I have always looked forward to the month of April in southeastern Arizona, for it brings a great diversity and large numbers of migrant birds to the land – or does it? The first time that I birded the San Pedro River was in April of 1977. In a word, that was a stunning experience. The numbers of birds were incredible, as were the variety of species. Today, the story could hardly be more different.
Migrant songbirds (and other migratory species) have been steadily declining ever since Europeans began to populate the North American continent. The rate of decline was slow at first, but it has increased continually through the centuries. During the past several decades, declines in bird populations have become so severe that some birds have become extinct, while others are persisting by the thinnest of threads.
Here in the Middle San Pedro Valley, I have been participating in avian surveys and have been keeping detailed records of local bird life for 21 years. The data is disheartening, but this year has been the worst thus far. Numerous species that have appeared on schedule at our property every past April are simply not appearing. Many others are here in very low numbers. Sadly, close to 100% of these declines are attributable to mankind. Overpopulation, urban expansion, climate change, pesticides and herbicides, tremendous habitat losses, loose house cats, and more add up to a world that is becoming quieter and quieter every spring.
What is spring without bird song?
Other happenings in the natural world have been occurring as well, ones that are not disheartening. Lizards and snakes have awakened from their winter brumation to add their grace, color, and life to the land. A few days ago, a Sonoran gopher snake appeared a few feet from my doorway, followed by the year’s first diamondback rattlesnake and the emergence of Clark’s spiny lizards. Our resident ravens, Mike and Mavis, have successfully hatched yet another brood and are very busy keeping their youngsters well fed. A nice abundance of wildflowers is coloring the upland slopes.
The gopher snake mentioned above. We always welcome these harmless and beautiful reptiles. They play an effective role in controlling rodent populations.
This was a slender male, close to 3 1/2 feet in length. Sonoran gopher snakes can attain lengths approaching eight feet, making them one of the nation’s longest native ophidians.A closer look reveals the large, curved, robust rostral scale at the forward tip of the snake’s head. This kind of scalation evolved to shield and protect the heads of gopher snakes as they push their way through soil and pursue rodents deep into their burrows.
Every year in this valley seems to bring its own explosion of certain insects. Earlier this month, incredible numbers of crane flies could be seen. I recall walks where every step flushed 20 or more from the surface of the ground. Crane flies belong to the family Tipulidae, with over 15,000 species worldwide. They are a successful and adaptable group of insects, for their presence in the fossil record dates back over 70,000,000 million years.
A pair of crane flies, busy assuring that their kind has a future. These innocuous insects are sometimes called “mosquito hawks,” for the mistaken belief that they prey on mosquitoes. On a recent walk in the valley with a friend, we paused to admire this rare cristate saguaro, made even rarer by its unusual paired, symmetrical shape.
Incredibly, on the very same day, another friend was roaming the valley when he discovered this huge, cristate specimen. Photo by Gilbert Urias. April brings the return of turkey vultures. Here, one has landed to scrutinize one of our bird watering dishes. Among several unique aspects of these vultures is the fact that they have no syrinx – the organ that allows birds to vocalize. Turkey vultures can hiss by expelling air rapidly, but they cannot call to one another nor utter any sort of song.A close look at the vulture’s head reveals a large perforation in the bird’s beak. When viewed at just the right angle, one can see that the large hole goes all the way through the beak to the other side. Turkey vultures locate the majority of their food via a keen sense of smell, an unusual trait among most other birds. The perforated beak likely helps these birds to smell with great facility, channeling airflow into their nasal scent receptors. (The quality of this enlarged image is poor due to limits that my blog hosting service places on image resolution.)
Shallow watering dishes can do wonders for attracting bird life and many other desert animals as well.
A wonderful and always reassuring sight! The riparian forest that is so deeply important to the valley’s wildlife glows with a verdant spring canopy of cottonwood and willow leaves. The color contrast between the riverside forest and the surrounding uplands is strong in April. The forest – a true hallmark of this valley – is completely dependent upon the San Pedro River and its subterranean aquifers.
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.
Early summer in the Middle San Pedro Valley has brought us some uncommon sights. One of our nation’s most dazzling – and sneaky – songbirds is the varied bunting. No larger than a small sparrow, varied buntings often appear black unless they are viewed at just the right angle in favorable light. They occur in small numbers here; we typically see only one or two of them in our bosque every summer. They are sneaky because we never know when they will appear, which is infrequently at best. A beautiful male will drop from the mesquites to grab a quick drink of water from our bird pond, then quickly disappear into the depths of the woodland, not to be seen again for days or even weeks.
My wife Kathleen photographed this male varied bunting through the kitchen window just days ago. When viewed from an elevated position (like our kitchen window), a blazing scarlet patch can be seen adorning the top of the male bunting’s head. This is no accident. Birds often view one another from above, so bright patches of identifying color on the top of their heads help them to keep track of who’s who. Photo by Kathleen Waldt. An even rarer sight here in Cochise County, Arizona comes in the form of another bunting species, the painted bunting. When this female landed at our water dishes in May, Kathleen identified it immediately. The males are among our most brightly colored songbirds, but females are far more subtle. The softly colored green back gives this one away.
Last week, a rare find presented itself in the form of a fresh Gila monster trackway etched into the fine dust along the side of our shop building. The only other animals that can leave similar trackways here are turtles, but a close look at this trackway leaves no doubt as to its maker.
I discovered this trackway less than an hour after it was made, but try as I might, I could not locate the Gila monster that made it. Finding Gila monster tracks is uncommon; finding an entire trackway like this one is downright rare. The animal that made these tracks was a young individual, roughly 9 – 11 inches in length. A closer look reveals distinctive footprints and a drag mark left by the lizard’s tail down the center of the trackway.
The month of May brought the expected blooming of saguaros, but this year the huge cacti did something very strange. Instead of crowning the tips of their trunks and arms with halos of blossoms, they grew flowers both on the tops and down the sides of their heavy arms. I had never seen this phenomenon until this year. Locals are saying that this is a response to the severe drought we are experiencing in the desert southwest. I want to know why the plants are behaving like this.
A very rare sight! Flowers extending far down the sides of saguaro arms. Normally, they are located only at the tips of the arms and atop the crowns of saguaros. Photo by Kathleen Waldt. Another rare sight in the form of a cristate saguaro. Like its neighbors, this one had blossoms sprouting down the sides of its arms.
