“I love to watch the jumpers when I water my houseplants,” she said.
“What jumpers?” I asked.
“Whenever I water them, you can see little bugs jump up. Want to see them?” She went to get her watering can. As she soaked the largest plant, a Norfolk Island Pine, I could see nearly microscopic beings jumping several inches from the soil.
“Do you see them?” she asked. “Aren’t they cute?”
“I do see them—and, yes, they are cute. And I think I know what they are.”
Some years ago, when I first began to study ecology, the class set up a Berlese funnel, a device designed to capture animals in the leaf litter, the topmost layer of the forest floor. It consisted of a large metallic funnel into which a sample of leaves, sticks, and soil had been placed. Above was an incandescent bulb, low wattage, which provided the heat required to bake the critters out. As the sample dried, they would migrate to the narrow part of the funnel, eventually falling into a jar of alcohol. The menagerie of tiny animals was too diverse to describe in detail here, but one inhabitant was both abundant and memorable: springtails.
Springtails are only a millimeter or so long, only visible to our eyes if we are paying careful attention. They have six legs and an odd lever at the end of their abdomens that springs forward, propelling them up in the air. In the past they were regarded as insects, but now, in the day of DNA analysis, they have been removed from that taxon. They are now classified in their own taxonomic group Entognatha, that name pointing to the animal’s internal mouthparts.
Mostly springtails live on dead and decaying plant matter. They are partly responsible for converting the dead leaves of autumn into black humus. It takes hordes of them to accomplish that work: one estimate of their abundance suggests there might be at least 100,000 of them per square meter.
In winter, not all species of springtails are dormant. On warm days some of them—snowfleas as they are commonly called–can be seen hopping on the granular snow, sometimes discoloring it with their tiny bodies which measure less than a millimeter in many cases. They have small lever affairs on their abdomens that are under tension when locked in position. When aroused, they unlock the mechanism and spring upwards, sometimes 50 or 100 times their body length. One wonders how much fun that must be!
In the waning days of winter, look carefully at the snow at the base of trees. Can you see them hop when you move your hand close? I will include a link to an encounter with snowfleas. You can watch it without the sting of cold, though it would be better if you got out there to see the real thing! https://www.youtube.com/watch?v=VjLKzogOj8Q
Richard Fidler is co-author of Grand Traverse Journal.