Originally published in Seven Mile Times' Endless Summer issue, 9/1/2017 We do not see nature with our e understandings and our hearts yes, but with our . ~ Wi l l i a m H a z l e t t
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The Incredible
MONARCH MIGRATION
Monarch butterfly on Red Milkweed.
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t’s fall in Cape May and that means one thing – it’s time for the great migrations of wildlife headed south to warmer climates and abundant food. Cape May sits in one of the world’s great migration corridors and, in addition to being on one of these great highways, the narrow peninsula between the Atlantic Ocean and Delaware Bay is also a stopover point. Think of it as a great truck stop on an interstate system. The abundant beaches, farms, meadows, and forests of the peninsula are a perfect place for migratory wildlife to rest and refuel before making the first of many dangerous crossings over open water. Most people are familiar with the globally famous fall migration of eagles, hawks and falcons through Cape May, and spending time at the Hawkwatch Platform in Cape May Point State Park on a sunny fall day with a good north wind is a rewarding venture. Perhaps fewer are familiar with the great southbound migration of seabirds that occurs just offshore of Cape May. The Seawatch on the north end of Avalon is where scientists count the strings of nearly a million seabirds migrating south from their North Atlantic breeding areas. More than 60 percent of all sea ducks breeding in the Western Atlantic pass by or winter off Seven Mile Beach, making Avalon Seawatch one of the greatest natural spectacles in North America. Cape May is also an important breeding area for monarchs and a stopover for migratory monarch butterflies as they
By Dr. Lenore Tedesco of The Wetlands Institute make their way south to the mountains tough. Every time I think of their life of Mexico to spend the winter. Butterflies history and journey, I marvel at all the migrate to avoid unfavorable circum- things about nature that we just don’t stances that can range from weather, understand. It takes four generations of food shortages or even overpopulation. monarchs to complete a full migration The best-known migration is that of the cycle! Monarchs arrive in central Mexico eastern population of monarch butter- in October and overwinter in the mounflies. Several other species of butter- tains, where they huddle in great masses flies and moths are also migratory. The in a type of pine tree. They sleep in these painted lady, common buckeye, Amer- groupings and rely on mild weather and ican lady, red admiral, cloudless sulphur, shared body heat to stay warm. They don’t numerous skippers, question mark and eat and only occasionally drop to the mourning cloak are all butterflies that ground to find moisture. In late February migrate and many can to early March, hiberbe seen in the area nating monarchs in Mexico nectaring and roosting reawaken, become active, as they pause on their find a mate, and begin the long journeys. flight northward to lay their Monarch buttereggs. They will likely make it Monarch caterpillar on milkweed. flies are remarkable and into southern Texas before
Monarch caterpillar on milkweed.
Monarch caterpillar beginning to form chrysalis.
Monarch chrysalis.
they finally die. These special monarchs have lived about six months through the long winter and as you will see are very different from the other generations that make the monarch migration work. In March/April, this first generation is born and goes through the various life cycle stages – egg, caterpillar, chrysalis and adult butterfly. These adults fly a little further north moving into the Midwest and mid-Atlantic where they lay eggs and die. This second generation is born in May/June and go through the various life stages – egg, caterpillar, chrysalis and adult butterfly. They have moved further north where they lay eggs and die. The third generation moves into our area, New England and upstate New York and Pennsylvania, arriving in July/August. Perhaps you have noticed that we don’t see monarch butterflies until later in the summer. This is why – it’s taken them three generations and flying from Mexico to get here! These butterflies lay eggs and it is their offspring – the fourth generation – born in September/October that does not die! They are the ones that will migrate to Mexico, live 6-8 months and overwinter there to start the journey back north again next spring. I often ponder this: How is it that a creature as seemingly delicate and fragile can fly that far? How do they transmit the information from generation to generation about their role? None of them has made the flight – or completed the segment. And they pass the information through four generations to make one complete migration. continued on page 86
Endless Summer 2017
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