The Siege of the Spiny Baskettails

May 23, 2010. As I navigated he Wildlife Drive at Sherburne National Wildlife Refuge today I was confronted by clouds of hungry two inch long Odonata. They showed no fear, and refused to get out of my way. I figured that no matter how slowly I drove some might die on my radiator grill. On the other hand to stop would be a commitment to spending the whole day sitting on the drive since they seemed to be hovering and darting back and forth with no particular purpose or direction to their travel. I got out of the truck  to get a closer look. They were everywhere.

These large insects were flying endless loops, back and forth, at heights from about four feet up to ten or twelve feet above the road. Looking up I could see them dashing back and forth through my visual field. They filled the sky like the aeroplanes one sees in old war movies.

 Odonata Darting, Looping, and Diving Like Aeroplanes in an Old War Movie

A number of them were perched on a roadside stick. With my close-up butterfly binoculars I was able to identify them as Spiny Baskettails (Tetragoneuria  spinigera), one of Minnesota's earliest dragonflies.

Spiny Baskettail Dragonflies Resting. Perching Posture 
Is Often A Clue in Identifying A Dragonfly Species.

Spiney Baskettails are among the earliest dragonflies to emerge in Minnesota. They appear in May and by midJuly they will be gone. But other species which emerge later will take their place plucking insects out of our air. Dragonfly species have definite time slots during which they emerge, feed, mate, and die. And like all other living organisms, each species has particular habitat requirements if it is to complete its life cycle: ponds, lakes, slow moving streams, fast moving streams, sand bottoms, mud bottoms, water acidity, and oxygen level are some of the characteristics that define dragonfly habitats. This is just one of the ways these marvelous creatures have been differentiated to increase their chance of survival.

I remember once spending a half hour watching members of four different dragonfly species patrolling a length of a leisurely flowing Florida stream. I was fascinated to observe that each species kept to it's own part of the stream habitat and used a unique flight pattern to cover the area. Three of the dragonflies defined their foraging territory by the height they flew above the water, and it never varied. The fourth patrolled only the area where the grassy bank met the water. One dragonfly never strayed into another's foraging space. Each of the three dragonflies patrolling over the open water had its own particular zig-zag pattern which it repeated again and again. In this regard dragonflies live much like forest birds where each has its own preferred foraging height, food, and behaviors, referred to as a niche. But not all dragonflies patrol continuously, Like some birds, some dragonfly species prefer to perch, then pounce on a passing meal. And like birds, dragonflies can be very territorial, with a dominant male chasing away all male intruders. Some male dragonflies guard and protect their mate while she is laying her eggs in or around the water.

As a little kid I was somewhat afraid of dragonflies. Their long sleek bodies made me think that they could sting. Their size made me think the sting would be mighty painful. Their quick erratic flight made me think there would be no way to elude one that wanted to sting me. All of these scary myths were reinforced by the kinds of folk beliefs and horror stories kids like to share.

Damsel flies, the other major component of the order Odonata, were in some ways scarier than dragonflies. Their bodies were longer and slimmer, even more suggestive of a stinger than a dragonfly body. I grew up in the age before swimming pools were common and these guys sometimes induced a little fright as they hovered around us down at the swimming holes on the local creeks.

Damsel Flies, Smaller Relatives of Dragonflies, Are Every Bit as Interesting.

Today I know that dragon flies and their much smaller relatives, the damsel flies, do not sting or attack people. I know that their Latin name, Odonata, means "tooth" and refers to the toothed lower lip that dragonflies (and their water-dwelling nymphs) use to grab and grasp the species they prey upon. Adult dragonflies eat mosquitoes and other flying insects they capture in midair. Close up I have actually heard a perched dragonfly munching on a captured prey insect. Dragonflies  can capture even the fastest flying insects because they are amazing aerobatic fliers, able to make high-speed turns that seem to be right angles and they are the only insect that can truly hover and even fly backwards.


With all these fascinating characteristics its no wonder people love learning about dragonflies and have organized societies to observe and study them, much as they have organized societies to observe and study birds. Here are some internet resources where you can get more information about dragonflies and damselflies. Keep in mind that with an estimated 5,000 dragonfly and damselfly species in the world, of which about 435 are found in North America and  more than 100 are found in Minnesota and Wisconsin, opportunities for observation abound.

