Stop 12
Animal Evidence

Living underground gives the packrat the advantage of cooler temperatures and higher humidity in a hot, arid climate.

Spotting animals in the desert is dependent on the weather and time of day. In the summer, the middle of the day is not the optimal time for animals to be out. While air temperatures may be pushing 100°F, the ground temperature could be over 140°F! But even if you don't actually get to view any animals, you can tell what lives there by finding evidence of animals such as bite marks on plants and burrows.

Under prickly pear cactus and mesquite, you can find piles of sticks, cactus pads, and other materials. These piles are called middens and are created by packrats (also known as woodrats). Middens are occupied by successive generations of solitary packrats and are often also home to beetles, crickets, and a variety of small mites and collembolans (springtails).

Some packrat middens are more than 50,000 years old and have been important for making paleoecological reconstructions of an area. The leaves, seeds, bones, and other debris collected for the midden are often found well-preserved by crystallized packrat urine. Examining these fossilized middens tells scientists about the plant community and climate of the area thousands of years ago.