Today I awoke to a thermometer reading of 32˚F. This marks the first day the temperature has plummeted to the freezing mark this fall.  While I do not have any idea how long the temperature hovered this low, I know it could not have been too long since none of the plants flowering in my backyard showed any signs of frost damage.

When I ventured outside for the first time on this sunny, cool day the temperature had risen to 57˚.  Much to my surprise the first creature I saw this morning was a monarch butterfly.  The monarch was nectaring on the purple blossoms displayed on two butterfly bushes.

Needless to say, I was startled to see a monarch on such a cold morning since even on a sunny day, monarchs are rarely seen when the air temperature is in the 50s.  When it is cloudy, this magnificent butterfly often does not take to the air until the air temperature reaches 60˚.  That being the case how was this butterfly out and about feeding?

More than likely it must have spent the night roosting nearby in a location where the temperature remained above freezing.

In autumn, when monarchs are passing through the south on their way to Mexico they seem to prefer to roost in pecan and oak trees; especially those growing close to a nearby source of nectar. These trees offer protection from the wind and their dense foliage provide places to roost that at are often warmer than the air temperature.

During the past few years, I have noticed that late in the afternoon during the monarch migration, monarchs will nectar on one particular butterfly bush growing on the north side of my home.  Just beyond my driveway stand three water oaks.  Several times as the sunlight melted away, the monarchs would flutter up into the oaks and vanish from sight.  While I am not positive this is their nighttime roost, I suspect it is.

Wherever the monarch I saw this morning roosted, it could not move until the temperature rose above 40˚.  As the temperature slowly climbed, the butterfly had to crawl to a sunny spot and open its wings and bask in the warming rays of the sun.  The butterfly’s black scales and abdomen enabled to it to absorb the heat needed to raise its body temperature.  Once its flight muscles reached 55˚ degrees, the monarch was capable of flight.

I am certain the monarch I saw this morning is now miles away from my backyard.  As the sun begins to dip below the horizon this afternoon, I hope it finds another suitable roost site and the night will not be as chilly as it was last night in Monroe County.