A major resource for beginners and experts.
http://www.odesforbeginners.com/resources/res-organizations.aspx

Dragonfly Society of the Americas
http://www.odonatacentral.org/index.php/PageAction.get/name/HomePage

United States Geological Survey
http://www.npwrc.usgs.gov/resource/distr/insects/dfly/index.htm

Another good source of dragonfly information is the online Wikipedia, keywords Odonata and dragonflies.


For interested Minnesotans: The MN Odonata Survey Project
http://www.mndragonfly.org/resources.html

Any internet search will turn up lots of dragon fly books. For a beginner the best books are generally field guides focused on a local region because it is too easy to get lost and discouraged with the more comprehensive books. 

An excellent field guide for Minnesota and Wisconsin residents is:
Mead, Kurt. Dragonflies of the North Woods. Duluth: Kollath+Stensis Publishing, 2003.

The Case of the Lazy Snake

April 18. The northward bound warblers are passing through Sherburne National Wildlife Refuge at this time of year. The Woodland Trail, a walking loop along the Wildlife Drive, often a good place to spot these frenetically flitting fliers, called me in for a short hike. The patch of woodland was surprisingly quiet, a temporary ornithological desert. So in keeping with my motto "It's the small stuff that counts" I found enjoyment in checking the greenness of the spring moss along the path and the emerging shoots of woodland flowers to be.

I was so focused on the plant life that I almost missed something moving twenty feet down the trail. It was a gopher snake, also called a bull snake because it is one of the largest snakes in North America. Gopher snakes are non-venomous snakes that have a diet high in small mammals, thus are extremely valuable for rodent control. While these snakes do a very good rattlesnake imitation when threatened, I have been able to get quite near to them in the wild without arousing their "fight or flight" mode by simply being quiet and moving very slowly, or not at all. To read more about these most interesting animals go to:  http://en.wikipedia.org/wiki/Bullsnake

I slowly walked up to where this snake stretched out across the trail. Unfortunately it saw me coming, turned back, and disappeared behind a fallen tree that paralleled the trail. I could hear it rustling through the oak leaf litter and quickly determined it was going my way. Sure enough it reemerged ten yards further down the trail, apparently still determined to cross over. How are you as an observer? Can you spot the snake in the picture below?

Gopher Snake Emerging Downtrail

 

 I stood still to let the snake cross without disturbance. It's scales, beautifully patterned in brown, black, and gray, reflected the bright morning sun.  I estimated the length at close to six feet, the diameter at about two inches.

 Usually when we meet snakes they are hurrying away from us and our meeting is fleeting. I decided this snake was hunting for lunch and by being unobtrusive I might have a great opportunity to get some interesting pictures. Once I had watched a Florida coral snake as it went about its foraging, but that had been for just a few short minutes before it disappeared from sight. This was going to be different. This snake was in no hurry as it rustled through the oak leaf litter flicking its tongue in and out with a rhythm as regular as a metronome. And it was oblivious to me, so here was an opportunity to find out what everyday life is like for a snake this size in the wild.

The snake poked it's head under the leaf litter here and there, then withdrew and altered course a bit. It never went more than a few feet from the trail, so following along was easy.

Gopher Snake Paralleling the Trail

At one point the snake entered a crack in a hollow downed tree. I expected to see it come out with some unfortunate rodent in its jaws. I gripped the camera tighter in anticipation. Ready, focus, ---

Gopher Snake Exploring A Hollow Log

But my anticipation vanished as the snake made a U-turn somewhere in the log and reemerged, passing over its own middle section like some Chinese acrobat.

Gopher Snake Reemerging from Log

We traveled along the trail together for another ten minutes. A lot of poking around under piles of rustling leaves and a few more leisurely excursions over and along more downed trees turned up no lunch.

 More Downed Trees to Explore

We came up to another fallen oak, and again snake started exploring along one side, poking its head under the snag wherever there was space. I began to wonder how much longer we would have to spend before finding lunch. Snake had the answer in just a few minutes. It found  a patch of bright sun shining down through the newly leafing trees. There it curled up, piling itself on top of itself in the center of that sunny spot. Then it rested its head and went to sleep. At least as far as I could tell it was asleep. I waited about five minutes but the snake was as still as a stone. I walked up the trail for about fifteen minutes looking for birds, but found only a few American robins. On the way back I noted the snake was still in the same sunny spot. "Get up and get moving you lazy snake" I thought as I walked past on the way to my truck. Then I was struck by the realization that the snake was enjoying the gift of spring sunshine every bit as much as I was. Maybe next time we'll have a successful hunt together.

A Good Place for A Nap if You're A Snake