Monday, November 7, 2011
Sonoran Desert Fall: October and November
Fall in the Sonoran Desert is a return to paradise. After the long endured scorching summer, redemption comes to desert life. October begins with average highs in the 90's and ends with highs in the low 80's. But throughout the month summer isn't quite sure if it wants to stay or go. The mornings and evenings can be quite beautiful but afternoons will often hit 100 degrees. Other days temperatures will only hit the low 80's though. But eventually, by the end of October cooler temperatures win out and day after day beautiful temperatures will be the rule through April or early May. Typically, fall in the Sonoran Desert is quite dry but fortunately not nearly as dry as May and June. This year we are especially dry around Phoenix due to a very disappointing monsoon season. We have had a little rain in October and early November, but only just enough to help keep things cool and prevent things from being completely bone dry.
Fall is not quite as exciting in the desert as it is in deciduous forests (desert dwellers are absolutely ecstatic about cooler temperatures though!). For colorful leaf displays through, riparian areas that support cottonwoods, willows, sycamores, or ashes will produce ribbons of yellow across the desert landscape. Often, if summer rains were decent, an abundance of fruits available for migratory birds. Prickly pear fruit, wolfberry, and hackberry are often available for these birds providing both nourishment and hydration.
The most notable event of the fall is the arrival of migratory birds from the cold north. Hawks of many types are often seen soaring through the sky. With a little closer observation a great diversity of song birds can also be found. I have often come across small flocks of out of place birds passing the winter in certain localities. While Northern Cardinals can be found in the desert through out the year, they are by far most common during the winter months. In one particular year I frequently came across a small flock of Eastern Bluebirds living on a mountain slope. Areas with an abundance of water will typically host large flocks of many species of waterfowl, quite an unusual site to the desert. A part from birds, mule deer are preparing for their rutting (mating) season which begins in November. During the rut, bucks scrape the velvet of their antlers in preparation for mating sparing competitions. If you are fortunate enough to observe mule deer bucks this time of year you will often observe them running around and acting like they are crazy. Once, I was even charged by a large buck, which luckily changed his mind when he was about ten feet from me! Snakes are also commonly found due to the cooler temperatures which make them more sluggish. By November, nearly all reptiles will be hidden away in hibernation waiting for warmer temperatures.
In rare years, maybe once or twice a decade, El Nino in the Pacific Ocean will bring an abundance of rain in the fall. These El Nino storms will cause masses of wildflower seeds that lay dormant in the soil to germinate and begin to slowly grow through winter months before they bloom in spring. Typical dry fall weather though usually ends early December with gentle winter rainstorms blowing in from the Pacific Ocean. The first storm quite reliably hits during the first few weeks of December bringing the next big annual changes in the Sonoran Desert.