When we think of migration we automatically think of birds and although they predominate the scene, mammals, reptiles, fish, amphibians, insects, and even earthworms will also move from one location to another. This migration is a predictable movement of a species from one location and climate to another, according to Brian, and is usually precipitated by the changing of the seasons. Animals migrate to seek food resources and to find ideal nesting grounds to raise their young. An earthworm may move a few feet upward as the soil warms up in spring and the red-spotted salamander (one among many different amphibian species) will move a few hundred yards to the nearest vernal pool to reproduce. In contrast the monarch butterfly will cover thousands of miles to its breeding grounds as do many species of birds.

Did you ever wonder how animals know where they are going? Brian, who is Sanctuary Director of the NJ Audubon Plainsboro Preserve, and co-author of Wild Journeys: Migration in New Jersey, gave us some fascinating insights into how a bird’s sense of direction is enhanced by using the sun, stars and magnet field as guides. Possessing an internal sense of time, it is also guided by large permanent landmarks such as mountain ranges, rivers or ocean coastlines. In New Jersey the coastline, the Delaware River, the New Jersey Turnpike and mountain ranges are examples.

Some birds are diurnal migrators; they are usually heavier birds such as hawks, ducks or geese that take advantage of the thermals created by the heat of the sun rising from the earth. They feed while they are migrating, in contrast to smaller birds that feed during the day and migrate at night, eluding predators and flying in a calmer atmosphere. One interesting comment Brian made was how thrushes can be heard chirping to each other as they fly above.

Animals have different migratory styles: as Brian put it; a hop, skip and a jump. A hop would be a range of a few hundred yards as covered by salamanders to 200 miles a night by birds; a skip pertains to longer journeys broken up into two segments allowing the bird time to rest and eat; and a jump refers to flying non-stop for 48 hours, for instance, from New England to South America. Geological barriers and prevailing winds are key factors in determining the direction and length of a bird’s flight.

There are four major flyways in the U.S: the Atlantic, Central, Mississippi and the Pacific. Each border either the Atlantic Ocean, the Mississippi River, the Rocky Mountains or the Pacific Ocean. New Jersey is within the Atlantic Flyway, and according to Brian is the "crossroads of migration". Birds on their way from the Arctic to the tropics are funneled through the state with its mountains in the west and the coastline on the east. Fish and whales migrate off the shores in the Atlantic. Subsequently, all throughout the state there are sites where you can spot a variety of migrating animal life during different times of the year: hawks, the red knot, whales, striped bass, horseshoe crabs, the red eft and many other species. Some more popular spots are: Sandy Hook, Forsythe National Wildlife Preserve, Cape May, the Delaware Bay, the Kittatiny Mountain ridges or even you own backyard.

Brian likened migration to a trip that we might take from North Jersey to the Jersey Shore or further. We eat a meal before leaving, gas up the car and use a map and familiar landmarks to find our way. We may stop at our familiar restaurant to get a bite to eat on the way to our destination. Relying on these familiar spots is similar to birds who rely on a specific stopover location or habitat, if you will, to rest, eat and avoid predators.

According to Brian, "habitat is critical to successful migration". In this vein we as human beings can help. Brian would like to see people become more aware of the needs of the migratory animal, planting species of plants that can be used for shelter, volunteering in efforts to preserve open spaces, and supporting legislation which promotes conservation of land and water. He encouraged us to be more aware of the world around us and share this knowledge with others. When we travel to see natural wonders in a specific locale we should inform the businesses we patronize of our reason for being there.

We appreciate Brian sharing his knowledge of migration with us and hope we can be a positive factor in its process as he encouraged us. Thank you again, Brian.

by Sandy Norman

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