What do you get when you add water to the desert? A jungle, of course. The Sonoran Desert is already one of the wettest deserts on earth, pushing the limits of what constitutes a desert. Ask people to give their image of a desert and they'll say, "sandy", "hot", "barren". Occasionally someone will come up with the one true and necessary component - aridity. Deserts may not be sandy, they may not be barren, often they are hot, but just as likely may be cold. They are all dry. To be a desert, a region must be dry, where potential evapotranspiration is greater than precipitation. Generally, 10" of precipitation is the upper limit for being called a desert. So, even on a normal year, we're pushing it here in the Arizona Upland division around Tucson with our annual average of 12".
A couple of hurricane remnants plus a rewarding monsoon has turned our desert into a virtual jungle. As I introduce my Sonoran Desert Discovery tours at the Desert Museum and talk to people about what constitutes a desert, they look out across the landscape and see nothing but greenery. The looks turn skeptical. Desert? No Way!
Even now, in November, when other parts of the country are shivering and shoveling snow, the greenery dominates our views. Wildflowers still bloom. The cold-deciduous acacias and mesquites have given no thought to losing their leaves. Butterflies are abundant and very active.
|Queen on Milkweed|
|Southern Dogface nectaring on Lagascea decipiens|
I led the Butterfly Walk at the Desert Museum last Friday and my two guests from Ohio were boggled by the number and variety we saw. I believe our count was close to 20 species, even including a lone Monarch. Monarchs are not common here, though we do see them in small numbers. Much more common is the Monarch relative, the Queen, another of the milkweed butterflies. Many sulphurs, blues, hairstreaks, ladies, Empress Leilia, American Snouts, and more.
|Southern Dogface Butterfly (see the poodle head?)|
Another blast of color signals the day's close.
The desert is happy!