Wetland Dragons
by Javier Gonzalez
One of the things I personally look forward
to seeing as I walk the boardwalk in
the hot summer months are dragonflies.
Their colors and their flight movements
are mesmerizing as they swoop around
the wetlands, and to see one skim over
the water and perch perfectly balanced
at the end of a bare stick just gives me a
great sense of peace for some reason.
Dragonflies are beneficial insects and
indicator species that are symbolic of
wetlands. They are extraordinarily designed
and are able to fly in all directions
and even hover in mid-air as they are
capable of controlling each wing independently.
They also have big compound
eyes that let them see almost 360 degrees
around them, powerful spiny legs that enclose
their prey, and strong jaws to chew
through exoskeletons and other tough
food! These are just a couple of the amazing
morphological traits that have made
dragonflies extremely efficient and successful
hunters on this earth for the past
three million years!
When we see dragonflies around the
wetlands here at the South Padre Island
Birding & Nature Center, we take it
as a sign that our habitat and water are
healthy. Dragonflies are indicators of
clean water; they cannot tolerate polluted
waters, so dragonflies are reliant on healthy wetlands for survival
and reproduction.
Before we see the colorful
adults flying around, the larvae,
called “nymphs,” are swimming
underwater, preying like tiny
dragons on mosquito larvae, other
aquatic
invertebrates, and
even small fish and tadpoles!
Most of a dragonfly’s life is
spent in water as nymphs.
Unlike a butterfly that has a
4-stage lifecycle, dragonflies
only have a 3-stage lifecycle,
or an incomplete metamorphosis.
Once they have eaten and grown enough, the nymphs crawl out of
the water on emergent vegetation. This is
where the last event in their metamorphosis
takes place. They skip the pupa stage
and go right from larvae to adult. Once
the nymphs are out of the water, their
exoskeleton cracks open from the back
and the dragonfly emerges and unfolds
as an adult. This usually happens in the
early morning hours just before dawn. At
this point the adult dragonfly is vulnerable
to predators as it sits and waits for
its wings and body to straighten up and
harden so it may fly. Once they can fly
they are formidable predators that are
harmless to humans and extremely beneficial!
Dragonflies can eat 30-100 mosquitoes
in a day, greatly reducing the population
of these pesky and annoying insects that
are potential vectors for different types of
illnesses. Here at the birding center we’ve
recorded more than 17 species! Most of
the species we see here are “skimmer”
types that come in a variety of bright
colors and have some have really cool
names like Eastern Pondhawk, Thornbush
Dasher, and Variegated Meadowhawk!
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| Seaside Dragonlet Dragonfly |
Since most dragonfly species can’t
reproduce in water that’s highly saline,
most of the dragonflies we see along the
boardwalk are in greater numbers along
our freshwater wetlands, but we do have
one species which is special to our area
and environment that we see quite frequently
along the boardwalk which goes
through our saltmarsh. The beautiful Seaside
Dragonlet is the only North American
dragonfly capable of reproducing in
saltwater and one that you don’t see far
inland away from the coast. This is a
small dragonfly species and the males are
a dark navy blue while the females are
orange with black stripes. They are beautiful
and a delight to see as they perch on
the mangrove pneumatophore roots.
Late summer is the peak time for dragonflies
and every week it seems like we
are seeing new species and greater numbers!
Come August they will be swarming
around our wetlands! It is an incredible
sight to behold!
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