Saturday, June 04, 2016

There Will Be Bugs!

"We don't give a damn to the insects on our Earth, but if we could find even a single insect on Mars, the whole world would cherish it like crazy!"

― Mehmet Murat ildan

What lurks in the burrow?

I made a short trip to the Sauk City Canoe Launch this morning to see what tiger beetles I could find. For photographic purposes, the trick is to arrive just as the beetles emerge from their burrows before they're ready to hunt.

Tiger beetles are ectothermic, meaning they're largely dependent on external temperature sources for thermoregulation. A high internal body temperature (102 degrees Fahrenheit) helps them run and fly at maximum speed for hunting or evading. Being too cold can make a tiger beetle sluggish and become susceptible to predation. On the other hand, an overheated tiger beetle can experience problems with metabolism, water balance issues, and gamete production. This is why on hot days you might observe a tiger beetle moving back-and-forth from shade to sun-baked sand ― this is called shuttling. Tiger beetles will also reduce body surface area exposed to sunlight by standing up high on their legs facing the sun in behavior called stilting.

Bronzed Tiger Beetle

There were four species detected: Bronzed, Festive, Hairy-necked, and Big Sand. This location has produced eight tiger beetle species during past summer seasons, but so far this year the sandbar remains under water. That's where Sandy Stream Tiger Beetles were found last summer, so we might not have any of that species this year. I remain optimistic, though.

Festive Tiger Beetle emerging.

Festive Tiger Beetle on the prowl.

After about an hour, all of the tiger beetles became super fast and extremely difficult to approach. They're easier to spot in the open sand, but even then I was inadvertently flushing them every few steps. I did find at least one cooperative Festive Tiger Beetle that tolerated my macro lens for a few minutes.

Festive Tiger Beetle

Festive Tiger Beetle

Hairy-necked Tiger Beetle

I think the Hairy-necked is the fastest of all the tiger beetles I've encountered. Though I eventually got really nice portraits of this species last summer, it wasn't without immense effort.

Along the Wisconsin River

As I photographed my subjects, I was making a mental list of various bird songs and calls. So, it wasn't all about the tiger beetles ― I was birding, too! See the checklist at the bottom of this post.

Blue Toadflax

Big Sand Tiger Beetle

Big Sand Tiger Beetles where everywhere. At times I could see a half dozen or more scurrying ahead of me as I walked the sandy path. At times it was a little frustrating not noticing the camouflaged ones until they flushed a foot or two away from my shoes.

Big Sand Tiger Beetle

There seems to be a specific bearable working distance with these particular insects. If you can manage to get at least two or three feet away without flushing them, then you slowly drop to your knees, place your elbows in the sand, camera in hand, and move in. If you can get that close, they'll generally hold their position up to a minute or so while you photograph them. But make just one unacceptable move and they take to the air in an instant.

Big Sand Tiger Beetle

Big Sand Tiger Beetles preparing to mate.

All along this path!

It has all the appearance of a diminutive path in the sand along a river, but keen inspection reveals a thriving and astonishing plant and insect community. Though I didn't take time to photograph them, there were also various dragonflies, robber flies, spiders, butterflies, and wildflowers. I had a blast and look forward to returning in a few weeks to see how things change.

Sauk Prairie Canoe Landing, Sauk, Wisconsin, US
Jun 4, 2016 10:00 AM - 12:30 PM
36 species

Turkey Vulture
Spotted Sandpiper
Ring-billed Gull
Mourning Dove
Chimney Swift
Yellow-bellied Sapsucker
Eastern Wood-Pewee
Great Crested Flycatcher
Eastern Kingbird
Yellow-throated Vireo
Warbling Vireo
Blue Jay
Northern Rough-winged Swallow
Purple Martin
Barn Swallow
House Wren
Blue-gray Gnatcatcher
Eastern Bluebird
Gray Catbird
Cedar Waxwing
Common Yellowthroat
American Redstart
Yellow Warbler
Chipping Sparrow
Field Sparrow
Savannah Sparrow
Song Sparrow
Northern Cardinal
Rose-breasted Grosbeak
Indigo Bunting
Red-winged Blackbird
Common Grackle
Orchard Oriole
Baltimore Oriole
American Goldfinch

All images © 2016 Mike McDowell

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