Arrowwood Viburnam(Viburnam dentatum) berries are high in energy but low in protein. It is a choice fruit of hungry migrants and quickly replenishes stores of fat needed to sustain long-distance flights.
Rhode Island is very important to migratory songbirds in the fall as a place to rest and refuel before continuing their long journey south. The migration begins at the end of August and goes through the end of October. Of course the dates are not exact; they depend on wind direction, food availability, and many other subtle factors.
When the day length, which is also known as photo-period, starts to get shorter in August the migratory birds begin to get ready for their journey south. A chemical is released in the bird’s brain that causes it to continue to eat and put on the fat necessary for its long flight. This state of constant eating is called hyperphasia.
As the night of migration departure approaches the birds go in to a state of Zugunruhe; in German zug means to pull and unruhe means disquiet. In the bird world it is known as migratory restlessness. They wake up slightly after dark and are extremely active before leaving. In the fall this phenomenon only occurs when there is a north wind, so that the birds will be flying with the wind at their backs.
The migratory birds work their way south resting at various places called stopover sites. Shrubland habitat areas found in coastal Rhode Island are important stopover sites for birds to rest, rehydrate, and refuel. Depending on weather conditions they will stay from one day to two weeks. Migratory birds continue flying from one stopover site to the next until they reach their wintering grounds in the southeastern United States (short distant migrant) or the shores of the Gulf of Mexico (long distant migrant). The long distant migrants then fuel up one last time and fly about 20 hours straight across the gulf to their final destination in Central or South America.
It is truly amazing that such a small creature makes a journey this long twice a year!
Block Island is a major stopover site off the coast of Rhode Island, especially for inexperienced 'young-of-the-year' birds. Important migratory bird information has been gained from a rich history of bird banding activities here since birds were first banded in the 1960's. Over 150 species of birds have migrated through Block Island on their way south in the fall. Visit a "handful" of these migrant songbirds in the slideshow "A Bird in the Hand...".September 24, 2012