It’s Labor day weekend. Summer is not over but many people mark an unofficial end of summer with this weekend. Schools in the northern part of the U.S. head back to school and colleges start the fall semester. Families are less likely to go on vacations or even head to the beach for a weekend.

I see from my blog stats that people are once again clicking on past posts about autumn and even those that discuss the weather lore for predicting the coming winter.

I hope you will continue to enjoy summer weather for a few months, no matter what the calendar tells you. Southern hemisphere readers can really look forward to summer.

Did you know that according to the “meteorological calendar” autumn begins today, September 1, for those of us in the northern hemisphere?  The meteorological calendar uses our Gregorian calendar and splits up the four seasons into three clean month blocks to make it easier for forecasting and comparing seasonal statistics.  That makes spring March, April, May; Summer: June, July, August; Autumn: September, October, November; Winter: December, January, February.

Most of us stick to the astronomical calendar which tells us that September 22 is the start of autumn. That is when the autumnal equinox, when night and day are roughly equal length, arrives.

One of the many signs that summer is moving into autumn is the migrations of species to warmer areas.

Monarch on rough blazing star. Photo by Debbie Koenigs/USFWS.

In mid-August, I started to see some adult monarchs who are partway through their lifecycle heading south in their autumn migration.

According to the USFWS, these monarchs are different from their parents, grandparents and great grandparents who completed their life cycle in four weeks. Those monarch migrated north, resulting in four generations this summer. The ones we are seeing are members of the generation that migrates south, often called the monarch “super generation.”

It’s about 3,000 miles to Mexico guided by the sun. They do about 50 miles a day. These delicate creatures sometimes ride thermal air currents and can be up a mile high.

What triggers their migration? They are not so different from other creatures – including people – who consciously or unconsciously look for signs around them that the seasons are changing.  The monarch butterflies sense the decreasing day length and temperatures and even the aging milkweed and other nectar sources triggers the birth of the super generation and their migration.

These super monarchs live eight times longer than their parents and grandparents. That is still only 8 months, but they will travel 10 times farther.

They will conserve energy by storing fat in both the caterpillar and butterfly life stages. They will wait to lay their 700 eggs until spring.

Monarch on swamp milkweed

Monarchs are totally dependent on milkweed. Plant some! Don’t pull out the milkweed plants! The plant is their nursery for the caterpillars who only eat this plant, and the flowers are a nectar source for adults. Their population has decreased significantly over the last 20 years.

There are projects to improve habitat for pollinators, including monarchs, like planting native milkweed and nectar plants that are local to your area. Gardening organically minimizes your impacts on pollinators and their food plants. Become a citizen scientist and monitor monarchs in your area. Educate others about pollinators, conservation, and how they can help. Learn how you can play a role in reversing the population decline and save the monarch.

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