Enjoying the Wild Things column? Read more from Jay Ingram, including this article « They Went That-a-Way » in Canadian Wildlife magazine.
Traditionally, bird migration is thought of as a south-north movement. New research has found this may be wrong though.
When deciding to migrate, food supply is the number one factor (that’s the number one factor in many of my decisions too). This begs the question though, if birds are flying south to the bountiful food resources of the tropics, why would they ever come back?
One thing they face is overcrowding. Competing for resources means there is less to go around, so birds gradually expand their area they search for food, sometimes resulting in massive migrations if necessary.
Just as humans in Canada have summer homes and cottages away from all the hubbub of making their day-to-day living, so too do birds make trips north to have some space and avoid the crowds. Birds may also have bigger egg clutches in the north, so that is why they move.
Researchers still don’t have a definitive answer.
Read more about the history of bird migration and why researchers are still confused as to why it all happens in Canadian Wildlife magazine, Jan + Feb 2015 edition.
Feature image by Liam Ragan, a photo contest submission.