Wildlife

Climate Change Affecting Bat Migrations

What started out as a simple study of how to safely monitor migrating bat colonies turned into a major discovery. Climate change is causing bats to migrate sooner, and in some cases, not migrate at all.

When they travel, bats usually do so in a swarm consisting of millions. When Mexican free-tailed bats bats migrate from Mexico to the Bracken Cave in San Antonio, Texas, the size of the swarm is so large it can be tracked using weather radar.

The researchers found that the bats are migrating to Texas roughly two weeks earlier than they were 22 years ago. They now arrive, on average, in mid March rather than late March.

Additionally, as of 2017, roughly 3.5 percent of the bat population is staying through the winter. Climate change is causing spring to begin sooner, in turn prompting insects to move to Texas sooner and giving the bats something to eat without having to migrate.