Saguaro Land: A look at the vastly shifting landscape of the Sky Islands

Saguaro Land is a series from The Show looking at the Sonoran Desert — the lushest, hottest desert in the world that happens to be our home.

Within the Sonoran Desert sits what are called the Madrean Sky Islands.

There are 55 different sky islands in this region, to be exact — stretching from southern Arizona down to Sonora south of the border and even into parts of southwestern New Mexico. From desert floor to mountain tops, they can reach more than 10,000 feet in elevation. 

The Madrean Sky Islands region is incredibly environmentally unique. Traveling from the arid desert floor to the mountain peaks is equivalent in top to bottom distance as traveling from the Mexican border to the Canadian border — a distance moving from desert to grasslands to pine forests. 

They are some of the most biodiverse and environmentally unique regions in the world and a haven for scientists studying the ways plants and animals evolve to their surroundings. Emily Burns is the program director for the Sky Island Alliance. She joined The Show to talk about why they are a place to be protected.

Sky Island Alliance

Full conversation

LAUREN GILGER: In this series, we're exploring the desert we live in season by season, through music, art, literature, food, drink, flora and fauna. And today, I'd like to introduce you to someone who spends a lot of time studying wildlife here, or maybe I should say, spying on it.

EMILY BURNS: I've really fallen more in love with wildlife by studying them using wildlife cameras.

GILGER: Emily Burns is the program director for the Sky island Alliance, and they have wildlife cameras stationed across the region, triggered by the heat and motion of animals as they go about their lives.

BURNS: And so it's a really unobtrusive way to document animal activity, their behavior, and it has allowed us to see what is going on in these habitats when we're not there. You know, when humans go to bed, many of these mammals are out at night in these remote places where we can't be there as often as we would like to. In the field, we can leave these arrays of cameras out, and it gives us this wonderful picture of which species are here and what they're up to.

GILGER: What's the craziest species you've captured on one of these cameras?

BURNS: Our biggest surprise has been the North American porcupine.

GILGER: This species is not common in our region, and they weren't so easy to find. Even on camera.

BURNS: The first photographs that our cameras took of what we now know were North American porcupines were complete mysteries. They just looked like spiky, fuzzy beasts out there roaming around through the grass, and we couldn't figure out what animal it was and it wasn't until we finally got a photograph that showed the tail that we realized what animal we were looking at. And then eventually we've been able to get video and nice portraits of them and their faces, but it was just a real surprise. They're living in Cottonwood trees along the Santa Cruz River, right at the U.S.- Mexico border.

GILGER: The North American porcupine is just one of the multitudes of species Burns has found inhabits this biodiverse region within the Sonoran Desert sits what are called the Madrean Sky Islands. 

BURNS:The Sky islands are these amazing mountain ranges that jet up out of the desert, and you can see them from so many miles away because they are so tall.

GILGER: There are 55 different sky islands in this region, to be exact, stretching from Southern Arizona down to Sonora, south of the border and even into parts of southwestern New Mexico, from the desert floor to the mountain tops, they can reach over 10,000 feet in elevation.

BURNS: And if you imagine traveling from the Sonoran desert, where you're walking around among the Saguaro and start heading up upslope into these mountains, it transitions into grassland and then beautiful oak woodlands that remind me of California. And you keep going, and you get into pine topped forests at the top of these mountains, and the climate is so dramatically different. It's much cooler, it's usually much wetter.

GILGER: They are some of the most biodiverse and environmentally unique regions in the world, and a haven for scientists studying the ways that plants and animals evolve to their surroundings and to burns, they are a place to be protected.

BURNS: They say that driving from the bottom of a sky island to the top is the same as moving from the southern border of the US and Mexico driving all the way up to the Canadian border, because things shift so much in terms of vegetation and climate.

GILGER: Well, that's amazing. So the regions are incredibly diverse and also incredibly biodiverse, right? Like describe for us why the Madrean Sky Islands that exist right here are so unique and more unique than like other sky islands that exist in the world, right?

