Matt Vespa at Townhall reports that MSNBC found a new way to argue Trump's wall-building on the Mexican border is wrong. On Friday, MSNBC host Craig Melvin brought on biologist and Animal Planet host Jeff Corwin, who worried out loud that constructing a wall coult hurt not only the Mexican gray wolf, but birds and even bats: “if this border wall happens, it would be an unprecedented environmental catastrophe,” Corwin proclaimed.

Melvin promoted a new lawsuit by far-left Congressman Raul Grijalva of Arizona and the Center for Biological Diversity to delay construction until there can be a review of its biological impact. Corwin sounded like it was a catastrophe where no study would be necessary:

It’s poised to cut through more than 1200 miles of habitat along the border between the United States and Mexico. There are over 90 threatened and criticallly endangered species that are in the crosshairs because of this wall. And we’ve got over 100 migratory birds that will be impacted by this wall.

The Mexican gray wolf has only 133 animals counted in the wild (not counting a captive breeding population): “Its head is on the chopping block, and could likely head to extinction.” The jaguar “will be pushed back toward the precipice of extinction, because of this disastrous wall.”

Melvin tiptoed in with the obvious question about birds: “At the risk of sounding ignorant or foolish, the birds specifically. Wouldn’t they just be able to fly over the wall? “Excellent question,” said Corwin, and the answer was a keeper.

CORWIN: Certainly, many animals that fly can migrate over that wall. But many animals stay very low. For example, birds and bats are actually passing close to the ground surface because they’re heading toward plants for pollination, for seeds that they eat, or fruits. For example, Craig, you may not even know this, but 50 percent of the plants in the Sonoran desert, those cactus, 50 percent of them, have their seeds dispersed, or their flowers pollinated by bats, and bats use echo-location to navigate, and clearly a wall would be a terrible obstacle for them.

That makes bats sound so impaired it's a miracle they aren't extinct. The Arizona State University School of Life Sciences explains: "Using echolocation, bats can detect objects as thin as a human hair in complete darkness. Echolocation allows bats to find insects the size of mosquitoes, which many bats like to eat."

Corwin's helped cable-news networks hype green threats before. Also in 2007, Corwin was sponsored by CNN to be an environment correspondent for an Anderson Cooper 360 special called Planet in Peril. In 2009 Corwin also hosted a television special for MSNBC with the same title of his book Future Earth: 100 Heartbeats.

In 2009, Corwin also partnered with the activist group Defenders of Wildlife to host the documentary series Feeling the Heat with Jeff Corwin.