primary reason that our feathered friends migrate South in the Fall, or North
in the Spring, does not solely lie in the cold of winter, as most are well-equipped
to survive in extreme temperatures, but instead lies with the upcoming shortage
of food. Mother Nature endowed birds with an internal clock that warns them to
get out-of-town, or to face possible starvation. Because birds can to detect seasonal
changes, they take note when the days become shorter, and fly South in search
of alternate food sources, only to return home again in the Spring when there
is an abundance of tasty insects, or small, scurrying rodents.
additional trigger for birds to migrate is the need to breed to repopulate their
species. Often, they return in the spring to procreate in the exact nesting spot
they vacated in the fall. Birds certainly do qualify as creatures of habit!
streamlined, aerodynamic birds go to great lengths to make their migratory trips,
sometimes flying as far as to other continents, or from the lowlands to the highlands,
or from the interior of a country to the seashore. The Arctic tern holds the long-distance
medal for travel, as he travels from Antarctica to Massachusetts, logging up to
22,000 miles in stretches of up to 1,000 miles per week. Unfortunately, he does
not rack up frequent flyer miles! Most landlubbers make puddle-jumper like flights,
with the exception of the American Golden Plover, who undertakes a non-stop, direct
flight over the open expanse of ocean, from Nova Scotia to South America, without
making one pit stop!
some reason, most migratory birds schedule their annual departure and return dates
close to, or on the same day, as in the previous year. Their timing, however,
is not exact, as is the case with the legendary swallows of Capistrano, California.
Reportedly, their annual migration begins like clockwork on October 23, and ends
with their return on March 19. The legendary swallows sometimes do disappoint
and vary their migratory schedule, much to the chagrin of the California Division
scientific certainty exists as to how migratory birds establish their flight plans
or patterns. They are not blessed with the bat's radar system, so fly-by-night
birds have no physical landmarks to guide them, and those who make overseas flights
have no landmarks to go by, even during the daylight hours. The most prevalent,
plausible theory is that migratory birds sense the magnetic fields that surround
the earth, and guide their flights by these lines, which stretch from North to
South. How else would young birds, who have logged no flight miles, successfully
complete their migrations, especially in light of the fact that their mothers
leave them in the dust, and begin their migrations first? Whatever the reason,
neither snow nor rain nor heat nor gloom of night stays these birds from the swift
completion of their annual migrations.