Rare Autumn Color Transforms the San Pedro’s Forest

For the past three years in a row, I had made a date with the San Pedro River: I would spend my birthday walking the river under the gilded magnificence of tall willows and stately cottonwoods alight with prime autumn color. For the past three years, the autumn colors have failed to shine. “Autumn,” if you can call it that, comes late to this river’s riparian forest. Fall colors do not peak here until the second week of December. The timing does not vary due to temperature or climate, it functions via the most universal and reliable of nature’s temperate region chronometers: the photoperiod. In most years, the trees along the river either suffer a hard freeze before the second week of December, or they get stripped off by strong winds, or both. Freezes can rob the forest of its fall color overnight by turning all of the leaves a withered brown. 

When conditions are just right, chlorophyll fades from the leaves to reveal anthocyanic compounds that transform the forest canopy into a fluttering galaxy of bright yellow leaves. This year brought a reprieve from late November winds and early December freezes – this was one of those special years…so I set out for a walk on my birthday, a serene journey into the river forest. The following images help to tell the story of a rare day on the river.

The  first place I walked to that morning was a hilltop where I saw the lone cottonwoods pictured above, lifting plumes of sunlit gold skyward. As I watched, a great egret came sailing out from behind the trees! Imagine an elegant pair of outstretched wings spanning over four feet, the bird flawless, brilliant snow-white, set against a clear blue sky. My wonderful new binoculars brought this seldom seen creature in close and sharp – what a gift it was to witness the egret! My jaw went slack when a second egret appeared to join the first. The pair then departed northward, winging over the tops of the trees as they followed the river that sheltered and fed them. I envied their freedoms.

A rich blend of plant communities (and thus many habitat types) is underscored by the blaze of autumn color along the river. Here, a dense growth of velvet mesquite and catclaw acacia flank the riparian forest. Highlands are visible in the distance, providing more habitats for wildlife and wild plants that vary according to aspect and elevation.

I left the hilltop, then returned to the riparian forest, where I walked down to a favorite sitting spot by a bend in the stream just below a vertical cutbank. There, a set of cougar tracks was pressed into  the moist sand, made the night prior by an adult male. I sat under a willow to look, to watch, and to take in the morning’s biophony. The forest was quiet, the still air punctuated by a slight rustling of leaves above, the quiet murmur of the river water, and the voices of a few birds. As sunlight warmed the cool air, small clouds of midges began to rise within discreet, sunlit areas above the water. There, the air temperature was most favorable for their airborne gatherings. As the midges danced in the light, a gray flycatcher began sallying back and forth into the insect clouds, garnering breakfast with typically adroit flycatcher movements. Then another bird joined in the feast, flying into the swirling insects to garb morsel after morsel with some amazing acrobatics. It turned out to be a ruby-crowned kinglet! I had no that clue kinglets could – or would – engage in such feeding behavior.

A favorite and long-familiar reach of the San Pedro River in mid-December dress.

Next, I walked down the river until I got near the northern terminus of my trail. The going was easy, the stream shallow in most reaches. I was glad to find no recent signs of trespass cattle anywhere, nor any signs of feral pigs. There was little in the way of animal tracks, as a heavy mantle of recently shed leaves covered most of the ground thoroughly.

A dense carpet of crisp, shed leaves draped the forest floor. This made for noisy walking!

I heard these Gould’s turkeys before I saw them emerge from the forest to slake their thirst at river’s edge.

Gooding’s willows cast long shadows into a beguiling artist’s chiaroscuro of glistening water, dappled light, and autumn leaves.

As I neared the end of my walk, I veered into the forest to avoid some deep water. (For much of the way, I’d been wading.) The wind suddenly arrived, causing a blizzard of shimmering golden leaves to return to the ground that had bore them, an entrancing display of fluttering motion and light as one of nature’s grand cyclic acts of life unfolded all around me.

Truly a stellar birthday!

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.

