As children, we learn the archetypal signs of spring: robins and tulips; nests and eggs; April showers, May flowers, and even Easter bunnies. It’s a good starting point, but there is so much more. The seasonal transition happens in a thousand steps. This week I challenge you to notice some of the less obvious changes. Be alert for at least one current phenomenon, something you couldn’t observe in February and won’t see in May. Perhaps you’ll discover a new sign of early spring to add to your repertoire. Then, email your image, sound recording, or video clip to A Glimpse of Nature, and I’ll share it with readers.
Here are my contributions for this week.
Sunday, March 26, was a sunny weekend afternoon. Hooray! Grateful for extra light, I set off for a small, local stream where my friend saw a spotted turtle. Upon hearing a few determined wood frogs, I switched on my camera’s video and paused at a marshy area. Silence. That’s when some movement caught my attention. I faced the sun, aimed, and hoped the camera would see the action better than I could. It did.
Between my surprise and the sun’s glare, I could only discern a slender snake swimming toward the marsh grasses. Who could that be? A young northern water snake? A ribbon snake? No. The video’s zoom function brings the stripe and checkerboard pattern of an eastern garter snake into focus.
I have seen and photographed these snakes before. Indeed, this post from July 2011 featured a garter that was living in Queset Garden. My recent sighting is noteworthy because it happened early in the season. Each year, for the past five years, iNaturalist observers in southeastern Massachusetts begin reporting garter snakes during the latter part of March. You may recall that snakes rely on external heat sources to maintain their body temperature. They are ectothermic animals. When the weather gets too cold to sustain activity, garter snakes take shelter in winter dens where they go dormant. Thus, my snake’s emergence from hibernation was another sign of spring.
Once snakes emerge and absorb some heat, there are two imperatives: to find a mate and a meal. I didn’t notice more snakes. Then again, if I were a snake, I might have.
So what about a meal? According to Snakes of Massachusetts, “garter snakes' primary prey are earthworms and amphibians.” Amphibians like wood frogs, perhaps? I assumed the frogs grew quiet because of my presence. Maybe they sensed a more imminent threat.
Let’s have another look at the reptile, this time in slow motion with a brief freeze-frame showing its face.
At this slower speed, it’s possible to see the muscle contractions that enable the snake to move so gracefully. Watch the garter flick its tongue as it explores nooks among the grass stems. This snake will experience a few more chilly nights, but the active season has begun.
Further down the trail, I observed a sight that I hadn’t seen in a while: a swarm of small flying insects dancing over muddy soil. To the camera and my eyes, it looked like this.
“What’s the big deal?” you say. “They’re bugs.” Precisely! Most animals on earth are insects. According to the Royal Entomological Society in the UK, “Scientists estimate that insects make up to 90% of all species of animals on the planet and more than half of all living things.” Even if you can’t bring yourself to value the remarkable forms and adaptations of earth’s most numerous animals, it would be best to recall that insects pollinate most of the world’s flowering plants and feed its animals.
Check out “Going Buggy! Insect-eating Birds” from Journey North, a citizen-science program that concentrates on migration and seasonal change. This page offers a nice chart of insect-eating birds, their meals, and where the birds find them. The bluebird at the farm, the swallow over the pond, the warbler in migration, and even the chickadee in your backyard are all insectivores. They need to eat.
For a solid dose of discouragement, read “Empty Skies” by the National Wildlife Federation. This older article documents a serious population decline among aerial insectivores, that is, birds that feed on the wing. I’m afraid the situation hasn’t improved since the article was published 14 years ago.
It’s time for a new outlook towards our fellow creatures.
To steer us in a better direction, let’s apply a little curiosity. The swarm of insects at last Sunday’s walk was relatively small, but it was conspicuous on a cool March day. I can make no serious identification claims considering my lack of entomological skill and the lack of a specimen or closeup photo. All that is certain is that they were flies, that is, two-winged insects in the Order Diptera. Yet, based on past experience and research, I will venture a reasonable hypothesis that these were non-biting midges in the Family Chironomidae. Insects in this group have been recorded in my town at this time of year, and their behavior matches what I observed.
A few things to note about non-biting midges. First, they don’t bite. Really.
Secondly, most species are seen near water because that is where their eggs and larvae develop. Indeed, midge larvae (called bloodworms) are important food for fish.
The adults live very short lives, just long enough to mate and make more midges. This brings us to the “swarm.” In pop culture, the very word induces chills. Insect swarms of this kind are largely comprised of males who gather in a conspicuous display to attract mates. Females don’t linger in the swarm; as soon as she finds a partner, the female leaves the swarm to mate and lay eggs. According to Donald Stokes, the author of many fine guides to natural history and animal behavior, male midges use their feathery antennae to detect the high-pitched buzz of females.
While midge swarms congregate throughout the warm months, their early spring appearance is not unusual. BugLady from the University of Wisconsin notes that “Midges can tolerate pretty cold weather, bouncing up and down in the air of early spring and late fall, especially near wetlands (their rapid wing-beats raise their body temperature).” As always, her descriptions of this insect family are well-informed and engaging.
On a final note, Stokes’ A Guide to Observing Insect Lives describes the swarm patterns of midges. Apparently, some species swarm at the same time and under the same conditions each day. “If you see one in a certain time and in a certain place, chances are good that you will see it the next day at the same time and same place.” It’s been nearly a week, but I’m going back to the brook. Maybe I’ll see the swarm again and get a photo!
P.S. Just for fun, watch “Midges – What Are They?”, a Youtube video about midges that live near Lake Erie. Although it concentrates on a different species, the overall description is good.