Many North American monarch butterflies go on a migration journey so long it takes them an average of four generations. These monarchs overwinter in huge masses of butterflies covering oyamel fir trees in a dozen or fewer small areas of the mountains in Mexico. These fir forests provide the perfect microclimate for helping monarchs survive the winter. In the spring, these monarchs journey north over the course of a few generations, reproducing along the way and completing their travels as far north as Canada. In the fall, a “super generation” of monarchs emerges from their chrysalises. These butterflies are in a state of “reproductive diapause” triggered by shorter, cooler days and aging milkweed. This means that they will stay young longer and use the energy they would usually give to reproduction to instead fly up to 3000 miles south to their overwintering roosts in Mexico. In the spring, they will mature and reproduce after migrating again back to the United States. This “super generation” of butterflies are larger than other monarchs and live about 8 times longer. Two internal clocks help monarchs achieve their amazing migration. One tracks annual cycles. The other is a solar compass that also tells time, allowing them to find their way from different points all over the far north of North America to a few small forests in Mexico. Their antenna tells them what time of day it is, and they combine that with information from their eyes and the location of the sun to orient themselves on their epic journey.
This amazing migration is in danger. With so many monarchs wintering in such a small area--tens of thousands cluster on a single tree--storms, cold snaps, predators, or human habitat destruction or pollution in these areas can have a catastrophic effect on the size of each winter’s surviving monarch population. Monarchs also suffer from destruction of their habitat all along their migratory route. Monarch caterpillars only eat milkweed, so sufficient milkweed plants for the butterflies to reproduce are required all along their way. The butterflies also need nectar sources for energy, and safe environments free from pesticides and other chemicals. Monarch populations have been trending lower continually over a long period of time, and have recently hit lows that put the entire population overwintering in Mexico in danger of being wiped out by a single storm. The larger size of last year’s overwintering population provides hope for saving the epic migration of North American monarchs, however a sustained population of at least that size is the minimum target for monarch conservation efforts, and you will notice on the population graph that over recent time there is a pattern of decline after each population surge.
Monarchs need your help! How can you help monarchs?
Don’t use chemicals. Pesticides, herbicides, and other chemicals can harm monarchs.
Plant milkweeds. Milkweeds native to our piedmont area of NC include:
Butterfly Milkweed (Asclepias tuberosa) is a short, neatly growing milkweed that loves hot, dry, sunny areas and blooms with beautiful, orange compound flowers.
Common Milkweed (Asclepias syriaca) is a tall, sun-loving milkweed with big, pink blooms and large foliage for hungry caterpillars. Common Milkweed plants can be harder to find for sale, but once established Common Milkweed spreads well via rhizomes.
Swamp Milkweed (Asclepias incarnata) is a tall, pink milkweed that loves wet soils, but can thrive in average soil once established.
SOURCES: "It's Okay to be Smart" Youtube video ( https://www.youtube.com/watch?v=fBakLuH6kDY ) https://www.nbcnews.com/sciencemain/monarch-butterflies-may-take-five-generations-migrate-us-6C10910055 https://s3.us-east-2.amazonaws.com/journeynorth.org/images/graphics/monarch/annual_cycle_wheel.gif https://www.fws.gov/midwest/news/MonarchMigrationFall17.html
https://monarchlab.org/biology-and-research/biology-and-natural-history/breeding-life-cycle/annual-life-cycle/
https://monarchlab.org/biology-and-research/biology-and-natural-history/migration/ https://www.fs.fed.us/wildflowers/pollinators/Monarch_Butterfly/migration/index.shtml
This amazing migration is in danger. With so many monarchs wintering in such a small area--tens of thousands cluster on a single tree--storms, cold snaps, predators, or human habitat destruction or pollution in these areas can have a catastrophic effect on the size of each winter’s surviving monarch population. Monarchs also suffer from destruction of their habitat all along their migratory route. Monarch caterpillars only eat milkweed, so sufficient milkweed plants for the butterflies to reproduce are required all along their way. The butterflies also need nectar sources for energy, and safe environments free from pesticides and other chemicals. Monarch populations have been trending lower continually over a long period of time, and have recently hit lows that put the entire population overwintering in Mexico in danger of being wiped out by a single storm. The larger size of last year’s overwintering population provides hope for saving the epic migration of North American monarchs, however a sustained population of at least that size is the minimum target for monarch conservation efforts, and you will notice on the population graph that over recent time there is a pattern of decline after each population surge.
Monarchs need your help! How can you help monarchs?
Don’t use chemicals. Pesticides, herbicides, and other chemicals can harm monarchs.
Plant milkweeds. Milkweeds native to our piedmont area of NC include:
Butterfly Milkweed (Asclepias tuberosa) is a short, neatly growing milkweed that loves hot, dry, sunny areas and blooms with beautiful, orange compound flowers.
Common Milkweed (Asclepias syriaca) is a tall, sun-loving milkweed with big, pink blooms and large foliage for hungry caterpillars. Common Milkweed plants can be harder to find for sale, but once established Common Milkweed spreads well via rhizomes.
Swamp Milkweed (Asclepias incarnata) is a tall, pink milkweed that loves wet soils, but can thrive in average soil once established.
SOURCES: "It's Okay to be Smart" Youtube video ( https://www.youtube.com/watch?v=fBakLuH6kDY ) https://www.nbcnews.com/sciencemain/monarch-butterflies-may-take-five-generations-migrate-us-6C10910055 https://s3.us-east-2.amazonaws.com/journeynorth.org/images/graphics/monarch/annual_cycle_wheel.gif https://www.fws.gov/midwest/news/MonarchMigrationFall17.html
https://monarchlab.org/biology-and-research/biology-and-natural-history/breeding-life-cycle/annual-life-cycle/
https://monarchlab.org/biology-and-research/biology-and-natural-history/migration/ https://www.fs.fed.us/wildflowers/pollinators/Monarch_Butterfly/migration/index.shtml