Under the Cover of Nightfall

2024 was a very busy year for me. I started this blog, got a piece published in AZA's "Connect" publication, and went on countless hikes and excursions into the beautiful Arizona wilderness, among other things.  Amongst the chaos that was the second half of 2024, nestled in between responsibilities and life changes was something very special: my wedding.  I got married in late October, and it should surprise no one that our small ceremony was held outdoors beneath the desert sun.  But the sun, alone, would not have made for a perfect day.  We all stayed outside as the moon rose high and the constellations found their place in the night sky.  And, for one of the last nights of the season, I pulled out my ultraviolet flashlight and took our guests searching for scorpions.  My wedding day wouldn't have been the same without them.

Photo by Alex Bickers

This region of the world is known widely for the bright, sunny days that occur year-round.  When most people think of the desert, they picture cacti sprouting up from dry, dusty soil with the blinding sun beating down upon them.  I'll admit that even after living here for over three years, this is most often what I picture. 

But you don't really know a place until you've seen it at night. Under the cover of nightfall, an entirely new world begins to emerge... 

Western Desert Tarantulas - Photos by Alex Bickers

If you've never gone on a hike at night, I highly recommend it (while taking appropriate safety precautions, of course).  There is nothing quite like hiking in a desert canyon at night:  The Milkyway shimmers above while the glow of the moon illuminates the landscape below.  You feel so small, nuzzled deep in the canyon with mountains surrounding you on every side.  Along the edge of those mountains are the faint silhouettes of saguaros reaching up into the dark sky, as if the earth itself were trying to reach the distant stars.  The desert feels still, yet it has never been more alive.   

You could live here your whole life and never see what this land has to offer without venturing out at night.  Compared to the daytime, the night desert overflows with life and movement.  In this region especially, nighttime provides some sanctuary from the heat of the day and allows a plethora of animals to leave their shelter in search of food.  

Solpugid (Camel Spider, Sun Spider, Wind Scorpion)- Photos by Alex Bickers

Once the oppressive sun has finally left the sky, many creatures are free to wander. Insects come out, followed by those that feed on the insects, followed in turn by those that feed on them!  The entire food chain is awake and active.

As diurnal creatures, it can be hard for us to appreciate just how many animals are nocturnal.  It's easy to move to a place like this and wonder "Where are all the scorpions?  The tarantulas?  Where are all the coyotes, javelinas, bobcats, and foxes?  Where is anything?"  I've heard people complain that they never see much wildlife in this area compared to the Northeast, aside from small lizards.  In all honesty, hearing that made my heart ache a bit, because this region is absolutely crawling with life.  I consider it a tragedy for someone to miss the extraordinary wildlife the Sonoran Desert has to offer.

If you are willing to venture out at "unusual" hours, with patience, the desert will start to reveal to you her secrets.  And what a privilege it is to be able to witness these hidden beauties.

On a warm evening this past September, I was hiking at the base of the Santa Catalina Mountains when I shone my ultraviolet flashlight on a scorpion and noticed that its back didn't seem to glow under the UV light.  I looked a little closer to find a magnificent sight:

Photo by Alex Bickers

Can you see it?  Look a little closer, without the blacklight:

Photo by Alex Bickers

BABIES!!!  This was a first for me: A mother scorpion carrying her young on her back while she hunted insects.  Juvenile scorpions may not glow under UV, or may glow faintly, because their exoskeletons are not yet fully developed or hardened with the chemicals that cause fluorescence. 

Another first for me this past year was found when walking around my neighborhood at night after some heavy monsoon rains.  There are several washes that run through town; These are channels that remain dry for most of the year, but become prominent streams after heavy rainfall.  I love how the washes provide a little bit of wilderness throughout the city: With vegetation sprouting up on either side, they act as pathways for coyotes, bobcats, and other wildlife to travel through even a densely populated area without being detected.  

After a monsoon, these washes are truly a sight to behold.  It's amazing how within just a couple hours, this dry patch of desert transforms into a deep, flowing stream, complete with semi-aquatic life.

On that calm, humid night, my then-fiancé and I went out to investigate a strange noise.  As we approached the flooded wash, we heard a chorus of strange calls that sounded almost like sheep.  We shone a flashlight down the stream to see hundreds of little eyes staring back at us.

Video by Alex Bickers

We later identified these little fellas as Couch's spadefoot toads.  These toads spend much of their time dormant underground, until the formation of the streams signals them to emerge and breed (but not until nightfall!).  Their eggs hatch within a single day, and the tadpoles must metamorphosize into froglets within a few weeks, hopefully before the stream dries up!  Isn't it amazing how even amphibians have adapted to survive in this climate? 

The Sonoran Desert is active 24 hours a day, though each time of day presents different opportunities for wild animals trying to survive.  You can find some of the most fascinating creatures here- but make sure you venture out after dark, or you just might miss them!

Photo by Alex Bickers

References:

Stachel, Shawn J.; Stockwell, Scott A.; Van Vranken, David L. (August 1999). "The Fluorescence of Scorpions and Cataractogenesis". Chemistry & Biology. 

"Couch's Spadefoot (Scaphiopus couchi)." Arizona-Sonora Desert Museum. https://www.desertmuseum.org/books/nhsd_spadefoot.php.