A Spectacular Hidden Slot Canyon in Roadless Wilderness

Last week, two friends and I embarked on a short hike up a roadless drainage in an effort to scout the area for a group hike that I will be leading in a few days. We were also hoping to explore an amazing slot canyon that one of my friends had discovered more than a quarter century ago. 

I  refuse to publicly divulge the location of the canyon for several reasons. First, there is the matter of deep respect for the many living things that call the canyon and the surrounding area home – a rich  community of undisturbed native plants, insects, snakes, birds, mammals, etc. Secondly, when wild places are publicized, more and more people inevitably go there. Trails get carved into fragile desert soil. Litter appears…candy wrappers, used toilet paper, beer cans, broken bottles and spent shell  casings from those who carry weapons. Initials get carved into once pristine stone walls and the garish rudeness of graffiti mars the sanctity of the place. Sensitive wildlife species leave or disappear altogether. All I will disclose is that this area is somewhere within the 4,720 square-mile San Pedro River Drainage in southeastern Arizona.

Our walk led up a wash (desert speak for a streambed that remains dry during most of the year) under cloud-flecked skies on a warm spring morning. Less than a mile in, we came across the signature tracks of what has become the region’s apex predator (next to humans). Just two centuries ago, that role would have taken a back seat to the indigenous people, jaguars, wolves, and grizzlies that thrived here prior to the arrival of large numbers of Euro-Americans.

This track appeared in soft sand, made by an adult cougar that had walked by the night prior. The cat was a female – mingled with its tracks were the tracks of a single cub that had become large enough to be thinking about going out on its own before long. Mountain lions are primarily crepuscular and nocturnal hunters. They are incredibly adept at hiding quietly – even in scant cover. They utilize large home ranges. The combination of these factors adds up to a furred ghost that very few people ever get to glimpse in the wild.

March is a month that spurs changes in southern Arizona’s avian world. As we walked, turkey vultures soared overhead, recent arrivals from their wintering grounds. Mockingbirds and cactus wrens were singing with newfound spring zeal. Two other recently arrived migratory species made themselves known- one by voice, a gray hawk – and another by sight, a large, lone, black-colored bird flying over a distant ridgetop. Its silhouette formed a distinctive, familiar shape. The combination of broad wings and a wide, short tail nearly touching the trailing edges of the wing feathers strongly suggested a common black hawk. As the raptor curved its flight path, banking its body, the tail suddenly flashed a broad white band, cinching the identification. The hawk had just appeared here from migration; had we been in the same area only days sooner, it was likely that we would never had seen it.

Not long after the black hawk, we changed direction, exiting the wash to ascend a gentle slope leading toward my friend’s slot canyon. Two of us followed as he led the way to the base of some sandstone cliffs…

From a distance, these large, vertical rock outcroppings looked enticing, but the entrance to the canyon was not yet visible.

As our viewpoints changed, the entrance to the slot was revealed.

Just inside the canyon’s mouth was this western white-throated woodrat palace. The rodent’s nest (it was currently occupied) can be seen at the bottom of the rock wall. Woodrats literally evolved to prefer steep rock faces as integral parts of their habitat. They are highly adept climbers. Note the whitish stains on the rock wall a few feet above the nest, and the cavity in the rock face farther above with similar stains issuing from its base. The cavity is a frequently used hiding place for the rats, who mark their nocturnal trailways with frequent squirts of pungent urine.

Everyone knows about stalactites and stalagmites, but did you know that they can be made from urine? This is a closeup view of the white-stained area a few feet above the rat nest depicted in the photo above. Centuries of frequent use by woodrats depositing countless dribbbles of pee has caused actual stalactites to form. These are smaller than the stalactites often seen in caves (formed from water-borne mineral precipitates) but they are stalactites nonetheless.

A series of funnel-shaped walls towers above the person seated at the end of this short but fascinating canyon.

The view from inside looking straight up at a cerulean slice of sky.

The person aiming her camera gives a sense of scale to an otherworldly realm.

