This species of "packrat" is nicknamed for its habit of gathering wood, cactus parts, stones, cow dung, bones, beer cans, candy wrappers - just about every movable object in the vicinity - to build its large nest. Woodrat collections provide us with an important window into the past. Preserved inside ancient nests found in the desert are acorns, pine sticks, and other items which suggest a cooler, wetter climate. Using carbon dating, scientists have determined that 10,000 years ago areas such as Tonto National Monument were covered by oak woodlands. As the climate gradually grew warmer and dryer, woodrats began filling their nests with cacti and other desert plants we find today.
Did You Know?
Tonto National Monument is home to a crested saguaro. Botanists disagree as to why some saguaros grow in this unusual form. Some speculate that it is a genetic mutation. Others say it is the result of lightning or freeze damage. About one in 150,000 saguaros develop this unusual growth.