Sonoran Desert Spring
When lengthening days meet clearing skies that have been swept free of winter storm clouds intense sunshine spreads over the landscape bringing the “alchemy” of warmth that heralds spring in the Sonoran Desert.
During this time period, even as the days rapidly increase in temperature, the nights may still quickly become remarkably chilly following sunset. The clarity of the desert air coupled with its low relative humidity and the lack of clouds above allows most of the days heat to escape and freely radiate into space.
Throughout the spring in the desert, moisture from the passing weather fronts of winter that was trapped by the reaching heights of the needy desert mountain ranges may still find its way in surface streams cascading down onto the floors of the desert valleys that surround them.
Most of these flows would evaporate before they can sink in just a few weeks later in the year under the shimmering heat of the summer Sun.
However, in the spring the shade cast from miles of rocky canyon slopes and cliffs helps to hold down the heat and reduces evaporation of moisture for a large portion of each day as if to whisper, “Stay a while longer”. And, each mile of canyon bottom cups the precious fluid in fingers of stone that form numberless pools to prevent its loss. In open areas weathered rocky mantles of pebbles, gravel, and cobbles serve to protect and “mulch” the thin soils below from moisture loss due to heating and the wind.
If the canyon bottom pools are heavily shaded or if they are large enough the water in these rocky “Tinajas”( Tanks ) may last from the spring through the usually waterless months of May and June until the arrival of the rains of the Sonoran Desert monsoon season later in the summer. Given a general lack of flowing surface water in most desert regions for several months of the year, many Sonoran Desert plant types along with most birds and the larger animals have become dependant upon the tinajas and their friendly surroundings for their survival.
The signature cool nights and the persistence of moisture in the landscape through the spring come as relief and are promises to the inhabitants of the desert and its travelers that for some short weeks the Sun will not yet rule the land.
This is the setting that frames many peak experiences when viewing the spectacular sunrises and sunsets, forms of the majestic giant Saguaro Cacti, wildflower displays, and unusual animals of the Sonoran Desert spring.
The evidence for change that announces the arrival of spring in the Sonoran Desert is all about for those who use its desert trails, tracks, and routes.
Numbers of northward migrating raptors and other birds can be seen sailing above the desert slopes where countless small Mammalaria Cacti with light colored spines that are accented with dark fishhook-shaped spines are found. Their tiny pink and white striped flowers usually begin the annual blooming of the cacti that will last through the summer. Pink to magenta and plum colored showy flowers of short-stemmed clusters of scattered kinds of spiny Hedgehog Cacti will appear next. These are followed in turn by the yellow flowers found on the flattened disc-like “pads”(stems) of several types of Prickly Pear Cacti. The large white blooms of the Saguaros signal the end of spring in mid-April as they flower to get their red fruits ripe and seeds on the ground before the coming summer monsoon rains.
The dispersed flowers from several types of plants that grow from bulbs, such as the white flowered Desert Anemone or lavender to blue Papago Lily, begin the annual show of the classic wildflowers that may reach a crescendo in a riot of patches of color in the valleys and on hillsides that are acres in extent Areas that show gold Poppies mixed with blue Lupines, white Tackstems, and magenta Owls Clover are favorites for photographers of all ages.
Hill topping and canyon cruising butterflies hatch as early as February and begin their searches for mates and “butterfly” plants for their eggs as they are supported by the nectar from spring blooms.
When viewed close up the amount of plant growth and diversity seen in the bright greenery of annual plants germinated by winter rain and sheltering under the canopies of desert trees such as the “Palo Verdes”( in Spanish Green Sticks/ Woods ), “Palo Fieros”( Iron Woods ) and Mesquites and other shrubs and plants is astounding. Although it is greatly dwarfed in “amount” by the plant growth seen in other regions and climates, it should be appreciated that the Sonoran Desert supports several times the number of “species” of plants found in most biomes elsewhere!
This situation makes itself apparent again when one realizes the overwhelming amount of animal “diversity” that the plant life of the Sonoran Desert supports. All three members of the Racoon family in North America are only found together in the Sonoran Desert. This is notably the same for the four kinds of skunks! And the list continues……
For instance with the first days of warm temperatures each live branch of the gaunt and very spiny Ocotillo or Coachwhip is suddenly hidden within a sheath of bright green leaves in preparation for growth and blooming. Often a companion of the Ocotillo in the lower and driest areas of the Sonoran Desert is the “Chuparosa”( Hummingbird ) Bush which forms a tangled jumble of pencil thin bare stems for most of the year. But in the spring these plants can be the first desert plants to provide showy splashes of color as they both produce large numbers of intensely red nectar-bearing flowers that are the sole forage for migrating hummingbirds!
Wildlife activity picks up quickly leaving as signs increasing numbers of tracks and new spoils cast up from winter quarter holes and tunnels.
Cottontail rabbits and two kinds of Jack rabbits( actually “hares” ) are present year around but become much more noticeable in the spring as they increase their numbers on the abundant new plant growth. Nervous and hyperactive tan Round-tailed and white-striped bushy tailed Harris Ground Squirrels along with their more sedate larger cousin Rock Squirrels emerge from winter burrows and begin day-time activities.
The first reptiles to be seen are small lizards that immediately begin to “harvest” the plenty provided by numerous insects and other arthropods. And, it is no coincidence that they are pursued by, ever alert, Roadrunners that seemingly had disappeared during the winter! Desert toads and frogs will wait until the warmth of full summer and monsoon rains come to make their appearances.
By spring the half grown fawns of White-tailed and the much larger Mule Deer are being weaned and take tentative steps away from the sides of their does to browse upon tender new plant growth. And, in isolated desert mountains Bighorn Sheep browse upon “haloes” of bright yellow flowers at the tips of stalks on Brittle Bush.
Fleeting and compelling, spring in the Sonoran Desert is a call to experience adventure while it is abundant with life and the promise of its continuance.
This was written by Bill Peachey, Southwest Trekking Guide Extraordinaire.