Multiple funnel-like chimneys form the back of the canyon, where sediment-laden water has carved repetitive shapes in the sandstone, inching its way back through time. These cone-shaped circular funnels are narrow at the top, then widen progressively as they descend to the bottom. This has me mystified. Natural water funnels the world over form with wide mouths at their tops that narrow as the funnel goes down. The shapes in this photograph depict inverted funnels. Even when I try to understand this via methods that include something like the Coriolis effect, they do not make full sense to me. There are numerous singular rock funnels like these in this region, but few places feature multiple funnel shapes like this canyon does.

Our hike revealed another rare part of this wild landscape: a saguaro with multiple cristate heads. It will be interesting to watch this cactus as its deformed meristems grow larger in coming years.

A Rare Bird Surprise, a Huge Insect, and the San Pedro River in October

It has been quite a while since I crafted a new post for this blog. During the past month, my life had been turned upside down with growing trepidation over the presidential election. I was not in a frame of mind conducive to writing. Now that the election is over, I feel a huge sense of relief and renewed hope. This was an election not only for the people, but one that will benefit wildlife and wild places as well.

I walked a perennial reach of the San Pedro River recently. There was  a new beaver dam, just a tiny one that was still under construction. Turkey, javelina, bobcat, deer, coyote, opossum, raccoon, and skunk tracks were visible in the mud along the stream’s edges. I was intrigued to find a set of feline tracks that suggested ocelot or jaguarundi, for they were certainly not made by a bobcat and were just as surely not left by a cougar, even a very young one.

A small, new beaver dam was discovered. This one was constructed using quite a few stones in addition to the usual combination of mud and tree branches.

October has finally brought some relief from the heat that so characterized this summer…109 consecutive, record-setting days of temperatures cresting at 100°F. or higher. The nights have cooled off and crisp air now graces our mornings. Our local woodlands have quieted considerably with the departure of many migratory birds, but there have been some amazing avian happenings here this month. A very rare event happened not long after the sun had set a few weeks ago. My wife, Kathleen, and I stepped outside to listen to the nocturnal sounds coming from the mesquite forest that surrounds our home. 

We heard it almost at once, a mysterious, alien-sounding voice emanating from midway up in the trees, only a few dozen yards distant. It was certainly an owl, but not a species that we had ever heard here before. On many a night, we have listened to the calls of great horned, western screech, barn, and elf owls in this woodland, but this was something new, something distinctly different. It suggested a screech owl, but both of us readily agreed that it was not “right.”

I had a growing hunch, so we went back indoors where we consulted a very useful website (xeno-canto.org), one that offers a multitude of audio files for most bird species across the globe. The first species that we chose to listen to was a bird whose range barely extends into the United States, a bird that inhabits oak and conifer habitats high on mountain slopes in extreme southeastern Arizona… 

As soon as we heard the recordings, we realized we had a whiskered screech owl hidden in the darkness of the tall mesquites only yards from our home! This was an owl that should not be here, for we live far from the high mountain slopes in the floor of a low-elevation valley. I believe that a major wildfire event from this past summer may provide the answer to this enigma. Less than 20 miles distant, the Bighorn Fire torched nearly all of the mid-to high elevation habitats off the face of an entire mountain range, the Santa Catalinas. Countless birds were driven off of those mountains, subsequently appearing in nearby places where they would ordinarily not be expected. For example, my friend Woody Hume, a very capable naturalist, told me that he had numbers of western bluebirds appearing at his place of residence not long after the fire. That is a species one does not expect to see during summer in the valley floor. Other such unusual species have been reported here this year. I would not be surprised if the owl that galvanized our attention had been living high in the Catalinas and wound up here, temporarily, as it looked for a new place to live.

A fully grown praying mantis crawls across my screen door. This is a gravid female, ready to lay her egg case, as evidenced by her swollen abdomen.

October and November brings new happenings in the insect world of southeastern Arizona. It is common to find adult preying mantises at this time of year. It is impressive to see one of these three-inch, bright green insects in flight. The individual pictured is an introduced species that has become widespread and firmly established in southern Arizona and other parts of our country.