The wetlands are springing back to life in the Colorado River delta located mostly in Mexico just at the border with the United States. The endangered Yuma clapper rail croaks a funny song in the tall reeds that rise up out of the unexpected marshes in the Ciénega de Santa Clara. The snowy egret, vermilion flycatcher and Gila woodpecker are surging back in the Laguna Grande wetlands and the endangered yellow-billed cuckoo is found anew at this key stopover on the Pacific migratory bird flyway. Lured by water and habitat fix-ups through binational restoration efforts, bobcats and beavers are making a comeback, too.

These wetlands, to be clear, are south of the border line and may not be directly affected by any future border wall. But like other natural resources along the border whose health and well-being rests in a commitment to cross-border conservation, such as Big Bend National Park in Texas or the Sky Islands of Arizona and New Mexico, they are part of connected ecosystems already challenged by encroaching urbanization, increasing water demand and climate change.

The "migrant caravan" that has been dominating the news lately reminds us that human life is at stake at the border—and so is the health of entire ecosystems we humans depend on. Scientists are united in their assessment that a 30-foot high solid wall across the nearly 2,000-mile expanse of the border, along with the new lighting, roads and Border Patrol base camps that would accompany it, would threaten land and plant life as well as animals in this fragile and biodiverse place. It would threaten public lands that have protected status. And most important, it would fail to deter migrants fleeing violence and seeking security.

For 75 years, the U.S. and Mexico have worked together to manage their shared natural resources: a dozen rivers, protected lands, climate, even the air itself. The two nations' willingness to cooperate has grown in the last three decades as western states in both countries struggle with climate change, drought and growing water demand.

One success of this cooperation was the release of a one-time "pulse" of water on March 23, 2014. For the first time in anyone's living memory, children splashed joyously in the Colorado River as it flowed south from the U.S. into the delta towards the sea at the Gulf of California. Forty-three percent more birds now thrive in the restoration areas, 200,000 trees have been planted, and local people, especially women, are being trained to assist with scientific monitoring.

In July, over 2,500 scientists from the U.S. and Mexico, including MacArthur award winning biologist Paul Ehrlich, signed a letter published in the peer-reviewed journal BioScience decrying the waiver of federal and state environmental laws to build the wall, citing its irremediable consequences. The letter states that "the wall threatens some of the continent's most biologically diverse regions" and existing portions of the border fence are "compromising more than a century of binational investment in conservation."

Humans benefit from conserving a diversity of plants and animals both through economic gains to local economies from recreation-based tourism and via the ecological services nature provides, such as the medicinal benefits of plants, some of which are probably still waiting to be discovered. Restoration projects at the border provide jobs for local communities to help people stay home and earn a livelihood.

Research by the Center for Biological Diversity found a wall could affect 93 endangered, threatened and candidate species including jaguars, Mexican gray wolves and Quino checkerspot butterflies. The large mammals will not be able to move through their habitat to find water sources, food and mates. Twenty-five species, among them the Peninsular bighorn sheep and the desert pupfish, will find their living habitats degraded and destroyed on over 2 million acres within 50 miles of the border. Based on actual findings from the nearly 800 miles of border fence that already exist, we know that it isolates in Mexico some birds who can't fly over it, including the cactus ferruginous pygmy owl and many others. At a minimum, alternative designs should be seriously considered to include "virtual" walls of sensors and wildlife crossings.

The U.S. should draw on its innovative genius to think of new approaches that could benefit human migrants and nature alike, like investing in rural livelihoods and supporting democratic government institutions in Mexico and Central America so that people can stay home, survive and thrive. Binational cooperation shows us that visionary thinking has frequently led to more sustainable solutions on the environment. Let's challenge ourselves and our government to reject old-school ideas like a wall and get creative on finding workable ways to affect migration that are equally constructive, just, and humane.