Arboretum editor’s note: In the few days between receiving this blog that describes the Dog Days and “unseasonable heat” and before posting today, we hit a cold snap. After the frost: Although the National Weather Service in Chanhassen reported a low of 35 Degrees at 3 am, there was a lot of frost on the grass at the Arboretum in most locations. Only a few annual flowers were damaged, and the apple crop will not be affected at all. This is great news, and visitors will continue to enjoy the beautiful gardens.
Now we’re at the end of the “dog days” of summer, named for the Dog Star, Sirius, because it is eclipsed by the sun as it rises each morning. As the Earth travels along its yearly path, Sirius will start to be seen as a bright morning star, appearing just ahead of the rising sun. It is, in fact, the brightest star in the night sky. The three stars of Orion’s belt provide a celestial guide that signals that Sirius will soon be apparent. Look to their left.
This is the time of year of goldenrod, nuts, and big, clacky grasshoppers. Out in the open, the late summer sun beats down with unseasonable heat. So, into the woods we go, on the Ravine Trail, where it’s much cooler. Ah, that’s better.
It’s also quiet down in here, and there’s time to slow down and listen. The cacophony of the spring’s mating time for birds is over so that with all that chatter over, we can concentrate on the other sounds for a change. That buzz in the trees overhead? Those are the mate attracting sounds made by male cicadas. Our’s are not the famous 17-year variety but they’re still plenty interesting. Arguably not the prettiest bug in the world with their huge eyes and chunky bodies. They are some of the loudest animals in the world. The sound-producing organ has quite a complicated structure. Whole portions of its exoskeleton are vibrated with strongly attached muscles that create so much volume.
There’re also several kinds of male crickets and katydids making their “come hither” calls. Tree crickets and ground crickets can be heard as well as bush katydids. Their sounds are made by rubbing a comb-like part of one wing over the rough edge of the other wing. Since crickets are cold-blooded, the ambient temperature controls their level of activity. Try this.
On a calm evening, go outside and listen for the crickets with the slow chirps, not the trills. Count the chirps in fifteen seconds, add 35, and voila! that’s the air temperature of where that insect’s at. A pair of this year’s brood of Cooper’s hawks were squawking in the trees directly overhead from a whole flock of this year’s turkeys. Eleven youngsters and one older bird overseeing them – like a kindergarten class. They were ever so quiet as they picked their way up the ravine right by the bridge.
Along the eastern side, some planted hemlocks, Minnesota being just a tad too far west to have them altogether naturally, give the sense of place reminiscent of the small coves of the Smokies, rather subdued and almost introspective. “Where the sun comes up, at ten in the morning, and the sun goes down, ‘bout three in the day.” Describes rather well how a ravine stays so cool. Turtleheads (which I think should be called “turtle mouths” instead, as all of the cool stuff is inside the flower head) are blooming in the cool dampness. The ones here are the pink variety.
A spike of cardinal flower like a flame surrounded by dark green. And as for those nuts, the “nuts” of the squirrel world, the chipmunks, are busy eating and storing them. The husks of many a hazelnut today littered the path. Squirrels are so untidy. Get close to the heads of the goldenrod. It’s a battlefield.
Half a dozen denizens are doing their best to eat whatever comes their way. My favorite is the ambush bug. They lie in wait then jump on their unsuspecting victim, pierce their bodies with a tubular mouth, spit out some enzymes, and there you have it! A bug smoothie!
Boak Wiesner is a Master Naturalist volunteer.