The main thing I remember hearing about bird migration is that birds go south in winter and north in summer. Is that true? Actually, not all birds migrate like that.
In the Rocky Mountains, fall is an important time for wildlife, especially birds. As the days get colder and shorter birds need to do what is in their nature. For some, this means migrating long distances and for others it means staying put, but changing their diet. Here is why bird migrate and the different options that birds choose when it comes to migration.
Why Do Birds Migrate?
Birds migrate or not in order to find better resources of nesting sites. In other words, birds may go south in the winter because they know they can find more food there. Then in the summer they travel back north as food becomes available and they find a place to nest and raise babies.
Bird Migration – Complete Migrators
Some birds, the ones that we think of with the old saying that birds fly south for winter, are complete migrators. In wintertime these birds travel long distances to the south where it is warmer. These complete migrators may travel from the Rocky Mountains to Central or South America. Then in summer they migrate back to the Rocky Mountains where they breed (have babies). Roughly, birds migrate south in July to November and to the north from March to early June.
An example of a complete migrator includes the Turkey Vulture, which migrates to central America or South America.
Did you know? Some large birds migrate during the day, but most birds, especially small insect eating ones, migrate at night and rest during the day. They may be found in large groups during the day feeding in a forest or along a stream.
Bird Migration – Short Distance Migrators
Many birds migrate short distances. These birds are simply going somewhere else where they know food is more available. They may migrate from higher to lower elevations.
Examples of short distance migrators include…
Bird Migration – Non-Migrators or Resident
Some birds do not migrate during the cold winters of the Rocky Mountains. Rather they stay all year and adapt. This may mean they change their behavior such as what they eat or where they roost. Read more about how birds stay warm in winter here.
Examples of non-migrators include black capped chickadees.