|| Thermoregulation || Torpor || Water Conservation || Size Matters ||

In this section, I will cover the major ways plants and animals adapt to the water and temperature stresses they experience around Tucson, AZ. When we think of deserts, and Tucson's desert is no exception, we usually think of blistering heat and death by dehydration (you know the saying, "At least it's a dry heat"). You can go to the climate section to see just how hot and dry it is around Tucson. Yet, plants and animals still thrive in our desert. How do they do it? Below you will find a general outline.

There are three basic methods plants and animals use to live in the desert.

Expire When the going gets tough, die... but leave behind tough seeds/eggs. This is what our annual wildflowers do, like this bahia and its seeds.	Evade When the going gets tough, leave... go north or south, go up or down a mt., change activity from day to night or from above ground to below. Here is a kangaroo rat asleep in its burrow during the hot day (see torpor).	Endure When the going gets tough, take it... but you better have good desert adaptations like these plants.

Strategies to ENDURE the harsh desert conditions are many, but can be organized as follows:

Ways to Endure Lack of Water:

Store Water Water can be stored by animals in fatty deposits in their tails and other tissues (e.g., in the gila monster's tail). Water can be stored in the roots, stems, and/or leaves of plants (plants that do this are called succulents).	Conserve Water Minimize loss of water out of the skin (cutaneous loss), from urine and feces (excretory loss), and from "breathing" (respiratory loss) through various means (e.g., see torpor).	Tolerate Dehydration Many of the desert plants (e.g., this prickly pear cactus) and animals (e.g., desert toads) can tolerate great losses of water out of their bodies without dying.

Ways to Endure High Temperatures:

Reduce Heat Input This can be done by staying out of the sun, by shading (e.g., spines/fur), by posture and orientation (e.g., orienting leaves vertically to minimize surface area directly hit by sun), by insulation, by shiny surfaces that reflect sun, etc.	Dissipate Heat If heat reduction wasn't enough, then it is time to get rid of body heat by evaporation (costs water though), long appendages (legs, ears, etc.), or small "bodies" (e.g., whole body, leaves, etc.) that radiate heat.	Tolerate Hyperthermia Some plants and animals can survive body temperatures that would be dangerous to humans (e.g., this antelope squirrel tolerates body temperatures over 104 degrees F!).