NY Times article
here.

At dusk, 20 million Mexican free-tail bats would pour from the darkness inside
Bracken Cave on the outskirts of San Antonio, Tex., in a skillfully crafted
black tornado against the dimming orange sunset. But a few thousand feet away,
directly in their flight path, a community of 3,500 homes would soon stand.

That was the plan at least, until Halloween.

In an effort to protect both bats and would-be residents, The Nature Conservancy
of Texas and Bat Conservation International — with help from other groups,
including the Department of Defense and the City of San Antonio — purchased the
land for $20.5 million, providing a buffer between the bats and the encroaching
urban sprawl.