Arizona Arroyo

White Mountains Regional Park in Phoenix, AZ photographed by Jeff Zablow

Southwest Airlines flew me from Pittsburgh to Phoenix, Arizona. Depart from the temperate eastern United States to the southwestern desert that’s most of Arizona. Oak and maple slip away from my view, replaced soon by cactuses and a host of plants that are new to me.

Here in the White Mountains Regional Park, I park my rental car and hike to this arroyo (dry river bed). I’ve been here before. It is a source of fascination for me and here I’ve found a large number of butterflies.

That’s the wonder and mystery of this habitat. Hiking in an arroyo is generally not promoted. If there were to be an instant storm above, there is Big risk of raging floodwaters surging down through the bone-dry arroyo, and you’d risk being swept away. Gone. So the element of distant danger, even on such a day as this, is understood.

We’ve noted the relative abundance of butterflies in earlier arroyo posts. I’ve not studied arroyos. Are there aquifers resting below? Is that why plants endure the dry arroyo bed? Do the steep banks of the arroyo carry down the morning dew? Is there morning dew? Let us hope that we will find answers to these questions, from Comments made by our Arizona friends.

Working the rock strewn arroyo, you are constantly reminded of the presence of mammals, reptiles, birds, insects, spiders and more. They peek out at you, or dart away as you quietly traverse the rocks. There is scat here and there, both tiny scat and sightings of considerable scat. I found both herbivore scat and carnivore scat. I walk this arroyo in the morning. Who and what move in it during the black night?

I like the arroyo. It never disappoints.


Empress Leilia Butterfly on a Spiny Hackberry Hostplant

Empress Leila Butterfly photographed by Jeff Zablow at White Tanks Mountains, AZ. Jeff blogs about the art and science of butterflies at

The rock strewn arroyo bed was as dry as the proverbial bone. It was September 12th at White Tank Mountain Regional Park west of Phoenix, Arizona, and Nectaring plants were very hard to find. Though 9:40 in the morning and of course with full Arizona sun, Empress Leila butterflies were here and there, flying and perching, flying and perching. Their host plant is spiny hackberry.

Astercocampa leilia are similar to, and closely related to Hackberry butterflies (see our Hackbery Emperor posts). Photographing here was difficult. When we spotted the butterfly, our approach had to overcome huge rocks. How these rocks were randomly placed in that arroyo is a tantalizing exercise in Physics.

As they are territorial like the Tawny and Hackberry Emperors, persistence with Empress Leila butterflies paid off. That is if it fled my approach, I knew it wouldn’t fly much beyond a definable perimeter.

Heat, boulders, and nearly unapproachable Leilias made for good memories, and a fair enough photo.

The heat, the heat, the heat.