Tag: queen butterfly

Desert Life During Late Monsoon and a Bizarre Parasite

The 2021 monsoon season in southeastern Arizona has certainly been one of the most memorable. At our home acreage in the Middle San Pedro Valley, 9.81 inches of rain have graced the land since the rains began on the second day of July. Other locations within less than 40 miles of us have received over 16 inches! The result is a landscape – and an ecosystem – burgeoning with a refulgence of renewed life. Since regional records have been kept, only the 1955 and 1964 monsoon seasons can compare. The scene above, featuring a landscape bursting with fresh, vivid green growth crowned by a rainbow is emblematic of Arizona’s monsoon.

As the monsoon wanes, migrant birds visit our feeders and watering places; notable appearances this year have included large numbers of Nashville warblers and an exceedingly rare blue bunting, a species that has never been “officially” recorded anywhere in Arizona. As the season approaches autumn, many changes occur in the world of reptiles and insects as well. Rattlesnakes are moving toward their hibernacula sites. The year’s last generation of butterflies brings flashes of beautiful color to the ecosystem. Other insects are reaching maturity, such as several types of native grasshoppers and katydids.

During the past two weeks, great numbers of mature lubber grasshoppers could be seen in many places in the valley floor. Their presence and abundance are a reflection of the monsoon rains that have enabled an explosion of plant life – a smorgasbord for grasshoppers. At this time of year, these bulky creatures have reached their final instar and are actively seeking mates.

A mature lubber grasshopper, Brachystolla magna. It is normal to see large numbers of these heavy, slow-moving insects during the tail end of our monsoon season. Note the tiny vestigial wings – this grasshopper is incapable of flight.

In mid-August, just after an afternoon rainstorm, I watched a female ornate box turtle emerge from the bosque to drink from a rivulet of rainwater. As she was slaking her thirst, I caught a flicker of movement some forty feet beyond her at the edge of the trees. It was a male box turtle. He had spotted her, and this was mating season. If you think turtles are slow, you have never seen an amorous male box turtle chasing a female! There is nothing subtle about box turtle sex. The males literally run down and attempt to corner the females, who move nearly as fast in their attempts to elude the charging males. Once the pair is joined, mating can take upwards of an hour.

A male ornate box turtle in hot pursuit of a prospective mate. I have seen this happen a number of times; what is most amazing to me are the distances at which the males first spot the females when the chase begins. In relatively level areas with open ground, males can visually discern females located at least 30-40 feet distant. Once a female is spotted, the male immediately makes a beeline to her at top speed.

The chase ends with a successful mating, allowing the circle of life to continue as it has for countless millennia.

Last week, my wife Kathleen discovered a new species of beetle, (one we had never seen here before), floating in a rain collection bucket. She rescued the hapless insect – a gorgeous, iridescent creature known as  the Carolina tiger beetle.

This glittering, multi-colored tiger beetle got a new lease on life when it was rescued from a full water bucket.

Tiger beetles are incredible insects. The have been a part of my life since boyhood, when I often attempted to catch them as they raced across the ground with what seemed like otherworldly speed. Very few insects are faster on land than tiger beetles. Tiger beetles are hyper-alert predators equipped with unusually long hind legs for rapid propulsion. Their big heads house a pair of huge compound eyes capable of acute long-distance vision. The visual field of a tiger beetle encompasses more than a full hemisphere. When a prey item is spotted, tiger beetles run it down, then secure their meal with a set of long, formidable, serrated mandibles.

A lateral view of the Carolina tiger beetle, Megacephala carolina.

Most species of tiger beetles are diurnal, but the Carolina tiger beetle is an exception, preferring to be active after dark. I wonder if any part of these insects would glow under a UV light source? A number of other local nocturnal creatures glow under ultraviolet light, including scorpions and pocket gophers.

Butterflies are often abundant during the monsoon. As I was working outdoors one day, I noticed a fresh chrysalis hanging from some old wire fencing. I recognized its form; it had been made by a caterpillar that was a member of the butterfly subfamily Danainae. Insect species native to Arizona that belong to this group comprise three look-alike species: monarch, queen,  and soldier butterflies.

The chrysalis hatched in a short time – only a week or so – to reveal a gorgeous queen butterfly. After hatching, the butterfly clings to the shell of its empty chrysalis, pumping blood into its unfolding wings.

Once the butterfly’s wings have expanded to full size, it is normal to see the insect remain perched for some time as it slowly opens and closes its wings, readying itself for its maiden flight.

Many plants native to the desert southwest have specially adapted themselves in a variety of ways to the summer monsoon season. One of the weirdest, most bizarre, and fascinating is a plant known as dodder. The first time that I encountered dodder, I stared in sheer wonder for some time while thinking “what the hell is that?”

Patches of dodder are a common sight during the latter half of the monsoon season.

Dodder grows as a vine, commonly forming a scattered profusion of very fine, yellowish tendrils that snake their way through the vegetation. It is a plant that cannot manufacture chlorophyll. Dodder survives by obtaining water and nutrients from other plants – it is an obligate parasite.

A closer look at dodder, (genus Cuscuta).

The weirdness begins just after a dodder seed sprouts following a monsoon rain storm. The minuscule seed – nearly microscopic – sends a small, shallow root into the soil while raising a tiny, thin tendril above ground. As the tendril grows, it starts to turn in upwardly-ascending spirals. It is not seeking light as most plants do – it is searchingfor a host. As the tendril lengthens, its spirals correspondingly enlarge, until it makes contact with a nearby plant. The tip of the tendril is chemosensory; it can literally sniff out what sort of plant it touches. Dodder is selective about the company it keeps – only certain plants will do as suitable hosts. If the tendril likes what it senses, it wraps itself tightly around the plant’s stem, then sinks a feeding tube – known as a haustoria – into the stem.

