Nature Note:Meteorological Autumn Well Underway-woolly bear caterpillars active

Since September 1,it has been meteorological autumn.Seasonal change is becoming evident before the autumnal equinox,which occurs on September 22 this year.The Mid-Atlantic region has felt its first truly cool mornings,with lows in the 40sF in some places.
This morning,a woolly bear caterpillar was noted inching across a highway off-ramp,safely making it to the other side at a quiet time of day.The bristly creature's emergence is one of the quintessential marks of autumn nationwide and in Southern Canada.It is black on the ends with an orange central band.Children pick them up and stroke them.
The caterpillars feed on asters;clover;sunflowers;and other plants.
Over the winter months,the woolly bears will shelter among rocks,in logs and under bark.In the spring,they will spin silk for their cocoons,which they also adorn with their own hairs.They will emerge as Isabella tiger moths(Pyrrharctica isabella).
There is no scientific evidence for the folkloric notion that the severity of winter may be predicted by observing the relative length of the woolly bear's color bands.

Meteorological Autumn

September 1 marks the beginning of meteorological autumn.Meteorologists reckon seasons by calendar months,rather than astronomical phenomena.Its a way of rounding things off,and may more closely reflect seasonal reality over a broad geographical area.For example,the beginning of September will show substantial seasonal change in the Northern U.S.,though astronomical autumn is some weeks off.
In the Middle Atlantic region,Canada goldenrod has now come into bloom,and many American robins have moved on from their breeding territories.It can still be quite hot,but the plants and wildlife are experiencing change from the noticeably shorter days,if nothing else.Meteorological autumn makes good sense from their perspective.