Prompted by some good discussion I've read on TexBirds and elsewhere: I want to stress the point that the danger to birds is not so much the height of the wall, but more the wide swath of habitat that would be cleared for the wall and service roads. Chachalacas, Pygmy Owls, Green Jays, etc will fly over a wall, but they're less likely to cross 100 yards of barren gravel. This project might as well be a 4-lane highway.
So let's try to take immigration completely out of the picture for a moment and imagine that, instead of a wall, the federal government was proposing to build a 4-lane expressway along the river from Brownsville to Laredo. Wouldn't there be a unified grassroots uprising against it? What if they revealed that it would cut right through parts of the LRGV Wildlife Corridor, which has been so carefully patched together and cultivated over the last 20+ years? And what if there would be no exit or overpass anywhere near the Sabal Palm sanctuary and other sites, effectively cutting those places off from the existing road system? And, on top of all that, what if they announced that, in order to speed construction, all environmental review would be waived? Wouldn't we all be outraged?
People may feel conflicted or uncommitted about the border wall because it is tangled up in hot-button issues of immigration and National Security. But those issues are irrelevant to the birds. The reality is that the wall (like an expressway) would be catastrophic for birds and birding in the valley (and what's bad for birding is generally bad for the birds), and we need to speak out to demand that those concerns be addressed. Congress allowed all this to happen, and they can change it, but they need to hear from lots of us. See http://noborderwall-take-action.blogspot.com/