Wading a Desert River in the Magic of June and Nearly Bitten by a Rattlesnake

For the past twenty years or so, I have participated in a coordinated  volunteer project aimed at monitoring the presence of water along the length of the San Pedro River in southeastern Arizona. Organized by The Nature Conservancy, this project provides important data to scientists, land managers, and many others on the health of the river system during the hottest and driest month of the year. The data is collected the old-fashioned way – gathered by teams who experience the river in the best and most intimate manner possible, by walking and wading. Every June, I collect a portion of this data along a rare, perennially-flowing reach of the San Pedro located in the river’s middle valley, often accompanied by friends and neighbors. This year, two wonderful friends who also happen to be great neighbors assisted me in this worthwhile and delightful task.

Since June always brings oven-like temperatures, we began walking around 5:30am along a waterless stretch of the riverbed. Almost immediately, we discovered fresh tracks of an adult black bear and a cougar, etched in dry sand. One and a half miles in, the magic of water appeared. From that point on, the river flowed steadily. Because the brush is often nearly impenetrable along portions of the riverbanks, we waded, a much easier way to travel as long as one can avoid hidden lenses of quicksand. More mammal signs and tracks appeared; Coue’s whitetail deer, mule deer, javelina, coyote, bobcat, raccoon, coati, skunks, cottontail rabbits, mice and rock squirrels. Familiar bird songs spilled from the forest; summer tanagers and kingbirds, ash-throated flycatchers and song sparrows, southwestern willow flycatchers and black phoebes, grey hawks, tyrannulets, northern cardinals, Lucy’s and yellow warblers, and more.

The river in June is a different world from the surrounding vastness of desert habitat types – humid, verdant with profuse life, cool and shaded. It feels and smells almost subtropical. So much life graces the river and its forests in June that these annual walks have become my favorite time to explore and experience the beauty of the San Pedro.

Wading this desert river in the heat of June is magical. The cottonwood-willow forest stands tall and green, casting shade and coolness enabled by millions of fluttering leaves. The forest’s understory is verdant with lush growth. Eight-foot tall burr reed (genus Scirpus) plants crowd the riverbanks. Aquatic patches of speedwell (genus Veronica) glitter with multitudes of blue-purple blossoms. Tall willows form a vivid green arch overhanging the river. Birds sing from the depths of the forest, many butterflies, bees, and wasps drink from water’s edge, and scores of lowland leopard frogs leap at one’s every step. Below the surface, schools of long-finned dace are darting like shafts of animated light through the clear water. The continued presence of native frogs and fish are strong, positive indicators of the health of this aquatic ecosystem.

Among the most remarkable predators in the insect world, dragonflies are a common sight along the summer river. Some twenty-two years ago, an entomologist discovered nearly one dozen species of dragonflies and damsel flies that were new to science along this part of the river.

We waded for a couple of miles, feeling the warm, shallow waters of the river filling our shoes, until the waterway started to broaden and slowly deepen. I suspected a beaver dam was ahead. We climbed up on shore, then began to weave our way through a dense tangle of tamarisk and seep willow. Before long, we could see the beaver pond clearly, the water deeper and deeper, then the dam, plugging the river with a meter-tall, thirty-foot span of branches, twigs, tree limbs, rocks, and mud. I was elated to see that this reach of the river had beaver activity once again. The ecological and hydrologic benefits of beavers to this river – and many other waterways – are legion. I devoted an essay to this important topic in my book, The Life of the San Pedro River.

A cool, deep pond extends upstream of the beaver dam. Such dams hold more water within the river system, helping to recharge the aquifers that feed the river and its forest. The positive benefits of beaver ponds to plant life and many wildlife species could fill a book. Note the turbidity of the impounded water, a sign that the beaver(s) had been active there the night prior.

A moment of reflection seated atop the beaver dam before I was almost envenomated by a rattlesnake. Photo by Tom Talbott.