BURNS: Well, these aren't the only mountains of this size around the world, but we're in this amazing crossroads in North America where we get a blending of a bunch of different ecosystems. We have the Sonoran Desert. We also have the influence of the Chihuahuan Desert. Then we get Neotropics coming up from Central America that overlap in this region, and then we have the influence of the Rocky Mountains. And so these islands are like stepping stones between the Sierra Madre in Mexico and the Colorado Plateau. And they have all these corners tucked all over these mountaintops. With niches for different types of species. And so this is where temperate blends with tropical, and every animal and every plant finds a place somewhere on the mountains.

GILGER: And they're separated from each other. So it's, it's like a really interesting way to study your place, to study evolution, right of plants and species?

BURNS: Exactly, these mountains are called islands because these forests, in so many ways, are isolated. They're they stick up in elevation, up in the sky, and they're the forests on the top are an island away from the next one. They're separated by the desert and also by expansive grasslands. And those habitats are really different. It doesn't mean that animals don't move between the sky islands, and that's one of the things that that I work on the most, is thinking about, how do we allow this region to help animals on the move be able to reach different sky islands so they have access to all the habitat they need? Not everybody realizes that we have the American Black Bear here in Arizona.

GILGER: No, I did not.

BURNS: And they live in the mountains, and they will venture down, and you might encounter them in the desert as they're moving between sky islands. They'll come down, and apparently they will look for prickly pear fruit from time to time. So you may see them, but they are moving between the habitats that they depend on the most, the oak woodland forests and the pine forests. And they're more common in the Arizona sky islands than they are in Sonora, and they're endangered in Sonora. So when we think about habitat conservation and the sky islands, if we can make this region habitable, passable for bears and help them thrive, hopefully we can help them repopulate in Sonora as well.

GILGER: That's so interesting. So let me talk to you a little bit about what you love about sky islands, like you're this is part of your work, obviously. But why are you passionate about this

BURNS: I've really fallen in love with the region, because you can't go outside and not see so many different species. I was completely shocked just to learn about how many different animals we have in this area. More than half of the birds in North America either live here or fly through here during their annual migration. And there's 114 different species of mammals, which is more than anywhere else in the conterminous U.S.. These are species like black bear that I was talking about. We have four different cats, bobcat, mountain lion, Ocelot and Jaguar. We have American badger, North American porcupine, four different species of skunks, and it's just such a rich environment to encounter all of these species. And some of them have tropical origins, and some of them are temperate. I love that blending pot that we get to experience so much of what makes North America rich, right here? Yeah, in this area.

GILGER: So we have to also talk Emily about some of the threats that are facing this region, environmental threats, whether it comes to wildfires and climate change driven things like that, whether it's mining or just like human development. I know the border wall is a big discussion when it comes to preserving the sky islands, right, right?

BURNS: Well, because the sky island region is this diamond shape, right, north and south of the US Mexico border, everything that happens with border infrastructure goes right through the heart of the sky islands. And at this point, two thirds of the U.S. Mexico border in Southeast Arizona has a border wall, which means that the ability for animals to move between the sky islands on their historic migration routes, or just to reach the habitat they need to to have enough access to Food, water, mates and shelter, is completely restricted. The wall is stopping animals in their tracks.

GILGER: So let me ask you lastly, then about sort of your hopes for the future, or sort of your message here, in terms of how we all might appreciate and experience the sky islands that we live so close to in this region. Like, if you're listening to this for the first time. You've never heard of this. How would you recommend someone go out and sort of get a sense of how magnificent these are?

BURNS: Find a day where you can venture into a sky island, you know, take a picnic. Bring your binoculars. Bring a jacket. It's much cooler up there. This really, they call it summer haven on the top of Mount Lemmon near Tucson for a reason, and give yourself time to hike around and see just how many different habitats, how many different species are our neighbors here in the sky islands. I think that the more people that do that and understand how special this place is, the more we can work together. Or to keep it as intact as possible for future generations. It's just not replaceable, and it's really one, one of our best shared legacies here in this corner of Arizona, Northern Sonora.

GILGER: All right. Emily Burns is Program Director for the Sky Island Alliance, joining us to talk more about this region. Emily, thank you so much for coming on, for your expertise on this, for all of this information. I love it so much. Thank you. 

BURNS: Thank you.