By Ty Fitzmorris
October in the Mogollon Highlands is one of the great turning points of the year — the warmth and activity of summer drops into the lower deserts and valleys as the cold of the coming winter (borne by heavy, cold air) slithers down the creek beds from the uplands. The evening air carries a sliver of ice and brings smells of wood smoke and high mountains, while the days are filled with dried grasses and the last of the year’s butterflies, native bees and flowers. The monsoon showers have finally passed, leaving a wave of activity in their wake — insects laying eggs, plants setting seed, birds migrating, and mammals preparing winter stores and putting on fat for the coming time of scarcity.
In October the second dry season of the year typically begins as the heat-driven summer monsoon pattern, which draws moist air masses north from the Gulf of California, shifts to the storm-driven winter pattern based in the Pacific Ocean, where massive storm systems catapult smaller, moist low-pressure troughs across our region, bringing snow and rain. And during this changeover the skies over the Mogollon Highlands tend to stay clear, though it is also during this time that the Pacific hurricane season is at its peak, and some of these hurricanes move through our region, dropping sometimes large amounts of precipitation.
October reliably brings our first frosts, and temperatures become increasingly intolerable for many of our insects and spiders, who utilize a range of winter adaptations in response. The tarantulas create dens in which to hibernate, ants gather provisions into large underground storerooms, and Monarch butterflies migrate south to the frost-free Mexican forest, though most invertebrates simply conclude their egg-laying and die, leaving their eggs, which are specifically adapted to extreme temperatures and drought, to bear their next generation in the spring. As insects diminish, so do the creatures that rely on them as food. Many of the birds, most notably warblers and swallows, have already migrated south to areas with more prey, as have some of our bat species. Hawks, predators of insect predators, migrate southward through our region now in increasing numbers, following broad valleys and grasslands as they look for rodents, who are, in turn, busy now gathering seeds and catching the last insects.
For many animal species, this is the time when nearly grown offspring are leaving their parents to establish new territories. Young Bobcats, Badgers, River Otters, Gray Foxes, Abert’s Squirrels, Porcupines, and several species of skunk will all be looking for their own territories now, finding food for the first time by themselves. Among the birds, young Great Horned Owls, Roadrunners, Lesser Nighthawks, and Mountain Chickadees are all dispersing into new ranges. Encounters between humans and many species are more common during this time, since young are relatively unpracticed at avoiding humans. Of course, as with virtually all of our wild species in the Central Highlands of the Southwest, the only risk to humans in these encounters results from animals being harassed or aggravated. Generally, a quiet and respectful approach will be rewarded by some degree of trust and can lead to extraordinary observations.
A Very Brief Survey of What’s Happening in the Wilds
• Elk continue their rut (or breeding season) and the bugling of males can sometimes be heard in more remote areas, such as Woodchute Wilderness.
• Porcupines (Erethizon dorsatum), which stay near to Aspen trees in our area, continue mating, while their adolescent young establish their own territories.
• Pregnant female Black Bears search out winter dens, which are often in old mineshafts. In our area only the pregnant females hibernate, during which time they will give birth, usually in January.
• Gambel Oak and Aspen leaves change color and begin to fall.
Visit: Dandrea Trail, No. 285.
Ponderosa Pine Forests
• Young Abert’s Squirrels (Sciurus aberti) leave their parents and establish their own territories. These squirrels have a fascinating relationship with Ponderosas, eating the tips of the growing branches, but also eating, and thereby distributing, the truffles and mushrooms that grow on their roots. These fungi help their host pines to gain nutrients that they otherwise could not extract from soil.
• Ponderosas continue to shed needles as they do every year around this time, losing 40 percent of their needles over these several months.
• The leaves of New Mexico Locust (Robinia neomexicana), a pretty understory tree, change to a beautiful yellow, as do those of Arizona Walnut (Juglans major).
Visit: Aspen Creek Trail, No. 48.
• Young tarantulas disperse into new areas and can sometimes be seen in large numbers. These large spiders are harmless unless harassed, in which case they release mildly irritating hairs from their abdomen, which can cause slight stinging. Their bite is non-venomous and not painful.
