By Ty Fitzmorris
May is the great turning of spring to summer in the Mogollon Highlands of Arizona. Winter is firmly past, and in most years the seasonal creeks run with the very last percolating snowmelt while an extraordinary diversity of flowers abound. But May is also the beginning of the dry season, as regional climate patterns shift. The winter storms that had been flung our way from large storm systems over the Pacific are replaced by northering warm, wet air masses from the Gulf of California. Eventually these air masses will mature into the titanic cumulonimbus and torrential rains of our summer monsoon, but they are fueled by heat, which will not build sufficiently until late June.
We are lucky enough to have not one, but two distinct flowering seasons per year—our first great flowering happens this month, though it will be muted by extremely dry conditions, while the other great flowering is after the monsoon rains of mid-summer. Interestingly, many of our flowering plant species are unique to one or the other period. This bimodal flowering season is matched by peaks in activity in our animal species, as well. Insect activity follows flowering very closely, as insects either pollinate flowers or disperse the seeds that result from that pollination. The peak in bird, mammal, reptile and amphibian activity follows shortly after insects, as insects constitute much of the diets of these animals.
Because of this, the diversity of species and behaviors that can be seen by the observant naturalist this month is nearly bewildering, even in dry years such as this one. More new groups of insects emerge day by day. Look especially for the first damselflies of the season, flying near water like little, graceful dragonflies, blue and iridescent red. New butterflies continue to appear, including sisters, great purple hair streaks, metalmarks, snouts, checkerspots, skippers, and buckeyes.
As temperatures rise and relative humidity falls through this month, the risk of wildfire increases dramatically, which is exacerbated by woody plant die-offs from pest outbreaks. Fire has long been an integral part of the landscapes of western North America, and many of our ecosystems rely on it, but due to long-term fire suppression and changes in the fire regime from non-native grasses, fires now are often much larger and more destructive than any time in the past. It is extremely important that humans, as the primary cause of fires, handle all incendiary material carefully during this time, and refrain especially from throwing cigarettes out of car windows and driving cars and ATVs off road or in dry grasses. With careful management, such as that provided by the Prescott National Forest staff, fire can be carefully reintroduced into our wild areas, to the benefit of our fire-dependent landscapes.
A Very Brief Survey of What’s Happening in the Wilds
- Raven young begin hatching, and both parents begin around-the-clock nest brooding. During this time pairs are rarely seen flying, though groups of young Ravens can still be seen together.
- Fendler’s meadow rue begins flowering.
- Fendler’s ceanothus in full flower.
Visit: Spruce Mountain Loop, Trail No. 307.
Ponderosa Pine Forests
- Whitetail deer finish their spring molt, acquiring their soft reddish to tan summer coats.
- Porcupines give birth. These remarkable mammals are rare in the Central Highlands, but can be found sometimes in high aspen glades.
- Acorn woodpecker young begin fledging, and can sometimes be seen leaning out of nest holes in ponderosa pines. They might do this for weeks before attempting flight.
- Spikes of violet lupines (Lupinus spp.) and flocks of pink Woodhouse’s phlox (Phlox speciosa) abound, drawing bumblebees and digger bees.
Visit: Schoolhouse Gulch Trail, No. 67.
- Oak species continue to drop last year’s leaves, which change from orange-red to a soft light green as new leaves unfurl. Oaks flower during this time as well, causing allergies for many.
- Strawberry hedgehog cactus (Echinocereus triglochidiatus) flowers abundantly. Look for hummingbirds visiting the flowers.
- Mountain mahogany (Cercocarpus montanus) sets seed. These spiral seeds are fire-adapted, and drill themselves into the ground deep enough to survive mild fires. They drop now in advance of the upcoming fire season.
Visit: Little Granite Mountain Trail, No. 37.
- Pronghorn young are now over two months old, and can routinely be seen with herds, running as fast as adults.
- Globemallow (Sphaeralcea spp.), yellow evening primrose (Oenothera spp.), and Spanish bayonet (Yucca baccata) flowering.
- Antelope Horns (Asclepias asperula) flowers from now until August. This is one of over 20 species of milkweeds native to Arizona, all of which provide crucial food sources for monarch butterflies, the populations of which have been recently discovered to be declining rapidly. Many milkweeds can be cultivated, which helps monarch populations. For more information on this, go to MakeWayForMonarchs.org.
Visit: Mint Wash Trail, #345.
Rivers, Lakes, and Streams
- Fremont cottonwoods continue to release their fibrous, cottony seeds in large clouds. Cotton can form drifts several inches thick, especially in areas of dense cottonwoods, such as the Granite Dells, Watson and Willow Lakes, and Granite Creek in downtown Prescott.
- Riverside sedges flower while Texas mulberry bears its fruit.
- Young Anna’s hummingbirds begin fledging, while black-chinned hummingbirds finish building their nests of spider webs and lichen, and lay eggs.
- Warbler migration reaches its peak early in the month. Many exotic warblers have already been seen this year, including olive, Townsend’s, Wilson’s, hermit, and common yellowthroat. Our resident species are nearly all returned now as well, including Lucy’s, yellow, red-faced, Virginia’s, Grace’s, and orange-crowned warblers, as well as the yellow-breasted chat and the rare painted redstart, all of which are beginning to nest and lay eggs.
Visit: Sycamore Basin Trail in Sycamore Canyon Wilderness, USFS Trail #63.
- Many species of cacti flower, including pink and yellow prickly pears, hedgehog cacti and, at the upper limit of the Sonoran Desert, saguaros. Look for native solitary cactus bees visiting all of these flowers.
- Palo verde trees continue to flower, along with velvet mesquite and various acacias, mimosas, and some species of yucca.
- Sub-shrubs (small woody plants less than 2 feet high) flowering abundantly. Look especially for feather dalea (Dalea formosa), resplendent with vibrant, though tiny, purple flowers, which are surrounded by feathered filaments.
- Gila monsters become active, searching for mammals and bird nests in dry desert uplands.
Example: Agua Fria National Monument
- 4th—New Moon at 3:46pm.
- 6th— Eta Aquarid Meteor Shower. The peak of this moderate shower will be after midnight, with meteors appearing to radiate from the constellation Aquarius. This shower produces up to 20 meteors per hour, and since the waxing crescent Moon will set shortly after the Sun, the skies will be dark enough to see many of them.
- 18th—Full Moon at 2:11pm.
Average High Temperature: 75.5oF (+/-4o)
Average Low Temperature: 41.1oF (+/-3.9o)
All-time High Temperature: 97oF (1910)
All-time Low Temperature: 5oF (1899)
Average Precipitation: .47” (+/-.5”)
All Time High May Precipitation: 2.35” (1992)
All-time Low May Precipitation: 0” (22% years on record)
Maximum Precipitation In One Day: 1.3” (5/10/1922)
Source: Western Regional Climate Center