       My companions and I slithered down the steep riverbank to begin wading the final stretch below the dam. We had taken just a few steps when one of my friends suddenly threw his arm around me and pulled me out of harm’s way. A 3-foot western diamondback rattlesnake, coiled too close for comfort along the edge of the river channel, erupted in a frenzy of rattling. The forward third of the reptile’s body was off the ground and formed into an s-curve as the snake’s glistening black tongue waved slowly, curled backwards over its snout. Fully cocked, primed, and quite willing to strike. My fresh shoe print was about 14 inches from the rattlesnake. Had I not been yanked so suddenly by my alert friend, this snake would have probably tagged me. I have never come so close, despite encountering hundreds of diamondbacks here over the course of the last two decades. This experience underscores a crucial rule that I try to teach to everyone that I take into the wilds here – you should watch where every footstep is headed during the warmer months in southern Arizona! Sometimes, that is easier said than done.

This is the snake that I stepped far too close to, coiled, rattling, and very ready to strike defensively. Note the recent injury on its back, something that may have amplified its angry mood. If I weighed in at less than a pound or two, and a huge, towering, 200-pound bipedal mammal threatened to step on me, I’d be in a biting mood too.

READING LAND – AN ICONIC LIZARD AND A UNIQUE SOUTHWESTERN MAMMAL

This will be the first installment of “Reading Land” on this blog. More will come in the future. The art and science of reading a landscape and its life is at the very heart of what a naturalist does. Learning to read the tracks and other signs that creatures inscribe into the places they inhabit can reveal a great deal of information that may not be gleaned in any other way. “Reading sign” is instinctive with me after a lifetime of study in the outdoors. Read on to discover how animal signs can instill a sense of fascination and wonder in those who learn to notice – and interpret – them.

On a hot, midsummer day not long ago, I walked over to our shed; a simple, no-frills, three-sided building with a dirt floor that all manner of wildlife love to visit. The fine-grained, dry soil renders tracks with plenty of detail. As I walked in, a new set of tracks presented themselves, tracks made by a creature unique to this part of the world, a creature that is very rarely seen in the wild. A Gila monster had investigated the shed, leaving some fascinating tracks. Unlike other lizards in southeastern Arizona, this one has dimpled feet, so identifying its tracks is straightforward as long as the substrate will reveal fine detail. The lizard’s tracks reminded me immediately of porcupines, for they are among the few mammals that also have golf-ball-like dimples on the soles of their feet. I believe the porcupine’s dimples are an adaptation for climbing, and could serve Gila monsters in a similar way. I once thought that these big, bulky lizards were 100% terrestrial, but after living with them for many years, I have learned that it is not uncommon for them to climb up into trees. Bird eggs are highly sought after by Gila monsters; herpetologists state that they have a close association with quail…ground-nesting birds that provide roaming Gila monsters with a rich source of food via their eggs. Why not search the trees for the eggs of other birds?

Strange tracks in my shed revealed the unseen presence of a rare creature, a Gila monster. Note the unique dimples in the tracks.

Finding tracks of a rarely seen animal is exciting! I would have had no idea the lizard was around were it nor for those distinctive tracks. With respect to certain animals, reading their sign has taught me more about them than anything else. Wolverines, for example, roamed the Montana Rockies where I grew up. I have hiked more than 17,000 miles in occupied wolverine habitat in the wildest parts of Montana, but I have only seen a wild wolverine once. They are rare. I learned a lot about them, however, by following their trackways for long distances, particularly during the winter, when snow transformed the landscape into an open newspaper.

A coati in the barn…when lone individuals are encountered, they are usually adult males like this one. Otherwise, coatis are normally seen in social groups.

Here along the San Pedro River, interesting animal signs are often written into the face of the land. One of this region’s other unique animals is the coati. These social omnivores wander the river bottoms in groups of up to thirty or more individuals, foraging for food. 

A sand bank along the San Pedro River has stories to tell of the animals that live along the river…

Along a dry reach of the river, I discovered some long claw marks etched into the sand banks, along with some holes that furred paws had been digging into. The width of the claw marks, coupled with the place where I found them, and the animal’s investigation of many of the adjacent holes pointed strongly to the work of a coati. These raccoon relatives dig for a living, using a highly developed sense of smell to locate grubs, insect pupae, and other foods hidden underground. I find their tracks and their signs far more often than I see them.

A closer look at some of the claw marks in the sand bank. These were left by a coati.