Razor Wire Threatens Rare Bighorn Sheep at U.S.-Mexico Border

Conservation groups race to protect migratory path of endangered species as border wall construction continues

Feb. 1, 2026 at 7:15am

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Rare Peninsular bighorn sheep that have long migrated between the U.S. and Mexico are now facing a new obstacle - razor wire installed along the border. Wildlife advocates warn that the wire could trap and kill the sheep, cutting off their access to critical habitat on both sides of the border. They are working to install water sources and wildlife passages to mitigate the impact, but say more needs to be done to protect this endangered species.

Why it matters

The Peninsular bighorn sheep are a federally endangered species, with only around 1,000 remaining. Their ability to freely migrate between the U.S. and Mexico is crucial for their survival, allowing them to access food, water, and birthing grounds on both sides of the border. The new razor wire barrier threatens to sever this migratory path, putting the already fragile bighorn population at further risk.

The details

The U.S. Customs and Border Protection agency has announced plans to install razor wire along the entire 140-mile California-Mexico border, including in the remote Jacumba Wilderness where the bighorn sheep migrate. The sharp, glittering wire now extends up steep mountain slopes, blocking the sheep's traditional crossing points. Wildlife advocates have documented bighorn attempting to cross but turning back after encountering the barrier.

  • In mid-December 2025, a bighorn sheep was observed on the Mexico side walking along the border, apparently trying to cross but then turning back.
  • In October 2025, conservationists heard the sound of dynamite in jaguar habitat in Arizona, signaling the restart of border wall construction that had previously been halted.
  • In November 2025, an 81-year-old local resident witnessed Marines installing razor wire up a mountain slope in the Jacumba Wilderness, an area critical for bighorn sheep birthing grounds.

The players

Christina Aiello

A wildlife biologist and advocate with the Wildlands Network conservation nonprofit.

Jen Benedet

The acting deputy director for public affairs at the California Department of Fish and Wildlife.

Gregory Bovino

A U.S. Border Patrol official who previously advocated for adding a watering hole for bighorn sheep in the area.

Janene Colby

The former Peninsular bighorn biologist for the California Department of Fish and Wildlife.

Eamon Harrity

The wildlife program manager for Sky Island Alliance, a conservation group monitoring the impact of border wall construction.

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What they’re saying

“This is a little frightening.”

— Christina Aiello, Wildlife biologist (Los Angeles Times)

“The guzzler is something Chief Bovino wants, because he has an affinity for the Big Horn Sheep and wants to see them prosper.”

— Unidentified watch commander, U.S. Border Patrol El Centro sector (Los Angeles Times)

“We just keep throwing all types of barriers out in front of them, and we make it harder and harder for them to survive in their environment with what little they have left.”

— Janene Colby, Former Peninsular bighorn biologist (Los Angeles Times)

What’s next

The California Department of Fish and Wildlife is working with U.S. Customs and Border Protection to advocate for measures to protect the bighorn sheep, including installing water sources for sheep stranded on the U.S. side and creating small passages in the border wall for wildlife. However, conservationists say these steps are not enough and are calling on the state to take a more forceful stance in defending the endangered species.

The takeaway

The construction of the border wall, including the installation of razor wire, poses a serious threat to the survival of the rare Peninsular bighorn sheep. This highlights the broader impact of border militarization on sensitive ecosystems and endangered wildlife, underscoring the need for more comprehensive environmental protections and collaboration between government agencies and conservation groups.