It’s amazing how much more you can see when a dozen pairs of eyes are looking. We drove out to the central Minnesota prairie early yesterday morning to participate in a BioBlitz event organized by the Land Stewardship Project — i.e., walk the prairie and record as many species as you can find.
We had driven by The Nature Conservancy’s Sheepberry Fen property several times, but never walked it. In addition to the rarer plant and animal species that occur there, the area features a collection of calcareous fens fed by alkaline (high calcium and magnesium) ground water.
The weather looked ominous, with a giant storm front parked over central Minnesota, but it didn’t start raining until we had walked around for three hours and were eating lunch under cover.
Most of the birds were spotted from afar as they flew over us or perched in remote trees. Even on a dreary, cool morning, the birds were pretty active, if not highly visible nearby. However, the insects were mostly absent: a few Halloween Penant dragonflies and one Widow Skimmer comprised my entire species list for that group. We saw one or two Monarch butterflies (there were at least three species of milkweed blooming in our patch of the prairie), a couple of small unidentified skippers, a few flies (no mosquitoes were even out to “bug” us), and just a couple of bees.
However, we did see a few other unusual species that would not have been obvious without the help of those dozen pair of eyes, studying the ground as we walked.
Thatching Ants (Formica obscuripes) build their mounds in the sandy soils of arid scrub, old fields, and prairies, but they forage widely to feed on insects and milk the honeydew of aphids that they tend on plants near the mound. Through solar radiation and the heat provided by decomposing vegetation, the mound remains warm during the cooler months, and ants remain active repairing and adding to it. Some have lasted up to 40 years and reach a meter in height.
Sharp eyes detected movement in the crack of a rock, and we found a Prairie Skink (Plestiodon septentrionalis) hiding there.
Skinks have very smooth scales and look shiny. They tend to lose their tails rather easily when snatched by a predator, and the tail keeps wiggling after it is detached, so the predator concentrates on that rather than the skink itself.
BioBlitz is a great way to learn a great deal more about a particular place, and meet a few new friends along the way.