Nature Notes: Temperature Crickets Calling

Temperature has a great deal to do with the way a cricket behaves, just as it does with other insects.  The snowy tree cricket, a relative of the black field cricket, is also called the temperature cricket because it is a rather accurate thermometer.  This cricket chirps more times per minute when it is warm than when it is cool.  To produce their music, the males raise their wings straight above their backs and vibrate them rapidly from side to side.  Females are silent.  Males often sing in a chorus, and if the sound seems to be coming from all around, it often is.  Snowy tree crickets chirp with a shrill, tuneful and persistent “chee-chee-chee,” also described as “treat-treat-treat” sleigh bell-like sounds.

If you count the number of chirps in 15 seconds, and add 40, you will have a good approximation of the air temperature in degrees Fahrenheit.  Looking carefully with a flashlight into a shrub you may catch sight of this shy, pale-green creature hardly an inch in length.  Hawthorne described this melodious night singer as having music like “the sound of moonlight.”  It is commonly heard but seldom seen.  We first heard them July 14 this year, and hopefully will hear them well into October.

What’s happening outdoors now?
The fruit clusters on European mountain ash are bright orange.  The big native sugar maples along roadsides are showing patches of burnt-orange fall color, while sumacs have begun displaying some bright red autumn foliage.  Shrub and garden roses, rudbeckia and phlox, plus many hostas and annual garden flowers have very showy flowers.  Squirrels are gathering walnuts.

Now is the time a majority of Baltimore orioles leave for their wintering territories in Central America.  These orioles are among the might-migrating birds.  Like most temperate-zone birds, they begin their migrations because of the changes in the length of daylight.  The first Baltimore orioles return to the Carver County area on or close to May 1 each year, and nearly all leave by the first week in September.

At some feeding stations, offering sugar water or grape jelly, dozens of orioles will be coming one late August or very early September day, and the next day not a one.  It seems so quiet.  We miss their orange and back colors and their songs.

Jim Gilbert’s Nature Notes are an occasional feature of the Carver County News.