Here Be Dragonflies

Written on ancient maps as warnings to mariners, Here be Dragons conjured up images of fire-breathing monsters lurking in unknown regions of the world ready to incinerate the unwary.

Here be Dragonflies is not a warning, but instead an invitation to head down to our local lakes and ponds to see these intricate and beautiful creatures that are just now taking to the air as the full heat of summer has arrived. Not scary, and not fire-breathing, dragonflies compete with butterflies as one of the top insect attractions in our parks and gardens.

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The eight-spotted skimmer is common, easy to see, and easy to identify. Photographed at Burnaby Lake, this one’s a male.

Living Fossils

Whenever I watch dragonflies, I’m always awed by the thought that these insects are the modern descendants of a fantastically ancient lineage. Fossil dragonflies, very similar to those we see today, were flying around almost 300 million years ago. That’s a staggeringly long time ago. As a comparison, the last Ice Age ended about 10, 000 years ago. Dragonflies have been around about 30, 000 times longer. Few animals living today have remained essentially unchanged for such a long stretch of geological time. When dragonflies were darting around the giant forests of the Carboniferous Period, mammals had not yet even appeared on earth. A very successful evolutionary “design” indeed.

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Eight-spotted skimmer female. Notice the different body colour, and lack of blue in the wings found in the male. Compare her black spots to the male’s, and you’ll notice they are the same size, shape and position on the wings.

Below is a second common Burnaby dragonfly – the blue dasher. What a great name! No doubt why it’s called blue, and it is pretty zippy in flight too. However, this dragonfly’s wings are not boldly marked like the eight-spotted. However, look at the rakish angle they are held in contrast to the more conventional stance of the eight-spottted.

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Blue dasher – male. Photographed at Deer Lake

Climate Change Connection

The blue dasher is found only in the most southerly areas of Canada; however it is a species that is likely responding to global warming. It has extended its range northward in recent years, and continues to do so. Not one of the dramatic signals that things are changing rapidly on the planet, but nonetheless, a signal from nature that they are.

Acute Vision

Dragonflies mostly feed on flying insects, sometimes even other, smaller dragonflies. To see, pursue, and capture their fast-moving prey they need fantastically sharp vision. The two large compound eyes which take up a large proportion of their head have evolved to capture even the slightest movement. Made up of up to 30, 000 individual simple eyes, the compound eyes of dragonflies not only give very fine detection of movement, but because in some species they form an almost spherical array around the head, they give a field of view approaching 360 degrees. Click the image of the blue dasher above to get a close look at its stunning turquoise eyes.

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Blue dasher – immature female.

Powerful Wings

No doubt part of the evolutionary success of dragonflies can be attributed to their wings. The intricate pattern of veins (venation) which carries blood to the wings also provides structural strength for powerful wing beats. Coupling this with the ability to flap and rotate all four wings independently, makes dragonflies incredibly manoeuvrable fliers. They can hover, rotate on a dime, make rapid vertical climbs and descents, and maintain forward flight at high speeds, and even fly backwards, all the time keeping the body horizontal.

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Four-spotted skimmer – female. The striking venation on the leading edge of the wing on this beauty is worth a closer look. Click to enlarge.

Dragonfly Cousins

Much smaller than their larger and more aggressive cousins, damselflies are also emerging in numbers and flying around the water’s edge at our local lakes and ponds. Slower moving than dragonflies, they hunt mostly by gleaning insects (aphids) hiding in the waterside vegetation. Damselflies are distinguished from dragonflies by the way they generally hold their wings closed over their bodies. The males, and some females, are mostly eye-catchingly blue, like tiny electric-blue pencils floating in the air on almost invisible wings. To many people damselflies are known as bluets, which is an entirely appropriate name. Bluet is also frequently seen as part of the common name for a number of species of damselflies.

Much more difficult to identify than some dragonflies, many species of damselflies look superficially similar. The one I photographed below is, I think, a tule bluet – a common species hereabouts. However, birds are where I’m confident in my identifications; I’m far less certain when it comes to damselflies. Please correct me if I’ve made a misidentification.

