More than one in four North American birds—nearly three billion—have vanished since 1970. Pictured: an eastern meadowlark.

By Sandy Townsend

If you’ve been seeing fewer birds in the past few decades, you’re right. There’s a reason, and it’s not a good one.

More than one in four North American birds—nearly three billion—have vanished since 1970, according to a study published in the journal Science.

The study’s lead author, Ken Rosenberg, is a senior scientist at the Cornell Lab of Ornithology and American Bird Conservancy.

The reasons for the loss vary, including loss of habitat, domestic cats, collisions, pesticide use and climate change. Birds are indicators of environmental health—and their loss signals a widespread ecological crisis.

The loss is caused by humans, so it’s up to us to help. Here are things you can do now, according to bird experts at the Cornell Lab of Ornithology:

1) Reduce your lawn and incorporate native plants into your landscaping. They use less water and attract bugs and insects that birds need to live. Use Audubon’s database to find native plants that work for your area: www.audubon.org/native-plants.

2) Say no to pesticides. Pesticides kill insects that birds eat and exposure to pesticides can delay migration. As a result, this hinders a bird’s survival. Don’t use rat poison, either. If an owl or hawk eats a poisoned rat, that raptor can be poisoned.

3) Keep cats indoors. Outdoor cats kill about 2.4 billion birds a year in the U.S. Outdoor life isn’t healthy for cats, either. They can be hit by cars or killed by predators and are exposed to diseases.

4) Reduce plastics. Plastic is harming wildlife, including birds that eat plastic or get tangled in it.

5) Make your windows safer. Birds can die when they hit a window. Install screens or break up reflections on windows with film, paint or Acopian BirdSavers.

6) Drink shade-grown coffee. Most coffee farms grow their plants in the sun, which destroys forest wildlife’s sources for food and shelter.

7) Become a citizen scientist. Citizen science programs protect birds by providing data that helps conservation researchers and land managers make appropriate, informed decisions.

To learn more, visit www.TampaAudubon.org. To find out how to help birds, visit www.birds.cornell.edu/home/seven-simple-actions-to-help-birds.