Migrating Marvels By Dr. Lenore Tedesco
Originally Published in Cape May Magazine Winter 2014
Reprinted with permission from Cape May Magazine, December 2014
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Migrating
Marvels
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ape May sits in one of the world’s great migration corridors. 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. 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. At the Seawatch on the north end of Avalon, scientists count the strings of nearly a million seabirds migrating south from their North Atlantic breeding areas. Because these birds are spread over large areas and spend so much time out at sea or nesting on isolated rocky offshore islands, understanding their populations and population trends is extremely difficult. One of the best ways to do that is to monitor them as they are funneling past 7 Mile Island. The north end of Avalon juts almost a mile further out into the Atlantic than the rest of the barrier islands, bringing mixed flocks of migrating birds within view of the beach. Over sixty percent of all sea ducks breeding in the Western Atlantic pass by or winter off of Avalon, making Avalon Seawatch
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one of the greatest natural spectacles in North America. Cape May is an important stopover for migratory Monarch Butterflies as they make their way south to the mountains of Mexico to spend the winter. Butterflies (and some moths) migrate to avoid unfavorable circumstances that can range from weather, food shortages, or even overpopulation. Just like birds, migration in butterflies and moths can involve all individuals of a species or just a subgroup of the individuals. The most well known migration is that of the eastern population of Monarch Butterflies. Several other species of butterflies and moths are also migratory. The Painted Lady, Common Buckeye, American Lady, Red Admiral, Cloudless Sulphur, numerous Skippers, Question Mark, and Mourning Cloak are all butterflies that migrate, and many can be seen in the area nectaring and roosting as they pause on the long journeys. Of all the remarkable migrations, the migration of dragonflies is perhaps the least well-known, both to the general public as well as to the scientific community. Several species of dragonflies are known to migrate and many can be seen in Cape May in the late summer and throughout the fall. The Wandering Glider is a powerhouse. Touted as the most evolved dragonfly in the world, they drift on the wind and feed on windborne insects until different temperature air masses converge and produce rain pools, where they breed. They can fly day and night over the open ocean for thousands of miles. In North America, they straggle north to breeding areas, and, like
the Monarch, it is the offspring that migrate south in the fall. They are the only dragonfly found around the world, and they breed on all continents except Europe. On oceanic islands, they are the only dragonfly because of their ability to fly over open water for so long. These marvels are less than two inches long and are yelloworange with clear wings. They constantly hover eight to ten feet off the ground and only rarely perching. They are commonly seen at The Wetlands Institute hunting over the meadows. Among the other dragonflies migrating through Cape May are the Black Saddlebags. They are medium-sized dragonflies (two inches long) with a black body, clear wings and distinctive black “saddlebag� markings on the wings next to the body. There are both resident and migratory populations of Black Saddlebags, and they can be seen in swarms during the southbound migration in the fall. They too are commonly seen at The Wetlands Institute. Other migratory dragonflies in the Cape May area are the Twelve Spotted Skimmer, Common Green Darner, the Swamp Darner, and Red Saddlebags. The small Blue Dasher is a frequent swarmer on The Wetlands Institute Salt Marsh Trail in early fall. They appear suddenly in large numbers and feed over the marsh, perching on the trail vegetation for several weeks before disappearing again. Documentation of migratory behavior in Blue Dashers is relatively limited and mostly related to congregating behavior at the appropriate time for migration rather than actual evidence of migration. Cape May during the fall migration is a special place. The peninsula’s location makes it part of an important flyway, and its rich diversity of habitats and protected environments is a key reason that it has become and remained such an important migratory stopover. There are challenges. Development and habitat loss continue to be concerns. Invasive and non-native vegetation is also taking a toll. When these birds and insects make their stopovers, they are in desperate need of rest and food to empower them to continue on their journey and successfully reach their destinations. There is a lot you can do. Maintaining native plants in gardens and managing invasive plants on your property are two great ways to help. Making your patch of land welcoming and suitable for these travelers not only puts out the welcome mat so you can enjoy their visits, but also helps give them a helping hand along the way. There are lots of resources to help you plan garden improvements. The National Wildlife Federation has programs for creating backyard habitat and provides great resources for getting started. The Wetlands Institute has gardens promoting native plants or pollinators and wildlife and hosts periodic programs where you can see native plants in action.
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