News and ResourcesArrivals and Departures Signal Fall Migration - October 26, 2014
The leaves are changing color, apple and pumpkin spice drinks are here and the weather is cooling down, which means it is finally fall. Fall means going back to school, football season and preparing for Christmas and Thanksgiving, but for animals in our coastal bays it is also the time to either undergo migration or start to get ready for winter.
Migration is seen across the globe and is undertaken by countless species including birds, mammals, and fish. Ultimately, migration is the predictable movement of animals from one location to another location. Migration is dangerous as it presents many obstacles along the way, such as new developments causing historic habitat loss, predation and sheer exhaustion. Even though it is difficult, migration is often necessary to survive. Animals migrate for a variety of different reasons, including resource availability, reproduction and seasonal changes. Typically, animals will migrate during the spring and fall months, as they travel between summer feeding grounds and overwintering locations.
The coastal bays here in Maryland are an excellent stop-over spot for many migrating animals, as a place to rest and refuel during their long trips South or North. For some animals, the coastal bays is their final destination for the summer or winter, and they will migrate either North for the summer or South for the winter before returning to our coastal bays. Some of the most prevalent migrating animals on Delmarva are huge flocks of songbirds and waterfowl.
Songbirds, such as some Warblers and Sparrows, migrate through the Delmarva Peninsula on their way from Canada and the Northern U.S. all the way down to Central and South America. Warblers especially feed primarily on bugs so as the weather gets colder and there are fewer bugs around, these birds must fly south to more productive feeding areas. Because these birds are small and are often food for larger predatory birds, these migrating songbirds will migrate in large flocks, sometimes with several different species of birds in one flock.
Several species of waterfowl use the coastal bays during migration, as either a stop over point or a final destination. Common loons overwinter here in the coastal bays, their distinctive calls and wails a winter favorite among birders and outdoor enthusiasts. Juvenile loons will make the migration south in their first year, however they will stay in our coastal bays and similar environments for two years as they mature, before finally migrating North again to breed during the summer of their third year. Buffleheads, a diving duck species, are similar to loons in that they arrive in October and spend the winter in the coastal bays before heading back up to their Northern nesting ground in April and May.
Even predatory birds migrate. Osprey start their southward migration during the fall, mostly during autumn. They will overwinter in Central and South america before returning for the spring migration in late February and April. Unlike songbirds and waterfowl, osprey generally migrate alone and will return to the same nesting grounds used in previous years during the summer, if it is available.
Just like birds migrate to find more hospitable temperatures, better food availability and other resources, fish migrate for similar reasons. A prime example of a fish moving seasonally is the iconic Stripped bass. These fish will spend the summer here in Chesapeake and coastal bays however most adult females will migrate south to overwinter in the warmer waters of the offshore areas near North Carolina. Not all stripped bass migrate though, as some adult males and juveniles will overwinter in the coastal and Chesapeake bays in deeper channels.
Atlantic Menhaden, a favorite food for many larger fish, also migrate south in search of warmer waters during the winter. Menhaden will begin forming large schools during the spring and summer and by the fall, these schools start to move south for warmer waters. Most Menhaden that leave the Chesapeake and coastal bays will overwinter off the coast of North Carolina also.
Bluefish and weakfish are other seasonal migrants. During the spring and summer bluefish migrate northward towards the Chesapeake and coastal bays and even upward to Maine. During the fall and winter months, the bluefish will migrate south towards warmer waters between North Carolina and Florida. Similarly, Weakfish spend the spring and summer in our coastal bays, feeding and spawning. As waters start to cool during fall, weakfish schools will migrate south towards the offshore area near the Carolinas as well.
Fish are not the only aquatic animals that migrate as water temperatures cool though. Over the past few years, we have seen seals from Northern areas visiting our coastal bays during the winter to rest and feed. Thus far we have four different species of seal that will visit us during the winter; harp, hooded, harbor and grey seals. While we do not have any breeding populations in Maryland, we have seen more and more seals in our coastal bays over the past few years. Generally, these seals are juveniles traveling alone from their Northern summer grounds to warmer waters along the Atlantic coast.
Fall is a great time to go outside and birdwatch, go fishing or just be outside in nature. With the leaves changing colors and the departures/arrivals of seasonal animal visitors, there is a lot to see on the Delmarva peninsula so go check it out!
Harrison Jackson is the Coastal Stewards Coordinator for the Maryland Coastal Bays Program.
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