We’ve Detected Over 100 Species in the Borderlands!

In March 2020, Sky Island Alliance partnered with Mexican nonprofit Naturalia, A.C. to document the wildlife that lives in or migrates through the U.S.–Mexico borderlands, one of the last remaining stretches of open wildlife corridor in the region. How does the documentation work? An array of 58 trail cameras operates 24/7 along 34 miles of the border and triggers whenever movement is detected.

Called the Border Wildlife Study, this critical wildlife project has run for six months now! Not only are we excited to celebrate 180 continuous days of research—which wouldn’t have been possible without your support, especially during a pandemic—we recently hit an incredible milestone.

Out of 12,000 wildlife sightings, we’ve found more than 100 species crossing these landscapes!

To celebrate 180 days of Border Wildlife Study (March–October), we wanted to share some interesting findings from our initial data analysis. Here are seven findings from our detection data:

1. We really do live in a biodiversity hotspot. The diversity of species in our study area—which is 68 square miles, roughly the size of Washington D.C.—is incredibly high! Our wildlife detections over the last 180 days include 30 mammal species, 48 bird species, and 23 insect and reptile species.

2. Mammal diversity is greatest in the Patagonia Mountains. In the areas where the Patagonias had higher canopy cover than the Huachucas or the San Rafael Valley, we found that our mammal sightings were unique, showing the most diversity. This is likely due to the range’s plentiful oak woodlands that provide food and shade for many species.

3. Meanwhile, bird diversity is greatest in the San Rafael Valley. The grasslands of this valley are expansive and parallel the U.S.-Mexico border. We found that an extraordinary number of bird species live in or migrate through the valley.

4. We’ve found that continuous oak woodlands with connected canopy cover is vital habitat for the mammal species in our study area. More mammals were detected in places with this cover.

Watch our six-month Border Wildlife Study update for data graphics, photos, and a great Q&A session.

5. Seventy-one percent of our mammal sightings occurred between sunset and sunrise, and 15 of the 30 species we detected throughout the study were only seen at night. This is an interesting finding and indicates that light pollution from border construction could impact species if full-time wall lighting is installed, as mammals that travel or hunt at night may no longer have the luxury of complete darkness.

6. Since the start of the Border Wildlife Study, we have analyzed two million photos! This includes photos with wildlife sightings and hundreds of thousands of blanks that triggered because of grass, tree branches, or other flora moving in the wind.

7. In the last 90 days, we’ve detected four new and unique mammal species, including the porcupine and a Mexican subspecies of Viginia opossum. Our study area is the southern distribution limit for the porcupine and the northern distribution limit for the opossum (showing how important it is for these uninterrupted transboundary corridors to remain open).

8. Our most detected species is the white-tailed deer! Also in our top ten are Mexican jay, deer mice species, desert cottontail, coyote, gray fox, javelina, mule deer, Cassin’s kingbird, and hooded skunk.

We’ve hit a huge project milestone in our Border Wildlife Study.


We are honored to be a part of such an amazing six months, and it wouldn’t have been possible without Sky Island Alliance and Naturalia’s many staff members, volunteers, and supporters. Despite the border wall construction that has destroyed critical habitat at the eastern side of our project in the Huachuca Mountains, wildlife remains resilient and connected to these lands. It gives all of us hope for the future.

However, our work is far from over. Our six-month study findings highlight the great threat posed to biodiversity by continued border wall construction. Active construction of the wall will disrupt wildlife corridors used by many of the species we’ve observed and destroy vital habitat and water sources like perennial springs, which are crucial to maintaining a balanced ecosystem in this fragile region.

It’s up to us to protect these landscapes. If you can, please consider donating to the Border Wildlife Study. Just $18.80 USD a month is enough to sponsor a camera in the field—and with your donation, you can help us heal the Sky Islands and reconnect wildlife with our incredible borderlands.