• Acorn Woodpeckers, one of the very few social woodpecker species, gather acorns with alacrity, storing them in characteristic granaries — trees (and sometimes telephone poles) into which the woodpeckers have carved holes for acorn storage. Acorn Woodpecker colonies are composed of up to a dozen individuals, and usually have two granary trees, each containing as many as 50,000 acorns.
Visit: Miller Creek Trail, No. 367.
• Four-O-Clocks (genus Mirabilis), the most conspicuous of our post-monsoon plants, continue to flower on rocky slopes.
• Feathered Fingergrass (Chloris virgata), a distinctive, hand-like native grass, appears now in many habitats, bearing its seeds, though many have been eaten by finches.
• Junipers still bear some of their blue-white seed-cones, which grow increasingly important in the diets of birds, rodents, and sometimes Coyotes as the weather turns colder.
• Goldfinches, House Finches, and many species of sparrows forage in mixed-species flocks, grazing grass seeds.
Visit: Juniper Springs Trail, No. 2.
• Young Short-horned Lizards (Phrynosoma hernandezi) leave their parents and disperse in the early part of the month. This is the best time for encountering the small young of this ant-eating species, though they should be handled with care, as they are capable of spraying a defensive toxin from their eyes. This defense is most often used on dogs and Coyotes, however, and the defense humans usually see is simply a flattening of the lizard’s body, which appears to be an attempt to look larger.
• Several species of hawks migrate through grasslands, riding thermals (large rising columns of warm air) during the afternoons. Look for Rough-legged, Ferruginous, Swainson’s and Red-tailed Hawks, as well as Turkey Vultures, with several species sometimes in the same thermal.
Visit: Mint Wash Trail, No. 345.
• During fall evenings, river drainages are often colder than surrounding uplands, as cold air from higher ground flows down them. This is especially noticeable in the evening. For this reason some rivers that drain off of high mountains will be the first areas to freeze, and leaves change here first, as well, beginning with Black Walnut and Velvet Ash trees, which drop their last leaves this month.
• Young Great Blue Herons (Ardea herodias) disperse into new areas, and some will migrate south through our rivers. These gangly fishing birds will sometimes migrate in large groups, occasionally up to 50 or 100 individuals, and are thought to travel as far south as Venezuela.
• Golden Columbines (Aquilegia chrysantha) bear their seeds.
Visit: Bell Trail, No. 13.
• Paloverdes, Velvet Mesquites (Prosopis velutina), and Wright’s Silktassel (Garrya wrightii) bear their seeds now, as do Southwestern Coral Beans (Erythrina flabelliformis), the poisonous seeds of which are sometimes used for jewelry.
• Ocotillo leaves change color and fall for the second time this year. These strange plants have photosynthetic bark, however, so they will continue to photosynthesize through the winter.
• The queens of our one species of bumblebee, Bombus sonorus, fly now in their nuptial mating flights and shortly afterward will look for overwintering refuges where they will remained buried singly through the freezes of the winter. Bumblebees can produce propylene glycol, a natural antifreeze, within their blood, which prevents them from being killed by freezing. In the spring, these queen bumblebees will emerge and begin new colonies.
Visit: Algonquin Trail, No. 225.
Average high temperature: 72.2 F (+/-3.8)
Average low temperature: 37.3 F (+/-3.5)
Record high temperature: 92 F (1980)
Record low temperature: 13 F (1935)
Average precipitation: 1.06” (+/-1.23”)
Record high precipitation: 7.82” (1972)
Record low precipitation: 0” (10.3 percent of years on record)
Max daily precipitation: 2.4” (Oct. 6, 1916)
Source: Western Regional Climate Center
Note: These figures do not reflect 2017 data
Ty Fitzmorris is an itinerant and often distractible naturalist who lives in Prescott and is proprietor of the Peregrine Book Company, the Raven Café, Raven Sound Studio and Gray Dog Guitars, all as a sideline to his natural history pursuits. He is also the Curator of Insects at the Natural History Institute. He can be reached at Ty@PeregrineBookCompany.com with questions or comments.