Migration of The Monarchs
By Steffen Klenk
South Jersey is part of a major migratory pathway for many mammals and birds. Whales, dolphins, red knots and swallows make up just a small number of creatures that make their presence known. But this time of year, is special. Over the past few weeks, the monarch butterflies have made their way into our region, but they won’t be around for long. Right now, the monarchs are making their trek to the south.
For 40 years, Dr. Fred Urquhart studied the track of the monarch butterflies as they migrated to the south. He had noticed an unusual pattern in their flight track. These butterflies, the numbers in the hundreds and thousands, make the 3,000-mile journey south to the mountains of Michoacán, Mexico, where the fourth generation of monarchs will live for six to nine months. The 10,000-foot elevation provides the coolness and wetness to sustain them through the winter.
The frame of one life cycle from egg to butterfly is about six to eight weeks. This cycle starts late in the winter when the first generation of monarchs leaves their winter sanctuary to begin the northern migration to the states and continues through the summer months until the fourth generation is born. Most monarchs only live two to six weeks as an adult butterfly. Those lucky enough to migrate, will live longer.
Each year during the migratory process, researchers and scientists will tag these butterflies with a special identification tag. These tags are used to keep track of their location and can be spotted on the strongest part of the butterfly’s wing. When the monarchs return in the spring, researchers will use this important piece of data to determine any differences in the path of the migration and how weather has played a role.
In recent years, researchers have noticed a drop in their counts. This is most likely due to the increased use herbicides by farmers to protect crops, which can effectively kill the precious milkweed plant. Milkweed is essential for the survival of the monarch butterfly. The monarchs will lay their eggs on the milkweed, and the caterpillars eat milkweed. Local conservational groups have encouraged farmers to leave marked areas of the milkweed plant unsprayed. Efforts have also been made to teach residents about butterfly-friendly gardens. Plants such as aster, lily, coneflowers, daisy and goldenrod provide much-needed food for the monarchs and can host caterpillars.
The New Jersey Audubon, Wetlands Institute and Cape May Monarch Monitoring Project are just a few of the local organizations offering its resources and support during migration. Throughout the season, you can find updated sighting locations in Atlantic and Cape May counties. You may just find a roost in your own backyard. So be sure to have your cameras out and get ready for a photo-op.
