the swamps. (Today the dragonfly with the largest wingspan in North America is 4 3/4 inches and in South America 7 1/2 inches.) Dragonflies have been around for 300 million years!! (Some scientists think during the Paleozoic era high oxygen levels allowed dragonflies to grow to monster sizes.)
Dragonflies and damselflies are both considered dragonflies, but they have certain differences that set them apart from one another. Damselflies are smaller and more slender, the eyes are more widely separated, and most damselflies when they are sitting at rest fold their wings over their backs (like a damsels cone shaped hat). The dragonflies are generally larger and stockier, they have enormous eyes which are close together and when at rest their wings are outstretched like an airplane. (Put your arms over your back like a damselfly and then outstretched like a dragonfly.)
Like other insects the dragonflies go through metamorphosis. Egg to larva (nymph) then it molts (sheds it’s exoskeleton) many times before it becomes an adult.
As a nymph it has a lower jaw (labium) that fits like a mask over the face and it springs out t o capture its prey. The dragonfly spends most of its life in water as a nymph, from months to 3-5 years. Some dragonfly nymphs can grow to 3″ and in addition to eating mosquitoes, other insect larvae and even each other they can catch and eat tadpoles and fish.
When ready the nymph climbs out of the water and attaches onto a plant stem or something similar, the back splits open and the adult pulls free. The dragonfly pumps its body full of air, sends fluids into the veins in the wings and expands into the adult form. At first it is pale and soft, definitely a more dangerous time. Predators – spiders, other insects, fish, frogs and turtles might make a meal of it before it hardens up and flies away. That can take a day or two!!
Now this “flying jewel” is ready to begin acrobatics in the sky!
They are expert flyers and can hover like a helicopter. If they can’t fly they starve because they only eat prey they catch while flying. As adults they catch the prey with their feet.
The males are often “territorial” and will defend their space from other kinds of dragonflies, but especially other males. A female might come into their territory and that is ok. After they mate, she will deposit her eggs into stems of plants; they can be laid directly on the surface of leaves or you might see her depositing eggs directly on the water. And the cycle begins again!!
Dragonflies help to control the mosquito population. A single dragonfly can eat 30 to hundreds of mosquitoes per day.
Like the monarch butterfly some dragonflies migrate. One green darner in New Jersey was found to migrate 7.5 miles/day. A dragonfly called the globe skimmer has the longest migration of any insect – 11,000 miles back and forth across the Indian Ocean. How do we know? There is a group of scientists who track them by attaching tiny transmitters to wings with a combination of eyelash adhesive and superglue.
Now aren’t dragonflies your favorite animals?
Resources:
Dragonflies and Damselflies of Cape Cod by Virginia Carpenter
Dragonflies through Binoculars by Sidney W. Dunkle
A Guide to Northeastern Dragonflies and Damselflies by Mass Audubon
A Field Guide to the Dragonflies and Damselflies of MA by B. Nikula, J. Loose, M. Burne; The
The Pond by Thompson, Coldrey, Bernard
Smithsonian Magazine, S. Zielinski, 14 Fun Facts about Dragonflies