Home
Oases
Why is NJ important for migrating birds?

What is a migratory flyway?
New Jersey's location in the Atlantic Flyway
Physiographic regions and diversity of habitats
Habitat is key

 

WHAT IS A MIGRATORY FLYWAY?


    
In the Western Hemisphere, birds typically migrate in a north-south direction.  There are certain places throughout the world and certain places in New Jersey, where the paths of migratory animals cross and concentrate, the same way tributaries feed into a river.  The migratory paths are called flyways and there are four major flyways in North America.  Each of these flyways corresponds to a major land feature that acts as a barrier or navigational tool to migrating animals. The barriers include coastlines, mountain ranges and major river valleys and floodplains.   The coastlines have abundant food resources and the temperature differences between the land and ocean provide constant breezes that help give lift to migrants.   The mountain ranges with their nearly north-south orientation and by causing updrafts from wind reflected off their surfaces help to direct migrants. 



NEW JERSEY'S LOCATION IN THE ATLANTIC FLYWAY

     Birds migrate nearly everywhere in New Jersey.  "Location, location, location," is the cry of the real estate broker as he tries to close the deal.  Well, in terms of migration, New Jersey has the corner on the market for a superb location - more importantly, because the state exists at this crossroads, the natural resources of its habitats are extremely important to the success of migrating animals.

     The Atlantic Flyway runs north to south or south to north and is defined by the Appalachian Mountains to the west and the Atlantic Ocean to the east.  The Appalachians are part of an ancient ridge system that has been used as a visual guide by birds for thousands of years.  A piece of this range slices through the northwestern corner of New Jersey and then bookends the state on its western edge effectively putting New Jersey between a rock and about 125 miles of coastline.  The ocean acts as a physical barrier to migrating land birds and insects. 

     New Jersey's latitude puts it about midway between the equator and northern forests and the Arctic.  Its central location means that the state serves many populations of migrants.  Northern populations pass through the state as they head south in the fall or return northward in the spring.    Migrant populations to the west are pushed eastward each fall by prevailing weather patterns.  Southern populations disperse northward after breeding.  Some migrants end in New Jersey, while others begin here. If we conceive of migration as a transit system, New Jersey is the hub where major flight lanes along the coast, the river valleys and the mountains converge and radiate out to destinations north and south.  New Jersey is truly at the crossroads of migration.

PHYSIOGRAPHIC REGIONS AND DIVERSITY OF HABITATS

     At a point when the needs of the migrating animal are at their height, New Jersey becomes a prime stopping spot.  If these animals were to stop, and their needs were not met, they would pay dearly for time and energy wasted on such a stop. Location may be what forces the migrants to stop here, but it is what is in that location that has made the state an evolutionary mecca for migrants. 

     The geological forces at work have divided New Jersey into five distinctly different physiographic regions each identified by the types of habitats and plant communities associated with their geology and soils.  As far as bird distribution, these regions have been divided further into seven physiographic provinces.  From the forested regions of the highlands to the marshes and beaches of the coastal plain, these habitats are a veritable marketplace for migrating birds.

HABITAT IS KEY



     Habitat.
The word carries such importance today, but what does it mean? What exactly is habitat? Ask any third grader and they will gladly tell you that a habitat is an animal's home. They may even go as far as to describe a house with the appropriate rooms to accommodate the needs of the animal. Sort of like the three bears' house in the woods that Goldilocks stumbled upon - a room to eat, a room to rest, and a room to sleep make up the abode of these forest creatures. This oversimplification is nearly accurate, but habitat is much more than that.

     In essence we define habitat as the place where an organism lives, permanently or temporarily, which provides the things needed for that organism's survival and ultimately reproduction. 
Habitat is the key, not only to survival of organisms, but also to their migratory successes. Habitats utilized during migration provide a temporary home for animals to rest, refuel and reorient themselves. Habitat is the single most important need of migrating animals. Habitat arrangement and availability enables migration to happen the way it does. 

     Food, water, and shelter are key elements of an animal's habitat, but the habitat's suitability is based on whether it provides appropriate and substantial amounts of each of these components. A suitable habitat is one that increases the survival and reproductive output of organisms. The various needs of different species of migrating organisms differs from species to species, so what is suitable for one type may not be suitable for another.