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A damselfly (tule bluet?) perched on lakeside vegetation at Deer Lake.

So whether it’s dragonflies or damselflies that catch your fancy, it’s time to take a look because Here (they) be….

And take your binoculars and camera. Close-ups are definitely in order when viewing these beauties.

If you’re interested to learn more about our local dragonflies, I suggest Dennis Paulson’s Dragonflies and Damselflies of the West. It’s also available in Burnaby libraries. I consulted the book extensively for this post.

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Butterfly Bonanza

As we move into July and the weather really starts to warm up, the long grass meadows in our parks are the centre of a remarkable, once-a-year explosion of skipper butterflies.

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Skippers, crowding on to a blackberry flowerhead feeding on nectar from the flowers

What these small butterflies lack in size, they more than make up for in the sheer numbers that hatch, take to the air, and adorn almost every flowering plant in and around the fields at this time of year. It’s a spectacle, and one well worth a closer look. The Deer Lake meadows, at the western end of the lake, are a particularly good place to see the action, and enjoy what is by far our largest flight of butterflies in Burnaby.

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Purple vetch flowers are a favourite for nectaring skippers

Taking a closer look at these small butterflies, it’s noticeable right away that they’re not quite conventional butterfly shape. To some people they suggest moths, rather than butterflies. Their wings are more “swept-back” instead of being held either flat and open, or upright and closed, like “regular” butterflies. The hind wings are held out flat, while the forewings are held above them at a 45-degree angle – very rakish! They do at times, however, close both wings over their backs like regular butterflies. As you can see from the pictures, the open-winged stance is very common. This distinctive shape and stance shows that these butterflies are members of the grass skipper family.

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Skippers feeding (nectaring) on a dandelion – click to enlarge

So let’s take a close-up look. When you click to enlarge the photo above, you’ll see a couple of good clues as to why these insects are butterflies, and not moths. First take a look at the antennae which emerge from the head, angling outwards. They’re thin and thread-like with noticeable, club-shaped ends. In contrast, many moth antennae are feathery, and if they are thin like a butterfly’s, they lack the club end. Most moths are, of course, nocturnal, whereas these “guys” are active in the daytime. Two ticks for butterfly.

Now take a look at the skipper on the far right on the dandelion. You’ll see a third, thread-like organ emerging from the centre of the head, which then makes an angular curve downward into the flower. This is the proboscis, the hollow tube through which the butterfly draws up the nectar on which it is feeding. Now that you’ve looked at one skipper, a quick glance reveals that they’re all at it. This single flower is feeding a whole bunch of skippers.

Skipper Profusion

So what species of skipper are these? Well, thereby hangs a tale. These are European skippers. That’s right, they’re an introduced species from Europe.  First accidentally introduced to Ontario in 1910 they’ve spread across the country, and there have been many subsequent introductions since, including Duncan on Vancouver Island about 15 years ago. Ours could have spread from there, or they could have been introduced here separately. A particular aspect of the European skipper’s reproduction makes spreading to new locations very easy. And as usual, it’s we humans that are big contributors to skipper profusion, and skipper spread.

Unlike all native species of North American skippers, which overwinter as pupae, European skippers overwinter as eggs. This makes it very easy to survive being mowed, and then moved when hay is transported from one place to another. And hay fields is where skippers thrive. They’re called grass skippers because the larvae, the caterpillars, feed on grasses. As we can see, the adults get their food from flowers.

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European skippers feeding on clover

Although an introduced species, the European skipper is yet another example of a benign addition to our fauna. In this case, a very beautiful one too. There is no evidence that this introduced skipper has negatively affected our native skippers. It seems to have found a place here without causing problems for other species.

As John Acorn says in Butterflies of British Columbia  … we now have more butterflies on the wing than we ever could have without this cute little addition to our fauna. Here, here!

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European skippers – a welcome addition to our butterfly fauna