npr:

In northeastern Kansas, there’s an open-air ecological laboratory called Konza Prairie. Scientists like Ellen Welti go there to study plants, insects, and big animals. “In the spring it has a lot of beautiful flowers, it has bison; everybody should go visit and check it out for themselves,” says Welti, who is currently a post-doctoral researcher at the University of Oklahoma.

In this landscape, grasshoppers play a crucial role. They eat the grass; birds eat them.

Welti and her colleagues noticed that data collected over the past two decades showed the number of grasshoppers declining. Yet it wasn’t for lack of food. The amount of grass on this prairie actually has been increasing, which Welti found “kind of interesting.”