At this point, the seedling’s tiny root dies. The dodder plant then obtains all of its water and nutrients from its host. It will continue to grow and search, attaching itself to more plants. Once it has inserted enough feeding tubes into its victim(s), dodder reaches a point in its physiology that enables it to reproduce. Clusters of tiny white flowers erupt from the vine’s stem, ensuring the plant’s future.

Our local species of dodder sprouts clusters of small, white flowers – these grew from a dodder vine that had entwined itself on the stem of a pigweed (Amaranthus palmeri) plant.

So what is truly bizarre about this parasitic plant? Research has documented the fact that dodder actually steals sequences of DNA from its host plants’ genes, then incorporates them into its own DNA. The process is called “horizontal gene transfer.” This results in better survival for the dodder plants. It also enables them to manufacture strings of RNA that it sends back into the host plant, causing the host to weaken its defenses.

Dodder plants are classified as  members of the Convolvulaceae – the morning glory family – with over 200 species worldwide. The genus,  (Cuscuta), has a global range, occurring in tropical, subtropical, and temperate habitats. Dodder has a slew of common names, many of them derogatory – strangleweed, witch’s hair, devil’s guts, scaldweed, devil’s hair, and hellbine.

When considering this plant, we should strive to avoid the common propensity of our species to pass judgement on other life forms….often the result of our high capacity for arrogance-as-a-species combined with ecological  ignorance. Simply because dodder is a parasite does not make it bad. Estimates place the percentage of parasitic organisms on Earth at 40-50% of all species. Clearly, parasitism is an essential part of the recipe for life on Earth. Here in the Middle San Pedro Valley, one of dodder’s favorite host plants is pigweed. Even when heavily infested with dodder, local pigweed plants continue to grow and produce viable seed.

A Photographic Tour of Early Summer Life Along the San Pedro River

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Summer has come to the river and its valleys, bringing a cavalcade of change to the animal world. Today, my thermometer registered 113° F. I don’t leave southern Arizona during the summer like so many people do every year. This is my favorite season here, because so much happens in the natural world during the fierce heat of summer…

Mike and Mavis have successfully raised their seventh brood here on our land. This year, four new ravens have fledged and left the nest. Here are two of them. Note the pinkish-white bordering around their beaks and their pink mouths. As they mature, the pinkish color on their beaks disappears, and the inside of their mouths turns black.

Several weeks ago, the velvet mesquite trees erupted with fresh blossoms. These are the precursors to an abundance of bean pods that provide one of the most crucially important food sources for the valley’s wildlife.

A closer look at the flowers of a velvet mesquite tree. These blossoms perfume the air with a sweet, heady fragrance.

A queen butterfly alights to drink from the wet mud surrounding our watering hole. This insect is often mistaken for its well-known cousin, the monarch.

The back side of a male Gould’s turkey in full display. These birds – and their tails – are huge! The white tips on the tail feathers are one of the field marks that distinguish this race of wild turkeys from their eastern relatives. Part of the display involves dragging the wing tips on the ground, an action that creates a loud rasping sound, meant to intimidate rival males.

A male summer tanager comes to feed from a block of suet. This is America’s only all-red bird, a living statement of resplendent color and grace. Their future in this valley is being threatened by large numbers of brown-headed cowbirds.

This male black-headed grosbeak has been sending his voice through the bosque every morning, a series of loud, robin-like notes.

Few of our western birds are more strikingly colored than the western tanager. A different race of this species stays here in the valley floor to breed every summer. Most western tanagers utilize very different breeding habitats – namely, conifer forests at higher elevations.

A male blue grosbeak that visits daily for water. Blue is one of the rarest of colors among Earth’s terrestrial vertebrate animals.

A new beaver dam graces the flow of the San Pedro River. Dams like this permit substantially more water to infiltrate the ground below their surfaces, recharging the shallow aquifers that give life to the river’s riparian forests of cottonwoods and willow trees. There were five more dams below this one. I cannot think of a single mammalian species that is more beneficial to the river and its forests than beavers are.

I awoke one morning to find this characteristic fresh imprint at the foot of my entry steps. A rattlesnake had curled up there the night prior, leaving its signature circular mark. No other Arizona snakes rest in such a circular position. For reference, the grizzly track cast in concrete is six inches in width. Grizzlies were once common along this river until they were wiped out by Spanish and American settlers.

A black-tailed jackrabbit resting in the shade of a mesquite trunk on a toasty summer day. When the heat cranks up, animal behavior changes. This hare let me approach within four feet, something it would not have allowed on a cooler day. The name “jackrabbit” is a misnomer, as these creatures are hares, not rabbits.


Until I came to live in southeastern Arizona, I would not have believed that there could be pink snakes native to our country. This coachwhip snake appeared on a hot afternoon, five feet of blazing bubblegum pinkness!

Coachwhip snakes are expert climbers. Kathleen and I looked out a window one day to see this tail protruding from an active Gila woodpecker nest. Fortunately, the snake did not wipe out the entire brood – it consumed one or two nestlings and moved on.

A gopher snake encountered on a sandy bank of the San Pedro River. These snakes attain lengths of seven feet or more and are often mistaken for rattlesnakes. They are among the most effective rodent controllers we have. Favored food items include mice, rats, and gophers.

A diamondback rattlesnake slithers through the mesquite bosque, traveling in a manner common among rattlesnakes, using caterpillar motion. When snakes crawl in this fashion, their bodies remain almost straight rather than sinuously curved. We never kill these animals. They have a right to live here, no less than we do. When summer comes, we are always on guard, watching closely where we place every footstep, especially after dark.

Beavers add a special touch of beauty to the river, creating ponds that mirror their surroundings and provide needed habitat for a long list of other creatures.