India, Oct. 29 -- In one desert river in the Southwest, there is a small bug and a small bird that are intertwined together. From satellite photos, it is found that when beetles were introduced to eat an invasive bush, 90 percent of the habitat required by the rare songbird has been reduced. The reason behind such reduction tells us how difficult it is to solve one issue without causing another.

The bird in question is the Southwestern willow flycatcher, an endangered songbird that spends from May to September in the rivers and streams of the Southwestern region. This bird builds its nest in tangled vegetation 10-13 feet off the ground, often near water sources. The 2007 survey numbers, as cited in the 2016 U.S. Geological Survey report ...